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  • How to turn a DSL wireless modem to a wifi hub

    - by my_question
    I used to use DSL for my home internet and used Qwest Q1000 wireless modem. Now I switched to cable and use wireless router to cover the home. One problem is I just bought a desktop and I like to put it in a place far away from the router. The desktop only has cable interface, it does not receive wifi. The obvious solution is I go buy that little USB dongle which can receive wifi and plug it to the desktop. But before doig that, I am wondering if somehow I can re-use the Q1000 modem. The modem has 4 LAN ports and it has wifi antenna. I tried connecting the desktop to Q1000's LAN port, the system shows wire connection is in place, but I cannot access internet. It seems to me Q1000's wifi function is to broadcast the wifi signal out instead of receiving signal. I went to the Q1000 configuration page by going to web page of "192.168.0.1", it is not clear how to set it up. I also wonder one thing, my home wifi is encrypted, so if I want to let Q1000 to join the wifi, I need to somehow type in the password, I am not sure how to do that either. Anyway, maybe this thing cannot be used in this fashion. If you have any suggestion, please shed some light. Thanks.

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  • WebSphere hung threads, how can I track then down?

    - by Puzzled
    We have an application running on WebSphere (unfortunately it is 6.1 which is no longer supported, it has not yet been migrated in production to a later version) which becomes entirely unresponsive because of hung threads. As far as I can tell we entirely exhaust one of the thread pools. I have activated hung thread detection and I get a core/thread dump when hung threads are detected. The server can run for several days without problems but has crashed twice this week. When load the core/thread dump in "IBM Thread and Monitor Dump Analyzer for Java", it tells me that there are a certain number of hung threads (this time it was 2, last time 11) and multiple (usually around 40) threads "waiting on condition" and some running threads. I believe one of the thread pool has around that size (50). Now what I see in there are threads waiting for locks, having locks or in wait. Most of them show a stack track which always ends like this: at java/lang/Object.wait(Native Method) at java/lang/Object.wait(Object.java:231) Now, how can I track this down to either a server configuration problem, application issue, WebSphere problem or something else? How is this supposed to help me track down the problem when almost everything in there refers to IBM code? I cannot ask IBM's help as 6.1 is now an unsupported version of WebSphere and while work has been done to make it work under WebSphere 7 we are not yet ready to switch to it in Production yet.

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  • Nginx and 1000 WordPress Installs - Optimization

    - by GTE
    Hey, I'm trying to create a rather unusual (imo) configuration where I have: nginx php-fastcgi mysql 1000 seperate WordPress installs (with WP Super Cache). Each WP install corresponds to a seperate subdomain. Furthermore, I have 1000 cron jobs being called every hour that in turn call a WP plugin (using wget) which retrieves data from an API and posts it to the respective blog. This is all being run on a virtual server with 1024MB of RAM, 4 shared processors, etc. The server is not doing well, especially during the times that the cron jobs are being executed. Nginx constantly throws 504 errors and the site has a significant lag. 1) Am I crazy for having 1000 individual WP installs? Should I be using WP-MU and will this help significantly? (I have certain plugin restrictions that I prefer having seperate installs but could switch if need be.) 2) Instead of having 1000 unique cron jobs - should be calling say a bash script that will then process the 1000 HTTP requests I need? Could this be done in a succesive order instead of a sequential one? 3) Any other kind of suggestion you may have for optimization? Should I be proxying to Apache instead of just using nginx, etc. Any kind of advice would be appreciated. Thanks in advance

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  • Apache mod_disk_cache on a seperate drive

    - by pavs
    how can I set Apache mod_disk_cache on a separate drive from where the OS/Apache is installed? I have set up this on my apache2.conf: <IfModule mod_cache_disk.c> # cache cleaning is done by htcacheclean, which can be configured in # /etc/default/apache2 # # For further information, see the comments in that file, # /usr/share/doc/apache2/README.Debian, and the htcacheclean(8) # man page. # This path must be the same as the one in /etc/default/apache2 CacheRoot /media/cacheHD # This will also cache local documents. It usually makes more sense to # put this into the configuration for just one virtual host. CacheEnable disk / # The result of CacheDirLevels * CacheDirLength must not be higher than # 20. Moreover, pay attention on file system limits. Some file systems # do not support more than a certain number of inodes and # subdirectories (e.g. 32000 for ext3) CacheDirLevels 2 CacheDirLength 1 </IfModule> and it doesn't seem to be caching anything at all. The drive itself is a freshly installed ssd drive formatted with ext4.

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  • Configuring two subnets with two NICS. Access from a NAS to the internet

    - by archipestre
    I am having trouble configuring my NAS. I have a DSL router with WIFI (192.168.1.1) in my flatmates room. In my room I have a server with two NICS: 1) wlan0 (192.168.1.2) that connects to the DSL router via wireless 2) em1 (192.168.0.1) that connects to the NAS (192.168.0.20) with a crossover cable. I have Fedora 17 and I have enable packet forwarding. My IP configuration is as follows: WLAN0 inet 192.168.0.1 netmask 255.255.255.0 broadcast 192.168.0.255 EM1 inet 192.168.1.2 netmask 255.255.255.0 broadcast 192.168.1.255 My routing table looks like: Destination Gateway G enmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 em1 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0 I have enable a static route in the DSL server: Status Network Destination Subnet Mask Interface Gateway Remove Edit Active 192.168.0.0 255.255.255.0 LAN 192.168.1.2 From my server I can ping the DSL router and the NAS. From the NAS I can ping both NICS of the server. However the NAS is unable to ping the DSL router or any address in the Internet. Any idea of what is wrong. Thank you in advance

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  • Intermittent 403 errors when using allow to limit access to url with both explicit IP and SetEnvIf

    - by rbieber
    We are running Apache 2.2.22 on a Solaris 10 environment. We have a specific URL that we want to limit access to by IP. We recently implemented a CDN and now have the added complexity that the IP's that a request are shown to be coming from are actually the CDN servers and not the ultimate end user. In the case that we need to back the CDN out, we want to handle the case where either the CDN is forwarding the request, or the ultimate client is sending the request directly. The CDN sends the end user IP address in an HTTP header (for this scenario that header is called "User-IP"). Here is the configuration that we have put in place: SetEnvIf User-IP (\d+\.\d+\.\d+\.\d+) REAL_USER_IP=$1 SetEnvIf REAL_USER_IP "(10\.1\.2\.3|192\.168\..+)" access_allowed=1 <Location /uri/> Order deny,allow Allow from 10.1.2.3 192.168. allow from env=access_allowed Deny from all </Location> This seems to work fine for a time, however at some point the web server starts serving 403 errors to the end user - so for some reason it is restricting access. The odd thing is that a bounce of the web server seems to resolve the issue, but only for a time - then the behavior comes back. It might be worthwhile to note as well that this URL is delegated to a JBoss server via mod_jk. The denial of access is, however; confirmed to be at the Apache layer and the issue only seems to happen after the server has been running for some time.

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  • Renaming VLAN Interfaces in Linux

    - by rhololkeolke
    I need to know how to rename VLAN interfaces. I'm currently running Ubuntu 11.04. I'm running a networking application that takes frames on one interface applies things like delays and errors and then forwards the frames out another interface. The default naming convention which names things <interface>.<vlan> e.g. eth0.2 will not work for my purposes because the program which parses the configuration script for the networking application doesn't like the decimal in the interface name. I ran vconfig set_name_type VLAN_PLUS_VID which solves the decimal in the interface name problem, however, I can then no longer assign the same vlan id to multiple interfaces because they have the same name. I know how to change physical interface names using udev rules, but because the vlan's will have the same MAC address and they aren't physical interfaces I can't use those rules to rename the interfaces. Is there a way to rename any interface in linux, including the virtual ones? Is there a way to specify your own naming convention for config set_name_type option without having to recompile the source of vconfig?

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  • Nginx as reverse proxy: how to properly configure gateway timeout?

    - by user1281376
    We have configured Nginx as a reverse proxy to an Apache server farm, but I'm running into trouble with the gateway timeouts. Our Goal in human readable form is: "Deliver a request within one second, but if it really takes longer, deliver anyway", which for me translates into "Try the first Apache server in upstream for max 500ms. If we get a timeout / an error, try the next one and so on until we finally succeed." Now our relevant configuration is this: location @proxy { proxy_pass http://apache$request_uri; proxy_connect_timeout 1s; proxy_read_timeout 2s; } [...] upstream apache { server 127.0.0.1:8001 max_fails=1 fail_timeout=10s; server 10.1.x.x:8001 max_fails=1 fail_timeout=10s backup; server 10.1.x.x:8001 max_fails=1 fail_timeout=10s backup; server 10.1.x.x:8001 max_fails=1 fail_timeout=10s backup; } The problem here is that nginx seems to misunderstand this as "Try to get a response from the whole upstream cluster within one second and deliver a 50X error if we don't - without any limit on how long to try any upstream server", which is obviously not what we had in mind. Is there any way to get nginx to do what we want?

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  • Merging two separate DNS zones

    - by cube
    This is a hypothetical question. Let's suppose I have two networks, each with its own DNS server. Network A has names a1.local, a2.local, ... and network B has b1.local, b2.local, .... Zone file for each of the networks looks something like this: $ORIGIN local @ IN SOA .... blah blah blah a1 A 1.2.3.4 a2 A 2.3.4.5 ... for A, and $ORIGIN local @ IN SOA .... blah blah blah b1 A 3.4.5.6 b2 A 4.5.6.7 ... for B. Now I also have a regular internet domain example.com and I want to access the machines as a1.A.example.com, b1.B.example.com, ... How will I have to change the configuration of name servers in networks A and B? (in fact I am writing a super-magic DNS server, currently serving A and B separately, but there is a chance that I will have to add the ability to merge the networks; so I'm interested in knowing the problems which lie ahead of me and how to prepare for the possibility)

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  • Windows Server 2008 (x64): Wont boot past bios page

    - by WebSolProv
    Happy New Year, Since a month or so ago I inherited responsibility for small network administration for my sins. The domain controller (yes there is only one, and yes I know it is best practice to have two even in a small domain setup) went down overnight and I have been trying all day to get it back up and running. Unfortunately this machine also administers our entire ActiveDirectory setup: 1) It goes thru the BIOS without any errors, nothing whatsoever 2) It gets into the “select safe mode, safe mode with networking, normal” etc and if you select either of the safe mode options it loads a few files then reboots. If you select normal it just runs for a bit (doesn’t get to the windows splash screen) and then reboots again. 3) If you select windows repair, it asks for an image to repair too: however it would appear that none was taken that can be used (!!) or one is not being shown. 4) I have tried repairing the boot sector and the boot configuration using Bootrec.exe, both which it says were completed successfully but still it doesn’t work. 5) I have tried swapping the drives into another server to rule out hardware and that didn’t work either so clearly it’s the OS. 6) I have tried running chkdsk which ran fine, and also memory check which was also fine. We do have another machine on the network that was installed as a DC so when we decommission the current infrastructure but when I try and "promote" this to the lead DC then I get “you cannot modify domain or trust information because a PDC emulator cannot be contacted" so I am unable to replicare the ActiveDirectory details. If anyone can think of any direction I should follow it would be greatly appreciated, Thanks, Alex

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  • Open source app to manage and run commands on cloud servers? [closed]

    - by Mark Theunissen
    I'm creating a SaaS platform, and I need a component / library that can create, delete and store the connection details for cloud servers. It also needs to support executing shell commands on these servers and returning the response to the caller. I want a central database of servers and their configuration, plus the ability to reach out and manage the servers via SSH execution of bash scripts. I don't want something that needs agents on every server like Chef. For example, this command is received by the hypothetical application: CREATE USER server = server12345 name = myuser It's translated into the following set of actions and executed by the app, which knows how to connect to server12345, and how to create a user on that server: $ ssh root@server12345 $ adduser myuser And returns the output from the shell: Added user myuser. I've done research on Google and can't quite quite find something that does this already. I've found: fabric This part handles the executing of the shell commands very elegantly, and can take multiple server definitions, but it's supposed to be a deployment tool so doesn't do everything that would be required above - for example, it doesn't have a daemon mode where it listens for commands - it expects to be executed on the shell. It also can't provide the central database functionality. libcloud This library can handle the server admin (CRUD) part, but doesn't have a command interface daemon either, and doesn't let you execute commands on the servers. I guess I need something that is a combination of libcloud, fabric and django for an API. Or something else that does that same thing regardless of language. Overmind Overmind is a GUI and wrapper around libcloud, but doesn't support the command execution part. What am I missing here?

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  • schroot build environment setup how to avoid bind-mount home

    - by minghua
    The recent linux distributions such as Fedora and Ubuntu all use chroot environment to make the build. Because when making the build often it needs to install some special tools, and to install to the existing system. Using chroot avoids making any changes to the host system. To set up such a build environment, the first step is to make a chroot. I'm following the setup guide at https://wiki.debian.org/Schroot [wheezy-test] description=Contains the SPICE program aliases=test type=directory directory=/srv/chroot/test users=jsmith root-groups=root script-config=desktop/config personality=linux preserve-environment=true In the host on my setup the /home is on /dev/mapper. When schroot is entered, the same home is bind-mounted. Is there a way to avoid this? I prefer to use a different /home inside chroot. When changing the type from directory to plain, the binding is not performed. However that also loses /proc, /sys, etc. You'd have to manually bind-mount them. That does not seem to be a good solution. If a simple configuration change is unavailable, any idea where the script is for type=directory? Probably I'll manually modify the script. Thanks in advance for any answers or hints!

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  • Trouble Starting MySL Community Server on Windows 7

    - by CodeAngel
    I have installed Netbeans 7 on my Windows 7. In addition, the MySQL Community Server 5.6.12 is installed with the MSI installer on thesame 7 PC. The MySQL server is integrated with the Netbeans IDE. However , it is not possible to start or stop the MySQL server from the command prompt or the Netbeans IDE. I am only able to start or stop the server from the Windows 7 services tool. Also , it is difficult running SQL queries from the Netbeans IDE even though it shows there is connection with the MySQL server. I have added the my.ini file to the installed directory of the MySQL server , that is : C:\Program Files\MySQL\MySQL Server 5.6 below is the my.ini file : # For advice on how to change settings please see # http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html # *** DO NOT EDIT THIS FILE. It's a template which will be copied to the # *** default location during install, and will be replaced if you # *** upgrade to a newer version of MySQL. [mysqld] # Remove leading # and set to the amount of RAM for the most important data # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%. # innodb_buffer_pool_size = 128M # Remove leading # to turn on a very important data integrity option: logging # changes to the binary log between backups. # log_bin # These are commonly set, remove the # and set as required. # basedir = ..... # datadir = ..... port = 3306 # server_id = ..... # Remove leading # to set options mainly useful for reporting servers. # The server defaults are faster for transactions and fast SELECTs. # Adjust sizes as needed, experiment to find the optimal values. # join_buffer_size = 128M # sort_buffer_size = 2M # read_rnd_buffer_size = 2M sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES Any suggestion is welcomed.

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  • How do I change the default ftp folder in Mac OS X 10.6?

    - by Wild_Eep
    I'm running WordPress 2.9.1 from a Mac running 10.6.3. WordPress is installed to the /Library/WebServer/Documents folder. WordPress has a feature called Auto Update. Clicking an auto update button will download and install updated versions of the WordPress software, or third-party plugin tools. It's a convenient way to keep things up to date. WordPress uses FTP to download the files. I've enabled FTP and set up a user account and opened the requisite ports in my firewall for FTP traffic. This doesn't seem to be enough for my self-hosted installation, though. I'm sure this feature was originally designed for someone who has access to a remote shared webserver, and that it's merely a configuration challenge related to the FTP setup. I feel that if I can adjust the initial directory that the FTP service presents to the AutoUpdate feature, everything else will work properly. So, my question is, how do I adjust what folder is presented when a given user connects to a Mac running 10.6.3 via FTP?

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  • Provide a user with service start/stop permissions

    - by slakr007
    I have a very basic domain that I use for development. I want to create a GPO that provides users in the Backup Operators group with start/stop permissions for two specific services on a specific server. I have read several articles about this, and they all indicate that this is very easy. Create a GPO, give the user start/stop permissions to the services under Computer Configuration Policies Windows Settings Security Settings System Services, and voila. Done. Not so much, but I have to be doing something wrong. My install is pretty much the default. The domain controller is in the Domain Controllers OU, the Backup Operators group is under Builtin, and I created a user called Backup under Users. I created a GPO and linked it to the Domain Controllers OU. In the GPO I give the Backup user permission to start/stop two specific services on the server. I forced an update with gpupdate. I used Group Policy Results to verify that my GPO is the winning GPO giving the user the permission to start/stop the two services. However, the user is still unable to start/stop the services. I attempted different loopback settings on the GPO to no avail. I'm sort of at a loss here.

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  • SSH access to VM on windows 8 hyper-v

    - by samw
    I'm currently attending University and prefer a Linux environment to do much of my work, but all I have is a ThinkPad running Windows 8 Pro. Cygwin is nice, but it leaves me missing things like apt-get. My latest solution is to run an Ubuntu 12.04 VM with Windows 8's Client Hyper-V and use Cygwin for SSH access. I've looked everywhere online trying to set this up, but I haven't found much help. I've done this before using VirtualBox, so I figured this would be possible as well. Could anyone provide advice for setting up this environment? I'm completely uninitiated to Linux networking, virtual networking, and... pretty much all networking configuration, so this has been quite a challenge for me. What I've done so far: Created an external virtual switch to my wireless NIC. With this, I could successfully SSH to the VM with the leased IP address. But without a static IP, I would soon get disconnected. Created an internal virtual switch and attempt to "share" my main internet connection. (I was following the description on this page) Thank you all in advance!

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  • How to ensure local file is up-to-date or ahead (dropbox sync) before truecrypt auto-mount it?

    - by user620965
    There are a lot tutorials out there that states that dropbox build-in encryption is not secure enought. That tutorials recommands to sync a truecrypt container file to have all files in it securely encrypted. This setup is know to be limited. You can NOT have that truecrypt container file mounted on the same time on more than one location - if you have inserted changes to the contents of the container in more then one location at a time then this setup produces a conflict on the container file in the dropbox system - resulting in one container file for each location. In my case that issue is not relevant - i do not use my data on more than one location at a time. I want to use the auto-mount feature of truecrypt on startup of windows 7 to have a zero configuration environment - and start working right away. But i want to ensure that the local truecrypt container file is up-to-date before truecrypt mounts it automatically - imagine you updated the contents of the container on your primary location and your secondary location was off for a long time. In that case it can take "a long time" till dropbox sync is complete (e.g. depending on your internet connection and the size of the container file). There is a option in truecrypt that ensures that truecrypt do not update the timestamp of the container file - which speeds up the sync, because dropbox client is doing a differential sync then instead of a time consuming full-sync. That is an improvement to that setup, but this do not fix my issue. The question is how to make the auto-mount function wait for the container file to be up-to-date (updated by dropbox)? In contrast: if the file was changed local, but remote file (in the dropbox cloud system) is still old (not jet updated by the sync process / or process is progress), should not make truecrypt to wait for the sync. Suggestions?

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  • A way of doing real-world test-driven development (and some thoughts about it)

    - by Thomas Weller
    Lately, I exchanged some arguments with Derick Bailey about some details of the red-green-refactor cycle of the Test-driven development process. In short, the issue revolved around the fact that it’s not enough to have a test red or green, but it’s also important to have it red or green for the right reasons. While for me, it’s sufficient to initially have a NotImplementedException in place, Derick argues that this is not totally correct (see these two posts: Red/Green/Refactor, For The Right Reasons and Red For The Right Reason: Fail By Assertion, Not By Anything Else). And he’s right. But on the other hand, I had no idea how his insights could have any practical consequence for my own individual interpretation of the red-green-refactor cycle (which is not really red-green-refactor, at least not in its pure sense, see the rest of this article). This made me think deeply for some days now. In the end I found out that the ‘right reason’ changes in my understanding depending on what development phase I’m in. To make this clear (at least I hope it becomes clear…) I started to describe my way of working in some detail, and then something strange happened: The scope of the article slightly shifted from focusing ‘only’ on the ‘right reason’ issue to something more general, which you might describe as something like  'Doing real-world TDD in .NET , with massive use of third-party add-ins’. This is because I feel that there is a more general statement about Test-driven development to make:  It’s high time to speak about the ‘How’ of TDD, not always only the ‘Why’. Much has been said about this, and me myself also contributed to that (see here: TDD is not about testing, it's about how we develop software). But always justifying what you do is very unsatisfying in the long run, it is inherently defensive, and it costs time and effort that could be used for better and more important things. And frankly: I’m somewhat sick and tired of repeating time and again that the test-driven way of software development is highly preferable for many reasons - I don’t want to spent my time exclusively on stating the obvious… So, again, let’s say it clearly: TDD is programming, and programming is TDD. Other ways of programming (code-first, sometimes called cowboy-coding) are exceptional and need justification. – I know that there are many people out there who will disagree with this radical statement, and I also know that it’s not a description of the real world but more of a mission statement or something. But nevertheless I’m absolutely sure that in some years this statement will be nothing but a platitude. Side note: Some parts of this post read as if I were paid by Jetbrains (the manufacturer of the ReSharper add-in – R#), but I swear I’m not. Rather I think that Visual Studio is just not production-complete without it, and I wouldn’t even consider to do professional work without having this add-in installed... The three parts of a software component Before I go into some details, I first should describe my understanding of what belongs to a software component (assembly, type, or method) during the production process (i.e. the coding phase). Roughly, I come up with the three parts shown below:   First, we need to have some initial sort of requirement. This can be a multi-page formal document, a vague idea in some programmer’s brain of what might be needed, or anything in between. In either way, there has to be some sort of requirement, be it explicit or not. – At the C# micro-level, the best way that I found to formulate that is to define interfaces for just about everything, even for internal classes, and to provide them with exhaustive xml comments. The next step then is to re-formulate these requirements in an executable form. This is specific to the respective programming language. - For C#/.NET, the Gallio framework (which includes MbUnit) in conjunction with the ReSharper add-in for Visual Studio is my toolset of choice. The third part then finally is the production code itself. It’s development is entirely driven by the requirements and their executable formulation. This is the delivery, the two other parts are ‘only’ there to make its production possible, to give it a decent quality and reliability, and to significantly reduce related costs down the maintenance timeline. So while the first two parts are not really relevant for the customer, they are very important for the developer. The customer (or in Scrum terms: the Product Owner) is not interested at all in how  the product is developed, he is only interested in the fact that it is developed as cost-effective as possible, and that it meets his functional and non-functional requirements. The rest is solely a matter of the developer’s craftsmanship, and this is what I want to talk about during the remainder of this article… An example To demonstrate my way of doing real-world TDD, I decided to show the development of a (very) simple Calculator component. The example is deliberately trivial and silly, as examples always are. I am totally aware of the fact that real life is never that simple, but I only want to show some development principles here… The requirement As already said above, I start with writing down some words on the initial requirement, and I normally use interfaces for that, even for internal classes - the typical question “intf or not” doesn’t even come to mind. I need them for my usual workflow and using them automatically produces high componentized and testable code anyway. To think about their usage in every single situation would slow down the production process unnecessarily. So this is what I begin with: namespace Calculator {     /// <summary>     /// Defines a very simple calculator component for demo purposes.     /// </summary>     public interface ICalculator     {         /// <summary>         /// Gets the result of the last successful operation.         /// </summary>         /// <value>The last result.</value>         /// <remarks>         /// Will be <see langword="null" /> before the first successful operation.         /// </remarks>         double? LastResult { get; }       } // interface ICalculator   } // namespace Calculator So, I’m not beginning with a test, but with a sort of code declaration - and still I insist on being 100% test-driven. There are three important things here: Starting this way gives me a method signature, which allows to use IntelliSense and AutoCompletion and thus eliminates the danger of typos - one of the most regular, annoying, time-consuming, and therefore expensive sources of error in the development process. In my understanding, the interface definition as a whole is more of a readable requirement document and technical documentation than anything else. So this is at least as much about documentation than about coding. The documentation must completely describe the behavior of the documented element. I normally use an IoC container or some sort of self-written provider-like model in my architecture. In either case, I need my components defined via service interfaces anyway. - I will use the LinFu IoC framework here, for no other reason as that is is very simple to use. The ‘Red’ (pt. 1)   First I create a folder for the project’s third-party libraries and put the LinFu.Core dll there. Then I set up a test project (via a Gallio project template), and add references to the Calculator project and the LinFu dll. Finally I’m ready to write the first test, which will look like the following: namespace Calculator.Test {     [TestFixture]     public class CalculatorTest     {         private readonly ServiceContainer container = new ServiceContainer();           [Test]         public void CalculatorLastResultIsInitiallyNull()         {             ICalculator calculator = container.GetService<ICalculator>();               Assert.IsNull(calculator.LastResult);         }       } // class CalculatorTest   } // namespace Calculator.Test       This is basically the executable formulation of what the interface definition states (part of). Side note: There’s one principle of TDD that is just plain wrong in my eyes: I’m talking about the Red is 'does not compile' thing. How could a compiler error ever be interpreted as a valid test outcome? I never understood that, it just makes no sense to me. (Or, in Derick’s terms: this reason is as wrong as a reason ever could be…) A compiler error tells me: Your code is incorrect, but nothing more.  Instead, the ‘Red’ part of the red-green-refactor cycle has a clearly defined meaning to me: It means that the test works as intended and fails only if its assumptions are not met for some reason. Back to our Calculator. When I execute the above test with R#, the Gallio plugin will give me this output: So this tells me that the test is red for the wrong reason: There’s no implementation that the IoC-container could load, of course. So let’s fix that. With R#, this is very easy: First, create an ICalculator - derived type:        Next, implement the interface members: And finally, move the new class to its own file: So far my ‘work’ was six mouse clicks long, the only thing that’s left to do manually here, is to add the Ioc-specific wiring-declaration and also to make the respective class non-public, which I regularly do to force my components to communicate exclusively via interfaces: This is what my Calculator class looks like as of now: using System; using LinFu.IoC.Configuration;   namespace Calculator {     [Implements(typeof(ICalculator))]     internal class Calculator : ICalculator     {         public double? LastResult         {             get             {                 throw new NotImplementedException();             }         }     } } Back to the test fixture, we have to put our IoC container to work: [TestFixture] public class CalculatorTest {     #region Fields       private readonly ServiceContainer container = new ServiceContainer();       #endregion // Fields       #region Setup/TearDown       [FixtureSetUp]     public void FixtureSetUp()     {        container.LoadFrom(AppDomain.CurrentDomain.BaseDirectory, "Calculator.dll");     }       ... Because I have a R# live template defined for the setup/teardown method skeleton as well, the only manual coding here again is the IoC-specific stuff: two lines, not more… The ‘Red’ (pt. 2) Now, the execution of the above test gives the following result: This time, the test outcome tells me that the method under test is called. And this is the point, where Derick and I seem to have somewhat different views on the subject: Of course, the test still is worthless regarding the red/green outcome (or: it’s still red for the wrong reasons, in that it gives a false negative). But as far as I am concerned, I’m not really interested in the test outcome at this point of the red-green-refactor cycle. Rather, I only want to assert that my test actually calls the right method. If that’s the case, I will happily go on to the ‘Green’ part… The ‘Green’ Making the test green is quite trivial. Just make LastResult an automatic property:     [Implements(typeof(ICalculator))]     internal class Calculator : ICalculator     {         public double? LastResult { get; private set; }     }         One more round… Now on to something slightly more demanding (cough…). Let’s state that our Calculator exposes an Add() method:         ...   /// <summary>         /// Adds the specified operands.         /// </summary>         /// <param name="operand1">The operand1.</param>         /// <param name="operand2">The operand2.</param>         /// <returns>The result of the additon.</returns>         /// <exception cref="ArgumentException">         /// Argument <paramref name="operand1"/> is &lt; 0.<br/>         /// -- or --<br/>         /// Argument <paramref name="operand2"/> is &lt; 0.         /// </exception>         double Add(double operand1, double operand2);       } // interface ICalculator A remark: I sometimes hear the complaint that xml comment stuff like the above is hard to read. That’s certainly true, but irrelevant to me, because I read xml code comments with the CR_Documentor tool window. And using that, it looks like this:   Apart from that, I’m heavily using xml code comments (see e.g. here for a detailed guide) because there is the possibility of automating help generation with nightly CI builds (using MS Sandcastle and the Sandcastle Help File Builder), and then publishing the results to some intranet location.  This way, a team always has first class, up-to-date technical documentation at hand about the current codebase. (And, also very important for speeding up things and avoiding typos: You have IntelliSense/AutoCompletion and R# support, and the comments are subject to compiler checking…).     Back to our Calculator again: Two more R# – clicks implement the Add() skeleton:         ...           public double Add(double operand1, double operand2)         {             throw new NotImplementedException();         }       } // class Calculator As we have stated in the interface definition (which actually serves as our requirement document!), the operands are not allowed to be negative. So let’s start implementing that. Here’s the test: [Test] [Row(-0.5, 2)] public void AddThrowsOnNegativeOperands(double operand1, double operand2) {     ICalculator calculator = container.GetService<ICalculator>();       Assert.Throws<ArgumentException>(() => calculator.Add(operand1, operand2)); } As you can see, I’m using a data-driven unit test method here, mainly for these two reasons: Because I know that I will have to do the same test for the second operand in a few seconds, I save myself from implementing another test method for this purpose. Rather, I only will have to add another Row attribute to the existing one. From the test report below, you can see that the argument values are explicitly printed out. This can be a valuable documentation feature even when everything is green: One can quickly review what values were tested exactly - the complete Gallio HTML-report (as it will be produced by the Continuous Integration runs) shows these values in a quite clear format (see below for an example). Back to our Calculator development again, this is what the test result tells us at the moment: So we’re red again, because there is not yet an implementation… Next we go on and implement the necessary parameter verification to become green again, and then we do the same thing for the second operand. To make a long story short, here’s the test and the method implementation at the end of the second cycle: // in CalculatorTest:   [Test] [Row(-0.5, 2)] [Row(295, -123)] public void AddThrowsOnNegativeOperands(double operand1, double operand2) {     ICalculator calculator = container.GetService<ICalculator>();       Assert.Throws<ArgumentException>(() => calculator.Add(operand1, operand2)); }   // in Calculator: public double Add(double operand1, double operand2) {     if (operand1 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand1");     }     if (operand2 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand2");     }     throw new NotImplementedException(); } So far, we have sheltered our method from unwanted input, and now we can safely operate on the parameters without further caring about their validity (this is my interpretation of the Fail Fast principle, which is regarded here in more detail). Now we can think about the method’s successful outcomes. First let’s write another test for that: [Test] [Row(1, 1, 2)] public void TestAdd(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       double result = calculator.Add(operand1, operand2);       Assert.AreEqual(expectedResult, result); } Again, I’m regularly using row based test methods for these kinds of unit tests. The above shown pattern proved to be extremely helpful for my development work, I call it the Defined-Input/Expected-Output test idiom: You define your input arguments together with the expected method result. There are two major benefits from that way of testing: In the course of refining a method, it’s very likely to come up with additional test cases. In our case, we might add tests for some edge cases like ‘one of the operands is zero’ or ‘the sum of the two operands causes an overflow’, or maybe there’s an external test protocol that has to be fulfilled (e.g. an ISO norm for medical software), and this results in the need of testing against additional values. In all these scenarios we only have to add another Row attribute to the test. Remember that the argument values are written to the test report, so as a side-effect this produces valuable documentation. (This can become especially important if the fulfillment of some sort of external requirements has to be proven). So your test method might look something like that in the end: [Test, Description("Arguments: operand1, operand2, expectedResult")] [Row(1, 1, 2)] [Row(0, 999999999, 999999999)] [Row(0, 0, 0)] [Row(0, double.MaxValue, double.MaxValue)] [Row(4, double.MaxValue - 2.5, double.MaxValue)] public void TestAdd(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       double result = calculator.Add(operand1, operand2);       Assert.AreEqual(expectedResult, result); } And this will produce the following HTML report (with Gallio):   Not bad for the amount of work we invested in it, huh? - There might be scenarios where reports like that can be useful for demonstration purposes during a Scrum sprint review… The last requirement to fulfill is that the LastResult property is expected to store the result of the last operation. I don’t show this here, it’s trivial enough and brings nothing new… And finally: Refactor (for the right reasons) To demonstrate my way of going through the refactoring portion of the red-green-refactor cycle, I added another method to our Calculator component, namely Subtract(). Here’s the code (tests and production): // CalculatorTest.cs:   [Test, Description("Arguments: operand1, operand2, expectedResult")] [Row(1, 1, 0)] [Row(0, 999999999, -999999999)] [Row(0, 0, 0)] [Row(0, double.MaxValue, -double.MaxValue)] [Row(4, double.MaxValue - 2.5, -double.MaxValue)] public void TestSubtract(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       double result = calculator.Subtract(operand1, operand2);       Assert.AreEqual(expectedResult, result); }   [Test, Description("Arguments: operand1, operand2, expectedResult")] [Row(1, 1, 0)] [Row(0, 999999999, -999999999)] [Row(0, 0, 0)] [Row(0, double.MaxValue, -double.MaxValue)] [Row(4, double.MaxValue - 2.5, -double.MaxValue)] public void TestSubtractGivesExpectedLastResult(double operand1, double operand2, double expectedResult) {     ICalculator calculator = container.GetService<ICalculator>();       calculator.Subtract(operand1, operand2);       Assert.AreEqual(expectedResult, calculator.LastResult); }   ...   // ICalculator.cs: /// <summary> /// Subtracts the specified operands. /// </summary> /// <param name="operand1">The operand1.</param> /// <param name="operand2">The operand2.</param> /// <returns>The result of the subtraction.</returns> /// <exception cref="ArgumentException"> /// Argument <paramref name="operand1"/> is &lt; 0.<br/> /// -- or --<br/> /// Argument <paramref name="operand2"/> is &lt; 0. /// </exception> double Subtract(double operand1, double operand2);   ...   // Calculator.cs:   public double Subtract(double operand1, double operand2) {     if (operand1 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand1");     }       if (operand2 < 0.0)     {         throw new ArgumentException("Value must not be negative.", "operand2");     }       return (this.LastResult = operand1 - operand2).Value; }   Obviously, the argument validation stuff that was produced during the red-green part of our cycle duplicates the code from the previous Add() method. So, to avoid code duplication and minimize the number of code lines of the production code, we do an Extract Method refactoring. One more time, this is only a matter of a few mouse clicks (and giving the new method a name) with R#: Having done that, our production code finally looks like that: using System; using LinFu.IoC.Configuration;   namespace Calculator {     [Implements(typeof(ICalculator))]     internal class Calculator : ICalculator     {         #region ICalculator           public double? LastResult { get; private set; }           public double Add(double operand1, double operand2)         {             ThrowIfOneOperandIsInvalid(operand1, operand2);               return (this.LastResult = operand1 + operand2).Value;         }           public double Subtract(double operand1, double operand2)         {             ThrowIfOneOperandIsInvalid(operand1, operand2);               return (this.LastResult = operand1 - operand2).Value;         }           #endregion // ICalculator           #region Implementation (Helper)           private static void ThrowIfOneOperandIsInvalid(double operand1, double operand2)         {             if (operand1 < 0.0)             {                 throw new ArgumentException("Value must not be negative.", "operand1");             }               if (operand2 < 0.0)             {                 throw new ArgumentException("Value must not be negative.", "operand2");             }         }           #endregion // Implementation (Helper)       } // class Calculator   } // namespace Calculator But is the above worth the effort at all? It’s obviously trivial and not very impressive. All our tests were green (for the right reasons), and refactoring the code did not change anything. It’s not immediately clear how this refactoring work adds value to the project. Derick puts it like this: STOP! Hold on a second… before you go any further and before you even think about refactoring what you just wrote to make your test pass, you need to understand something: if your done with your requirements after making the test green, you are not required to refactor the code. I know… I’m speaking heresy, here. Toss me to the wolves, I’ve gone over to the dark side! Seriously, though… if your test is passing for the right reasons, and you do not need to write any test or any more code for you class at this point, what value does refactoring add? Derick immediately answers his own question: So why should you follow the refactor portion of red/green/refactor? When you have added code that makes the system less readable, less understandable, less expressive of the domain or concern’s intentions, less architecturally sound, less DRY, etc, then you should refactor it. I couldn’t state it more precise. From my personal perspective, I’d add the following: You have to keep in mind that real-world software systems are usually quite large and there are dozens or even hundreds of occasions where micro-refactorings like the above can be applied. It’s the sum of them all that counts. And to have a good overall quality of the system (e.g. in terms of the Code Duplication Percentage metric) you have to be pedantic on the individual, seemingly trivial cases. My job regularly requires the reading and understanding of ‘foreign’ code. So code quality/readability really makes a HUGE difference for me – sometimes it can be even the difference between project success and failure… Conclusions The above described development process emerged over the years, and there were mainly two things that guided its evolution (you might call it eternal principles, personal beliefs, or anything in between): Test-driven development is the normal, natural way of writing software, code-first is exceptional. So ‘doing TDD or not’ is not a question. And good, stable code can only reliably be produced by doing TDD (yes, I know: many will strongly disagree here again, but I’ve never seen high-quality code – and high-quality code is code that stood the test of time and causes low maintenance costs – that was produced code-first…) It’s the production code that pays our bills in the end. (Though I have seen customers these days who demand an acceptance test battery as part of the final delivery. Things seem to go into the right direction…). The test code serves ‘only’ to make the production code work. But it’s the number of delivered features which solely counts at the end of the day - no matter how much test code you wrote or how good it is. With these two things in mind, I tried to optimize my coding process for coding speed – or, in business terms: productivity - without sacrificing the principles of TDD (more than I’d do either way…).  As a result, I consider a ratio of about 3-5/1 for test code vs. production code as normal and desirable. In other words: roughly 60-80% of my code is test code (This might sound heavy, but that is mainly due to the fact that software development standards only begin to evolve. The entire software development profession is very young, historically seen; only at the very beginning, and there are no viable standards yet. If you think about software development as a kind of casting process, where the test code is the mold and the resulting production code is the final product, then the above ratio sounds no longer extraordinary…) Although the above might look like very much unnecessary work at first sight, it’s not. With the aid of the mentioned add-ins, doing all the above is a matter of minutes, sometimes seconds (while writing this post took hours and days…). The most important thing is to have the right tools at hand. Slow developer machines or the lack of a tool or something like that - for ‘saving’ a few 100 bucks -  is just not acceptable and a very bad decision in business terms (though I quite some times have seen and heard that…). Production of high-quality products needs the usage of high-quality tools. This is a platitude that every craftsman knows… The here described round-trip will take me about five to ten minutes in my real-world development practice. I guess it’s about 30% more time compared to developing the ‘traditional’ (code-first) way. But the so manufactured ‘product’ is of much higher quality and massively reduces maintenance costs, which is by far the single biggest cost factor, as I showed in this previous post: It's the maintenance, stupid! (or: Something is rotten in developerland.). In the end, this is a highly cost-effective way of software development… But on the other hand, there clearly is a trade-off here: coding speed vs. code quality/later maintenance costs. The here described development method might be a perfect fit for the overwhelming majority of software projects, but there certainly are some scenarios where it’s not - e.g. if time-to-market is crucial for a software project. So this is a business decision in the end. It’s just that you have to know what you’re doing and what consequences this might have… Some last words First, I’d like to thank Derick Bailey again. His two aforementioned posts (which I strongly recommend for reading) inspired me to think deeply about my own personal way of doing TDD and to clarify my thoughts about it. I wouldn’t have done that without this inspiration. I really enjoy that kind of discussions… I agree with him in all respects. But I don’t know (yet?) how to bring his insights into the described production process without slowing things down. The above described method proved to be very “good enough” in my practical experience. But of course, I’m open to suggestions here… My rationale for now is: If the test is initially red during the red-green-refactor cycle, the ‘right reason’ is: it actually calls the right method, but this method is not yet operational. Later on, when the cycle is finished and the tests become part of the regular, automated Continuous Integration process, ‘red’ certainly must occur for the ‘right reason’: in this phase, ‘red’ MUST mean nothing but an unfulfilled assertion - Fail By Assertion, Not By Anything Else!

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  • AngularJS on top of ASP.NET: Moving the MVC framework out to the browser

    - by Varun Chatterji
    Heavily drawing inspiration from Ruby on Rails, MVC4’s convention over configuration model of development soon became the Holy Grail of .NET web development. The MVC model brought with it the goodness of proper separation of concerns between business logic, data, and the presentation logic. However, the MVC paradigm, was still one in which server side .NET code could be mixed with presentation code. The Razor templating engine, though cleaner than its predecessors, still encouraged and allowed you to mix .NET server side code with presentation logic. Thus, for example, if the developer required a certain <div> tag to be shown if a particular variable ShowDiv was true in the View’s model, the code could look like the following: Fig 1: To show a div or not. Server side .NET code is used in the View Mixing .NET code with HTML in views can soon get very messy. Wouldn’t it be nice if the presentation layer (HTML) could be pure HTML? Also, in the ASP.NET MVC model, some of the business logic invariably resides in the controller. It is tempting to use an anti­pattern like the one shown above to control whether a div should be shown or not. However, best practice would indicate that the Controller should not be aware of the div. The ShowDiv variable in the model should not exist. A controller should ideally, only be used to do the plumbing of getting the data populated in the model and nothing else. The view (ideally pure HTML) should render the presentation layer based on the model. In this article we will see how Angular JS, a new JavaScript framework by Google can be used effectively to build web applications where: 1. Views are pure HTML 2. Controllers (in the server sense) are pure REST based API calls 3. The presentation layer is loaded as needed from partial HTML only files. What is MVVM? MVVM short for Model View View Model is a new paradigm in web development. In this paradigm, the Model and View stuff exists on the client side through javascript instead of being processed on the server through postbacks. These frameworks are JavaScript frameworks that facilitate the clear separation of the “frontend” or the data rendering logic from the “backend” which is typically just a REST based API that loads and processes data through a resource model. The frameworks are called MVVM as a change to the Model (through javascript) gets reflected in the view immediately i.e. Model > View. Also, a change on the view (through manual input) gets reflected in the model immediately i.e. View > Model. The following figure shows this conceptually (comments are shown in red): Fig 2: Demonstration of MVVM in action In Fig 2, two text boxes are bound to the same variable model.myInt. Thus, changing the view manually (changing one text box through keyboard input) also changes the other textbox in real time demonstrating V > M property of a MVVM framework. Furthermore, clicking the button adds 1 to the value of model.myInt thus changing the model through JavaScript. This immediately updates the view (the value in the two textboxes) thus demonstrating the M > V property of a MVVM framework. Thus we see that the model in a MVVM JavaScript framework can be regarded as “the single source of truth“. This is an important concept. Angular is one such MVVM framework. We shall use it to build a simple app that sends SMS messages to a particular number. Application, Routes, Views, Controllers, Scope and Models Angular can be used in many ways to construct web applications. For this article, we shall only focus on building Single Page Applications (SPAs). Many of the approaches we will follow in this article have alternatives. It is beyond the scope of this article to explain every nuance in detail but we shall try to touch upon the basic concepts and end up with a working application that can be used to send SMS messages using Sent.ly Plus (a service that is itself built using Angular). Before you read on, we would like to urge you to forget what you know about Models, Views, Controllers and Routes in the ASP.NET MVC4 framework. All these words have different meanings in the Angular world. Whenever these words are used in this article, they will refer to Angular concepts and not ASP.NET MVC4 concepts. The following figure shows the skeleton of the root page of an SPA: Fig 3: The skeleton of a SPA The skeleton of the application is based on the Bootstrap starter template which can be found at: http://getbootstrap.com/examples/starter­template/ Apart from loading the Angular, jQuery and Bootstrap JavaScript libraries, it also loads our custom scripts /app/js/controllers.js /app/js/app.js These scripts define the routes, views and controllers which we shall come to in a moment. Application Notice that the body tag (Fig. 3) has an extra attribute: ng­app=”smsApp” Providing this tag “bootstraps” our single page application. It tells Angular to load a “module” called smsApp. This “module” is defined /app/js/app.js angular.module('smsApp', ['smsApp.controllers', function () {}]) Fig 4: The definition of our application module The line shows above, declares a module called smsApp. It also declares that this module “depends” on another module called “smsApp.controllers”. The smsApp.controllers module will contain all the controllers for our SPA. Routing and Views Notice that in the Navbar (in Fig 3) we have included two hyperlinks to: “#/app” “#/help” This is how Angular handles routing. Since the URLs start with “#”, they are actually just bookmarks (and not server side resources). However, our route definition (in /app/js/app.js) gives these URLs a special meaning within the Angular framework. angular.module('smsApp', ['smsApp.controllers', function () { }]) //Configure the routes .config(['$routeProvider', function ($routeProvider) { $routeProvider.when('/binding', { templateUrl: '/app/partials/bindingexample.html', controller: 'BindingController' }); }]); Fig 5: The definition of a route with an associated partial view and controller As we can see from the previous code sample, we are using the $routeProvider object in the configuration of our smsApp module. Notice how the code “asks for” the $routeProvider object by specifying it as a dependency in the [] braces and then defining a function that accepts it as a parameter. This is known as dependency injection. Please refer to the following link if you want to delve into this topic: http://docs.angularjs.org/guide/di What the above code snippet is doing is that it is telling Angular that when the URL is “#/binding”, then it should load the HTML snippet (“partial view”) found at /app/partials/bindingexample.html. Also, for this URL, Angular should load the controller called “BindingController”. We have also marked the div with the class “container” (in Fig 3) with the ng­view attribute. This attribute tells Angular that views (partial HTML pages) defined in the routes will be loaded within this div. You can see that the Angular JavaScript framework, unlike many other frameworks, works purely by extending HTML tags and attributes. It also allows you to extend HTML with your own tags and attributes (through directives) if you so desire, you can find out more about directives at the following URL: http://www.codeproject.com/Articles/607873/Extending­HTML­with­AngularJS­Directives Controllers and Models We have seen how we define what views and controllers should be loaded for a particular route. Let us now consider how controllers are defined. Our controllers are defined in the file /app/js/controllers.js. The following snippet shows the definition of the “BindingController” which is loaded when we hit the URL http://localhost:port/index.html#/binding (as we have defined in the route earlier as shown in Fig 5). Remember that we had defined that our application module “smsApp” depends on the “smsApp.controllers” module (see Fig 4). The code snippet below shows how the “BindingController” defined in the route shown in Fig 5 is defined in the module smsApp.controllers: angular.module('smsApp.controllers', [function () { }]) .controller('BindingController', ['$scope', function ($scope) { $scope.model = {}; $scope.model.myInt = 6; $scope.addOne = function () { $scope.model.myInt++; } }]); Fig 6: The definition of a controller in the “smsApp.controllers” module. The pieces are falling in place! Remember Fig.2? That was the code of a partial view that was loaded within the container div of the skeleton SPA shown in Fig 3. The route definition shown in Fig 5 also defined that the controller called “BindingController” (shown in Fig 6.) was loaded when we loaded the URL: http://localhost:22544/index.html#/binding The button in Fig 2 was marked with the attribute ng­click=”addOne()” which added 1 to the value of model.myInt. In Fig 6, we can see that this function is actually defined in the “BindingController”. Scope We can see from Fig 6, that in the definition of “BindingController”, we defined a dependency on $scope and then, as usual, defined a function which “asks for” $scope as per the dependency injection pattern. So what is $scope? Any guesses? As you might have guessed a scope is a particular “address space” where variables and functions may be defined. This has a similar meaning to scope in a programming language like C#. Model: The Scope is not the Model It is tempting to assign variables in the scope directly. For example, we could have defined myInt as $scope.myInt = 6 in Fig 6 instead of $scope.model.myInt = 6. The reason why this is a bad idea is that scope in hierarchical in Angular. Thus if we were to define a controller which was defined within the another controller (nested controllers), then the inner controller would inherit the scope of the parent controller. This inheritance would follow JavaScript prototypal inheritance. Let’s say the parent controller defined a variable through $scope.myInt = 6. The child controller would inherit the scope through java prototypical inheritance. This basically means that the child scope has a variable myInt that points to the parent scopes myInt variable. Now if we assigned the value of myInt in the parent, the child scope would be updated with the same value as the child scope’s myInt variable points to the parent scope’s myInt variable. However, if we were to assign the value of the myInt variable in the child scope, then the link of that variable to the parent scope would be broken as the variable myInt in the child scope now points to the value 6 and not to the parent scope’s myInt variable. But, if we defined a variable model in the parent scope, then the child scope will also have a variable model that points to the model variable in the parent scope. Updating the value of $scope.model.myInt in the parent scope would change the model variable in the child scope too as the variable is pointed to the model variable in the parent scope. Now changing the value of $scope.model.myInt in the child scope would ALSO change the value in the parent scope. This is because the model reference in the child scope is pointed to the scope variable in the parent. We did no new assignment to the model variable in the child scope. We only changed an attribute of the model variable. Since the model variable (in the child scope) points to the model variable in the parent scope, we have successfully changed the value of myInt in the parent scope. Thus the value of $scope.model.myInt in the parent scope becomes the “single source of truth“. This is a tricky concept, thus it is considered good practice to NOT use scope inheritance. More info on prototypal inheritance in Angular can be found in the “JavaScript Prototypal Inheritance” section at the following URL: https://github.com/angular/angular.js/wiki/Understanding­Scopes. Building It: An Angular JS application using a .NET Web API Backend Now that we have a perspective on the basic components of an MVVM application built using Angular, let’s build something useful. We will build an application that can be used to send out SMS messages to a given phone number. The following diagram describes the architecture of the application we are going to build: Fig 7: Broad application architecture We are going to add an HTML Partial to our project. This partial will contain the form fields that will accept the phone number and message that needs to be sent as an SMS. It will also display all the messages that have previously been sent. All the executable code that is run on the occurrence of events (button clicks etc.) in the view resides in the controller. The controller interacts with the ASP.NET WebAPI to get a history of SMS messages, add a message etc. through a REST based API. For the purposes of simplicity, we will use an in memory data structure for the purposes of creating this application. Thus, the tasks ahead of us are: Creating the REST WebApi with GET, PUT, POST, DELETE methods. Creating the SmsView.html partial Creating the SmsController controller with methods that are called from the SmsView.html partial Add a new route that loads the controller and the partial. 1. Creating the REST WebAPI This is a simple task that should be quite straightforward to any .NET developer. The following listing shows our ApiController: public class SmsMessage { public string to { get; set; } public string message { get; set; } } public class SmsResource : SmsMessage { public int smsId { get; set; } } public class SmsResourceController : ApiController { public static Dictionary<int, SmsResource> messages = new Dictionary<int, SmsResource>(); public static int currentId = 0; // GET api/<controller> public List<SmsResource> Get() { List<SmsResource> result = new List<SmsResource>(); foreach (int key in messages.Keys) { result.Add(messages[key]); } return result; } // GET api/<controller>/5 public SmsResource Get(int id) { if (messages.ContainsKey(id)) return messages[id]; return null; } // POST api/<controller> public List<SmsResource> Post([FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { SmsResource res = (SmsResource) value; res.smsId = currentId++; messages.Add(res.smsId, res); //SentlyPlusSmsSender.SendMessage(value.to, value.message); return Get(); } } // PUT api/<controller>/5 public List<SmsResource> Put(int id, [FromBody] SmsMessage value) { //Synchronize on messages so we don't have id collisions lock (messages) { if (messages.ContainsKey(id)) { //Update the message messages[id].message = value.message; messages[id].to = value.message; } return Get(); } } // DELETE api/<controller>/5 public List<SmsResource> Delete(int id) { if (messages.ContainsKey(id)) { messages.Remove(id); } return Get(); } } Once this class is defined, we should be able to access the WebAPI by a simple GET request using the browser: http://localhost:port/api/SmsResource Notice the commented line: //SentlyPlusSmsSender.SendMessage The SentlyPlusSmsSender class is defined in the attached solution. We have shown this line as commented as we want to explain the core Angular concepts. If you load the attached solution, this line is uncommented in the source and an actual SMS will be sent! By default, the API returns XML. For consumption of the API in Angular, we would like it to return JSON. To change the default to JSON, we make the following change to WebApiConfig.cs file located in the App_Start folder. public static class WebApiConfig { public static void Register(HttpConfiguration config) { config.Routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); var appXmlType = config.Formatters.XmlFormatter. SupportedMediaTypes. FirstOrDefault( t => t.MediaType == "application/xml"); config.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType); } } We now have our backend REST Api which we can consume from Angular! 2. Creating the SmsView.html partial This simple partial will define two fields: the destination phone number (international format starting with a +) and the message. These fields will be bound to model.phoneNumber and model.message. We will also add a button that we shall hook up to sendMessage() in the controller. A list of all previously sent messages (bound to model.allMessages) will also be displayed below the form input. The following code shows the code for the partial: <!--­­ If model.errorMessage is defined, then render the error div -­­> <div class="alert alert-­danger alert-­dismissable" style="margin­-top: 30px;" ng­-show="model.errorMessage != undefined"> <button type="button" class="close" data­dismiss="alert" aria­hidden="true">&times;</button> <strong>Error!</strong> <br /> {{ model.errorMessage }} </div> <!--­­ The input fields bound to the model --­­> <div class="well" style="margin-­top: 30px;"> <table style="width: 100%;"> <tr> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Phone number (eg; +44 7778 609466)" ng­-model="model.phoneNumber" class="form-­control" style="width: 90%" onkeypress="return checkPhoneInput();" /> </td> <td style="width: 45%; text-­align: center;"> <input type="text" placeholder="Message" ng­-model="model.message" class="form-­control" style="width: 90%" /> </td> <td style="text-­align: center;"> <button class="btn btn-­danger" ng-­click="sendMessage();" ng-­disabled="model.isAjaxInProgress" style="margin­right: 5px;">Send</button> <img src="/Content/ajax-­loader.gif" ng­-show="model.isAjaxInProgress" /> </td> </tr> </table> </div> <!--­­ The past messages ­­--> <div style="margin-­top: 30px;"> <!­­-- The following div is shown if there are no past messages --­­> <div ng­-show="model.allMessages.length == 0"> No messages have been sent yet! </div> <!--­­ The following div is shown if there are some past messages --­­> <div ng-­show="model.allMessages.length == 0"> <table style="width: 100%;" class="table table-­striped"> <tr> <td>Phone Number</td> <td>Message</td> <td></td> </tr> <!--­­ The ng-­repeat directive is line the repeater control in .NET, but as you can see this partial is pure HTML which is much cleaner --> <tr ng-­repeat="message in model.allMessages"> <td>{{ message.to }}</td> <td>{{ message.message }}</td> <td> <button class="btn btn-­danger" ng-­click="delete(message.smsId);" ng­-disabled="model.isAjaxInProgress">Delete</button> </td> </tr> </table> </div> </div> The above code is commented and should be self explanatory. Conditional rendering is achieved through using the ng-­show=”condition” attribute on various div tags. Input fields are bound to the model and the send button is bound to the sendMessage() function in the controller as through the ng­click=”sendMessage()” attribute defined on the button tag. While AJAX calls are taking place, the controller sets model.isAjaxInProgress to true. Based on this variable, buttons are disabled through the ng-­disabled directive which is added as an attribute to the buttons. The ng-­repeat directive added as an attribute to the tr tag causes the table row to be rendered multiple times much like an ASP.NET repeater. 3. Creating the SmsController controller The penultimate piece of our application is the controller which responds to events from our view and interacts with our MVC4 REST WebAPI. The following listing shows the code we need to add to /app/js/controllers.js. Note that controller definitions can be chained. Also note that this controller “asks for” the $http service. The $http service is a simple way in Angular to do AJAX. So far we have only encountered modules, controllers, views and directives in Angular. The $http is new entity in Angular called a service. More information on Angular services can be found at the following URL: http://docs.angularjs.org/guide/dev_guide.services.understanding_services. .controller('SmsController', ['$scope', '$http', function ($scope, $http) { //We define the model $scope.model = {}; //We define the allMessages array in the model //that will contain all the messages sent so far $scope.model.allMessages = []; //The error if any $scope.model.errorMessage = undefined; //We initially load data so set the isAjaxInProgress = true; $scope.model.isAjaxInProgress = true; //Load all the messages $http({ url: '/api/smsresource', method: "GET" }). success(function (data, status, headers, config) { this callback will be called asynchronously //when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { //called asynchronously if an error occurs //or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); $scope.delete = function (id) { //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource/' + id, method: "DELETE" }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } $scope.sendMessage = function () { $scope.model.errorMessage = undefined; var message = ''; if($scope.model.message != undefined) message = $scope.model.message.trim(); if ($scope.model.phoneNumber == undefined || $scope.model.phoneNumber == '' || $scope.model.phoneNumber.length < 10 || $scope.model.phoneNumber[0] != '+') { $scope.model.errorMessage = "You must enter a valid phone number in international format. Eg: +44 7778 609466"; return; } if (message.length == 0) { $scope.model.errorMessage = "You must specify a message!"; return; } //We are making an ajax call so we set this to true $scope.model.isAjaxInProgress = true; $http({ url: '/api/smsresource', method: "POST", data: { to: $scope.model.phoneNumber, message: $scope.model.message } }). success(function (data, status, headers, config) { // this callback will be called asynchronously // when the response is available $scope.model.allMessages = data; //We are done with AJAX loading $scope.model.isAjaxInProgress = false; }). error(function (data, status, headers, config) { // called asynchronously if an error occurs // or server returns response with an error status. $scope.model.errorMessage = "Error occurred status:" + status // We are done with AJAX loading $scope.model.isAjaxInProgress = false; }); } }]); We can see from the previous listing how the functions that are called from the view are defined in the controller. It should also be evident how easy it is to make AJAX calls to consume our MVC4 REST WebAPI. Now we are left with the final piece. We need to define a route that associates a particular path with the view we have defined and the controller we have defined. 4. Add a new route that loads the controller and the partial This is the easiest part of the puzzle. We simply define another route in the /app/js/app.js file: $routeProvider.when('/sms', { templateUrl: '/app/partials/smsview.html', controller: 'SmsController' }); Conclusion In this article we have seen how much of the server side functionality in the MVC4 framework can be moved to the browser thus delivering a snappy and fast user interface. We have seen how we can build client side HTML only views that avoid the messy syntax offered by server side Razor views. We have built a functioning app from the ground up. The significant advantage of this approach to building web apps is that the front end can be completely platform independent. Even though we used ASP.NET to create our REST API, we could just easily have used any other language such as Node.js, Ruby etc without changing a single line of our front end code. Angular is a rich framework and we have only touched on basic functionality required to create a SPA. For readers who wish to delve further into the Angular framework, we would recommend the following URL as a starting point: http://docs.angularjs.org/misc/started. To get started with the code for this project: Sign up for an account at http://plus.sent.ly (free) Add your phone number Go to the “My Identies Page” Note Down your Sender ID, Consumer Key and Consumer Secret Download the code for this article at: https://docs.google.com/file/d/0BzjEWqSE31yoZjZlV0d0R2Y3eW8/edit?usp=sharing Change the values of Sender Id, Consumer Key and Consumer Secret in the web.config file Run the project through Visual Studio!

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  • SQL Server 2012 - AlwaysOn

    - by Claus Jandausch
    Ich war nicht nur irritiert, ich war sogar regelrecht schockiert - und für einen kurzen Moment sprachlos (was nur selten der Fall ist). Gerade eben hatte mich jemand gefragt "Wann Oracle denn etwas Vergleichbares wie AlwaysOn bieten würde - und ob überhaupt?" War ich hier im falschen Film gelandet? Ich konnte nicht anders, als meinen Unmut kundzutun und zu erklären, dass die Fragestellung normalerweise anders herum läuft. Zugegeben - es mag vielleicht strittige Punkte geben im Vergleich zwischen Oracle und SQL Server - bei denen nicht unbedingt immer Oracle die Nase vorn haben muss - aber das Thema Clustering für Hochverfügbarkeit (HA), Disaster Recovery (DR) und Skalierbarkeit gehört mit Sicherheit nicht dazu. Dieses Erlebnis hakte ich am Nachgang als Einzelfall ab, der so nie wieder vorkommen würde. Bis ich kurz darauf eines Besseren belehrt wurde und genau die selbe Frage erneut zu hören bekam. Diesmal sogar im Exadata-Umfeld und einem Oracle Stretch Cluster. Einmal ist keinmal, doch zweimal ist einmal zu viel... Getreu diesem alten Motto war mir klar, dass man das so nicht länger stehen lassen konnte. Ich habe keine Ahnung, wie die Microsoft Marketing Abteilung es geschafft hat, unter dem AlwaysOn Brading eine innovative Technologie vermuten zu lassen - aber sie hat ihren Job scheinbar gut gemacht. Doch abgesehen von einem guten Marketing, stellt sich natürlich die Frage, was wirklich dahinter steckt und wie sich das Ganze mit Oracle vergleichen lässt - und ob überhaupt? Damit wären wir wieder bei der ursprünglichen Frage angelangt.  So viel zum Hintergrund dieses Blogbeitrags - von meiner Antwort handelt der restliche Blog. "Windows was the God ..." Um den wahren Unterschied zwischen Oracle und Microsoft verstehen zu können, muss man zunächst das bedeutendste Microsoft Dogma kennen. Es lässt sich schlicht und einfach auf den Punkt bringen: "Alles muss auf Windows basieren." Die Überschrift dieses Absatzes ist kein von mir erfundener Ausspruch, sondern ein Zitat. Konkret stammt es aus einem längeren Artikel von Kurt Eichenwald in der Vanity Fair aus dem August 2012. Er lautet Microsoft's Lost Decade und sei jedem ans Herz gelegt, der die "Microsoft-Maschinerie" unter Steve Ballmer und einige ihrer Kuriositäten besser verstehen möchte. "YOU TALKING TO ME?" Microsoft C.E.O. Steve Ballmer bei seiner Keynote auf der 2012 International Consumer Electronics Show in Las Vegas am 9. Januar   Manche Dinge in diesem Artikel mögen überspitzt dargestellt erscheinen - sind sie aber nicht. Vieles davon kannte ich bereits aus eigener Erfahrung und kann es nur bestätigen. Anderes hat sich mir erst so richtig erschlossen. Insbesondere die folgenden Passagen führten zum Aha-Erlebnis: “Windows was the god—everything had to work with Windows,” said Stone... “Every little thing you want to write has to build off of Windows (or other existing roducts),” one software engineer said. “It can be very confusing, …” Ich habe immer schon darauf hingewiesen, dass in einem SQL Server Failover Cluster die Microsoft Datenbank eigentlich nichts Nenneswertes zum Geschehen beiträgt, sondern sich voll und ganz auf das Windows Betriebssystem verlässt. Deshalb muss man auch die Windows Server Enterprise Edition installieren, soll ein Failover Cluster für den SQL Server eingerichtet werden. Denn hier werden die Cluster Services geliefert - nicht mit dem SQL Server. Er ist nur lediglich ein weiteres Server Produkt, für das Windows in Ausfallszenarien genutzt werden kann - so wie Microsoft Exchange beispielsweise, oder Microsoft SharePoint, oder irgendein anderes Server Produkt das auf Windows gehostet wird. Auch Oracle kann damit genutzt werden. Das Stichwort lautet hier: Oracle Failsafe. Nur - warum sollte man das tun, wenn gleichzeitig eine überlegene Technologie wie die Oracle Real Application Clusters (RAC) zur Verfügung steht, die dann auch keine Windows Enterprise Edition voraussetzen, da Oracle die eigene Clusterware liefert. Welche darüber hinaus für kürzere Failover-Zeiten sorgt, da diese Cluster-Technologie Datenbank-integriert ist und sich nicht auf "Dritte" verlässt. Wenn man sich also schon keine technischen Vorteile mit einem SQL Server Failover Cluster erkauft, sondern zusätzlich noch versteckte Lizenzkosten durch die Lizenzierung der Windows Server Enterprise Edition einhandelt, warum hat Microsoft dann in den vergangenen Jahren seit SQL Server 2000 nicht ebenfalls an einer neuen und innovativen Lösung gearbeitet, die mit Oracle RAC mithalten kann? Entwickler hat Microsoft genügend? Am Geld kann es auch nicht liegen? Lesen Sie einfach noch einmal die beiden obenstehenden Zitate und sie werden den Grund verstehen. Anders lässt es sich ja auch gar nicht mehr erklären, dass AlwaysOn aus zwei unterschiedlichen Technologien besteht, die beide jedoch wiederum auf dem Windows Server Failover Clustering (WSFC) basieren. Denn daraus ergeben sich klare Nachteile - aber dazu später mehr. Um AlwaysOn zu verstehen, sollte man sich zunächst kurz in Erinnerung rufen, was Microsoft bisher an HA/DR (High Availability/Desaster Recovery) Lösungen für SQL Server zur Verfügung gestellt hat. Replikation Basiert auf logischer Replikation und Pubisher/Subscriber Architektur Transactional Replication Merge Replication Snapshot Replication Microsoft's Replikation ist vergleichbar mit Oracle GoldenGate. Oracle GoldenGate stellt jedoch die umfassendere Technologie dar und bietet High Performance. Log Shipping Microsoft's Log Shipping stellt eine einfache Technologie dar, die vergleichbar ist mit Oracle Managed Recovery in Oracle Version 7. Das Log Shipping besitzt folgende Merkmale: Transaction Log Backups werden von Primary nach Secondary/ies geschickt Einarbeitung (z.B. Restore) auf jedem Secondary individuell Optionale dritte Server Instanz (Monitor Server) für Überwachung und Alarm Log Restore Unterbrechung möglich für Read-Only Modus (Secondary) Keine Unterstützung von Automatic Failover Database Mirroring Microsoft's Database Mirroring wurde verfügbar mit SQL Server 2005, sah aus wie Oracle Data Guard in Oracle 9i, war funktional jedoch nicht so umfassend. Für ein HA/DR Paar besteht eine 1:1 Beziehung, um die produktive Datenbank (Principle DB) abzusichern. Auf der Standby Datenbank (Mirrored DB) werden alle Insert-, Update- und Delete-Operationen nachgezogen. Modi Synchron (High-Safety Modus) Asynchron (High-Performance Modus) Automatic Failover Unterstützt im High-Safety Modus (synchron) Witness Server vorausgesetzt     Zur Frage der Kontinuität Es stellt sich die Frage, wie es um diesen Technologien nun im Zusammenhang mit SQL Server 2012 bestellt ist. Unter Fanfaren seinerzeit eingeführt, war Database Mirroring das erklärte Mittel der Wahl. Ich bin kein Produkt Manager bei Microsoft und kann hierzu nur meine Meinung äußern, aber zieht man den SQL AlwaysOn Team Blog heran, so sieht es nicht gut aus für das Database Mirroring - zumindest nicht langfristig. "Does AlwaysOn Availability Group replace Database Mirroring going forward?” “The short answer is we recommend that you migrate from the mirroring configuration or even mirroring and log shipping configuration to using Availability Group. Database Mirroring will still be available in the Denali release but will be phased out over subsequent releases. Log Shipping will continue to be available in future releases.” Damit wären wir endlich beim eigentlichen Thema angelangt. Was ist eine sogenannte Availability Group und was genau hat es mit der vielversprechend klingenden Bezeichnung AlwaysOn auf sich?   SQL Server 2012 - AlwaysOn Zwei HA-Features verstekcne sich hinter dem “AlwaysOn”-Branding. Einmal das AlwaysOn Failover Clustering aka SQL Server Failover Cluster Instances (FCI) - zum Anderen die AlwaysOn Availability Groups. Failover Cluster Instances (FCI) Entspricht ungefähr dem Stretch Cluster Konzept von Oracle Setzt auf Windows Server Failover Clustering (WSFC) auf Bietet HA auf Instanz-Ebene AlwaysOn Availability Groups (Verfügbarkeitsgruppen) Ähnlich der Idee von Consistency Groups, wie in Storage-Level Replikations-Software von z.B. EMC SRDF Abhängigkeiten zu Windows Server Failover Clustering (WSFC) Bietet HA auf Datenbank-Ebene   Hinweis: Verwechseln Sie nicht eine SQL Server Datenbank mit einer Oracle Datenbank. Und auch nicht eine Oracle Instanz mit einer SQL Server Instanz. Die gleichen Begriffe haben hier eine andere Bedeutung - nicht selten ein Grund, weshalb Oracle- und Microsoft DBAs schnell aneinander vorbei reden. Denken Sie bei einer SQL Server Datenbank eher an ein Oracle Schema, das kommt der Sache näher. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema. Wenn Sie die genauen Unterschiede kennen möchten, finden Sie eine detaillierte Beschreibung in meinem Buch "Oracle10g Release 2 für Windows und .NET", erhältich bei Lehmanns, Amazon, etc.   Windows Server Failover Clustering (WSFC) Wie man sieht, basieren beide AlwaysOn Technologien wiederum auf dem Windows Server Failover Clustering (WSFC), um einerseits Hochverfügbarkeit auf Ebene der Instanz zu gewährleisten und andererseits auf der Datenbank-Ebene. Deshalb nun eine kurze Beschreibung der WSFC. Die WSFC sind ein mit dem Windows Betriebssystem geliefertes Infrastruktur-Feature, um HA für Server Anwendungen, wie Microsoft Exchange, SharePoint, SQL Server, etc. zu bieten. So wie jeder andere Cluster, besteht ein WSFC Cluster aus einer Gruppe unabhängiger Server, die zusammenarbeiten, um die Verfügbarkeit einer Applikation oder eines Service zu erhöhen. Falls ein Cluster-Knoten oder -Service ausfällt, kann der auf diesem Knoten bisher gehostete Service automatisch oder manuell auf einen anderen im Cluster verfügbaren Knoten transferriert werden - was allgemein als Failover bekannt ist. Unter SQL Server 2012 verwenden sowohl die AlwaysOn Avalability Groups, als auch die AlwaysOn Failover Cluster Instances die WSFC als Plattformtechnologie, um Komponenten als WSFC Cluster-Ressourcen zu registrieren. Verwandte Ressourcen werden in eine Ressource Group zusammengefasst, die in Abhängigkeit zu anderen WSFC Cluster-Ressourcen gebracht werden kann. Der WSFC Cluster Service kann jetzt die Notwendigkeit zum Neustart der SQL Server Instanz erfassen oder einen automatischen Failover zu einem anderen Server-Knoten im WSFC Cluster auslösen.   Failover Cluster Instances (FCI) Eine SQL Server Failover Cluster Instanz (FCI) ist eine einzelne SQL Server Instanz, die in einem Failover Cluster betrieben wird, der aus mehreren Windows Server Failover Clustering (WSFC) Knoten besteht und so HA (High Availability) auf Ebene der Instanz bietet. Unter Verwendung von Multi-Subnet FCI kann auch Remote DR (Disaster Recovery) unterstützt werden. Eine weitere Option für Remote DR besteht darin, eine unter FCI gehostete Datenbank in einer Availability Group zu betreiben. Hierzu später mehr. FCI und WSFC Basis FCI, das für lokale Hochverfügbarkeit der Instanzen genutzt wird, ähnelt der veralteten Architektur eines kalten Cluster (Aktiv-Passiv). Unter SQL Server 2008 wurde diese Technologie SQL Server 2008 Failover Clustering genannt. Sie nutzte den Windows Server Failover Cluster. In SQL Server 2012 hat Microsoft diese Basistechnologie unter der Bezeichnung AlwaysOn zusammengefasst. Es handelt sich aber nach wie vor um die klassische Aktiv-Passiv-Konfiguration. Der Ablauf im Failover-Fall ist wie folgt: Solange kein Hardware-oder System-Fehler auftritt, werden alle Dirty Pages im Buffer Cache auf Platte geschrieben Alle entsprechenden SQL Server Services (Dienste) in der Ressource Gruppe werden auf dem aktiven Knoten gestoppt Die Ownership der Ressource Gruppe wird auf einen anderen Knoten der FCI transferriert Der neue Owner (Besitzer) der Ressource Gruppe startet seine SQL Server Services (Dienste) Die Connection-Anforderungen einer Client-Applikation werden automatisch auf den neuen aktiven Knoten mit dem selben Virtuellen Network Namen (VNN) umgeleitet Abhängig vom Zeitpunkt des letzten Checkpoints, kann die Anzahl der Dirty Pages im Buffer Cache, die noch auf Platte geschrieben werden müssen, zu unvorhersehbar langen Failover-Zeiten führen. Um diese Anzahl zu drosseln, besitzt der SQL Server 2012 eine neue Fähigkeit, die Indirect Checkpoints genannt wird. Indirect Checkpoints ähnelt dem Fast-Start MTTR Target Feature der Oracle Datenbank, das bereits mit Oracle9i verfügbar war.   SQL Server Multi-Subnet Clustering Ein SQL Server Multi-Subnet Failover Cluster entspricht vom Konzept her einem Oracle RAC Stretch Cluster. Doch dies ist nur auf den ersten Blick der Fall. Im Gegensatz zu RAC ist in einem lokalen SQL Server Failover Cluster jeweils nur ein Knoten aktiv für eine Datenbank. Für die Datenreplikation zwischen geografisch entfernten Sites verlässt sich Microsoft auf 3rd Party Lösungen für das Storage Mirroring.     Die Verbesserung dieses Szenario mit einer SQL Server 2012 Implementierung besteht schlicht darin, dass eine VLAN-Konfiguration (Virtual Local Area Network) nun nicht mehr benötigt wird, so wie dies bisher der Fall war. Das folgende Diagramm stellt dar, wie der Ablauf mit SQL Server 2012 gehandhabt wird. In Site A und Site B wird HA jeweils durch einen lokalen Aktiv-Passiv-Cluster sichergestellt.     Besondere Aufmerksamkeit muss hier der Konfiguration und dem Tuning geschenkt werden, da ansonsten völlig inakzeptable Failover-Zeiten resultieren. Dies liegt darin begründet, weil die Downtime auf Client-Seite nun nicht mehr nur von der reinen Failover-Zeit abhängt, sondern zusätzlich von der Dauer der DNS Replikation zwischen den DNS Servern. (Rufen Sie sich in Erinnerung, dass wir gerade von Multi-Subnet Clustering sprechen). Außerdem ist zu berücksichtigen, wie schnell die Clients die aktualisierten DNS Informationen abfragen. Spezielle Konfigurationen für Node Heartbeat, HostRecordTTL (Host Record Time-to-Live) und Intersite Replication Frequeny für Active Directory Sites und Services werden notwendig. Default TTL für Windows Server 2008 R2: 20 Minuten Empfohlene Einstellung: 1 Minute DNS Update Replication Frequency in Windows Umgebung: 180 Minuten Empfohlene Einstellung: 15 Minuten (minimaler Wert)   Betrachtet man diese Werte, muss man feststellen, dass selbst eine optimale Konfiguration die rigiden SLAs (Service Level Agreements) heutiger geschäftskritischer Anwendungen für HA und DR nicht erfüllen kann. Denn dies impliziert eine auf der Client-Seite erlebte Failover-Zeit von insgesamt 16 Minuten. Hierzu ein Auszug aus der SQL Server 2012 Online Dokumentation: Cons: If a cross-subnet failover occurs, the client recovery time could be 15 minutes or longer, depending on your HostRecordTTL setting and the setting of your cross-site DNS/AD replication schedule.    Wir sind hier an einem Punkt unserer Überlegungen angelangt, an dem sich erklärt, weshalb ich zuvor das "Windows was the God ..." Zitat verwendet habe. Die unbedingte Abhängigkeit zu Windows wird zunehmend zum Problem, da sie die Komplexität einer Microsoft-basierenden Lösung erhöht, anstelle sie zu reduzieren. Und Komplexität ist das Letzte, was sich CIOs heutzutage wünschen.  Zur Ehrenrettung des SQL Server 2012 und AlwaysOn muss man sagen, dass derart lange Failover-Zeiten kein unbedingtes "Muss" darstellen, sondern ein "Kann". Doch auch ein "Kann" kann im unpassenden Moment unvorhersehbare und kostspielige Folgen haben. Die Unabsehbarkeit ist wiederum Ursache vieler an der Implementierung beteiligten Komponenten und deren Abhängigkeiten, wie beispielsweise drei Cluster-Lösungen (zwei von Microsoft, eine 3rd Party Lösung). Wie man die Sache auch dreht und wendet, kommt man an diesem Fakt also nicht vorbei - ganz unabhängig von der Dauer einer Downtime oder Failover-Zeiten. Im Gegensatz zu AlwaysOn und der hier vorgestellten Version eines Stretch-Clusters, vermeidet eine entsprechende Oracle Implementierung eine derartige Komplexität, hervorgerufen duch multiple Abhängigkeiten. Den Unterschied machen Datenbank-integrierte Mechanismen, wie Fast Application Notification (FAN) und Fast Connection Failover (FCF). Für Oracle MAA Konfigurationen (Maximum Availability Architecture) sind Inter-Site Failover-Zeiten im Bereich von Sekunden keine Seltenheit. Wenn Sie dem Link zur Oracle MAA folgen, finden Sie außerdem eine Reihe an Customer Case Studies. Auch dies ist ein wichtiges Unterscheidungsmerkmal zu AlwaysOn, denn die Oracle Technologie hat sich bereits zigfach in höchst kritischen Umgebungen bewährt.   Availability Groups (Verfügbarkeitsgruppen) Die sogenannten Availability Groups (Verfügbarkeitsgruppen) sind - neben FCI - der weitere Baustein von AlwaysOn.   Hinweis: Bevor wir uns näher damit beschäftigen, sollten Sie sich noch einmal ins Gedächtnis rufen, dass eine SQL Server Datenbank nicht die gleiche Bedeutung besitzt, wie eine Oracle Datenbank, sondern eher einem Oracle Schema entspricht. So etwas wie die SQL Server Northwind Datenbank ist vergleichbar mit dem Oracle Scott Schema.   Eine Verfügbarkeitsgruppe setzt sich zusammen aus einem Set mehrerer Benutzer-Datenbanken, die im Falle eines Failover gemeinsam als Gruppe behandelt werden. Eine Verfügbarkeitsgruppe unterstützt ein Set an primären Datenbanken (primäres Replikat) und einem bis vier Sets von entsprechenden sekundären Datenbanken (sekundäre Replikate).       Es können jedoch nicht alle SQL Server Datenbanken einer AlwaysOn Verfügbarkeitsgruppe zugeordnet werden. Der SQL Server Spezialist Michael Otey zählt in seinem SQL Server Pro Artikel folgende Anforderungen auf: Verfügbarkeitsgruppen müssen mit Benutzer-Datenbanken erstellt werden. System-Datenbanken können nicht verwendet werden Die Datenbanken müssen sich im Read-Write Modus befinden. Read-Only Datenbanken werden nicht unterstützt Die Datenbanken in einer Verfügbarkeitsgruppe müssen Multiuser Datenbanken sein Sie dürfen nicht das AUTO_CLOSE Feature verwenden Sie müssen das Full Recovery Modell nutzen und es muss ein vollständiges Backup vorhanden sein Eine gegebene Datenbank kann sich nur in einer einzigen Verfügbarkeitsgruppe befinden und diese Datenbank düerfen nicht für Database Mirroring konfiguriert sein Microsoft empfiehl außerdem, dass der Verzeichnispfad einer Datenbank auf dem primären und sekundären Server identisch sein sollte Wie man sieht, eignen sich Verfügbarkeitsgruppen nicht, um HA und DR vollständig abzubilden. Die Unterscheidung zwischen der Instanzen-Ebene (FCI) und Datenbank-Ebene (Availability Groups) ist von hoher Bedeutung. Vor kurzem wurde mir gesagt, dass man mit den Verfügbarkeitsgruppen auf Shared Storage verzichten könne und dadurch Kosten spart. So weit so gut ... Man kann natürlich eine Installation rein mit Verfügbarkeitsgruppen und ohne FCI durchführen - aber man sollte sich dann darüber bewusst sein, was man dadurch alles nicht abgesichert hat - und dies wiederum für Desaster Recovery (DR) und SLAs (Service Level Agreements) bedeutet. Kurzum, um die Kombination aus beiden AlwaysOn Produkten und der damit verbundene Komplexität kommt man wohl in der Praxis nicht herum.    Availability Groups und WSFC AlwaysOn hängt von Windows Server Failover Clustering (WSFC) ab, um die aktuellen Rollen der Verfügbarkeitsreplikate einer Verfügbarkeitsgruppe zu überwachen und zu verwalten, und darüber zu entscheiden, wie ein Failover-Ereignis die Verfügbarkeitsreplikate betrifft. Das folgende Diagramm zeigt de Beziehung zwischen Verfügbarkeitsgruppen und WSFC:   Der Verfügbarkeitsmodus ist eine Eigenschaft jedes Verfügbarkeitsreplikats. Synychron und Asynchron können also gemischt werden: Availability Modus (Verfügbarkeitsmodus) Asynchroner Commit-Modus Primäres replikat schließt Transaktionen ohne Warten auf Sekundäres Synchroner Commit-Modus Primäres Replikat wartet auf Commit von sekundärem Replikat Failover Typen Automatic Manual Forced (mit möglichem Datenverlust) Synchroner Commit-Modus Geplanter, manueller Failover ohne Datenverlust Automatischer Failover ohne Datenverlust Asynchroner Commit-Modus Nur Forced, manueller Failover mit möglichem Datenverlust   Der SQL Server kennt keinen separaten Switchover Begriff wie in Oracle Data Guard. Für SQL Server werden alle Role Transitions als Failover bezeichnet. Tatsächlich unterstützt der SQL Server keinen Switchover für asynchrone Verbindungen. Es gibt nur die Form des Forced Failover mit möglichem Datenverlust. Eine ähnliche Fähigkeit wie der Switchover unter Oracle Data Guard ist so nicht gegeben.   SQL Sever FCI mit Availability Groups (Verfügbarkeitsgruppen) Neben den Verfügbarkeitsgruppen kann eine zweite Failover-Ebene eingerichtet werden, indem SQL Server FCI (auf Shared Storage) mit WSFC implementiert wird. Ein Verfügbarkeitesreplikat kann dann auf einer Standalone Instanz gehostet werden, oder einer FCI Instanz. Zum Verständnis: Die Verfügbarkeitsgruppen selbst benötigen kein Shared Storage. Diese Kombination kann verwendet werden für lokale HA auf Ebene der Instanz und DR auf Datenbank-Ebene durch Verfügbarkeitsgruppen. Das folgende Diagramm zeigt dieses Szenario:   Achtung! Hier handelt es sich nicht um ein Pendant zu Oracle RAC plus Data Guard, auch wenn das Bild diesen Eindruck vielleicht vermitteln mag - denn alle sekundären Knoten im FCI sind rein passiv. Es existiert außerdem eine weitere und ernsthafte Einschränkung: SQL Server Failover Cluster Instanzen (FCI) unterstützen nicht das automatische AlwaysOn Failover für Verfügbarkeitsgruppen. Jedes unter FCI gehostete Verfügbarkeitsreplikat kann nur für manuelles Failover konfiguriert werden.   Lesbare Sekundäre Replikate Ein oder mehrere Verfügbarkeitsreplikate in einer Verfügbarkeitsgruppe können für den lesenden Zugriff konfiguriert werden, wenn sie als sekundäres Replikat laufen. Dies ähnelt Oracle Active Data Guard, jedoch gibt es Einschränkungen. Alle Abfragen gegen die sekundäre Datenbank werden automatisch auf das Snapshot Isolation Level abgebildet. Es handelt sich dabei um eine Versionierung der Rows. Microsoft versuchte hiermit die Oracle MVRC (Multi Version Read Consistency) nachzustellen. Tatsächlich muss man die SQL Server Snapshot Isolation eher mit Oracle Flashback vergleichen. Bei der Implementierung des Snapshot Isolation Levels handelt sich um ein nachträglich aufgesetztes Feature und nicht um einen inhärenten Teil des Datenbank-Kernels, wie im Falle Oracle. (Ich werde hierzu in Kürze einen weiteren Blogbeitrag verfassen, wenn ich mich mit der neuen SQL Server 2012 Core Lizenzierung beschäftige.) Für die Praxis entstehen aus der Abbildung auf das Snapshot Isolation Level ernsthafte Restriktionen, derer man sich für den Betrieb in der Praxis bereits vorab bewusst sein sollte: Sollte auf der primären Datenbank eine aktive Transaktion zu dem Zeitpunkt existieren, wenn ein lesbares sekundäres Replikat in die Verfügbarkeitsgruppe aufgenommen wird, werden die Row-Versionen auf der korrespondierenden sekundären Datenbank nicht sofort vollständig verfügbar sein. Eine aktive Transaktion auf dem primären Replikat muss zuerst abgeschlossen (Commit oder Rollback) und dieser Transaktions-Record auf dem sekundären Replikat verarbeitet werden. Bis dahin ist das Isolation Level Mapping auf der sekundären Datenbank unvollständig und Abfragen sind temporär geblockt. Microsoft sagt dazu: "This is needed to guarantee that row versions are available on the secondary replica before executing the query under snapshot isolation as all isolation levels are implicitly mapped to snapshot isolation." (SQL Storage Engine Blog: AlwaysOn: I just enabled Readable Secondary but my query is blocked?)  Grundlegend bedeutet dies, dass ein aktives lesbares Replikat nicht in die Verfügbarkeitsgruppe aufgenommen werden kann, ohne das primäre Replikat vorübergehend stillzulegen. Da Leseoperationen auf das Snapshot Isolation Transaction Level abgebildet werden, kann die Bereinigung von Ghost Records auf dem primären Replikat durch Transaktionen auf einem oder mehreren sekundären Replikaten geblockt werden - z.B. durch eine lang laufende Abfrage auf dem sekundären Replikat. Diese Bereinigung wird auch blockiert, wenn die Verbindung zum sekundären Replikat abbricht oder der Datenaustausch unterbrochen wird. Auch die Log Truncation wird in diesem Zustant verhindert. Wenn dieser Zustand längere Zeit anhält, empfiehlt Microsoft das sekundäre Replikat aus der Verfügbarkeitsgruppe herauszunehmen - was ein ernsthaftes Downtime-Problem darstellt. Die Read-Only Workload auf den sekundären Replikaten kann eingehende DDL Änderungen blockieren. Obwohl die Leseoperationen aufgrund der Row-Versionierung keine Shared Locks halten, führen diese Operatioen zu Sch-S Locks (Schemastabilitätssperren). DDL-Änderungen durch Redo-Operationen können dadurch blockiert werden. Falls DDL aufgrund konkurrierender Lese-Workload blockiert wird und der Schwellenwert für 'Recovery Interval' (eine SQL Server Konfigurationsoption) überschritten wird, generiert der SQL Server das Ereignis sqlserver.lock_redo_blocked, welches Microsoft zum Kill der blockierenden Leser empfiehlt. Auf die Verfügbarkeit der Anwendung wird hierbei keinerlei Rücksicht genommen.   Keine dieser Einschränkungen existiert mit Oracle Active Data Guard.   Backups auf sekundären Replikaten  Über die sekundären Replikate können Backups (BACKUP DATABASE via Transact-SQL) nur als copy-only Backups einer vollständigen Datenbank, Dateien und Dateigruppen erstellt werden. Das Erstellen inkrementeller Backups ist nicht unterstützt, was ein ernsthafter Rückstand ist gegenüber der Backup-Unterstützung physikalischer Standbys unter Oracle Data Guard. Hinweis: Ein möglicher Workaround via Snapshots, bleibt ein Workaround. Eine weitere Einschränkung dieses Features gegenüber Oracle Data Guard besteht darin, dass das Backup eines sekundären Replikats nicht ausgeführt werden kann, wenn es nicht mit dem primären Replikat kommunizieren kann. Darüber hinaus muss das sekundäre Replikat synchronisiert sein oder sich in der Synchronisation befinden, um das Beackup auf dem sekundären Replikat erstellen zu können.   Vergleich von Microsoft AlwaysOn mit der Oracle MAA Ich komme wieder zurück auf die Eingangs erwähnte, mehrfach an mich gestellte Frage "Wann denn - und ob überhaupt - Oracle etwas Vergleichbares wie AlwaysOn bieten würde?" und meine damit verbundene (kurze) Irritation. Wenn Sie diesen Blogbeitrag bis hierher gelesen haben, dann kennen Sie jetzt meine darauf gegebene Antwort. Der eine oder andere Punkt traf dabei nicht immer auf Jeden zu, was auch nicht der tiefere Sinn und Zweck meiner Antwort war. Wenn beispielsweise kein Multi-Subnet mit im Spiel ist, sind alle diesbezüglichen Kritikpunkte zunächst obsolet. Was aber nicht bedeutet, dass sie nicht bereits morgen schon wieder zum Thema werden könnten (Sag niemals "Nie"). In manch anderes Fettnäpfchen tritt man wiederum nicht unbedingt in einer Testumgebung, sondern erst im laufenden Betrieb. Erst recht nicht dann, wenn man sich potenzieller Probleme nicht bewusst ist und keine dedizierten Tests startet. Und wer AlwaysOn erfolgreich positionieren möchte, wird auch gar kein Interesse daran haben, auf mögliche Schwachstellen und den besagten Teufel im Detail aufmerksam zu machen. Das ist keine Unterstellung - es ist nur menschlich. Außerdem ist es verständlich, dass man sich in erster Linie darauf konzentriert "was geht" und "was gut läuft", anstelle auf das "was zu Problemen führen kann" oder "nicht funktioniert". Wer will schon der Miesepeter sein? Für mich selbst gesprochen, kann ich nur sagen, dass ich lieber vorab von allen möglichen Einschränkungen wissen möchte, anstelle sie dann nach einer kurzen Zeit der heilen Welt schmerzhaft am eigenen Leib erfahren zu müssen. Ich bin davon überzeugt, dass es Ihnen nicht anders geht. Nachfolgend deshalb eine Zusammenfassung all jener Punkte, die ich im Vergleich zur Oracle MAA (Maximum Availability Architecture) als unbedingt Erwähnenswert betrachte, falls man eine Evaluierung von Microsoft AlwaysOn in Betracht zieht. 1. AlwaysOn ist eine komplexe Technologie Der SQL Server AlwaysOn Stack ist zusammengesetzt aus drei verschiedenen Technlogien: Windows Server Failover Clustering (WSFC) SQL Server Failover Cluster Instances (FCI) SQL Server Availability Groups (Verfügbarkeitsgruppen) Man kann eine derartige Lösung nicht als nahtlos bezeichnen, wofür auch die vielen von Microsoft dargestellten Einschränkungen sprechen. Während sich frühere SQL Server Versionen in Richtung eigener HA/DR Technologien entwickelten (wie Database Mirroring), empfiehlt Microsoft nun die Migration. Doch weshalb dieser Schwenk? Er führt nicht zu einem konsisten und robusten Angebot an HA/DR Technologie für geschäftskritische Umgebungen.  Liegt die Antwort in meiner These begründet, nach der "Windows was the God ..." noch immer gilt und man die Nachteile der allzu engen Kopplung mit Windows nicht sehen möchte? Entscheiden Sie selbst ... 2. Failover Cluster Instanzen - Kein RAC-Pendant Die SQL Server und Windows Server Clustering Technologie basiert noch immer auf dem veralteten Aktiv-Passiv Modell und führt zu einer Verschwendung von Systemressourcen. In einer Betrachtung von lediglich zwei Knoten erschließt sich auf Anhieb noch nicht der volle Mehrwert eines Aktiv-Aktiv Clusters (wie den Real Application Clusters), wie er von Oracle bereits vor zehn Jahren entwickelt wurde. Doch kennt man die Vorzüge der Skalierbarkeit durch einfaches Hinzufügen weiterer Cluster-Knoten, die dann alle gemeinsam als ein einziges logisches System zusammenarbeiten, versteht man was hinter dem Motto "Pay-as-you-Grow" steckt. In einem Aktiv-Aktiv Cluster geht es zwar auch um Hochverfügbarkeit - und ein Failover erfolgt zudem schneller, als in einem Aktiv-Passiv Modell - aber es geht eben nicht nur darum. An dieser Stelle sei darauf hingewiesen, dass die Oracle 11g Standard Edition bereits die Nutzung von Oracle RAC bis zu vier Sockets kostenfrei beinhaltet. Möchten Sie dazu Windows nutzen, benötigen Sie keine Windows Server Enterprise Edition, da Oracle 11g die eigene Clusterware liefert. Sie kommen in den Genuss von Hochverfügbarkeit und Skalierbarkeit und können dazu die günstigere Windows Server Standard Edition nutzen. 3. SQL Server Multi-Subnet Clustering - Abhängigkeit zu 3rd Party Storage Mirroring  Die SQL Server Multi-Subnet Clustering Architektur unterstützt den Aufbau eines Stretch Clusters, basiert dabei aber auf dem Aktiv-Passiv Modell. Das eigentlich Problematische ist jedoch, dass man sich zur Absicherung der Datenbank auf 3rd Party Storage Mirroring Technologie verlässt, ohne Integration zwischen dem Windows Server Failover Clustering (WSFC) und der darunterliegenden Mirroring Technologie. Wenn nun im Cluster ein Failover auf Instanzen-Ebene erfolgt, existiert keine Koordination mit einem möglichen Failover auf Ebene des Storage-Array. 4. Availability Groups (Verfügbarkeitsgruppen) - Vier, oder doch nur Zwei? Ein primäres Replikat erlaubt bis zu vier sekundäre Replikate innerhalb einer Verfügbarkeitsgruppe, jedoch nur zwei im Synchronen Commit Modus. Während dies zwar einen Vorteil gegenüber dem stringenten 1:1 Modell unter Database Mirroring darstellt, fällt der SQL Server 2012 damit immer noch weiter zurück hinter Oracle Data Guard mit bis zu 30 direkten Stanbdy Zielen - und vielen weiteren durch kaskadierende Ziele möglichen. Damit eignet sich Oracle Active Data Guard auch für die Bereitstellung einer Reader-Farm Skalierbarkeit für Internet-basierende Unternehmen. Mit AwaysOn Verfügbarkeitsgruppen ist dies nicht möglich. 5. Availability Groups (Verfügbarkeitsgruppen) - kein asynchrones Switchover  Die Technologie der Verfügbarkeitsgruppen wird auch als geeignetes Mittel für administrative Aufgaben positioniert - wie Upgrades oder Wartungsarbeiten. Man muss sich jedoch einem gravierendem Defizit bewusst sein: Im asynchronen Verfügbarkeitsmodus besteht die einzige Möglichkeit für Role Transition im Forced Failover mit Datenverlust! Um den Verlust von Daten durch geplante Wartungsarbeiten zu vermeiden, muss man den synchronen Verfügbarkeitsmodus konfigurieren, was jedoch ernstzunehmende Auswirkungen auf WAN Deployments nach sich zieht. Spinnt man diesen Gedanken zu Ende, kommt man zu dem Schluss, dass die Technologie der Verfügbarkeitsgruppen für geplante Wartungsarbeiten in einem derartigen Umfeld nicht effektiv genutzt werden kann. 6. Automatisches Failover - Nicht immer möglich Sowohl die SQL Server FCI, als auch Verfügbarkeitsgruppen unterstützen automatisches Failover. Möchte man diese jedoch kombinieren, wird das Ergebnis kein automatisches Failover sein. Denn ihr Zusammentreffen im Failover-Fall führt zu Race Conditions (Wettlaufsituationen), weshalb diese Konfiguration nicht länger das automatische Failover zu einem Replikat in einer Verfügbarkeitsgruppe erlaubt. Auch hier bestätigt sich wieder die tiefere Problematik von AlwaysOn, mit einer Zusammensetzung aus unterschiedlichen Technologien und der Abhängigkeit zu Windows. 7. Problematische RTO (Recovery Time Objective) Microsoft postioniert die SQL Server Multi-Subnet Clustering Architektur als brauchbare HA/DR Architektur. Bedenkt man jedoch die Problematik im Zusammenhang mit DNS Replikation und den möglichen langen Wartezeiten auf Client-Seite von bis zu 16 Minuten, sind strenge RTO Anforderungen (Recovery Time Objectives) nicht erfüllbar. Im Gegensatz zu Oracle besitzt der SQL Server keine Datenbank-integrierten Technologien, wie Oracle Fast Application Notification (FAN) oder Oracle Fast Connection Failover (FCF). 8. Problematische RPO (Recovery Point Objective) SQL Server ermöglicht Forced Failover (erzwungenes Failover), bietet jedoch keine Möglichkeit zur automatischen Übertragung der letzten Datenbits von einem alten zu einem neuen primären Replikat, wenn der Verfügbarkeitsmodus asynchron war. Oracle Data Guard hingegen bietet diese Unterstützung durch das Flush Redo Feature. Dies sichert "Zero Data Loss" und beste RPO auch in erzwungenen Failover-Situationen. 9. Lesbare Sekundäre Replikate mit Einschränkungen Aufgrund des Snapshot Isolation Transaction Level für lesbare sekundäre Replikate, besitzen diese Einschränkungen mit Auswirkung auf die primäre Datenbank. Die Bereinigung von Ghost Records auf der primären Datenbank, wird beeinflusst von lang laufenden Abfragen auf der lesabaren sekundären Datenbank. Die lesbare sekundäre Datenbank kann nicht in die Verfügbarkeitsgruppe aufgenommen werden, wenn es aktive Transaktionen auf der primären Datenbank gibt. Zusätzlich können DLL Änderungen auf der primären Datenbank durch Abfragen auf der sekundären blockiert werden. Und imkrementelle Backups werden hier nicht unterstützt.   Keine dieser Restriktionen existiert unter Oracle Data Guard.

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  • Why should you choose Oracle WebLogic 12c instead of JBoss EAP 6?

    - by Ricardo Ferreira
    In this post, I will cover some technical differences between Oracle WebLogic 12c and JBoss EAP 6, which was released a couple days ago from Red Hat. This article claims to help you in the evaluation of key points that you should consider when choosing for an Java EE application server. In the following sections, I will present to you some important aspects that most customers ask us when they are seriously evaluating for an middleware infrastructure, specially if you are considering JBoss for some reason. I would suggest that you keep the following question in mind while you are reading the points: "Why should I choose JBoss instead of WebLogic?" 1) Multi Datacenter Deployment and Clustering - D/R ("Disaster & Recovery") architecture support is embedded on the WebLogic Server 12c product. JBoss EAP 6 on the other hand has no direct D/R support included, Red Hat relies on third-part tools with higher prices. When you consider a middleware solution to host your business critical application, you should worry with every architectural aspect that are related with the solution. Fail-over support is one little aspect of a truly reliable solution. If you do not worry about D/R, your solution will not be reliable. Having said that, with Red Hat and JBoss EAP 6, you have this extra cost that will increase considerably the total cost of ownership of the solution. As we commonly hear from analysts, open-source are not so cheaper when you start seeing the big picture. - WebLogic Server 12c supports advanced LAN clustering, detection of death servers and have a common alert framework. JBoss EAP 6 on the other hand has limited LAN clustering support with no server death detection. They do not generate any alerts when servers goes down (only if you buy JBoss ON which is a separated technology, but until now does not support JBoss EAP 6) and manual intervention are required when servers goes down. In most cases, admin people must rely on "kill -9", "tail -f someFile.log" and "ps ax | grep java" commands to manage failures and clustering anomalies. - WebLogic Server 12c supports the concept of Node Manager, which is a separated process that runs on the physical | virtual servers that allows extend the administration of the cluster to WebLogic managed servers that are often distributed across multiple machines and geographic locations. JBoss EAP 6 on the other hand has no equivalent technology. Whole server instances must be managed individually. - WebLogic Server 12c Node Manager supports Coherence to boost performance when managing servers. JBoss EAP 6 on the other hand has no similar technology. There is no way to coordinate JBoss and infiniband instances provided by JBoss using high throughput and low latency protocols like InfiniBand. The Node Manager feature also allows another very important feature that JBoss EAP lacks: secure the administration. When using WebLogic Node Manager, all the administration tasks are sent to the managed servers in a secure tunel protected by a certificate, which means that the transport layer that separates the WebLogic administration console from the managed servers are secured by SSL. - WebLogic Server 12c are now integrated with OTD ("Oracle Traffic Director") which is a web server technology derived from the former Sun iPlanet Web Server. This software complements the web server support offered by OHS ("Oracle HTTP Server"). Using OTD, WebLogic instances are load-balanced by a high powerful software that knows how to handle SDP ("Socket Direct Protocol") over InfiniBand, which boost performance when used with engineered systems technologies like Oracle Exalogic Elastic Cloud. JBoss EAP 6 on the other hand only offers support to Apache Web Server with custom modules created to deal with JBoss clusters, but only across standard TCP/IP networks.  2) Application and Runtime Diagnostics - WebLogic Server 12c have diagnostics capabilities embedded on the server called WLDF ("WebLogic Diagnostic Framework") so there is no need to rely on third-part tools. JBoss EAP 6 on the other hand has no diagnostics capabilities. Their only diagnostics tool is the log generated by the application server. Admin people are encouraged to analyse thousands of log lines to find out what is going on. - WebLogic Server 12c complement WLDF with JRockit MC ("Mission Control"), which provides to administrators and developers a complete insight about the JVM performance, behavior and possible bottlenecks. WebLogic Server 12c also have an classloader analysis tool embedded, and even a log analyzer tool that enables administrators and developers to view logs of multiple servers at the same time. JBoss EAP 6 on the other hand relies on third-part tools to do something similar. Again, only log searching are offered to find out whats going on. - WebLogic Server 12c offers end-to-end traceability and monitoring available through Oracle EM ("Enterprise Manager"), including monitoring of business transactions that flows through web servers, ESBs, application servers and database servers, all of this with high deep JVM analysis and diagnostics. JBoss EAP 6 on the other hand, even using JBoss ON ("Operations Network"), which is a separated technology, does not support those features. Red Hat relies on third-part tools to provide direct Oracle database traceability across JVMs. One of those tools are Oracle EM for non-Oracle middleware that manage JBoss, Tomcat, Websphere and IIS transparently. - WebLogic Server 12c with their JRockit support offers a tool called JRockit Flight Recorder, which can give developers a complete visibility of a certain period of application production monitoring with zero extra overhead. This automatic recording allows you to deep analyse threads latency, memory leaks, thread contention, resource utilization, stack overflow damages and GC ("Garbage Collection") cycles, to observe in real time stop-the-world phenomenons, generational, reference count and parallel collects and mutator threads analysis. JBoss EAP 6 don't even dream to support something similar, even because they don't have their own JVM. 3) Application Server Administration - WebLogic Server 12c offers a complete administration console complemented with scripting and macro-like recording capabilities. A single WebLogic console can managed up to hundreds of WebLogic servers belonging to the same domain. JBoss EAP 6 on the other hand has a limited console and provides a XML centric administration. JBoss, after ten years, started the development of a rudimentary centralized administration that still leave a lot of administration tasks aside, so admin people and developers must touch scripts and XML configuration files for most advanced and even simple administration tasks. This lead applications to error prone and risky deployments. Even using JBoss ON, JBoss EAP are not able to offer decent administration features for admin people which must be high skilled in JBoss internal architecture and its managing capabilities. - Oracle EM is available to manage multiple domains, databases, application servers, operating systems and virtualization, with a complete end-to-end visibility. JBoss ON does not provide management capabilities across the complete architecture, only basic monitoring. Even deployment must be done aside JBoss ON which does no integrate well with others softwares than JBoss. Until now, JBoss ON does not supports JBoss EAP 6, so even their minimal support for JBoss are not available for JBoss EAP 6 leaving customers uncovered and subject to high skilled JBoss admin people. - WebLogic Server 12c has the same administration model whatever is the topology selected by the customer. JBoss EAP 6 on the other hand differentiates between two operational models: standalone-mode and domain-mode, that are not consistent with each other. Depending on the mode used, the administration skill is different. - WebLogic Server 12c has no point-of-failures processes, and it does not need to define any specialized server. Domain model in WebLogic is available for years (at least ten years or more) and is production proven. JBoss EAP 6 on the other hand needs special processes to garantee JBoss integrity, the PC ("Process-Controller") and the HC ("Host-Controller"). Different from WebLogic, the domain model in JBoss is quite new (one year at tops) of maturity, and need to mature considerably until start doing things like WebLogic domain model does. - WebLogic Server 12c supports parallel deployment model which enables some artifacts being deployed at the same time. JBoss EAP 6 on the other hand does not have any similar feature. Every deployment are done atomically in the containers. This means that if you have a huge EAR (an EAR of 120 MB of size for instance) and deploy onto JBoss EAP 6, this EAR will take some minutes in order to starting accept thread requests. The same EAR deployed onto WebLogic Server 12c will reduce the deployment time at least in 2X compared to JBoss. 4) Support and Upgrades - WebLogic Server 12c has patch management available. JBoss EAP 6 on the other hand has no patch management available, each JBoss EAP instance should be patched manually. To achieve such feature, you need to buy a separated technology called JBoss ON ("Operations Network") that manage this type of stuff. But until now, JBoss ON does not support JBoss EAP 6 so, in practice, JBoss EAP 6 does not have this feature. - WebLogic Server 12c supports previuous WebLogic domains without any reconfiguration since its kernel is robust and mature since its creation in 1995. JBoss EAP 6 on the other hand has a proven lack of supportability between JBoss AS 4, 5, 6 and 7. Different kernels and messaging engines were implemented in JBoss stack in the last five years reveling their incapacity to create a well architected and proven middleware technology. - WebLogic Server 12c has patch prescription based on customer configuration. JBoss EAP 6 on the other hand has no such capability. People need to create ticket supports and have their installations revised by Red Hat support guys to gain some patch prescription from them. - Oracle WebLogic Server independent of the version has 8 years of support of new patches and has lifetime release of existing patches beyond that. JBoss EAP 6 on the other hand provides patches for a specific application server version up to 5 years after the release date. JBoss EAP 4 and previous versions had only 4 years. A good question that Red Hat will argue to answer is: "what happens when you find issues after year 5"?  5) RAC ("Real Application Clusters") Support - WebLogic Server 12c ships with a specific JDBC driver to leverage Oracle RAC clustering capabilities (Fast-Application-Notification, Transaction Affinity, Fast-Connection-Failover, etc). Oracle JDBC thin driver are also available. JBoss EAP 6 on the other hand ships only the standard Oracle JDBC thin driver. Load balancing with Oracle RAC are not supported. Manual intervention in case of planned or unplanned RAC downtime are necessary. In JBoss EAP 6, situation does not reestablish automatically after downtime. - WebLogic Server 12c has a feature called Active GridLink for Oracle RAC which provides up to 3X performance on OLTP applications. This seamless integration between WebLogic and Oracle database enable more value added to critical business applications leveraging their investments in Oracle database technology and Oracle middleware. JBoss EAP 6 on the other hand has no performance gains at all, even when admin people implement some kind of connection-pooling tuning. - WebLogic Server 12c also supports transaction and web session affinity to the Oracle RAC, which provides aditional gains of performance. This is particularly interesting if you are creating a reliable solution that are distributed not only in an LAN cluster, but into a different data center. JBoss EAP 6 on the other hand has no such support. 6) Standards and Technology Support - WebLogic Server 12c is fully Java EE 6 compatible and production ready since december of 2011. JBoss EAP 6 on the other hand became fully compatible with Java EE 6 only in the community version after three months, and production ready only in a few days considering that this article was written in June of 2012. Red Hat says that they are the masters of innovation and technology proliferation, but compared with Oracle and even other proprietary vendors like IBM, they historically speaking are lazy to deliver the most newest technologies and standards adherence. - Oracle is the steward of Java, driving innovation into the platform from commercial and open-source vendors. Red Hat on the other hand does not have its own JVM and relies on third-part JVMs to complete their application server offer. 95% of Red Hat customers are using Oracle HotSpot as JVM, which means that without Oracle involvement, their support are limited exclusively to the application server layer and we all know that most problems are happens in the JVM layer. - WebLogic Server 12c supports natively JDK 7, which empower developers to explore the maximum of the Java platform productivity when writing code. This feature differentiate WebLogic from others application servers (except GlassFish that are also managed by Oracle) because the usage of JDK 7 introduce such remarkable productivity features like the "try-with-resources" enhancement, catching multiple exceptions with one try block, Strings in the switch statements, JVM improvements in terms of JDBC, I/O, networking, security, concurrency and of course, the most important feature of Java 7: native support for multiple non-Java languages. More features regarding JDK 7 can be found here. JBoss EAP 6 on the other hand does not support JDK 7 officially, they comment in their community version that "Java SE 7 can be used with JBoss 7" which does not gives you any guarantees of enterprise support for JDK 7. - Oracle WebLogic Server 12c supports integration with Spring framework allowing Spring applications to use WebLogic special transaction manager, exposing bean interfaces to WebLogic MBeans to take advantage of all WebLogic monitoring and administration advantages. JBoss EAP 6 on the other hand has no special integration with Spring. In fact, Red Hat offers a suspicious package called "JBoss Web Platform" that in theory supports Spring, but in practice this package does not offers any special integration. It is just a facility for Red Hat customers to have support from both JBoss and Spring technology using the same customer support. 7) Lightweight Development - Oracle WebLogic Server 12c and Oracle GlassFish are completely integrated and can share applications without any modifications. Starting with the 12c version, WebLogic now understands natively GlassFish deployment descriptors and specific configurations in order to offer you a truly and reliable migration path from a community Java EE application server to a enterprise middleware product like WebLogic. JBoss EAP 6 on the other hand has no support to natively reuse an existing (or still in development) application from JBoss AS community server. Users of JBoss suffer of critical issues during deployment time that includes: changing the libraries and dependencies of the application, patching the DTD or XSD deployment descriptors, refactoring of the application layers due classloading issues and anomalies, rebuilding of persistence, business and web layers due issues with "usage of the certified version of an certain dependency" or "frameworks that Red Hat potentially does not recommend" etc. If you have the culture or enterprise IT directive of developing Java EE applications using community middleware to in a certain future, transition to enterprise (supported by a vendor) middleware, Oracle WebLogic plus Oracle GlassFish offers you a more sustainable solution. - WebLogic Server 12c has a very light ZIP distribution (less than 165 MB). JBoss EAP 6 ZIP size is around 130 MB, together with JBoss ON you have more 100 MB resulting in a higher download footprint. This is particularly interesting if you plan to use automated setup of application server instances (for example, to rapidly setup a development or staging environment) using Maven or Hudson. - WebLogic Server 12c has a complete integration with Maven allowing developers to setup WebLogic domains with few commands. Tasks like downloading WebLogic, installation, domain creation, data sources deployment are completely integrated. JBoss EAP 6 on the other hand has a limited offer integration with those tools.  - WebLogic Server 12c has a startup mode called WLX that turns-off EJB, JMS and JCA containers leaving enabled only the web container with Java EE 6 web profile. JBoss EAP 6 on the other hand has no such feature, you need to disable manually the containers that you do not want to use. - WebLogic Server 12c supports fastswap, which enables you to change classes without redeployment. This is particularly interesting if you are developing patches for the application that is already deployed and you do not want to redeploy the entire application. This is the same behavior that most application servers offers to JSP pages, but with WebLogic Server 12c, you have the same feature for Java classes in general. JBoss EAP 6 on the other hand has no such support. Even JBoss EAP 5 does not support this until now. 8) JMS and Messaging - WebLogic Server 12c has a proven and high scalable JMS implementation since its initial release in 1995. JBoss EAP 6 on the other hand has a still immature technology called HornetQ, which was introduced in JBoss EAP 5 replacing everything that was implemented in the previous versions. Red Hat loves to introduce new technologies across JBoss versions, playing around with customers and their investments. And when they are asked about why they have changed the implementation and caused such a mess, their answer is always: "the previous implementation was inadequate and not aligned with the community strategy so we are creating a new a improved one". This Red Hat practice leads to uncomfortable investments that in a near future (sometimes less than a year) will be affected in someway. - WebLogic Server 12c has troubleshooting and monitoring features included on the WebLogic console and WLDF. JBoss EAP 6 on the other hand has no direct monitoring on the console, activity is reflected only on the logs, no debug logs available in case of JMS issues. - WebLogic Server 12c has extremely good performance and scalability. JBoss EAP 6 on the other hand has a JMS storage mechanism relying on Oracle database or MySQL. This means that if an issue in production happens and Red Hat affirms that an performance issue is happening due to database problems, they will not support you on the performance issue. They will orient you to call Oracle instead. - WebLogic Server 12c supports messaging enterprise features like SAF ("Store and Forward"), Distributed Queues/Topics and Foreign JMS providers support that leverage JMS implementations without compromise developer code making things completely transparent. JBoss EAP 6 on the other hand do not even dream to support such features. 9) Caching and Grid - Coherence, which is the leading and most mature data grid technology from Oracle, is available since early 2000 and was integrated with WebLogic in 2009. Coherence and WebLogic clusters can be both managed from WebLogic administrative console. Even Node Manager supports Coherence. JBoss on the other hand discontinued JBoss Cache, which was their caching implementation just like they did with the messaging implementation (JBossMQ) which was a issue for long term customers. JBoss EAP 6 ships InfiniSpan version 1.0 which is immature and lack a proven record of successful cases and reliability. - WebLogic Server 12c has a feature called ActiveCache which uses Coherence to, without any code changes, replicate HTTP sessions from both WebLogic and other application servers like JBoss, Tomcat, Websphere, GlassFish and even Microsoft IIS. JBoss EAP 6 on the other hand does have such support and even when they do in the future, they probably will support only their own application server. - Coherence can be used to manage both L1 and L2 cache levels, providing support to Oracle TopLink and others JPA compliant implementations, even Hibernate. JBoss EAP 6 and Infinispan on the other hand supports only Hibernate. And most important of all: Infinispan does not have any successful case of L1 or L2 caching level support using Hibernate, which lead us to reflect about its viability. 10) Performance - WebLogic Server 12c is certified with Oracle Exalogic Elastic Cloud and can run unchanged applications at this engineered system. This approach can benefit customers from Exalogic optimization's of both kernel and JVM layers to boost performance in terms of 10X for web, OLTP, JMS and grid applications. JBoss EAP 6 on the other hand has no investment on engineered systems: customers do not have the choice to deploy on a Java ultra fast system if their project becomes relevant and performance issues are detected. - WebLogic Server 12c maintains a performance gain across each new release: starting on WebLogic 5.1, the overall performance gain has been close to 4X, which close to a 20% gain release by release. JBoss on the other hand does not provide SPECJAppServer or SPECJEnterprise performance benchmarks. Their so called "performance gains" remains hidden in their customer environments, which lead us to think if it is true or not since we will never get access to those environments. - WebLogic Server 12c has industry performance benchmarks with submissions across platforms and configurations leading SPECJ. Oracle WebLogic leads SPECJAppServer performance in multiple categories, fitting all customer topologies like: dual-node, single-node, multi-node and multi-node with RAC. JBoss... again, does not provide any SPECJAppServer performance benchmarks. - WebLogic Server 12c has a feature called work manager which allows your application to embrace new performance levels based on critical resource utilization of the CPUs usage. Work managers prioritizes work and allocates threads based on an execution model that takes into account administrator-defined parameters and actual run-time performance and throughput. JBoss EAP 6 on the other hand has no compared feature and probably they never will. Not supporting such feature like work managers, JBoss EAP 6 forces admin people and specially developers to uncover performance gains in a intrusive way, rewriting the code and doing performance refactorings. 11) Professional Services Support - WebLogic Server 12c and any other technology sold by Oracle give customers the possibility of hire OCS ("Oracle Consulting Services") to manage critical scenarios, deployment assistance of new applications, high skilled consultancy of architecture, best practices and people allocation together with customer teams. All OCS services are available without any restrictions, having the customer bought software from Oracle or just starting their implementation before any acquisition. JBoss EAP 6 or Red Hat to be more specifically, only offers professional services if you buy subscriptions from them. If you are developing a new critical application for your business and need the help of Red Hat for a serious issue or architecture decision, they will probably say: "OK... I can help you but after you buy subscriptions from me". Red Hat also does not allows their professional services consultants to manage environments that uses community based software. They will probably force you to first buy a subscription, download their "enterprise" version and them, optionally hire their consultants. - Oracle provides you our university to educate your team into our technologies, including of course specialized trainings of WebLogic application server. At any time and location, you can hire Oracle to train your team so you get trustful knowledge according to your specific needs. Certifications for the products are also available if your technical people desire to differentiate themselves as professionals. Red Hat on the other hand have a limited pool of resources to train your team in their technologies. Basically they are selling training and certification for RHEL ("Red Hat Enterprise Linux") but if you demand more specialized training in JBoss middleware, they will probably connect you to some "certified" partner localized training since they are apparently discontinuing their education center, at least here in Brazil. They were not able to reproduce their success with RHEL education to their middleware division since they need first sell the subscriptions to after gives you specialized training. And again, they only offer you specialized training based on their enterprise version (EAP in the case of JBoss) which means that the courses will be a quite outdated. There are reports of developers that took official training's from Red Hat at this year (2012) and in a certain JBoss advanced course, Red Hat supposedly covered JBossMQ as the messaging subsystem, and even the printed material provided was based on JBossMQ since the training was created for JBoss EAP 4.3. 12) Encouraging Transparency without Ulterior Motives - WebLogic Server 12c like any other software from Oracle can be downloaded any time from anywhere, you should only possess an OTN ("Oracle Technology Network") credential and you can download any enterprise software how many times you want. And is not some kind of "trial" version. It is the official binaries that will be running for ever in your data center. Oracle does not encourages the usage of "specific versions" of our software. The binaries you buy from Oracle are the same binaries anyone in the world could download and use for testing and personal education. JBoss EAP 6 on the other hand are not available for download unless you buy a subscription and get access to the Red Hat enterprise repositories. If you need to test, learn or just start creating your application using Red Hat's middleware software, you should download it from the community website. You are not allowed to download the enterprise version that, according to Red Hat are more secure, reliable and robust. But no one of us want to start the development of a software with an unsecured, unreliable and not scalable middleware right? So what you do? You are "invited" by Red Hat to buy subscriptions from them to get access to the "cool" version of the software. - WebLogic Server 12c prices are publicly available in the Oracle website. If you want to know right now how much WebLogic will cost to your organization, just click here and get access to our price list. In the case of WebLogic, check out the "US Oracle Technology Commercial Price List". Oracle also encourages you to get in touch with a sales representative to discuss discounts that would make possible the investment into our technology. But you are not required to do this, only if you are interested in buying our technology or maybe you want to discuss some discount scenarios. JBoss EAP 6 on the other hand does not have its cost publicly available in Red Hat's website or in any other media, at least is not so easy to get such information. The only link you will possibly find in their website is a "Contact a Sales Representative" link. This is not a very good relationship between an customer and an vendor. This is not an example of transparency, mainly when the software are sold as open. In this situations, customers expects to see the software prices publicly available, so they can have the chance to decide, based on the existing features of the software, if the cost is fair or not. Conclusion Oracle WebLogic is the most mature, secure, reliable and scalable Java EE application server of the market, and have a proven record of success around the globe to prove it's majority. Don't lose the chance to discover today how WebLogic could fit your needs and sustain your global IT middleware strategy, no matter if your strategy are completely based on the Cloud or not.

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  • SPARC T5-4 LDoms for RAC and WebLogic Clusters

    - by Jeff Taylor-Oracle
    I wanted to use two Oracle SPARC T5-4 servers to simultaneously host both Oracle RAC and a WebLogic Server Cluster. I chose to use Oracle VM Server for SPARC to create a cluster like this: There are plenty of trade offs and decisions that need to be made, for example: Rather than configuring the system by hand, you might want to use an Oracle SuperCluster T5-8 My configuration is similar to jsavit's: Availability Best Practices - Example configuring a T5-8 but I chose to ignore some of the advice. Maybe I should have included an  alternate service domain, but I decided that I already had enough redundancy Both Oracle SPARC T5-4 servers were to be configured like this: Cntl 0.25  4  64GB                     App LDom                    2.75 CPU's                                        44 cores                                          704 GB              DB LDom      One CPU         16 cores         256 GB   The systems started with everything in the primary domain: # ldm list NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  NORM  UPTIME primary          active     -n-c--  UART    512   1023G    0.0%  0.0%  11m # ldm list-spconfig factory-default [current] primary # ldm list -o core,memory,physio NAME              primary           CORE     CID    CPUSET     0      (0, 1, 2, 3, 4, 5, 6, 7)     1      (8, 9, 10, 11, 12, 13, 14, 15)     2      (16, 17, 18, 19, 20, 21, 22, 23) -- SNIP     62     (496, 497, 498, 499, 500, 501, 502, 503)     63     (504, 505, 506, 507, 508, 509, 510, 511) MEMORY     RA               PA               SIZE                 0x30000000       0x30000000       255G     0x80000000000    0x80000000000    256G     0x100000000000   0x100000000000   256G     0x180000000000   0x180000000000   256G # Give this memory block to the DB LDom IO     DEVICE                           PSEUDONYM        OPTIONS     pci@300                          pci_0                pci@340                          pci_1                pci@380                          pci_2                pci@3c0                          pci_3                pci@400                          pci_4                pci@440                          pci_5                pci@480                          pci_6                pci@4c0                          pci_7                pci@300/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE1     pci@300/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE2     pci@300/pci@1/pci@0/pci@4/pci@0/pci@c /SYS/MB/SASHBA0     pci@300/pci@1/pci@0/pci@4/pci@0/pci@8 /SYS/RIO/NET0        pci@340/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE3     pci@340/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE4     pci@380/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE9     pci@380/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE10     pci@3c0/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE11     pci@3c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE12     pci@400/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE5     pci@400/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE6     pci@440/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE7     pci@440/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE8     pci@480/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE13     pci@480/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE14     pci@4c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE15     pci@4c0/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE16     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c /SYS/MB/SASHBA1     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4 /SYS/RIO/NET2    Added an additional service processor configuration: # ldm add-spconfig split # ldm list-spconfig factory-default primary split [current] And removed many of the resources from the primary domain: # ldm start-reconf primary # ldm set-core 4 primary # ldm set-memory 32G primary # ldm rm-io pci@340 primary # ldm rm-io pci@380 primary # ldm rm-io pci@3c0 primary # ldm rm-io pci@400 primary # ldm rm-io pci@440 primary # ldm rm-io pci@480 primary # ldm rm-io pci@4c0 primary # init 6 Needed to add resources to the guest domains: # ldm add-domain db # ldm set-core cid=`seq -s"," 48 63` db # ldm add-memory mblock=0x180000000000:256G db # ldm add-io pci@480 db # ldm add-io pci@4c0 db # ldm add-domain app # ldm set-core 44 app # ldm set-memory 704G  app # ldm add-io pci@340 app # ldm add-io pci@380 app # ldm add-io pci@3c0 app # ldm add-io pci@400 app # ldm add-io pci@440 app Needed to set up services: # ldm add-vds primary-vds0 primary # ldm add-vcc port-range=5000-5100 primary-vcc0 primary Needed to add a virtual network port for the WebLogic application domain: # ipadm NAME              CLASS/TYPE STATE        UNDER      ADDR lo0               loopback   ok           --         --    lo0/v4         static     ok           --         ...    lo0/v6         static     ok           --         ... net0              ip         ok           --         ...    net0/v4        static     ok           --         xxx.xxx.xxx.xxx/24    net0/v6        addrconf   ok           --         ....    net0/v6        addrconf   ok           --         ... net8              ip         ok           --         --    net8/v4        static     ok           --         ... # dladm show-phys LINK              MEDIA                STATE      SPEED  DUPLEX    DEVICE net1              Ethernet             unknown    0      unknown   ixgbe1 net0              Ethernet             up         1000   full      ixgbe0 net8              Ethernet             up         10     full      usbecm2 # ldm add-vsw net-dev=net0 primary-vsw0 primary # ldm add-vnet vnet1 primary-vsw0 app Needed to add a virtual disk to the WebLogic application domain: # format Searching for disks...done AVAILABLE DISK SELECTIONS:        0. c0t5000CCA02505F874d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca02505f874           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD0/disk        1. c0t5000CCA02506C468d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca02506c468           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD1/disk        2. c0t5000CCA025067E5Cd0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca025067e5c           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD2/disk        3. c0t5000CCA02506C258d0 <HITACHI-H106060SDSUN600G-A2B0-558.91GB>           /scsi_vhci/disk@g5000cca02506c258           /dev/chassis/SPARC_T5-4.AK00084038/SYS/SASBP0/HDD3/disk Specify disk (enter its number): ^C # ldm add-vdsdev /dev/dsk/c0t5000CCA02506C468d0s2 HDD1@primary-vds0 # ldm add-vdisk HDD1 HDD1@primary-vds0 app Add some additional spice to the pot: # ldm set-variable auto-boot\\?=false db # ldm set-variable auto-boot\\?=false app # ldm set-var boot-device=HDD1 app Bind the logical domains: # ldm bind db # ldm bind app At the end of the process, the system is set up like this: # ldm list -o core,memory,physio NAME             primary          CORE     CID    CPUSET     0      (0, 1, 2, 3, 4, 5, 6, 7)     1      (8, 9, 10, 11, 12, 13, 14, 15)     2      (16, 17, 18, 19, 20, 21, 22, 23)     3      (24, 25, 26, 27, 28, 29, 30, 31) MEMORY     RA               PA               SIZE                0x30000000       0x30000000       32G IO     DEVICE                           PSEUDONYM        OPTIONS     pci@300                          pci_0               pci@300/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE1     pci@300/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE2     pci@300/pci@1/pci@0/pci@4/pci@0/pci@c /SYS/MB/SASHBA0     pci@300/pci@1/pci@0/pci@4/pci@0/pci@8 /SYS/RIO/NET0   ------------------------------------------------------------------------------ NAME             app              CORE     CID    CPUSET     4      (32, 33, 34, 35, 36, 37, 38, 39)     5      (40, 41, 42, 43, 44, 45, 46, 47)     6      (48, 49, 50, 51, 52, 53, 54, 55)     7      (56, 57, 58, 59, 60, 61, 62, 63)     8      (64, 65, 66, 67, 68, 69, 70, 71)     9      (72, 73, 74, 75, 76, 77, 78, 79)     10     (80, 81, 82, 83, 84, 85, 86, 87)     11     (88, 89, 90, 91, 92, 93, 94, 95)     12     (96, 97, 98, 99, 100, 101, 102, 103)     13     (104, 105, 106, 107, 108, 109, 110, 111)     14     (112, 113, 114, 115, 116, 117, 118, 119)     15     (120, 121, 122, 123, 124, 125, 126, 127)     16     (128, 129, 130, 131, 132, 133, 134, 135)     17     (136, 137, 138, 139, 140, 141, 142, 143)     18     (144, 145, 146, 147, 148, 149, 150, 151)     19     (152, 153, 154, 155, 156, 157, 158, 159)     20     (160, 161, 162, 163, 164, 165, 166, 167)     21     (168, 169, 170, 171, 172, 173, 174, 175)     22     (176, 177, 178, 179, 180, 181, 182, 183)     23     (184, 185, 186, 187, 188, 189, 190, 191)     24     (192, 193, 194, 195, 196, 197, 198, 199)     25     (200, 201, 202, 203, 204, 205, 206, 207)     26     (208, 209, 210, 211, 212, 213, 214, 215)     27     (216, 217, 218, 219, 220, 221, 222, 223)     28     (224, 225, 226, 227, 228, 229, 230, 231)     29     (232, 233, 234, 235, 236, 237, 238, 239)     30     (240, 241, 242, 243, 244, 245, 246, 247)     31     (248, 249, 250, 251, 252, 253, 254, 255)     32     (256, 257, 258, 259, 260, 261, 262, 263)     33     (264, 265, 266, 267, 268, 269, 270, 271)     34     (272, 273, 274, 275, 276, 277, 278, 279)     35     (280, 281, 282, 283, 284, 285, 286, 287)     36     (288, 289, 290, 291, 292, 293, 294, 295)     37     (296, 297, 298, 299, 300, 301, 302, 303)     38     (304, 305, 306, 307, 308, 309, 310, 311)     39     (312, 313, 314, 315, 316, 317, 318, 319)     40     (320, 321, 322, 323, 324, 325, 326, 327)     41     (328, 329, 330, 331, 332, 333, 334, 335)     42     (336, 337, 338, 339, 340, 341, 342, 343)     43     (344, 345, 346, 347, 348, 349, 350, 351)     44     (352, 353, 354, 355, 356, 357, 358, 359)     45     (360, 361, 362, 363, 364, 365, 366, 367)     46     (368, 369, 370, 371, 372, 373, 374, 375)     47     (376, 377, 378, 379, 380, 381, 382, 383) MEMORY     RA               PA               SIZE                0x30000000       0x830000000      192G     0x4000000000     0x80000000000    256G     0x8080000000     0x100000000000   256G IO     DEVICE                           PSEUDONYM        OPTIONS     pci@340                          pci_1               pci@380                          pci_2               pci@3c0                          pci_3               pci@400                          pci_4               pci@440                          pci_5               pci@340/pci@1/pci@0/pci@6        /SYS/RCSA/PCIE3     pci@340/pci@1/pci@0/pci@c        /SYS/RCSA/PCIE4     pci@380/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE9     pci@380/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE10     pci@3c0/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE11     pci@3c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE12     pci@400/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE5     pci@400/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE6     pci@440/pci@1/pci@0/pci@e        /SYS/RCSA/PCIE7     pci@440/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE8 ------------------------------------------------------------------------------ NAME             db               CORE     CID    CPUSET     48     (384, 385, 386, 387, 388, 389, 390, 391)     49     (392, 393, 394, 395, 396, 397, 398, 399)     50     (400, 401, 402, 403, 404, 405, 406, 407)     51     (408, 409, 410, 411, 412, 413, 414, 415)     52     (416, 417, 418, 419, 420, 421, 422, 423)     53     (424, 425, 426, 427, 428, 429, 430, 431)     54     (432, 433, 434, 435, 436, 437, 438, 439)     55     (440, 441, 442, 443, 444, 445, 446, 447)     56     (448, 449, 450, 451, 452, 453, 454, 455)     57     (456, 457, 458, 459, 460, 461, 462, 463)     58     (464, 465, 466, 467, 468, 469, 470, 471)     59     (472, 473, 474, 475, 476, 477, 478, 479)     60     (480, 481, 482, 483, 484, 485, 486, 487)     61     (488, 489, 490, 491, 492, 493, 494, 495)     62     (496, 497, 498, 499, 500, 501, 502, 503)     63     (504, 505, 506, 507, 508, 509, 510, 511) MEMORY     RA               PA               SIZE                0x80000000       0x180000000000   256G IO     DEVICE                           PSEUDONYM        OPTIONS     pci@480                          pci_6               pci@4c0                          pci_7               pci@480/pci@1/pci@0/pci@a        /SYS/RCSA/PCIE13     pci@480/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE14     pci@4c0/pci@1/pci@0/pci@8        /SYS/RCSA/PCIE15     pci@4c0/pci@1/pci@0/pci@4        /SYS/RCSA/PCIE16     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c /SYS/MB/SASHBA1     pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4 /SYS/RIO/NET2   Start the domains: # ldm start app LDom app started # ldm start db LDom db started Make sure to start the vntsd service that was created, above. # svcs -a | grep ldo disabled        8:38:38 svc:/ldoms/vntsd:default online          8:38:58 svc:/ldoms/agents:default online          8:39:25 svc:/ldoms/ldmd:default # svcadm enable vntsd Now use the MAC address to configure the Solaris 11 Automated Installation. Database Logical Domain # telnet localhost 5000 {0} ok devalias screen                   /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@7/display@0 disk7                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p3 disk6                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p2 disk5                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p1 disk4                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0/disk@p0 scsi1                    /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@c/scsi@0 net3                     /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0,1 net2                     /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0 virtual-console          /virtual-devices/console@1 name                     aliases {0} ok boot net2 Boot device: /pci@4c0/pci@1/pci@0/pci@c/pci@0/pci@4/network@0  File and args: 1000 Mbps full duplex Link up Requesting Internet Address for xx:xx:xx:xx:xx:xx Requesting Internet Address for xx:xx:xx:xx:xx:xx WLS Logical Domain # telnet localhost 5001 {0} ok devalias hdd1                     /virtual-devices@100/channel-devices@200/disk@0 vnet1                    /virtual-devices@100/channel-devices@200/network@0 net                      /virtual-devices@100/channel-devices@200/network@0 disk                     /virtual-devices@100/channel-devices@200/disk@0 virtual-console          /virtual-devices/console@1 name                     aliases {0} ok boot net Boot device: /virtual-devices@100/channel-devices@200/network@0  File and args: Requesting Internet Address for xx:xx:xx:xx:xx:xx Requesting Internet Address for xx:xx:xx:xx:xx:xx Repeat the process for the second SPARC T5-4, install Solaris, RAC and WebLogic Cluster, and you are ready to go. Maybe buying a SuperCluster would have been easier.

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  • Creating a thematic map

    - by jsharma
    This post describes how to create a simple thematic map, just a state population layer, with no underlying map tile layer. The map shows states color-coded by total population. The map is interactive with info-windows and can be panned and zoomed. The sample code demonstrates the following: Displaying an interactive vector layer with no background map tile layer (i.e. purpose and use of the Universe object) Using a dynamic (i.e. defined via the javascript client API) color bucket style Dynamically changing a layer's rendering style Specifying which attribute value to use in determining the bucket, and hence style, for a feature (FoI) The result is shown in the screenshot below. The states layer was defined, and stored in the user_sdo_themes view of the mvdemo schema, using MapBuilder. The underlying table is defined as SQL> desc states_32775  Name                                      Null?    Type ----------------------------------------- -------- ----------------------------  STATE                                              VARCHAR2(26)  STATE_ABRV                                         VARCHAR2(2) FIPSST                                             VARCHAR2(2) TOTPOP                                             NUMBER PCTSMPLD                                           NUMBER LANDSQMI                                           NUMBER POPPSQMI                                           NUMBER ... MEDHHINC NUMBER AVGHHINC NUMBER GEOM32775 MDSYS.SDO_GEOMETRY We'll use the TOTPOP column value in the advanced (color bucket) style for rendering the states layers. The predefined theme (US_STATES_BI) is defined as follows. SQL> select styling_rules from user_sdo_themes where name='US_STATES_BI'; STYLING_RULES -------------------------------------------------------------------------------- <?xml version="1.0" standalone="yes"?> <styling_rules highlight_style="C.CB_QUAL_8_CLASS_DARK2_1"> <hidden_info> <field column="STATE" name="Name"/> <field column="POPPSQMI" name="POPPSQMI"/> <field column="TOTPOP" name="TOTPOP"/> </hidden_info> <rule column="TOTPOP"> <features style="states_totpop"> </features> <label column="STATE_ABRV" style="T.BLUE_SERIF_10"> 1 </label> </rule> </styling_rules> SQL> The theme definition specifies that the state, poppsqmi, totpop, state_abrv, and geom columns will be queried from the states_32775 table. The state_abrv value will be used to label the state while the totpop value will be used to determine the color-fill from those defined in the states_totpop advanced style. The states_totpop style, which we will not use in our demo, is defined as shown below. SQL> select definition from user_sdo_styles where name='STATES_TOTPOP'; DEFINITION -------------------------------------------------------------------------------- <?xml version="1.0" ?> <AdvancedStyle> <BucketStyle> <Buckets default_style="C.S02_COUNTRY_AREA"> <RangedBucket seq="0" label="10K - 5M" low="10000" high="5000000" style="C.SEQ6_01" /> <RangedBucket seq="1" label="5M - 12M" low="5000001" high="1.2E7" style="C.SEQ6_02" /> <RangedBucket seq="2" label="12M - 20M" low="1.2000001E7" high="2.0E7" style="C.SEQ6_04" /> <RangedBucket seq="3" label="&gt; 20M" low="2.0000001E7" high="5.0E7" style="C.SEQ6_05" /> </Buckets> </BucketStyle> </AdvancedStyle> SQL> The demo defines additional advanced styles via the OM.style object and methods and uses those instead when rendering the states layer.   Now let's look at relevant snippets of code that defines the map extent and zoom levels (i.e. the OM.universe),  loads the states predefined vector layer (OM.layer), and sets up the advanced (color bucket) style. Defining the map extent and zoom levels. function initMap() {   //alert("Initialize map view");     // define the map extent and number of zoom levels.   // The Universe object is similar to the map tile layer configuration   // It defines the map extent, number of zoom levels, and spatial reference system   // well-known ones (like web mercator/google/bing or maps.oracle/elocation are predefined   // The Universe must be defined when there is no underlying map tile layer.   // When there is a map tile layer then that defines the map extent, srid, and zoom levels.      var uni= new OM.universe.Universe(     {         srid : 32775,         bounds : new OM.geometry.Rectangle(                         -3280000, 170000, 2300000, 3200000, 32775),         numberOfZoomLevels: 8     }); The srid specifies the spatial reference system which is Equal-Area Projection (United States). SQL> select cs_name from cs_srs where srid=32775 ; CS_NAME --------------------------------------------------- Equal-Area Projection (United States) The bounds defines the map extent. It is a Rectangle defined using the lower-left and upper-right coordinates and srid. Loading and displaying the states layer This is done in the states() function. The full code is at the end of this post, however here's the snippet which defines the states VectorLayer.     // States is a predefined layer in user_sdo_themes     var  layer2 = new OM.layer.VectorLayer("vLayer2",     {         def:         {             type:OM.layer.VectorLayer.TYPE_PREDEFINED,             dataSource:"mvdemo",             theme:"us_states_bi",             url: baseURL,             loadOnDemand: false         },         boundingTheme:true      }); The first parameter is a layer name, the second is an object literal for a layer config. The config object has two attributes: the first is the layer definition, the second specifies whether the layer is a bounding one (i.e. used to determine the current map zoom and center such that the whole layer is displayed within the map window) or not. The layer config has the following attributes: type - specifies whether is a predefined one, a defined via a SQL query (JDBC), or in a json-format file (DATAPACK) theme - is the predefined theme's name url - is the location of the mapviewer server loadOnDemand - specifies whether to load all the features or just those that lie within the current map window and load additional ones as needed on a pan or zoom The code snippet below dynamically defines an advanced style and then uses it, instead of the 'states_totpop' style, when rendering the states layer. // override predefined rendering style with programmatic one    var theRenderingStyle =      createBucketColorStyle('YlBr5', colorSeries, 'States5', true);   // specify which attribute is used in determining the bucket (i.e. color) to use for the state   // It can be an array because the style could be a chart type (pie/bar)   // which requires multiple attribute columns     // Use the STATE.TOTPOP column (aka attribute) value here    layer2.setRenderingStyle(theRenderingStyle, ["TOTPOP"]); The style itself is defined in the createBucketColorStyle() function. Dynamically defining an advanced style The advanced style used here is a bucket color style, i.e. a color style is associated with each bucket. So first we define the colors and then the buckets.     numClasses = colorSeries[colorName].classes;    // create Color Styles    for (var i=0; i < numClasses; i++)    {         theStyles[i] = new OM.style.Color(                      {fill: colorSeries[colorName].fill[i],                        stroke:colorSeries[colorName].stroke[i],                       strokeOpacity: useGradient? 0.25 : 1                      });    }; numClasses is the number of buckets. The colorSeries array contains the color fill and stroke definitions and is: var colorSeries = { //multi-hue color scheme #10 YlBl. "YlBl3": {   classes:3,                  fill: [0xEDF8B1, 0x7FCDBB, 0x2C7FB8],                  stroke:[0xB5DF9F, 0x72B8A8, 0x2872A6]   }, "YlBl5": {   classes:5,                  fill:[0xFFFFCC, 0xA1DAB4, 0x41B6C4, 0x2C7FB8, 0x253494],                  stroke:[0xE6E6B8, 0x91BCA2, 0x3AA4B0, 0x2872A6, 0x212F85]   }, //multi-hue color scheme #11 YlBr.  "YlBr3": {classes:3,                  fill:[0xFFF7BC, 0xFEC44F, 0xD95F0E],                  stroke:[0xE6DEA9, 0xE5B047, 0xC5360D]   }, "YlBr5": {classes:5,                  fill:[0xFFFFD4, 0xFED98E, 0xFE9929, 0xD95F0E, 0x993404],                  stroke:[0xE6E6BF, 0xE5C380, 0xE58A25, 0xC35663, 0x8A2F04]     }, etc. Next we create the bucket style.    bucketStyleDef = {       numClasses : colorSeries[colorName].classes, //      classification: 'custom',  //since we are supplying all the buckets //      buckets: theBuckets,       classification: 'logarithmic',  // use a logarithmic scale       styles: theStyles,       gradient:  useGradient? 'linear' : 'off' //      gradient:  useGradient? 'radial' : 'off'     };    theBucketStyle = new OM.style.BucketStyle(bucketStyleDef);    return theBucketStyle; A BucketStyle constructor takes a style definition as input. The style definition specifies the number of buckets (numClasses), a classification scheme (which can be equal-ranged, logarithmic scale, or custom), the styles for each bucket, whether to use a gradient effect, and optionally the buckets (required when using a custom classification scheme). The full source for the demo <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Oracle Maps V2 Thematic Map Demo</title> <script src="http://localhost:8080/mapviewer/jslib/v2/oraclemapsv2.js" type="text/javascript"> </script> <script type="text/javascript"> //var $j = jQuery.noConflict(); var baseURL="http://localhost:8080/mapviewer"; // location of mapviewer OM.gv.proxyEnabled =false; // no mvproxy needed OM.gv.setResourcePath(baseURL+"/jslib/v2/images/"); // location of resources for UI elements like nav panel buttons var map = null; // the client mapviewer object var statesLayer = null, stateCountyLayer = null; // The vector layers for states and counties in a state var layerName="States"; // initial map center and zoom var mapCenterLon = -20000; var mapCenterLat = 1750000; var mapZoom = 2; var mpoint = new OM.geometry.Point(mapCenterLon,mapCenterLat,32775); var currentPalette = null, currentStyle=null; // set an onchange listener for the color palette select list // initialize the map // load and display the states layer $(document).ready( function() { $("#demo-htmlselect").change(function() { var theColorScheme = $(this).val(); useSelectedColorScheme(theColorScheme); }); initMap(); states(); } ); /** * color series from ColorBrewer site (http://colorbrewer2.org/). */ var colorSeries = { //multi-hue color scheme #10 YlBl. "YlBl3": { classes:3, fill: [0xEDF8B1, 0x7FCDBB, 0x2C7FB8], stroke:[0xB5DF9F, 0x72B8A8, 0x2872A6] }, "YlBl5": { classes:5, fill:[0xFFFFCC, 0xA1DAB4, 0x41B6C4, 0x2C7FB8, 0x253494], stroke:[0xE6E6B8, 0x91BCA2, 0x3AA4B0, 0x2872A6, 0x212F85] }, //multi-hue color scheme #11 YlBr. "YlBr3": {classes:3, fill:[0xFFF7BC, 0xFEC44F, 0xD95F0E], stroke:[0xE6DEA9, 0xE5B047, 0xC5360D] }, "YlBr5": {classes:5, fill:[0xFFFFD4, 0xFED98E, 0xFE9929, 0xD95F0E, 0x993404], stroke:[0xE6E6BF, 0xE5C380, 0xE58A25, 0xC35663, 0x8A2F04] }, // single-hue color schemes (blues, greens, greys, oranges, reds, purples) "Purples5": {classes:5, fill:[0xf2f0f7, 0xcbc9e2, 0x9e9ac8, 0x756bb1, 0x54278f], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Blues5": {classes:5, fill:[0xEFF3FF, 0xbdd7e7, 0x68aed6, 0x3182bd, 0x18519C], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Greens5": {classes:5, fill:[0xedf8e9, 0xbae4b3, 0x74c476, 0x31a354, 0x116d2c], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Greys5": {classes:5, fill:[0xf7f7f7, 0xcccccc, 0x969696, 0x636363, 0x454545], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Oranges5": {classes:5, fill:[0xfeedde, 0xfdb385, 0xfd8d3c, 0xe6550d, 0xa63603], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] }, "Reds5": {classes:5, fill:[0xfee5d9, 0xfcae91, 0xfb6a4a, 0xde2d26, 0xa50f15], stroke:[0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3, 0xd3d3d3] } }; function createBucketColorStyle( colorName, colorSeries, rangeName, useGradient) { var theBucketStyle; var bucketStyleDef; var theStyles = []; var theColors = []; var aBucket, aStyle, aColor, aRange; var numClasses ; numClasses = colorSeries[colorName].classes; // create Color Styles for (var i=0; i < numClasses; i++) { theStyles[i] = new OM.style.Color( {fill: colorSeries[colorName].fill[i], stroke:colorSeries[colorName].stroke[i], strokeOpacity: useGradient? 0.25 : 1 }); }; bucketStyleDef = { numClasses : colorSeries[colorName].classes, // classification: 'custom', //since we are supplying all the buckets // buckets: theBuckets, classification: 'logarithmic', // use a logarithmic scale styles: theStyles, gradient: useGradient? 'linear' : 'off' // gradient: useGradient? 'radial' : 'off' }; theBucketStyle = new OM.style.BucketStyle(bucketStyleDef); return theBucketStyle; } function initMap() { //alert("Initialize map view"); // define the map extent and number of zoom levels. // The Universe object is similar to the map tile layer configuration // It defines the map extent, number of zoom levels, and spatial reference system // well-known ones (like web mercator/google/bing or maps.oracle/elocation are predefined // The Universe must be defined when there is no underlying map tile layer. // When there is a map tile layer then that defines the map extent, srid, and zoom levels. var uni= new OM.universe.Universe( { srid : 32775, bounds : new OM.geometry.Rectangle( -3280000, 170000, 2300000, 3200000, 32775), numberOfZoomLevels: 8 }); map = new OM.Map( document.getElementById('map'), { mapviewerURL: baseURL, universe:uni }) ; var navigationPanelBar = new OM.control.NavigationPanelBar(); map.addMapDecoration(navigationPanelBar); } // end initMap function states() { //alert("Load and display states"); layerName = "States"; if(statesLayer) { // states were already visible but the style may have changed // so set the style to the currently selected one var theData = $('#demo-htmlselect').val(); setStyle(theData); } else { // States is a predefined layer in user_sdo_themes var layer2 = new OM.layer.VectorLayer("vLayer2", { def: { type:OM.layer.VectorLayer.TYPE_PREDEFINED, dataSource:"mvdemo", theme:"us_states_bi", url: baseURL, loadOnDemand: false }, boundingTheme:true }); // add drop shadow effect and hover style var shadowFilter = new OM.visualfilter.DropShadow({opacity:0.5, color:"#000000", offset:6, radius:10}); var hoverStyle = new OM.style.Color( {stroke:"#838383", strokeThickness:2}); layer2.setHoverStyle(hoverStyle); layer2.setHoverVisualFilter(shadowFilter); layer2.enableFeatureHover(true); layer2.enableFeatureSelection(false); layer2.setLabelsVisible(true); // override predefined rendering style with programmatic one var theRenderingStyle = createBucketColorStyle('YlBr5', colorSeries, 'States5', true); // specify which attribute is used in determining the bucket (i.e. color) to use for the state // It can be an array because the style could be a chart type (pie/bar) // which requires multiple attribute columns // Use the STATE.TOTPOP column (aka attribute) value here layer2.setRenderingStyle(theRenderingStyle, ["TOTPOP"]); currentPalette = "YlBr5"; var stLayerIdx = map.addLayer(layer2); //alert('State Layer Idx = ' + stLayerIdx); map.setMapCenter(mpoint); map.setMapZoomLevel(mapZoom) ; // display the map map.init() ; statesLayer=layer2; // add rt-click event listener to show counties for the state layer2.addListener(OM.event.MouseEvent.MOUSE_RIGHT_CLICK,stateRtClick); } // end if } // end states function setStyle(styleName) { // alert("Selected Style = " + styleName); // there may be a counties layer also displayed. // that wll have different bucket ranges so create // one style for states and one for counties var newRenderingStyle = null; if (layerName === "States") { if(/3/.test(styleName)) { newRenderingStyle = createBucketColorStyle(styleName, colorSeries, 'States3', false); currentStyle = createBucketColorStyle(styleName, colorSeries, 'Counties3', false); } else { newRenderingStyle = createBucketColorStyle(styleName, colorSeries, 'States5', false); currentStyle = createBucketColorStyle(styleName, colorSeries, 'Counties5', false); } statesLayer.setRenderingStyle(newRenderingStyle, ["TOTPOP"]); if (stateCountyLayer) stateCountyLayer.setRenderingStyle(currentStyle, ["TOTPOP"]); } } // end setStyle function stateRtClick(evt){ var foi = evt.feature; //alert('Rt-Click on State: ' + foi.attributes['_label_'] + // ' with pop ' + foi.attributes['TOTPOP']); // display another layer with counties info // layer may change on each rt-click so create and add each time. var countyByState = null ; // the _label_ attribute of a feature in this case is the state abbreviation // we will use that to query and get the counties for a state var sqlText = "select totpop,geom32775 from counties_32775_moved where state_abrv="+ "'"+foi.getAttributeValue('_label_')+"'"; // alert(sqlText); if (currentStyle === null) currentStyle = createBucketColorStyle('YlBr5', colorSeries, 'Counties5', false); /* try a simple style instead new OM.style.ColorStyle( { stroke: "#B8F4FF", fill: "#18E5F4", fillOpacity:0 } ); */ // remove existing layer if any if(stateCountyLayer) map.removeLayer(stateCountyLayer); countyByState = new OM.layer.VectorLayer("stCountyLayer", {def:{type:OM.layer.VectorLayer.TYPE_JDBC, dataSource:"mvdemo", sql:sqlText, url:baseURL}}); // url:baseURL}, // renderingStyle:currentStyle}); countyByState.setVisible(true); // specify which attribute is used in determining the bucket (i.e. color) to use for the state countyByState.setRenderingStyle(currentStyle, ["TOTPOP"]); var ctLayerIdx = map.addLayer(countyByState); // alert('County Layer Idx = ' + ctLayerIdx); //map.addLayer(countyByState); stateCountyLayer = countyByState; } // end stateRtClick function useSelectedColorScheme(theColorScheme) { if(map) { // code to update renderStyle goes here //alert('will try to change render style'); setStyle(theColorScheme); } else { // do nothing } } </script> </head> <body bgcolor="#b4c5cc" style="height:100%;font-family:Arial,Helvetica,Verdana"> <h3 align="center">State population thematic map </h3> <div id="demo" style="position:absolute; left:68%; top:44px; width:28%; height:100%"> <HR/> <p/> Choose Color Scheme: <select id="demo-htmlselect"> <option value="YlBl3"> YellowBlue3</option> <option value="YlBr3"> YellowBrown3</option> <option value="YlBl5"> YellowBlue5</option> <option value="YlBr5" selected="selected"> YellowBrown5</option> <option value="Blues5"> Blues</option> <option value="Greens5"> Greens</option> <option value="Greys5"> Greys</option> <option value="Oranges5"> Oranges</option> <option value="Purples5"> Purples</option> <option value="Reds5"> Reds</option> </select> <p/> </div> <div id="map" style="position:absolute; left:10px; top:50px; width:65%; height:75%; background-color:#778f99"></div> <div style="position:absolute;top:85%; left:10px;width:98%" class="noprint"> <HR/> <p> Note: This demo uses HTML5 Canvas and requires IE9+, Firefox 10+, or Chrome. No map will show up in IE8 or earlier. </p> </div> </body> </html>

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  • Diving into OpenStack Network Architecture - Part 2 - Basic Use Cases

    - by Ronen Kofman
      rkofman Normal rkofman 4 138 2014-06-05T03:38:00Z 2014-06-05T05:04:00Z 3 2735 15596 Oracle Corporation 129 36 18295 12.00 Clean Clean false false false false EN-US X-NONE HE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi; mso-bidi-language:AR-SA;} In the previous post we reviewed several network components including Open vSwitch, Network Namespaces, Linux Bridges and veth pairs. In this post we will take three simple use cases and see how those basic components come together to create a complete SDN solution in OpenStack. With those three use cases we will review almost the entire network setup and see how all the pieces work together. The use cases we will use are: 1.       Create network – what happens when we create network and how can we create multiple isolated networks 2.       Launch a VM – once we have networks we can launch VMs and connect them to networks. 3.       DHCP request from a VM – OpenStack can automatically assign IP addresses to VMs. This is done through local DHCP service controlled by OpenStack Neutron. We will see how this service runs and how does a DHCP request and response look like. In this post we will show connectivity, we will see how packets get from point A to point B. We first focus on how a configured deployment looks like and only later we will discuss how and when the configuration is created. Personally I found it very valuable to see the actual interfaces and how they connect to each other through examples and hands on experiments. After the end game is clear and we know how the connectivity works, in a later post, we will take a step back and explain how Neutron configures the components to be able to provide such connectivity.  We are going to get pretty technical shortly and I recommend trying these examples on your own deployment or using the Oracle OpenStack Tech Preview. Understanding these three use cases thoroughly and how to look at them will be very helpful when trying to debug a deployment in case something does not work. Use case #1: Create Network Create network is a simple operation it can be performed from the GUI or command line. When we create a network in OpenStack the network is only available to the tenant who created it or it could be defined as “shared” and then it can be used by all tenants. A network can have multiple subnets but for this demonstration purpose and for simplicity we will assume that each network has exactly one subnet. Creating a network from the command line will look like this: # neutron net-create net1 Created a new network: +---------------------------+--------------------------------------+ | Field                     | Value                                | +---------------------------+--------------------------------------+ | admin_state_up            | True                                 | | id                        | 5f833617-6179-4797-b7c0-7d420d84040c | | name                      | net1                                 | | provider:network_type     | vlan                                 | | provider:physical_network | default                              | | provider:segmentation_id  | 1000                                 | | shared                    | False                                | | status                    | ACTIVE                               | | subnets                   |                                      | | tenant_id                 | 9796e5145ee546508939cd49ad59d51f     | +---------------------------+--------------------------------------+ Creating a subnet for this network will look like this: # neutron subnet-create net1 10.10.10.0/24 Created a new subnet: +------------------+------------------------------------------------+ | Field            | Value                                          | +------------------+------------------------------------------------+ | allocation_pools | {"start": "10.10.10.2", "end": "10.10.10.254"} | | cidr             | 10.10.10.0/24                                  | | dns_nameservers  |                                                | | enable_dhcp      | True                                           | | gateway_ip       | 10.10.10.1                                     | | host_routes      |                                                | | id               | 2d7a0a58-0674-439a-ad23-d6471aaae9bc           | | ip_version       | 4                                              | | name             |                                                | | network_id       | 5f833617-6179-4797-b7c0-7d420d84040c           | | tenant_id        | 9796e5145ee546508939cd49ad59d51f               | +------------------+------------------------------------------------+ We now have a network and a subnet, on the network topology view this looks like this: Now let’s dive in and see what happened under the hood. Looking at the control node we will discover that a new namespace was created: # ip netns list qdhcp-5f833617-6179-4797-b7c0-7d420d84040c   The name of the namespace is qdhcp-<network id> (see above), let’s look into the namespace and see what’s in it: # ip netns exec qdhcp-5f833617-6179-4797-b7c0-7d420d84040c ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo     inet6 ::1/128 scope host        valid_lft forever preferred_lft forever 12: tap26c9b807-7c: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN     link/ether fa:16:3e:1d:5c:81 brd ff:ff:ff:ff:ff:ff     inet 10.10.10.3/24 brd 10.10.10.255 scope global tap26c9b807-7c     inet6 fe80::f816:3eff:fe1d:5c81/64 scope link        valid_lft forever preferred_lft forever   We see two interfaces in the namespace, one is the loopback and the other one is an interface called “tap26c9b807-7c”. This interface has the IP address of 10.10.10.3 and it will also serve dhcp requests in a way we will see later. Let’s trace the connectivity of the “tap26c9b807-7c” interface from the namespace.  First stop is OVS, we see that the interface connects to bridge  “br-int” on OVS: # ovs-vsctl show 8a069c7c-ea05-4375-93e2-b9fc9e4b3ca1     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2"                 type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"     Bridge br-ex         Port br-ex             Interface br-ex                 type: internal     Bridge br-int         Port "int-br-eth2"             Interface "int-br-eth2"         Port "tap26c9b807-7c"             tag: 1             Interface "tap26c9b807-7c"                 type: internal         Port br-int             Interface br-int                 type: internal     ovs_version: "1.11.0"   In the picture above we have a veth pair which has two ends called “int-br-eth2” and "phy-br-eth2", this veth pair is used to connect two bridge in OVS "br-eth2" and "br-int". In the previous post we explained how to check the veth connectivity using the ethtool command. It shows that the two are indeed a pair: # ethtool -S int-br-eth2 NIC statistics:      peer_ifindex: 10 . .   #ip link . . 10: phy-br-eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 . . Note that “phy-br-eth2” is connected to a bridge called "br-eth2" and one of this bridge's interfaces is the physical link eth2. This means that the network which we have just created has created a namespace which is connected to the physical interface eth2. eth2 is the “VM network” the physical interface where all the virtual machines connect to where all the VMs are connected. About network isolation: OpenStack supports creation of multiple isolated networks and can use several mechanisms to isolate the networks from one another. The isolation mechanism can be VLANs, VxLANs or GRE tunnels, this is configured as part of the initial setup in our deployment we use VLANs. When using VLAN tagging as an isolation mechanism a VLAN tag is allocated by Neutron from a pre-defined VLAN tags pool and assigned to the newly created network. By provisioning VLAN tags to the networks Neutron allows creation of multiple isolated networks on the same physical link.  The big difference between this and other platforms is that the user does not have to deal with allocating and managing VLANs to networks. The VLAN allocation and provisioning is handled by Neutron which keeps track of the VLAN tags, and responsible for allocating and reclaiming VLAN tags. In the example above net1 has the VLAN tag 1000, this means that whenever a VM is created and connected to this network the packets from that VM will have to be tagged with VLAN tag 1000 to go on this particular network. This is true for namespace as well, if we would like to connect a namespace to a particular network we have to make sure that the packets to and from the namespace are correctly tagged when they reach the VM network. In the example above we see that the namespace interface “tap26c9b807-7c” has vlan tag 1 assigned to it, if we examine OVS we see that it has flows which modify VLAN tag 1 to VLAN tag 1000 when a packet goes to the VM network on eth2 and vice versa. We can see this using the dump-flows command on OVS for packets going to the VM network we see the modification done on br-eth2: #  ovs-ofctl dump-flows br-eth2 NXST_FLOW reply (xid=0x4):  cookie=0x0, duration=18669.401s, table=0, n_packets=857, n_bytes=163350, idle_age=25, priority=4,in_port=2,dl_vlan=1 actions=mod_vlan_vid:1000,NORMAL  cookie=0x0, duration=165108.226s, table=0, n_packets=14, n_bytes=1000, idle_age=5343, hard_age=65534, priority=2,in_port=2 actions=drop  cookie=0x0, duration=165109.813s, table=0, n_packets=1671, n_bytes=213304, idle_age=25, hard_age=65534, priority=1 actions=NORMAL   For packets coming from the interface to the namespace we see the following modification: #  ovs-ofctl dump-flows br-int NXST_FLOW reply (xid=0x4):  cookie=0x0, duration=18690.876s, table=0, n_packets=1610, n_bytes=210752, idle_age=1, priority=3,in_port=1,dl_vlan=1000 actions=mod_vlan_vid:1,NORMAL  cookie=0x0, duration=165130.01s, table=0, n_packets=75, n_bytes=3686, idle_age=4212, hard_age=65534, priority=2,in_port=1 actions=drop  cookie=0x0, duration=165131.96s, table=0, n_packets=863, n_bytes=160727, idle_age=1, hard_age=65534, priority=1 actions=NORMAL   To summarize we can see that when a user creates a network Neutron creates a namespace and this namespace is connected through OVS to the “VM network”. OVS also takes care of tagging the packets from the namespace to the VM network with the correct VLAN tag and knows to modify the VLAN for packets coming from VM network to the namespace. Now let’s see what happens when a VM is launched and how it is connected to the “VM network”. Use case #2: Launch a VM Launching a VM can be done from Horizon or from the command line this is how we do it from Horizon: Attach the network: And Launch Once the virtual machine is up and running we can see the associated IP using the nova list command : # nova list +--------------------------------------+--------------+--------+------------+-------------+-----------------+ | ID                                   | Name         | Status | Task State | Power State | Networks        | +--------------------------------------+--------------+--------+------------+-------------+-----------------+ | 3707ac87-4f5d-4349-b7ed-3a673f55e5e1 | Oracle Linux | ACTIVE | None       | Running     | net1=10.10.10.2 | +--------------------------------------+--------------+--------+------------+-------------+-----------------+ The nova list command shows us that the VM is running and that the IP 10.10.10.2 is assigned to this VM. Let’s trace the connectivity from the VM to VM network on eth2 starting with the VM definition file. The configuration files of the VM including the virtual disk(s), in case of ephemeral storage, are stored on the compute node at/var/lib/nova/instances/<instance-id>/. Looking into the VM definition file ,libvirt.xml,  we see that the VM is connected to an interface called “tap53903a95-82” which is connected to a Linux bridge called “qbr53903a95-82”: <interface type="bridge">       <mac address="fa:16:3e:fe:c7:87"/>       <source bridge="qbr53903a95-82"/>       <target dev="tap53903a95-82"/>     </interface>   Looking at the bridge using the brctl show command we see this: # brctl show bridge name     bridge id               STP enabled     interfaces qbr53903a95-82          8000.7e7f3282b836       no              qvb53903a95-82                                                         tap53903a95-82    The bridge has two interfaces, one connected to the VM (“tap53903a95-82 “) and another one ( “qvb53903a95-82”) connected to “br-int” bridge on OVS: # ovs-vsctl show 83c42f80-77e9-46c8-8560-7697d76de51c     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2"                 type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"     Bridge br-int         Port br-int             Interface br-int                 type: internal         Port "int-br-eth2"             Interface "int-br-eth2"         Port "qvo53903a95-82"             tag: 3             Interface "qvo53903a95-82"     ovs_version: "1.11.0"   As we showed earlier “br-int” is connected to “br-eth2” on OVS using the veth pair int-br-eth2,phy-br-eth2 and br-eth2 is connected to the physical interface eth2. The whole flow end to end looks like this: VM è tap53903a95-82 (virtual interface)è qbr53903a95-82 (Linux bridge) è qvb53903a95-82 (interface connected from Linux bridge to OVS bridge br-int) è int-br-eth2 (veth one end) è phy-br-eth2 (veth the other end) è eth2 physical interface. The purpose of the Linux Bridge connecting to the VM is to allow security group enforcement with iptables. Security groups are enforced at the edge point which are the interface of the VM, since iptables nnot be applied to OVS bridges we use Linux bridge to apply them. In the future we hope to see this Linux Bridge going away rules.  VLAN tags: As we discussed in the first use case net1 is using VLAN tag 1000, looking at OVS above we see that qvo41f1ebcf-7c is tagged with VLAN tag 3. The modification from VLAN tag 3 to 1000 as we go to the physical network is done by OVS  as part of the packet flow of br-eth2 in the same way we showed before. To summarize, when a VM is launched it is connected to the VM network through a chain of elements as described here. During the packet from VM to the network and back the VLAN tag is modified. Use case #3: Serving a DHCP request coming from the virtual machine In the previous use cases we have shown that both the namespace called dhcp-<some id> and the VM end up connecting to the physical interface eth2  on their respective nodes, both will tag their packets with VLAN tag 1000.We saw that the namespace has an interface with IP of 10.10.10.3. Since the VM and the namespace are connected to each other and have interfaces on the same subnet they can ping each other, in this picture we see a ping from the VM which was assigned 10.10.10.2 to the namespace: The fact that they are connected and can ping each other can become very handy when something doesn’t work right and we need to isolate the problem. In such case knowing that we should be able to ping from the VM to the namespace and back can be used to trace the disconnect using tcpdump or other monitoring tools. To serve DHCP requests coming from VMs on the network Neutron uses a Linux tool called “dnsmasq”,this is a lightweight DNS and DHCP service you can read more about it here. If we look at the dnsmasq on the control node with the ps command we see this: dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tap26c9b807-7c --except-interface=lo --pid-file=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/pid --dhcp-hostsfile=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/host --dhcp-optsfile=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/opts --leasefile-ro --dhcp-range=tag0,10.10.10.0,static,120s --dhcp-lease-max=256 --conf-file= --domain=openstacklocal The service connects to the tap interface in the namespace (“--interface=tap26c9b807-7c”), If we look at the hosts file we see this: # cat  /var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/host fa:16:3e:fe:c7:87,host-10-10-10-2.openstacklocal,10.10.10.2   If you look at the console output above you can see the MAC address fa:16:3e:fe:c7:87 which is the VM MAC. This MAC address is mapped to IP 10.10.10.2 and so when a DHCP request comes with this MAC dnsmasq will return the 10.10.10.2.If we look into the namespace at the time we initiate a DHCP request from the VM (this can be done by simply restarting the network service in the VM) we see the following: # ip netns exec qdhcp-5f833617-6179-4797-b7c0-7d420d84040c tcpdump -n 19:27:12.191280 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:fe:c7:87, length 310 19:27:12.191666 IP 10.10.10.3.bootps > 10.10.10.2.bootpc: BOOTP/DHCP, Reply, length 325   To summarize, the DHCP service is handled by dnsmasq which is configured by Neutron to listen to the interface in the DHCP namespace. Neutron also configures dnsmasq with the combination of MAC and IP so when a DHCP request comes along it will receive the assigned IP. Summary In this post we relied on the components described in the previous post and saw how network connectivity is achieved using three simple use cases. These use cases gave a good view of the entire network stack and helped understand how an end to end connection is being made between a VM on a compute node and the DHCP namespace on the control node. One conclusion we can draw from what we saw here is that if we launch a VM and it is able to perform a DHCP request and receive a correct IP then there is reason to believe that the network is working as expected. We saw that a packet has to travel through a long list of components before reaching its destination and if it has done so successfully this means that many components are functioning properly. In the next post we will look at some more sophisticated services Neutron supports and see how they work. We will see that while there are some more components involved for the most part the concepts are the same. @RonenKofman

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  • struts2-json-plugin not retrieving json data from action class for Struts-JQuery-Plugin grid

    - by thebravedave
    Hello, Im having an issue getting json working with the struts-jquery-plugin-2.1.0 I have included the struts2-json-plugin-2.1.8.1 in my classpath as well. Im sure that I have my struts-jquery-plugin configured correctly because the grid loads, but doesnt load the data its supposed to get from the action class that has been json'ized. The documentation with the json plugin and the struts-jquery plugin leaves ALOT of gaps that I cant even find with examples/tutorials, so I come to the community at stackoverflow. My action class has a property called gridModel thats a List with a basic POJO called Customer. Customer is a pojo with one property, id. I have a factory that supplies the populated List to the actions List property which i mentioned called gridModel. Heres how i set up my struts.xml file: <constant name="struts.devMode" value="true"/> <constant name="struts.objectFactory" value="guice"/> <package name="org.webhop.ywdc" namespace="/" extends="struts-default,json-default"> <result-types> <result-type name="json" class="com.googlecode.jsonplugin.JSONResult"> </result-type> </result-types> <action name="login" class="org.webhop.ywdc.LoginAction" > <result type="json"></result> <result name="success" type="dispatcher">/pages/uiTags/Success.jsp</result> <result name="error" type="redirect">/pages/uiTags/Login.jsp</result> <interceptor-ref name="cookie"> <param name="cookiesName">JSESSIONID</param> </interceptor-ref> </action> <action name="logout" class="org.webhop.ywdc.LogoutAction" > <result name="success" type="redirect">/pages/uiTags/Login.jsp</result> </action> </package> In the struts.xml file i set the and in my action i listed in the action configuration. Heres my jsp page that the action loads: <%@ taglib prefix="s" uri="/struts-tags" % <%@ taglib prefix="sj" uri="/struts-jquery-tags"% <%@ taglib prefix="sjg" uri="/struts-jquery-grid-tags"% <%@ page language="java" contentType="text/html" import="java.util.*"% Welcome, you have logged in! <s:url id="remoteurl" action="login"/> <sjg:grid id="gridtable" caption="Customer Examples" dataType="json" href="%{remoteurl}" pager="false" gridModel="gridModel" > <sjg:gridColumn name="id" key="true" index="id" title="ID" formatter="integer" sortable="false"/> </sjg:grid> Welcome, you have logged in. <br /> <b>Session Time: </b><%=new Date(session.getLastAccessedTime())%> <h2>Password:<s:property value="password"/></h2> <h2>userId:<s:property value="userId"/></h2> <br /> <a href="<%= request.getContextPath() %>/logout.action">Logout</a><br /><br /> ID: <s:property value="id"/> session id: <s:property value="JSESSIONID"/> </body> Im not really sure how to tell what json the json plugin is creating from the action class. If i did know how i could tell if it wasnt formed properly. As far as I know if I specificy in my action configuration in struts.xml, that the grid, which is set to read json and knows to look for "gridModel" will then automatically load the json to the grid, but its not. Heres my action class: public class LoginAction extends ActionSupport { public String JSESSIONID; public int id; private String userId; private String password; public Members member; public List<Customer> gridModel; public String execute() { Cookie cookie = new Cookie("ywdcsid", password); cookie.setMaxAge(3600); HttpServletResponse response = ServletActionContext.getResponse(); response.addCookie(cookie); HttpServletRequest request = ServletActionContext.getRequest(); Cookie[] ckey = request.getCookies(); for(Cookie c: ckey) { System.out.println(c.getName() + "/cookie_name + " + c.getValue() + "/cookie_value"); } Map requestParameters = ActionContext.getContext().getParameters();//getParameters(); String[] testString = (String[])requestParameters.get("password"); String passwordString = testString[0]; String[] usernameArray = (String[])requestParameters.get("userId"); String usernameString = usernameArray[0]; Injector injector = Guice.createInjector(new GuiceModule()); HibernateConnection connection = injector.getInstance(HibernateConnection.class); AuthenticationServices currentService = injector.getInstance(AuthenticationServices.class); currentService.setConnection(connection); currentService.setInjector(injector); member = currentService.getMemberByUsernamePassword(usernameString, passwordString); userId = member.getUsername(); password = member.getPassword(); CustomerFactory customerFactory = new CustomerFactory(); gridModel = customerFactory.getCustomers(); if(member == null) { return ERROR; } else { id = member.getId(); Map session = ActionContext.getContext().getSession(); session.put(usernameString, member); return SUCCESS; } } public String logout() throws Exception { Map session = ActionContext.getContext().getSession(); session.remove("logged-in"); return SUCCESS; } public List<Customer> getGridModel() { return gridModel; } public void setGridModel(List<Customer> gridModel) { this.gridModel = gridModel; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getUserId() { return userId; } public void setUserId(String userId) { this.userId = userId; } public String getJSESSIONID() { return JSESSIONID; } public void setJSESSIONID(String jsessionid) { JSESSIONID = jsessionid; } } Please help me with this problem. You will make my week, as this is a major bottleneck for me :( thanks so much, thebravedave

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