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• DHCPv6: Provide IPv6 information in your local network

  Even though IPv6 might not be that important within your local network it might be good to get yourself into shape, and be able to provide some details of your infrastructure automatically to your network clients. This is the second article in a series on IPv6 configuration: Configure IPv6 on your Linux system DHCPv6: Provide IPv6 information in your local network Enabling DNS for IPv6 infrastructure Accessing your web server via IPv6 Piece of advice: This is based on my findings on the internet while reading other people's helpful articles and going through a couple of man-pages on my local system. IPv6 addresses for everyone (in your network) Okay, after setting up the configuration of your local system, it might be interesting to enable all your machines in your network to use IPv6. There are two options to solve this kind of requirement... Either you're busy like a bee and you go around to configure each and every system manually, or you're more the lazy and effective type of network administrator and you prefer to work with Dynamic Host Configuration Protocol (DHCP). Obviously, I'm of the second type. Enabling dynamic IPv6 address assignments can be done with a new or an existing instance of a DHCPd. In case of Ubuntu-based installation this might be isc-dhcp-server. The isc-dhcp-server allows address pooling for IP and IPv6 within the same package, you just have to run to independent daemons for each protocol version. First, check whether isc-dhcp-server is already installed and maybe running your machine like so: $ service isc-dhcp-server6 status In case, that the service is unknown, you have to install it like so: $ sudo apt-get install isc-dhcp-server Please bear in mind that there is no designated installation package for IPv6. Okay, next you have to create a separate configuration file for IPv6 address pooling and network parameters called /etc/dhcp/dhcpd6.conf. This file is not automatically provided by the package, compared to IPv4. Again, use your favourite editor and put the following lines: $ sudo nano /etc/dhcp/dhcpd6.conf authoritative;default-lease-time 14400; max-lease-time 86400;log-facility local7;subnet6 2001:db8:bad:a55::/64 {    option dhcp6.name-servers 2001:4860:4860::8888, 2001:4860:4860::8844;    option dhcp6.domain-search "ios.mu";    range6 2001:db8:bad:a55::100 2001:db8:bad:a55::199;    range6 2001:db8:bad:a55::/64 temporary;} Next, save the file and start the daemon as a foreground process to see whether it is going to listen to requests or not, like so: $ sudo /usr/sbin/dhcpd -6 -d -cf /etc/dhcp/dhcpd6.conf eth0 The parameters are explained quickly as -6 we want to run as a DHCPv6 server, -d we are sending log messages to the standard error descriptor (so you should monitor your /var/log/syslog file, too), and we explicitely want to use our newly created configuration file (-cf). You might also use the command switch -t to test the configuration file prior to running the server. In my case, I ended up with a couple of complaints by the server, especially reporting that the necessary lease file wouldn't exist. So, ensure that the lease file for your IPv6 address assignments is present: $ sudo touch /var/lib/dhcp/dhcpd6.leases$ sudo chown dhcpd:dhcpd /var/lib/dhcp/dhcpd6.leases Now, you should be good to go. Stop your foreground process and try to run the DHCPv6 server as a service on your system: $ sudo service isc-dhcp-server6 startisc-dhcp-server6 start/running, process 15883 Check your log file /var/log/syslog for any kind of problems. Refer to the man-pages of isc-dhcp-server and you might check out Chapter 22.6 of Peter Bieringer's IPv6 Howto. The instructions regarding DHCPv6 on the Ubuntu Wiki are not as complete as expected and it might not be as helpful as this article or Peter's HOWTO. But see for yourself. Does the client get an IPv6 address? Running a DHCPv6 server on your local network surely comes in handy but it has to work properly. The following paragraphs describe briefly how to check the IPv6 configuration of your clients, Linux - ifconfig or ip command First, you have enable IPv6 on your Linux by specifying the necessary directives in the /etc/network/interfaces file, like so: $ sudo nano /etc/network/interfaces iface eth1 inet6 dhcp Note: Your network device might be eth0 - please don't just copy my configuration lines. Then, either restart your network subsystem, or enable the device manually using the dhclient command with IPv6 switch, like so: $ sudo dhclient -6 You would either use the ifconfig or (if installed) the ip command to check the configuration of your network device like so: $ sudo ifconfig eth1eth1      Link encap:Ethernet  HWaddr 00:1d:09:5d:8d:98            inet addr:192.168.160.147  Bcast:192.168.160.255  Mask:255.255.255.0          inet6 addr: 2001:db8:bad:a55::193/64 Scope:Global          inet6 addr: fe80::21d:9ff:fe5d:8d98/64 Scope:Link          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 Looks good, the client has an IPv6 assignment. Now, let's see whether DNS information has been provided, too. $ less /etc/resolv.conf # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTENnameserver 2001:4860:4860::8888nameserver 2001:4860:4860::8844nameserver 192.168.1.2nameserver 127.0.1.1search ios.mu Nicely done. Windows - netsh Per description on TechNet the netsh is defined as following: "Netsh is a command-line scripting utility that allows you to, either locally or remotely, display or modify the network configuration of a computer that is currently running. Netsh also provides a scripting feature that allows you to run a group of commands in batch mode against a specified computer. Netsh can also save a configuration script in a text file for archival purposes or to help you configure other servers." And even though TechNet states that it applies to Windows Server (only), it is also available on Windows client operating systems, like Vista, Windows 7 and Windows 8. In order to get or even set information related to IPv6 protocol, we have to switch the netsh interface context prior to our queries. Open a command prompt in Windows and run the following statements: C:\Users\joki>netshnetsh>interface ipv6netsh interface ipv6>show interfaces Select the device index from the Idx column to get more details about the IPv6 address and DNS server information (here: I'm going to use my WiFi device with device index 11), like so: netsh interface ipv6>show address 11 Okay, address information has been provided. Now, let's check the details about DNS and resolving host names: netsh interface ipv6> show dnsservers 11 Okay, that looks good already. Our Windows client has a valid IPv6 address lease with lifetime information and details about the configured DNS servers. Talking about DNS server... Your clients should be able to connect to your network servers via IPv6 using hostnames instead of IPv6 addresses. Please read on about how to enable a local named with IPv6.

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• The DOS DEBUG Environment

  - by MarkPearl

  Today I thought I would go back in time and have a look at the DEBUG command that has been available since the beginning of dawn in DOS, MS-DOS and Microsoft Windows. up to today I always knew it was there, but had no clue on how to use it so for those that are interested this might be a great geek party trick to pull out when you want the awe the younger generation and want to show them what “real” programming is about. But wait, you will have to do it relatively quickly as it seems like DEBUG was finally dumped from the Windows group in Windows 7. Not to worry, pull out that Windows XP box which will get you even more geek points and you can still poke DEBUG a bit. So, for those that are interested and want to find out a bit about the history of DEBUG read the wiki link here. That all put aside, lets get our hands dirty.. How to Start DEBUG in Windows Make sure your version of Windows supports DEBUG. Open up a console window Make a directory where you want to play with debug – in my instance I called it C221 Enter the directory and type Debug You will get a response with a – as illustrated in the image below…   The commands available in DEBUG There are several commands available in DEBUG. The most common ones are A (Assemble) R (Register) T (Trace) G (Go) D (Dump or Display) U (Unassemble) E (Enter) P (Proceed) N (Name) L (Load) W (Write) H (Hexadecimal) I (Input) O (Output) Q (Quit) I am not going to cover all these commands, but what I will do is go through a few of them briefly. A is for Assemble Command (to write code) The A command translates assembly language statements into machine code. It is quite useful for writing small assembly programs. Below I have written a very basic assembly program. The code typed out is as follows mov ax,0015 mov cx,0023 sub cx,ax mov [120],al mov cl,[120]A nop R is for Register (to jump to a point in memory) The r command turns out to be one of the most frequent commands you will use in DEBUG. It allows you to view the contents of registers and to change their values. It can be used with the following combinations… R – Displays the contents of all the registers R f – Displays the flags register R register_name – Displays the contents of a specific register All three methods are illustrated in the image above T is for Trace (To execute a program step by step) The t command allows us to execute the program step by step. Before we can trace the program we need to point back to the beginning of the program. We do this by typing in r ip, which moves us back to memory point 100. We then type trace which executes the first line of code (line 100) (As shown in the image below starting from the red arrow). You can see from the above image that the register AX now contains 0015 as per our instruction mov ax,0015 You can also see that the IP points to line 0103 which has the MOV CX,0023 command If we type t again it will now execute the second line of the program which moves 23 in the cx register. Again, we can see that the line of code was executed and that the CX register now holds the value of 23. What I would like to highlight now is the section underlined in red. These are the status flags. The ones we are going to look at now are 1st (NV), 4th (PL), 5th (NZ) & 8th (NC) NV means no overflow, the alternate would be OV PL means that the sign of the previous arithmetic operation was Plus, the alternate would be NG (Negative) NZ means that the results of the previous arithmetic operation operation was Not Zero, the alternate would be ZR NC means that No final Carry resulted from the previous arithmetic operation. CY means that there was a final Carry. We could now follow this process of entering the t command until the entire program is executed line by line. G is for Go (To execute a program up to a certain line number) So we have looked at executing a program line by line, which is fine if your program is minuscule BUT totally unpractical if we have any decent sized program. A quicker way to run some lines of code is to use the G command. The ‘g’ command executes a program up to a certain specified point. It can be used in connection with the the reset IP command. You would set your initial point and then run the G command with the line you want to end on. P is for Proceed (Similar to trace but slightly more streamlined) Another command similar to trace is the proceed command. All that the p command does is if it is called and it encounters a CALL, INT or LOOP command it terminates the program execution. In the example below I modified our example program to include an int 20 at the end of it as illustrated in the image below… Then when executing the code when I encountered the int 20 command I typed the P command and the program terminated normally (illustrated below). D is for Dump (or for those more polite Display) So, we have all these assembly lines of code, but if you have ever opened up an exe or com file in a text/hex editor, it looks nothing like assembly code. The D command is a way that we can see what our code looks like in memory (or in a hex editor). If we examined the image above, we can see that Debug is storing our assembly code with each instruction following immediately after the previous one. For instance in memory address 110 we have int and 111 we have 20. If we examine the dump of memory we can see at memory point 110 CD is stored and at memory point 111 20 is stored. U is for Unassemble (or Convert Machine code to Assembly Code) So up to now we have gone through a bunch of commands, but probably one of the most useful is the U command. Let’s say we don’t understand machine code so well and so instead we want to see it in its equivalent assembly code. We can type the U command followed by the start memory point, followed by the end memory point and it will show us the assembly code equivalent of the machine code. E is for a bunch of things… The E command can be used for a bunch of things… One example is to enter data or machine code instructions directly into memory. It can also be used to display the contents of memory locations. I am not going to worry to much about it in this post. N / L / W is for Name, Load & Write So we have written out assembly code in debug, and now we want to save it to disk, or write it as a com file or load it. This is where the N, L & W command come in handy. The n command is used to give a name to the executable program file and is pretty simple to use. The w command is a bit trickier. It saves to disk all the memory between point bx and point cx so you need to specify the bx memory address and the cx memory address for it to write your code. Let’s look at an example illustrated below. You do this by calling the r command followed by the either bx or cx. We can then go to the directory where we were working and will see the new file with the name we specified. The L command is relatively simple. You would first specify the name of the file you would like to load using the N command, and then call the L command. Q is for Quit The last command that I am going to write about in this post is the Q command. Simply put, calling the Q command exits DEBUG. Commands we did not Cover Out of the standard DEBUG commands we covered A, T, G, D, U, E, P, R, N, L & W. The ones we did not cover were H, I & O – I might make mention of these in a later post, but for the basics they are not really needed. Some Useful Resources Please note this post is based on the COS2213 handouts for UNISA A Guide to DEBUG - http://mirror.href.com/thestarman/asm/debug/debug.htm#NT

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• Azure, don't give me multiple VMs, give me one elastic VM

  - by FransBouma

  Yesterday, Microsoft revealed new major features for Windows Azure (see ScottGu's post). It all looks shiny and great, but after reading most of the material describing the new features, I still find the overall idea behind all of it flawed: why should I care on how much VMs my web app runs? Isn't that a problem to solve for the Windows Azure engineers / software? And what if I need the file system, why can't I simply get a virtual filesystem ? To illustrate my point, let's use a real example: a product website with a customer system/database and next to it a support site with accompanying database. Both are written in .NET, using ASP.NET and use a SQL Server database each. The product website offers files to download by customers, very simple. You have a couple of options to host these websites: Buy a server, place it in a rack at an ISP and run the sites on that server Use 'shared hosting' with an ISP, which means your sites' appdomains are running on the same machine, as well as the files stored, and the databases are hosted in the same server as the other shared databases. Hire a VM, install your OS of choice at an ISP, and host the sites on that VM, basically the same as the first option, except you don't have a physical server At some cloud-vendor, either host the sites 'shared' or in a VM. See above. With all of those options, scalability is a problem, even the cloud-based ones, though not due to the same reasons: The physical server solution has the obvious problem that if you need more power, you need to buy a bigger server or more servers which requires you to add replication and other overhead Shared hosting solutions are almost always capped on memory usage / traffic and database size: if your sites get too big, you have to move out of the shared hosting environment and start over with one of the other solutions The VM solution, be it a VM at an ISP or 'in the cloud' at e.g. Windows Azure or Amazon, in theory allows scaling out by simply instantiating more VMs, however that too introduces the same overhead problems as with the physical servers: suddenly more than 1 instance runs your sites. If a cloud vendor offers its services in the form of VMs, you won't gain much over having a VM at some ISP: the main problems you have to work around are still there: when you spin up more than one VM, your application must be completely stateless at any moment, including the DB sub system, because what's in memory in instance 1 might not be in memory in instance 2. This might sounds trivial but it's not. A lot of the websites out there started rather small: they were perfectly runnable on a single machine with normal memory and CPU power. After all, you don't need a big machine to run a website with even thousands of users a day. Moving these sites to a multi-VM environment will cause a problem: all the in-memory state they use, all the multi-page transitions they use while keeping state across the transition, they can't do that anymore like they did that on a single machine: state is something of the past, you have to store every byte of state in either a DB or in a viewstate or in a cookie somewhere so with the next request, all state information is available through the request, as nothing is kept in-memory. Our example uses a bunch of files in a file system. Using multiple VMs will require that these files move to a cloud storage system which is mounted in each VM so we don't have to store the files on each VM. This might require different file paths, but this change should be minor. What's perhaps less minor is the maintenance procedure in place on the new type of cloud storage used: instead of ftp-ing into a VM, you might have to update the files using different ways / tools. All in all this makes moving an existing website which was written for an environment that's based around a VM (namely .NET with its CLR) overly cumbersome and problematic: it forces you to refactor your website system to be able to be used 'in the cloud', which is caused by the limited way how e.g. Windows Azure offers its cloud services: in blocks of VMs. Offer a scalable, flexible VM which extends with my needs Instead, cloud vendors should offer simply one VM to me. On that VM I run the websites, store my DB and my files. As it's a virtual machine, how this machine is actually ran on physical hardware (e.g. partitioned), I don't care, as that's the problem for the cloud vendor to solve. If I need more resources, e.g. I have more traffic to my server, way more visitors per day, the VM stretches, like I bought a bigger box. This frees me from the problem which comes with multiple VMs: I don't have any refactoring to do at all: I can simply build my website as if it runs on my local hardware server, upload it to the VM offered by the cloud vendor, install it on the VM and I'm done. "But that might require changes to windows!" Yes, but Microsoft is Windows. Windows Azure is their service, they can make whatever change to what they offer to make it look like it's windows. Yet, they're stuck, like Amazon, in thinking in VMs, which forces developers to 'think ahead' and gamble whether they would need to migrate to a cloud with multiple VMs in the future or not. Which comes down to: gamble whether they should invest time in code / architecture which they might never need. (YAGNI anyone?) So the VM we're talking about, is that a low-level VM which runs a guest OS, or is that VM a different kind of VM? The flexible VM: .NET's CLR ? My example websites are ASP.NET based, which means they run inside a .NET appdomain, on the .NET CLR, which is a VM. The only physical OS resource the sites need is the file system, however this too is accessed through .NET. In short: all the websites see is what .NET allows the websites to see, the world as the websites know it is what .NET shows them and lets them access. How the .NET appdomain is run physically, that's the concern of .NET, not mine. This begs the question why Windows Azure doesn't offer virtual appdomains? Or better: .NET environments which look like one machine but could be physically multiple machines. In such an environment, no change has to be made to the websites to migrate them from a local machine or own server to the cloud to get proper scaling: the .NET VM will simply scale with the need: more memory needed, more CPU power needed, it stretches. What it offers to the application running inside the appdomain is simply increasing, but not fragmented: all resources are available to the application: this means that the problem of how to scale is back to where it should be: with the cloud vendor. "Yeah, great, but what about the databases?" The .NET application communicates with the database server through a .NET ADO.NET provider. Where the database is located is not a problem of the appdomain: the ADO.NET provider has to solve that. I.o.w.: we can host the databases in an environment which offers itself as a single resource and is accessible through one connection string without replication overhead on the outside, and use that environment inside the .NET VM as if it was a single DB. But what about memory replication and other problems? This environment isn't simple, at least not for the cloud vendor. But it is simple for the customer who wants to run his sites in that cloud: no work needed. No refactoring needed of existing code. Upload it, run it. Perhaps I'm dreaming and what I described above isn't possible. Yet, I think if cloud vendors don't move into that direction, what they're offering isn't interesting: it doesn't solve a problem at all, it simply offers a way to instantiate more VMs with the guest OS of choice at the cost of me needing to refactor my website code so it can run in the straight jacket form factor dictated by the cloud vendor. Let's not kid ourselves here: most of us developers will never build a website which needs a truck load of VMs to run it: almost all websites created by developers can run on just a few VMs at most. Yet, the most expensive change is right at the start: moving from one to two VMs. As soon as you have refactored your website code to run across multiple VMs, adding another one is just as easy as clicking a mouse button. But that first step, that's the problem here and as it's right there at the beginning of scaling the website, it's particularly strange that cloud vendors refuse to solve that problem and leave it to the developers to solve that. Which makes migrating 'to the cloud' particularly expensive.

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• How I do VCS

  - by Wes McClure

  After years of dabbling with different version control systems and techniques, I wanted to share some of what I like and dislike in a few blog posts.  To start this out, I want to talk about how I use VCS in a team environment.  These come in a series of tips or best practices that I try to follow.  Note: This list is subject to change in the future. Always use some form of version control for all aspects of software development. Development is an evolution.  Looking back at where we were is an invaluable asset in that process.  This includes data schemas and documentation. Reverting / reapplying changes is absolutely critical for efficient development. The tools I use: Code: Hg (preferred), SVN Database: TSqlMigrations Documents: Sometimes in code repository, also SharePoint with versioning Always tag a commit (changeset) with comments This is a quick way to describe to someone else (or your future self) what the changeset entails. Be brief but courteous. One or two sentences about the task, not the actual changes. Use precommit hooks or setup the central repository to reject changes without comments. Link changesets to documentation If your project management system integrates with version control, or has a way to externally reference stories, tasks etc then leave a reference in the commit.  This helps locate more information about the commit and/or related changesets. It’s best to have a precommit hook or system that requires this information, otherwise it’s easy to forget. Ability to work offline is required, including commits and history Yes this requires a DVCS locally but doesn’t require the central repository to be a DVCS.  I prefer to use either Git or Hg but if it isn’t possible to migrate the central repository, it’s still possible for a developer to push / pull changes to that repository from a local Hg or Git repository. Never lock resources (files) in a central repository… Rude! We have merge tools for a reason, merging sucked a long time ago, it doesn’t anymore… stop locking files! This is unproductive, rude and annoying to other team members. Always review everything in your commit. Never ever commit a set of files without reviewing the changes in each. Never add a file without asking yourself, deep down inside, does this belong? If you leave to make changes during a review, start the review over when you come back.  Never assume you didn’t touch a file, double check. This is another reason why you want to avoid large, infrequent commits. Requirements for tools Quickly show pending changes for the entire repository. Default action for a resource with pending changes is a diff. Pluggable diff & merge tool Produce a unified diff or a diff of all changes.  This is helpful to bulk review changes instead of opening each file. The central repository is not your own personal dump yard.  Breaking this rule is a sure fire way to get the F bomb dropped in front of your name, multiple times. If you turn on Visual Studio’s commit on closing studio option, I will personally break your fingers. By the way, the person(s) in charge of this feature should be fired and never be allowed near programming, ever again. Commit (integrate) to the central repository / branch frequently I try to do this before leaving each day, especially without a DVCS.  One never knows when they might need to work from remote the following day. Never commit commented out code If it isn’t needed anymore, delete it! If you aren’t sure if it might be useful in the future, delete it! This is why we have history. If you don’t know why it’s commented out, figure it out and then either uncomment it or delete it. Don’t commit build artifacts, user preferences and temporary files. Build artifacts do not belong in VCS, everything in them is present in the code. (ie: bin\*, obj\*, *.dll, *.exe) User preferences are your settings, stop overriding my preferences files! (ie: *.suo and *.user files) Most tools allow you to ignore certain files and Hg/Git allow you to version this as an ignore file.  Set this up as a first step when creating a new repository! Be polite when merging unresolved conflicts. Count to 10, cuss, grab a stress ball and realize it’s not a big deal.  Actually, it’s an opportunity to let you know that someone else is working in the same area and you might want to communicate with them. Following the other rules, especially committing frequently, will reduce the likelihood of this. Suck it up, we all have to deal with this unintended consequence at times.  Just be careful and GET FAMILIAR with your merge tool.  It’s really not as scary as you think.  I personally prefer KDiff3 as its merging capabilities rock. Don’t blindly merge and then blindly commit your changes, this is rude and unprofessional.  Make sure you understand why the conflict occurred and which parts of the code you want to keep.  Apply scrutiny when you commit a manual merge: review the diff! Make sure you test the changes (build and run automated tests) Become intimate with your version control system and the tools you use with it. Avoid trial and error as much as is possible, sit down and test the tool out, read some tutorials etc.  Create test repositories and walk through common scenarios. Find the most efficient way to do your work.  These tools will be used repetitively, so inefficiencies will add up. Sometimes this involves a mix of tools, both GUI and CLI. I like a combination of both Tortoise Hg and hg cli to get the job efficiently. Always tag releases Create a way to find a given release, whether this be in comments or an explicit tag / branch.  This should be readily discoverable. Create release branches to patch bugs and then merge the changes back to other development branch(es). If using feature branches, strive for periodic integrations. Feature branches often cause forked code that becomes irreconcilable.  Strive to re-integrate somewhat frequently with the branch this code will ultimately be merged into.  This will avoid merge conflicts in the future. Feature branches are best when they are mutually exclusive of active development in other branches. Use and abuse local commits , at least one per task in a story. This builds a trail of changes in your local repository that can be pushed to a central repository when the story is complete. Never commit a broken build or failing tests to the central repository. It’s ok for a local commit to break the build and/or tests.  In fact, I encourage this if it helps group the changes more logically.  This is one of the main reasons I got excited about DVCS, when I wanted more than one changeset for a set of pending changes but some files could be grouped into both changesets (like solution file / project file changes). If you have more than a dozen outstanding changed resources, there should probably be more than one commit involved. Exceptions when maintaining code bases that require shotgun surgery, in this case, it’s a design smell :) Don’t version sensitive information Especially usernames / passwords   There is one area I haven’t found a solution I like yet: versioning 3rd party libraries and/or code.  I really dislike keeping any assemblies in the repository, but seems to be a common practice for external libraries.  Please feel free to share your ideas about this below.    -Wes

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• Java EE 6 and NoSQL/MongoDB on GlassFish using JPA and EclipseLink 2.4 (TOTD #175)

  - by arungupta

  TOTD #166 explained how to use MongoDB in your Java EE 6 applications. The code in that tip used the APIs exposed by the MongoDB Java driver and so requires you to learn a new API. However if you are building Java EE 6 applications then you are already familiar with Java Persistence API (JPA). Eclipse Link 2.4, scheduled to release as part of Eclipse Juno, provides support for NoSQL databases by mapping a JPA entity to a document. Their wiki provides complete explanation of how the mapping is done. This Tip Of The Day (TOTD) will show how you can leverage that support in your Java EE 6 applications deployed on GlassFish 3.1.2. Before we dig into the code, here are the key concepts ... A POJO is mapped to a NoSQL data source using @NoSQL or <no-sql> element in "persistence.xml". A subset of JPQL and Criteria query are supported, based upon the underlying data store Connection properties are defined in "persistence.xml" Now, lets lets take a look at the code ... Download the latest EclipseLink 2.4 Nightly Bundle. There is a Installer, Source, and Bundle - make sure to download the Bundle link (20120410) and unzip. Download GlassFish 3.1.2 zip and unzip. Install the Eclipse Link 2.4 JARs in GlassFish Remove the following JARs from "glassfish/modules": org.eclipse.persistence.antlr.jar org.eclipse.persistence.asm.jar org.eclipse.persistence.core.jar org.eclipse.persistence.jpa.jar org.eclipse.persistence.jpa.modelgen.jar org.eclipse.persistence.moxy.jar org.eclipse.persistence.oracle.jar Add the following JARs from Eclipse Link 2.4 nightly build to "glassfish/modules": org.eclipse.persistence.antlr_3.2.0.v201107111232.jar org.eclipse.persistence.asm_3.3.1.v201107111215.jar org.eclipse.persistence.core.jpql_2.4.0.v20120407-r11132.jar org.eclipse.persistence.core_2.4.0.v20120407-r11132.jar org.eclipse.persistence.jpa.jpql_2.0.0.v20120407-r11132.jar org.eclipse.persistence.jpa.modelgen_2.4.0.v20120407-r11132.jar org.eclipse.persistence.jpa_2.4.0.v20120407-r11132.jar org.eclipse.persistence.moxy_2.4.0.v20120407-r11132.jar org.eclipse.persistence.nosql_2.4.0.v20120407-r11132.jar org.eclipse.persistence.oracle_2.4.0.v20120407-r11132.jar Start MongoDB Download latest MongoDB from here (2.0.4 as of this writing). Create the default data directory for MongoDB as: sudo mkdir -p /data/db/sudo chown `id -u` /data/db Refer to Quickstart for more details. Start MongoDB as: arungup-mac:mongodb-osx-x86_64-2.0.4 <arungup> ->./bin/mongod./bin/mongod --help for help and startup optionsMon Apr  9 12:56:02 [initandlisten] MongoDB starting : pid=3124 port=27017 dbpath=/data/db/ 64-bit host=arungup-mac.localMon Apr  9 12:56:02 [initandlisten] db version v2.0.4, pdfile version 4.5Mon Apr  9 12:56:02 [initandlisten] git version: 329f3c47fe8136c03392c8f0e548506cb21f8ebfMon Apr  9 12:56:02 [initandlisten] build info: Darwin erh2.10gen.cc 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386 BOOST_LIB_VERSION=1_40Mon Apr  9 12:56:02 [initandlisten] options: {}Mon Apr  9 12:56:02 [initandlisten] journal dir=/data/db/journalMon Apr  9 12:56:02 [initandlisten] recover : no journal files present, no recovery neededMon Apr  9 12:56:02 [websvr] admin web console waiting for connections on port 28017Mon Apr  9 12:56:02 [initandlisten] waiting for connections on port 27017 Check out the JPA/NoSQL sample from SVN repository. The complete source code built in this TOTD can be downloaded here. Create Java EE 6 web app Create a Java EE 6 Maven web app as: mvn archetype:generate -DarchetypeGroupId=org.codehaus.mojo.archetypes -DarchetypeArtifactId=webapp-javaee6 -DgroupId=model -DartifactId=javaee-nosql -DarchetypeVersion=1.5 -DinteractiveMode=false Copy the model files from the checked out workspace to the generated project as: cd javaee-nosqlcp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/model src/main/java Copy "persistence.xml" mkdir src/main/resources cp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/META-INF ./src/main/resources Add the following dependencies: <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.jpa</artifactId> <version>2.4.0-SNAPSHOT</version> <scope>provided</scope></dependency><dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.nosql</artifactId> <version>2.4.0-SNAPSHOT</version></dependency><dependency> <groupId>org.mongodb</groupId> <artifactId>mongo-java-driver</artifactId> <version>2.7.3</version></dependency> The first one is for the EclipseLink latest APIs, the second one is for EclipseLink/NoSQL support, and the last one is the MongoDB Java driver. And the following repository: <repositories> <repository> <id>EclipseLink Repo</id> <url>http://www.eclipse.org/downloads/download.php?r=1&amp;nf=1&amp;file=/rt/eclipselink/maven.repo</url> <snapshots> <enabled>true</enabled> </snapshots> </repository>  </repositories> Copy the "Test.java" to the generated project: mkdir src/main/java/examplecp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/example/Test.java ./src/main/java/example/ This file contains the source code to CRUD the JPA entity to MongoDB. This sample is explained in detail on EclipseLink wiki. Create a new Servlet in "example" directory as: package example;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * @author Arun Gupta */@WebServlet(name = "TestServlet", urlPatterns = {"/TestServlet"})public class TestServlet extends HttpServlet { protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); try { out.println("<html>"); out.println("<head>"); out.println("<title>Servlet TestServlet</title>"); out.println("</head>"); out.println("<body>"); out.println("<h1>Servlet TestServlet at " + request.getContextPath() + "</h1>"); try { Test.main(null); } catch (Exception ex) { ex.printStackTrace(); } out.println("</body>"); out.println("</html>"); } finally { out.close(); } } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); }} Build the project and deploy it as: mvn clean packageglassfish3/bin/asadmin deploy --force=true target/javaee-nosql-1.0-SNAPSHOT.war Accessing http://localhost:8080/javaee-nosql/TestServlet shows the following messages in the server.log: connecting(EISLogin( platform=> MongoPlatform user name=> "" MongoConnectionSpec())) . . .Connected: User: Database: 2.7  Version: 2.7 . . .Executing MappedInteraction() spec => null properties => {mongo.collection=CUSTOMER, mongo.operation=INSERT} input => [DatabaseRecord( CUSTOMER._id => 4F848E2BDA0670307E2A8FA4 CUSTOMER.NAME => AMCE)]. . .Data access result: [{TOTALCOST=757.0, ORDERLINES=[{DESCRIPTION=table, LINENUMBER=1, COST=300.0}, {DESCRIPTION=balls, LINENUMBER=2, COST=5.0}, {DESCRIPTION=rackets, LINENUMBER=3, COST=15.0}, {DESCRIPTION=net, LINENUMBER=4, COST=2.0}, {DESCRIPTION=shipping, LINENUMBER=5, COST=80.0}, {DESCRIPTION=handling, LINENUMBER=6, COST=55.0},{DESCRIPTION=tax, LINENUMBER=7, COST=300.0}], SHIPPINGADDRESS=[{POSTALCODE=L5J1H7, PROVINCE=ON, COUNTRY=Canada, CITY=Ottawa,STREET=17 Jane St.}], VERSION=2, _id=4F848E2BDA0670307E2A8FA8,DESCRIPTION=Pingpong table, CUSTOMER__id=4F848E2BDA0670307E2A8FA7, BILLINGADDRESS=[{POSTALCODE=L5J1H8, PROVINCE=ON, COUNTRY=Canada, CITY=Ottawa, STREET=7 Bank St.}]}] You'll not see any output in the browser, just the output in the console. But the code can be easily modified to do so. Once again, the complete Maven project can be downloaded here. Do you want to try accessing relational and non-relational (aka NoSQL) databases in the same PU ?

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• Documenting C# Library using GhostDoc and SandCastle

  - by sreejukg

  Documentation is an essential part of any IT project, especially when you are creating reusable components that will be used by other developers (such as class libraries). Without documentation re-using a class library is almost impossible. Just think of coding .net applications without MSDN documentation (Ooops I can’t think of it). Normally developers, who know the bits and pieces of their classes, see this as a boring work to write details again to generate the documentation. Also the amount of work to make this and manage it changes made the process of manual creation of Documentation impossible or tedious. So what is the effective solution? Let me divide this into two steps 1. Generate comments for your code while you are writing the code. 2. Create documentation file using these comments. Now I am going to examine these processes. Step 1: Generate XML Comments automatically Most of the developers write comments for their code. The best thing is that the comments will be entered during the development process. Additionally comments give a good reference to the code, make your code more manageable/readable. Later these comments can be converted into documentation, along with your source code by identifying properties and methods I found an add-in for visual studio, GhostDoc that automatically generates XML documentation comments for C#. The add-in is available in Visual Studio Gallery at MSDN. You can download this from the url http://visualstudiogallery.msdn.microsoft.com/en-us/46A20578-F0D5-4B1E-B55D-F001A6345748. I downloaded the free version from the above url. The free version suits my requirement. There is a professional version (you need to pay some $ for this) available that gives you some more features. I found the free version itself suits my requirements. The installation process is straight forward. A couple of clicks will do the work for you. The best thing with GhostDoc is that it supports multiple versions of visual studio such as 2005, 2008 and 2010. After Installing GhostDoc, when you start Visual studio, the GhostDoc configuration dialog will appear. The first screen asks you to assign a hot key, pressing this hotkey will enter the comment to your code file with the necessary structure required by GhostDoc. Click Assign to go to the next step where you configure the rules for generating the documentation from the code file. Click Create to start creating the rules. Click finish button to close this wizard. Now you performed the necessary configuration required by GhostDoc. Now In Visual Studio tools menu you can find the GhostDoc that gives you some options. Now let us examine how GhostDoc generate comments for a method. I have write the below code in my code behind file. public Char GetChar(string str, int pos) { return str[pos]; } Now I need to generate the comments for this function. Select the function and enter the hot key assigned during the configuration. GhostDoc will generate the comments as follows. /// <summary> /// Gets the char. /// </summary> /// <param name="str">The STR.</param> /// <param name="pos">The pos.</param> /// <returns></returns> public Char GetChar(string str, int pos) { return str[pos]; } So this is a very handy tool that helps developers writing comments easily. You can generate the xml documentation file separately while compiling the project. This will be done by the C# compiler. You can enable the xml documentation creation option (checkbox) under Project properties -> Build tab. Now when you compile, the xml file will created under the bin folder. Step 2: Generate the documentation from the XML file Now you have generated the xml file documentation. Sandcastle is the tool from Microsoft that generates MSDN style documentation from the compiler produced XML file. The project is available in codeplex http://sandcastle.codeplex.com/. Download and install Sandcastle to your computer. Sandcastle is a command line tool that doesn’t have a rich GUI. If you want to automate the documentation generation, definitely you will be using the command line tools. Since I want to generate the documentation from the xml file generated in the previous step, I was expecting a GUI where I can see the options. There is a GUI available for Sandcastle called Sandcastle Help File Builder. See the link to the project in codeplex. http://www.codeplex.com/wikipage?ProjectName=SHFB. You need to install Sandcastle and then the Sandcastle Help file builder. From here I assume that you have installed both sandcastle and Sandcastle help file builder successfully. Once you installed the help file builder, it will be available in your all programs list. Click on the Sandcastle Help File Builder GUI, will launch application. First you need to create a project. Click on File -> New project The New project dialog will appear. Choose a folder to store your project file and give a name for your documentation project. Click the save button. Now you will see your project properties. Now from the Project explorer, right click on the Documentation Sources, Click on the Add Documentation Source link. A documentation source is a file such as an assembly or a Visual Studio solution or project from which information will be extracted to produce API documentation. From the Add Documentation source dialog, I have selected the XML file generated by my project. Once you add the xml file to the project, you will see the dll file automatically added by the help file builder. Now click on the build button. Now the application will generate the help file. The Build window gives to the result of each steps. Once the process completed successfully, you will have the following output in the build window. Now navigate to your Help Project (I have selected the folder My Documents\Documentation), inside help folder, you can find the chm file. Open the chm file will give you MSDN like documentation. Documentation is an important part of development life cycle. Sandcastle with GhostDoc make this process easier so that developers can implement the documentation in the projects with simple to use steps.

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• OS Analytics - Deep Dive Into Your OS

  - by Eran_Steiner

  Enterprise Manager Ops Center provides a feature called "OS Analytics". This feature allows you to get a better understanding of how the Operating System is being utilized. You can research the historical usage as well as real time data. This post will show how you can benefit from OS Analytics and how it works behind the scenes. We will have a call to discuss this blog - please join us!Date: Thursday, November 1, 2012Time: 11:00 am, Eastern Daylight Time (New York, GMT-04:00)1. Go to https://oracleconferencing.webex.com/oracleconferencing/j.php?ED=209833067&UID=1512092402&PW=NY2JhMmFjMmFh&RT=MiMxMQ%3D%3D2. If requested, enter your name and email address.3. If a password is required, enter the meeting password: oracle1234. Click "Join". To join the teleconference:Call-in toll-free number:       1-866-682-4770  (US/Canada)      Other countries:                https://oracle.intercallonline.com/portlets/scheduling/viewNumbers/viewNumber.do?ownerNumber=5931260&audioType=RP&viewGa=true&ga=ONConference Code:       7629343#Security code:            7777# Here is quick summary of what you can do with OS Analytics in Ops Center: View historical charts and real time value of CPU, memory, network and disk utilization Find the top CPU and Memory processes in real time or at a certain historical day Determine proper monitoring thresholds based on historical data View Solaris services status details Drill down into a process details View the busiest zones if applicable Where to start To start with OS Analytics, choose the OS asset in the tree and click the Analytics tab. You can see the CPU utilization, Memory utilization and Network utilization, along with the current real time top 5 processes in each category (click the image to see a larger version):  In the above screen, you can click each of the top 5 processes to see a more detailed view of that process. Here is an example of one of the processes: One of the cool things is that you can see the process tree for this process along with some port binding and open file descriptors. On Solaris machines with zones, you get an extra level of tabs, allowing you to get more information on the different zones: This is a good way to see the busiest zones. For example, one zone may not take a lot of CPU but it can consume a lot of memory, or perhaps network bandwidth. To see the detailed Analytics for each of the zones, simply click each of the zones in the tree and go to its Analytics tab. Next, click the "Processes" tab to see real time information of all the processes on the machine: An interesting column is the "Target" column. If you configured Ops Center to work with Enterprise Manager Cloud Control, then the two products will talk to each other and Ops Center will display the correlated target from Cloud Control in this table. If you are only using Ops Center - this column will remain empty. Next, if you view a Solaris machine, you will have a "Services" tab: By default, all services will be displayed, but you can choose to display only certain states, for example, those in maintenance or the degraded ones. You can highlight a service and choose to view the details, where you can see the Dependencies, Dependents and also the location of the service log file (not shown in the picture as you need to scroll down to see the log file). The "Threshold" tab is particularly helpful - you can view historical trends of different monitored values and based on the graph - determine what the monitoring values should be: You can ask Ops Center to suggest monitoring levels based on the historical values or you can set your own. The different colors in the graph represent the current set levels: Red for critical, Yellow for warning and Blue for Information, allowing you to quickly see how they're positioned against real data. It's important to note that when looking at longer periods, Ops Center smooths out the data and uses averages. So when looking at values such as CPU Usage, try shorter time frames which are more detailed, such as one hour or one day. Applying new monitoring values When first applying new values to monitored attributes - a popup will come up asking if it's OK to get you out of the current Monitoring Policy. This is OK if you want to either have custom monitoring for a specific machine, or if you want to use this current machine as a "Gold image" and extract a Monitoring Policy from it. You can later apply the new Monitoring Policy to other machines and also set it as a default Monitoring Profile. Once you're done with applying the different monitoring values, you can review and change them in the "Monitoring" tab. You can also click the "Extract a Monitoring Policy" in the actions pane on the right to save all the new values to a new Monitoring Policy, which can then be found under "Plan Management" -> "Monitoring Policies". Visiting the past Under the "History" tab you can "go back in time". This is very helpful when you know that a machine was busy a few hours ago (perhaps in the middle of the night?), but you were not around to take a look at it in real time. Here's a view into yesterday's data on one of the machines: You can see an interesting CPU spike happening at around 3:30 am along with some memory use. In the bottom table you can see the top 5 CPU and Memory consumers at the requested time. Very quickly you can see that this spike is related to the Solaris 11 IPS repository synchronization process using the "pkgrecv" command. The "time machine" doesn't stop here - you can also view historical data to determine which of the zones was the busiest at a given time: Under the hood The data collected is stored on each of the agents under /var/opt/sun/xvm/analytics/historical/ An "os.zip" file exists for the main OS. Inside you will find many small text files, named after the Epoch time stamp in which they were taken If you have any zones, there will be a file called "guests.zip" containing the same small files for all the zones, as well as a folder with the name of the zone along with "os.zip" in it If this is the Enterprise Controller or the Proxy Controller, you will have folders called "proxy" and "sat" in which you will find the "os.zip" for that controller The actual script collecting the data can be viewed for debugging purposes as well: On Linux, the location is: /opt/sun/xvmoc/private/os_analytics/collect On Solaris, the location is /opt/SUNWxvmoc/private/os_analytics/collect If you would like to redirect all the standard error into a file for debugging, touch the following file and the output will go into it: # touch /tmp/.collect.stderr   The temporary data is collected under /var/opt/sun/xvm/analytics/.collectdb until it is zipped. If you would like to review the properties for the Analytics, you can view those per each agent in /opt/sun/n1gc/lib/XVM.properties. Find the section "Analytics configurable properties for OS and VSC" to view the Analytics specific values. I hope you find this helpful! Please post questions in the comments below. Eran Steiner

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• Running TeamCity from Amazon EC2 - Cloud based scalable build and continuous Integration

  - by RoyOsherove

  I’ve been having fun playing with the amazon EC2 cloud service. I set up a server running TeamCity, and an image of a server that just runs a TeamCity agent. I also setup TeamCity  to automatically instantiate agents on EC2 and shut them down based upon availability of free agents. Here’s how I did it: The first step was setting up the teamcity server. Create an account on amazon EC2 (BTW, amazon’s sites works better in IE than it does in chrome.. who knew!?) Open the EC2 dashboard, and click “Launch Instance” . From the “Quick Start” tab I selected from the list: “Getting Started on Microsoft Windows Server 2008 (AMI Id: ami-c5e40dac)” .  it’s good enough to just run teamcity. In the instance details, I used the default (Small instance, 1.7 GB mem). You might want to choose a close availability zone based on where you are. We want to “Launch instances” so click continue. Select the default kernel, RAM disk and all. No need to enable monitoring for now (you can do that later). click continue. If you don’t have a key pair, you will be prompted to create one. Once you do, select it in the list. Now you’ll be prompted to create a security group. I named mine “TC” as in “TeamCity”. each group is a bunch of settings on which ports can be let through into and out of a hosted machine.  keep it as the default settings. We will change them later. Click continue,  review and then click “Launch”. Now you’ll be able to see the new instance in the running instances list on your site. Now, you need to install stuff on that instance (TeamCity!) . To do that, you’ll need to Remote desktop into that instance. To do that, we’ll get the admin password for that instance: Check it on the list, and click “Instance Actions” - “Get Windows Admin Password”. You might have to wait about 10 minutes or so for the password to be generated for you. Once you have the password, you will remote desktop (start-run-‘mstsc’) into the instance. It’s address is a dns address shown below the list under “Public DNS”. it looks something like: ec2-256-226-194-91.compute-1.amazonaws.com Once you’re inside the instance – you’ll need to open IE (it is in hardened mode so you’ll have to relax its security settings to download stuff). I first downloaded chrome and using chrome I downloaded TeamCity. Note that the download speed is FAST. several MBs per second. To be able to see TeamCity from the outside, you will need to open the advanced firewall settings inside the remote machine, and add incoming and outgoing rules for port 80 (HTTP). Once you do that, you should be able to see the machine from the outside. If you still can’t, see the next step. I also enabled ports 9090 since I will use this machine to create an agent image later as well. Now configure the security group (TC) to enable talking to agents: IN the EC2 dashboard click on “Security Groups” and select your group. To add a rule, click on the empty list under the ‘protocol’ header. select TCP. from and ‘to’ ports are 9090. source ip is 0.0.0.0/0 (every ip is allowed). click “Save.  Also make sure you can see “HTTP” tcp 80 in that list. if you can’t see it, add it or you won’t be able to browse to the machine’s teamcity server home page. I also set an elastic IP for the machine: so I always have the same IP for the machine instance. Allocate and set one through the”Elastic IP” link on the EC2 dashboard.   you should now have a working instance of teamcity.   Now let’s create an agent image. Repeat steps 1-9, but this time, make sure you select a machine that fits what an agent might do. I selected Instance type – Hihg-CPU medium machine,  that is much faster. On that machine, I installed what I needed (VS 2010, PostSharp etc..). downloading VS 2010 from MSDN (2 GB took less than 10 min!) Now, instead of installing teamcity, browse using the browser to the teamcity homepage (from within the remote machine). go to the Administration page, and click the upper right link “Install agents”. Install the agent on he local machine – set it to the IP or DNS of the running TeamCity server. That way you’ll be able to check their connectivity live before making this machine your official agent image to reuse. Once the agent is installed, see that the TC server can see it and use it. see steps 13-14 above if they can’t. Once it works, you can take steps to make this image your agent image to be reused. next, here is a copy-paste of several steps to take from http://confluence.jetbrains.net/display/TCD5/Setting+Up+TeamCity+for+Amazon+EC2 Configure system so that agent it is started on machine boot (and make sure TeamCity server is accessible on machine boot). Test the setup by rebooting machine and checking that the agent connects normally to the server. Prepare the Image for bundling: Remove any temporary/history information in the system. Stop the agent (under Windows stop the service but leave it in Automatic startup type) Delete content agent logs and temp directories (not necessary) Delete "<Agent Home>/conf/amazon-*" file (not necessary) Change config/buildAgent.properties to remove properties: name, serverAddress, authToken (not necessary)   Now, we need to: Make AMI from the running instance. Configure TeamCity EC2 support on TeamCity server. Making an AMI: Check the instance of the agent in the EC2 dashboard instance list, and select instance actions->Create Image (EBS AMI) you’ll see the image pending in the APIs list in the EC2 dashboard. this could take 30 minutes or more. meanwhile we can configure the could support in the teamcity server. COPY THE AMI ID to the clipboard (looks like ami-a88aa4ce) Configuring TeamCity for Cloud: In TeamCity, click on “Agents” and then on “Cloud” tab. this is where you will control your cloud agents. to configure new cloud agents based on APIs, click on the right link to the “configuration page” Create a new profile and select AMazon EC2 as cloud type. Use your AMI ID that you copied to the clipboard into the “Images” field. Select an availability zone that is the same as the one your instance is running on for best communication perf between them make sure you select the ‘TC’ security group hopefully, that should be it, and teamcity will try to instantiate new instances on demand. Note that it may take around 10 minutes for an agent to become available to teamcity from the time it’s started.

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• SQL SERVER – SSMS: Disk Usage Report

  - by Pinal Dave

  Let us start with humor!  I think we the series on various reports, we come to a logical point. We covered all the reports at server level. This means the reports we saw were targeted towards activities that are related to instance level operations. These are mostly like how a doctor diagnoses a patient. At this point I am reminded of a dialog which I read somewhere: Patient: Doc, It hurts when I touch my head. Doc: Ok, go on. What else have you experienced? Patient: It hurts even when I touch my eye, it hurts when I touch my arms, it even hurts when I touch my feet, etc. Doc: Hmmm … Patient: I feel it hurts when I touch anywhere in my body. Doc: Ahh … now I get it. You need a plaster to your finger John. Sometimes the server level gives an indicator to what is happening in the system, but we need to get to the root cause for a specific database. So, this is the first blog in series where we would start discussing about database level reports. To launch database level reports, expand selected server in Object Explorer, expand the Databases folder, and then right-click any database for which we want to look at reports. From the menu, select Reports, then Standard Reports, and then any of database level reports. In this blog, we would talk about four “disk” reports because they are similar: Disk Usage Disk Usage by Top Tables Disk Usage by Table Disk Usage by Partition Disk Usage This report shows multiple information about the database. Let us discuss them one by one.  We have divided the output into 5 different sections. Section 1 shows the high level summary of the database. It shows the space used by database files (mdf and ldf). Under the hood, the report uses, various DMVs and DBCC Commands, it is using sys.data_spaces and DBCC SHOWFILESTATS. Section 2 and 3 are pie charts. One for data file allocation and another for the transaction log file. Pie chart for “Data Files Space Usage (%)” shows space consumed data, indexes, allocated to the SQL Server database, and unallocated space which is allocated to the SQL Server database but not yet filled with anything. “Transaction Log Space Usage (%)” used DBCC SQLPERF (LOGSPACE) and shows how much empty space we have in the physical transaction log file. Section 4 shows the data from Default Trace and looks at Event IDs 92, 93, 94, 95 which are for “Data File Auto Grow”, “Log File Auto Grow”, “Data File Auto Shrink” and “Log File Auto Shrink” respectively. Here is an expanded view for that section. If default trace is not enabled, then this section would be replaced by the message “Trace Log is disabled” as highlighted below. Section 5 of the report uses DBCC SHOWFILESTATS to get information. Here is the enhanced version of that section. This shows the physical layout of the file. In case you have In-Memory Objects in the database (from SQL Server 2014), then report would show information about those as well. Here is the screenshot taken for a different database, which has In-Memory table. I have highlighted new things which are only shown for in-memory database. The new sections which are highlighted above are using sys.dm_db_xtp_checkpoint_files, sys.database_files and sys.data_spaces. The new type for in-memory OLTP is ‘FX’ in sys.data_space. The next set of reports is targeted to get information about a table and its storage. These reports can answer questions like: Which is the biggest table in the database? How many rows we have in table? Is there any table which has a lot of reserved space but its unused? Which partition of the table is having more data? Disk Usage by Top Tables This report provides detailed data on the utilization of disk space by top 1000 tables within the Database. The report does not provide data for memory optimized tables. Disk Usage by Table This report is same as earlier report with few difference. First Report shows only 1000 rows First Report does order by values in DMV sys.dm_db_partition_stats whereas second one does it based on name of the table. Both of the reports have interactive sort facility. We can click on any column header and change the sorting order of data. Disk Usage by Partition This report shows the distribution of the data in table based on partition in the table. This is so similar to previous output with the partition details now. Here is the query taken from profiler. SELECT row_number() OVER (ORDER BY a1.used_page_count DESC, a1.index_id) AS row_number ,      (dense_rank() OVER (ORDER BY a5.name, a2.name))%2 AS l1 ,      a1.OBJECT_ID ,      a5.name AS [schema] ,       a2.name ,       a1.index_id ,       a3.name AS index_name ,       a3.type_desc ,       a1.partition_number ,       a1.used_page_count * 8 AS total_used_pages ,       a1.reserved_page_count * 8 AS total_reserved_pages ,       a1.row_count FROM sys.dm_db_partition_stats a1 INNER JOIN sys.all_objects a2  ON ( a1.OBJECT_ID = a2.OBJECT_ID) AND a1.OBJECT_ID NOT IN (SELECT OBJECT_ID FROM sys.tables WHERE is_memory_optimized = 1) INNER JOIN sys.schemas a5 ON (a5.schema_id = a2.schema_id) LEFT OUTER JOIN  sys.indexes a3  ON ( (a1.OBJECT_ID = a3.OBJECT_ID) AND (a1.index_id = a3.index_id) ) WHERE (SELECT MAX(DISTINCT partition_number) FROM sys.dm_db_partition_stats a4 WHERE (a4.OBJECT_ID = a1.OBJECT_ID)) >= 1 AND a2.TYPE <> N'S' AND  a2.TYPE <> N'IT' ORDER BY a5.name ASC, a2.name ASC, a1.index_id, a1.used_page_count DESC, a1.partition_number Using all of the above reports, you should be able to get the usage of database files and also space used by tables. I think this is too much disk information for a single blog and I hope you have used them in the past to get data. Do let me know if you found anything interesting using these reports in your environments. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL Tagged: SQL Reports

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• Of C# Iterators and Performance

  - by James Michael Hare

  Some of you reading this will be wondering, "what is an iterator" and think I'm locked in the world of C++.  Nope, I'm talking C# iterators.  No, not enumerators, iterators.   So, for those of you who do not know what iterators are in C#, I will explain it in summary, and for those of you who know what iterators are but are curious of the performance impacts, I will explore that as well.   Iterators have been around for a bit now, and there are still a bunch of people who don't know what they are or what they do.  I don't know how many times at work I've had a code review on my code and have someone ask me, "what's that yield word do?"   Basically, this post came to me as I was writing some extension methods to extend IEnumerable<T> -- I'll post some of the fun ones in a later post.  Since I was filtering the resulting list down, I was using the standard C# iterator concept; but that got me wondering: what are the performance implications of using an iterator versus returning a new enumeration?   So, to begin, let's look at a couple of methods.  This is a new (albeit contrived) method called Every(...).  The goal of this method is to access and enumeration and return every nth item in the enumeration (including the first).  So Every(2) would return items 0, 2, 4, 6, etc.   Now, if you wanted to write this in the traditional way, you may come up with something like this:       public static IEnumerable<T> Every<T>(this IEnumerable<T> list, int interval)     {         List<T> newList = new List<T>();         int count = 0;           foreach (var i in list)         {             if ((count++ % interval) == 0)             {                 newList.Add(i);             }         }           return newList;     }     So basically this method takes any IEnumerable<T> and returns a new IEnumerable<T> that contains every nth item.  Pretty straight forward.   The problem?  Well, Every<T>(...) will construct a list containing every nth item whether or not you care.  What happens if you were searching this result for a certain item and find that item after five tries?  You would have generated the rest of the list for nothing.   Enter iterators.  This C# construct uses the yield keyword to effectively defer evaluation of the next item until it is asked for.  This can be very handy if the evaluation itself is expensive or if there's a fair chance you'll never want to fully evaluate a list.   We see this all the time in Linq, where many expressions are chained together to do complex processing on a list.  This would be very expensive if each of these expressions evaluated their entire possible result set on call.    Let's look at the same example function, this time using an iterator:       public static IEnumerable<T> Every<T>(this IEnumerable<T> list, int interval)     {         int count = 0;         foreach (var i in list)         {             if ((count++ % interval) == 0)             {                 yield return i;             }         }     }   Notice it does not create a new return value explicitly, the only evidence of a return is the "yield return" statement.  What this means is that when an item is requested from the enumeration, it will enter this method and evaluate until it either hits a yield return (in which case that item is returned) or until it exits the method or hits a yield break (in which case the iteration ends.   Behind the scenes, this is all done with a class that the CLR creates behind the scenes that keeps track of the state of the iteration, so that every time the next item is asked for, it finds that item and then updates the current position so it knows where to start at next time.   It doesn't seem like a big deal, does it?  But keep in mind the key point here: it only returns items as they are requested. Thus if there's a good chance you will only process a portion of the return list and/or if the evaluation of each item is expensive, an iterator may be of benefit.   This is especially true if you intend your methods to be chainable similar to the way Linq methods can be chained.    For example, perhaps you have a List<int> and you want to take every tenth one until you find one greater than 10.  We could write that as:       List<int> someList = new List<int>();         // fill list here         someList.Every(10).TakeWhile(i => i <= 10);     Now is the difference more apparent?  If we use the first form of Every that makes a copy of the list.  It's going to copy the entire list whether we will need those items or not, that can be costly!    With the iterator version, however, it will only take items from the list until it finds one that is > 10, at which point no further items in the list are evaluated.   So, sounds neat eh?  But what's the cost is what you're probably wondering.  So I ran some tests using the two forms of Every above on lists varying from 5 to 500,000 integers and tried various things.    Now, iteration isn't free.  If you are more likely than not to iterate the entire collection every time, iterator has some very slight overhead:   Copy vs Iterator on 100% of Collection (10,000 iterations) Collection Size Num Iterated Type Total ms 5 5 Copy 5 5 5 Iterator 5 50 50 Copy 28 50 50 Iterator 27 500 500 Copy 227 500 500 Iterator 247 5000 5000 Copy 2266 5000 5000 Iterator 2444 50,000 50,000 Copy 24,443 50,000 50,000 Iterator 24,719 500,000 500,000 Copy 250,024 500,000 500,000 Iterator 251,521   Notice that when iterating over the entire produced list, the times for the iterator are a little better for smaller lists, then getting just a slight bit worse for larger lists.  In reality, given the number of items and iterations, the result is near negligible, but just to show that iterators come at a price.  However, it should also be noted that the form of Every that returns a copy will have a left-over collection to garbage collect.   However, if we only partially evaluate less and less through the list, the savings start to show and make it well worth the overhead.  Let's look at what happens if you stop looking after 80% of the list:   Copy vs Iterator on 80% of Collection (10,000 iterations) Collection Size Num Iterated Type Total ms 5 4 Copy 5 5 4 Iterator 5 50 40 Copy 27 50 40 Iterator 23 500 400 Copy 215 500 400 Iterator 200 5000 4000 Copy 2099 5000 4000 Iterator 1962 50,000 40,000 Copy 22,385 50,000 40,000 Iterator 19,599 500,000 400,000 Copy 236,427 500,000 400,000 Iterator 196,010       Notice that the iterator form is now operating quite a bit faster.  But the savings really add up if you stop on average at 50% (which most searches would typically do):     Copy vs Iterator on 50% of Collection (10,000 iterations) Collection Size Num Iterated Type Total ms 5 2 Copy 5 5 2 Iterator 4 50 25 Copy 25 50 25 Iterator 16 500 250 Copy 188 500 250 Iterator 126 5000 2500 Copy 1854 5000 2500 Iterator 1226 50,000 25,000 Copy 19,839 50,000 25,000 Iterator 12,233 500,000 250,000 Copy 208,667 500,000 250,000 Iterator 122,336   Now we see that if we only expect to go on average 50% into the results, we tend to shave off around 40% of the time.  And this is only for one level deep.  If we are using this in a chain of query expressions it only adds to the savings.   So my recommendation?  If you have a resonable expectation that someone may only want to partially consume your enumerable result, I would always tend to favor an iterator.  The cost if they iterate the whole thing does not add much at all -- and if they consume only partially, you reap some really good performance gains.   Next time I'll discuss some of my favorite extensions I've created to make development life a little easier and maintainability a little better.

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• Lessons from rewriting POP Forums for MVC, open source-like

  - by Jeff

  It has been a ton of work, interrupted over the last two years by unemployment, moving, a baby, failing to sell houses and other life events, but it's really exciting to see POP Forums v9 coming together. I'm not even sure when I decided to really commit to it as an open source project, but working on the same team as the CodePlex folks probably had something to do with it. Moving along the roadmap I set for myself, the app is now running on a quasi-production site... we launched MouseZoom last weekend. (That's a post-beta 1 build of the forum. There's also some nifty Silverlight DeepZoom goodness on that site.)I have to make a point to illustrate just how important starting over was for me. I started this forum thing for my sites in old ASP more than ten years ago. What a mess that stuff was, including SQL injection vulnerabilities and all kinds of crap. It went to ASP.NET in 2002, but even then, it felt a little too much like script. More than a year later, in 2003, I did an honest to goodness rewrite. If you've been in this business of writing code for any amount of time, you know how much you hate what you wrote a month ago, so just imagine that with seven years in between. The subsequent versions still carried a fair amount of crap, and that's why I had to start over, to make a clean break. Mind you, much of that crap is still running on some of my production sites in a stable manner, but it's a pain in the ass to maintain.So with that clean break, there is much that I have learned. These are a few of those lessons, in no particular order...Avoid shiny object syndromeOver the years, I've embraced new things without bothering to ask myself why. I remember spending the better part of a year trying to adapt this app to use the membership and profile API's in ASP.NET, just because they were there. They didn't solve any known problem. Early on in this version, I dabbled in exotic ORM's, even though I already had the fundamental SQL that I knew worked. I bloated up the client side code with all kinds of jQuery UI and plugins just because, and it got in the way. All the new shiny can be distracting, and I've come to realize that I've allowed it to be a distraction most of my professional life.Just query what you needI've spent a lot of time over-thinking how to query data. In the SQL world, this means exotic joins, special caches, the read-update-commit loop of ORM's, etc. There are times when you have to remind yourself that you aren't Facebook, you'll never be Facebook, and that databases are in fact intended to serve data. In a lot of projects, back in the day, I used to have these big, rich data objects and pass them all over the place, through various application tiers, when in reality, all I needed was some ID from the entity. I try to be mindful of how many queries hit the database on a given request, but I don't obsess over it. I just get what I need.Don't spend too much time worrying about your unit testsIf you've looked at any of the tests for POP Forums, you might offer an audible WTF. That's OK. There's a whole lot of mocking going on. In some cases, it points out where you're doing too much, and that's good for improving your design. In other cases it shows where your design sucks. But the biggest trap of unit testing is that you worry it should be prettier. That's a waste of time. When you write a test, in many cases before the production code, the important part is that you're testing the right thing. If you have to mock up a bunch of stuff to test the outcome, so be it, but it's not wasted time. You're still doing up the typical arrange-action-assert deal, and you'll be able to read that later if you need to.Get back to your HTTP rootsASP.NET Webforms did a reasonably decent job at abstracting us away from the stateless nature of the Web. A lot of people criticize it, but I think it all worked pretty well. These days, with MVC, jQuery, REST services, and what not, we've gone back to thinking about the wire. The nuts and bolts passing between our Web browser and server matters. This doesn't make things harder, in my opinion, it makes them easier. There is something incredibly freeing about how we approach development of Web apps now. HTTP is a really simple protocol, and the stuff we push through it, in particular HTML and JSON, are pretty simple too. The debugging points are really easy to trap and trace.Premature optimization is prematureI'll go back to the data thing for a moment. I've been known to look at a particular action or use case and stress about the number of calls that are made to the database. I'm not suggesting that it's a bad thing to keep these in mind, but if you worry about it outside of the context of the actual impact, you're wasting time. For example, I query the database for last read times in a forum separately of the user and the list of forums. The impact on performance barely exists. If I put it under load, exceeding the kind of load I expect, it still barely has an impact. Then consider it only counts for logged in users. The context of this "inefficient" action is that it doesn't matter. Did I mention I won't be Facebook?Solve your own problems firstThis is another trap I've fallen into. I've often thought about what other people might need for some feature or aspect of the app. In other words, I was willing to make design decisions based on non-existent data. How stupid is that? When I decided to truly open source this thing, building for myself first was a stated design goal. This app has to server the audiences of CoasterBuzz, MouseZoom and other sites first. In this development scenario, you don't have access to mountains of usability studies or user focus groups. You have to start with what you know.I'm sure there are other points I could make too. It has been a lot of fun to work on, and I look forward to evolving the UI as time goes on. That's where I hope to see more magic in the future.

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• Installing a DHCP Service On Win2k8 ( Windows Server 2008 )

  - by Akshay Deep Lamba

  Introduction Dynamic Host Configuration Protocol (DHCP) is a core infrastructure service on any network that provides IP addressing and DNS server information to PC clients and any other device. DHCP is used so that you do not have to statically assign IP addresses to every device on your network and manage the issues that static IP addressing can create. More and more, DHCP is being expanded to fit into new network services like the Windows Health Service and Network Access Protection (NAP). However, before you can use it for more advanced services, you need to first install it and configure the basics. Let’s learn how to do that. Installing Windows Server 2008 DHCP Server Installing Windows Server 2008 DCHP Server is easy. DHCP Server is now a “role” of Windows Server 2008 – not a windows component as it was in the past. To do this, you will need a Windows Server 2008 system already installed and configured with a static IP address. You will need to know your network’s IP address range, the range of IP addresses you will want to hand out to your PC clients, your DNS server IP addresses, and your default gateway. Additionally, you will want to have a plan for all subnets involved, what scopes you will want to define, and what exclusions you will want to create. To start the DHCP installation process, you can click Add Roles from the Initial Configuration Tasks window or from Server Manager à Roles à Add Roles. Figure 1: Adding a new Role in Windows Server 2008 When the Add Roles Wizard comes up, you can click Next on that screen. Next, select that you want to add the DHCP Server Role, and click Next. Figure 2: Selecting the DHCP Server Role If you do not have a static IP address assigned on your server, you will get a warning that you should not install DHCP with a dynamic IP address. At this point, you will begin being prompted for IP network information, scope information, and DNS information. If you only want to install DHCP server with no configured scopes or settings, you can just click Next through these questions and proceed with the installation. On the other hand, you can optionally configure your DHCP Server during this part of the installation. In my case, I chose to take this opportunity to configure some basic IP settings and configure my first DHCP Scope. I was shown my network connection binding and asked to verify it, like this: Figure 3: Network connection binding What the wizard is asking is, “what interface do you want to provide DHCP services on?” I took the default and clicked Next. Next, I entered my Parent Domain, Primary DNS Server, and Alternate DNS Server (as you see below) and clicked Next. Figure 4: Entering domain and DNS information I opted NOT to use WINS on my network and I clicked Next. Then, I was promoted to configure a DHCP scope for the new DHCP Server. I have opted to configure an IP address range of 192.168.1.50-100 to cover the 25+ PC Clients on my local network. To do this, I clicked Add to add a new scope. As you see below, I named the Scope WBC-Local, configured the starting and ending IP addresses of 192.168.1.50-192.168.1.100, subnet mask of 255.255.255.0, default gateway of 192.168.1.1, type of subnet (wired), and activated the scope. Figure 5: Adding a new DHCP Scope Back in the Add Scope screen, I clicked Next to add the new scope (once the DHCP Server is installed). I chose to Disable DHCPv6 stateless mode for this server and clicked Next. Then, I confirmed my DHCP Installation Selections (on the screen below) and clicked Install. Figure 6: Confirm Installation Selections After only a few seconds, the DHCP Server was installed and I saw the window, below: Figure 7: Windows Server 2008 DHCP Server Installation succeeded I clicked Close to close the installer window, then moved on to how to manage my new DHCP Server. How to Manage your new Windows Server 2008 DHCP Server Like the installation, managing Windows Server 2008 DHCP Server is also easy. Back in my Windows Server 2008 Server Manager, under Roles, I clicked on the new DHCP Server entry. Figure 8: DHCP Server management in Server Manager While I cannot manage the DHCP Server scopes and clients from here, what I can do is to manage what events, services, and resources are related to the DHCP Server installation. Thus, this is a good place to go to check the status of the DHCP Server and what events have happened around it. However, to really configure the DHCP Server and see what clients have obtained IP addresses, I need to go to the DHCP Server MMC. To do this, I went to Start à Administrative Tools à DHCP Server, like this: Figure 9: Starting the DHCP Server MMC When expanded out, the MMC offers a lot of features. Here is what it looks like: Figure 10: The Windows Server 2008 DHCP Server MMC The DHCP Server MMC offers IPv4 & IPv6 DHCP Server info including all scopes, pools, leases, reservations, scope options, and server options. If I go into the address pool and the scope options, I can see that the configuration we made when we installed the DHCP Server did, indeed, work. The scope IP address range is there, and so are the DNS Server & default gateway. Figure 11: DHCP Server Address Pool Figure 12: DHCP Server Scope Options So how do we know that this really works if we do not test it? The answer is that we do not. Now, let’s test to make sure it works. How do we test our Windows Server 2008 DHCP Server? To test this, I have a Windows Vista PC Client on the same network segment as the Windows Server 2008 DHCP server. To be safe, I have no other devices on this network segment. I did an IPCONFIG /RELEASE then an IPCONFIG /RENEW and verified that I received an IP address from the new DHCP server, as you can see below: Figure 13: Vista client received IP address from new DHCP Server Also, I went to my Windows 2008 Server and verified that the new Vista client was listed as a client on the DHCP server. This did indeed check out, as you can see below: Figure 14: Win 2008 DHCP Server has the Vista client listed under Address Leases With that, I knew that I had a working configuration and we are done!

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• techniques for an AI for a highly cramped turn-based tactics game

  - by Adam M.

  I'm trying to write an AI for a tactics game in the vein of Final Fantasy Tactics or Vandal Hearts. I can't change the game rules in any way, only upgrade the AI. I have experience programming AI for classic board games (basically minimax and its variants), but I think the branching factor is too great for the approach to be reasonable here. I'll describe the game and some current AI flaws that I'd like to fix. I'd like to hear ideas for applicable techniques. I'm a decent enough programmer, so I only need the ideas, not an implementation (though that's always appreciated). I'd rather not expend effort chasing (too many) dead ends, so although speculation and brainstorming are good and probably helpful, I'd prefer to hear from somebody with actual experience solving this kind of problem. For those who know it, the game is the land battle mini-game in Sid Meier's Pirates! (2004) and you can skim/skip the next two paragraphs. For those who don't, here's briefly how it works. The battle is turn-based and takes place on a 16x16 grid. There are three terrain types: clear (no hindrance), forest (hinders movement, ranged attacks, and sight), and rock (impassible, but does not hinder attacks or sight). The map is randomly generated with roughly equal amounts of each type of terrain. Because there are many rock and forest tiles, movement is typically very cramped. This is tactically important. The terrain is not flat; higher terrain gives minor bonuses. The terrain is known to both sides. The player is always the attacker and the AI is always the defender, so it's perfectly valid for the AI to set up a defensive position and just wait. The player wins by killing all defenders or by getting a unit to the city gates (a tile on the other side of the map). There are very few units on each side, usually 4-8. Because of this, it's crucial not to take damage without gaining some advantage from it. Units can take multiple actions per turn. All units on one side move before any units on the other side. Order of execution is important, and interleaving of actions between units is often useful. Units have melee and ranged attacks. Melee attacks vary widely in strength; ranged attacks have the same strength but vary in range. The main challenges I face are these: Lots of useful move combinations start with a "useless" move that gains no immediate advantage, or even loses advantage, in order to set up a powerful flank attack in the future. And, since the player units are stronger and have longer range, the AI pretty much always has to take some losses before they can start to gain kills. The AI must be able to look ahead to distinguish between sacrificial actions that provide a future benefit and those that don't. Because the terrain is so cramped, most of the tactics come down to achieving good positioning with multiple units that work together to defend an area. For instance, two defenders can often dominate a narrow pass by positioning themselves so an enemy unit attempting to pass must expose itself to a flank attack. But one defender in the same pass would be useless, and three units can defend a slightly larger pass. Etc. The AI should be able to figure out where the player must go to reach the city gates and how to best position its few units to cover the approaches, shifting, splitting, or combining them appropriately as the player moves. Because flank attacks are extremely deadly (and engineering flank attacks is key to the player strategy), the AI should be competent at moving its units so that they cover each other's flanks unless the sacrifice of a unit would give a substantial benefit. They should also be able to force flank attacks on players, for instance by threatening a unit from two different directions such that responding to one threat exposes the flank to the other. The AI should attack if possible, but sometimes there are no good ways to approach the player's position. In that case, the AI should be able to recognize this and set up a defensive position of its own. But the AI shouldn't be vulnerable to a trivial exploit where the player repeatedly opens and closes a hole in his defense and shoots at the AI as it approaches and retreats. That is, the AI should ideally be able to recognize that the player is capable of establishing a solid defense of an area, even if the defense is not currently in place. (I suppose if a good unit allocation algorithm existed, as needed for the second bullet point, the AI could run it on the player units to see where they could defend.) Because it's important to choose a good order of action and interleave actions between units, it's not as simple as just finding the best move for each unit in turn. All of these can be accomplished with a minimax search in theory, but the search space is too large, so specialized techniques are needed. I thought about techniques such as influence mapping, but I don't see how to use the technique to great effect. I thought about assigning goals to the units. This can help them work together in some limited way, and the problem of "how do I accomplish this goal?" is easier to solve than "how do I win this battle?", but assigning good goals is a hard problem in itself, because it requires knowing whether the goal is achievable and whether it's a good use of resources. So, does anyone have specific ideas for techniques that can help cleverize this AI? Update: I found a related question on Stackoverflow: http://stackoverflow.com/questions/3133273/ai-for-a-final-fantasy-tactics-like-game The selected answer gives a decent approach to choosing between alternative actions, but it doesn't seem to have much ability to look into the future and discern beneficial sacrifices from wasteful ones. It also focuses on a single unit at a time and it's not clear how it could be extended to support cooperation between units in defending or attacking.

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• Charms and the App Bar

  - by Dennis Vroegop

  Ok. I admit. I made a mistake in the last post about our planespotter app. I have dedicated a full part of the hub to Social. I also had a section called Friends but that made sense since I said that “Friends” is a special group of people that connect to each other through our app and only our app. Social however is sharing our spots with Twitter, Facebook and so on. Now, we could write that functionality in our app in a different section but there is one small problem with that: users don’t expect that. Ok, I admit. The mistake was quite deliberate to give me an excuse to write this part. But still: the mistake is one I see a lot. People are trying to do stuff in their application that they shouldn’t be doing. This always strike me as slightly odd: why do some work when others have already done it for you and you can just use it? After all: good developers are lazy (lazy people will always try to find the easiest way to do something and in development land this usually means the cleanest and best to support way…) So. What is that part that Microsoft has done for us and we don’t have to do ourselves? The answer lies on the right hand of your Win8 screen: This is a screenshot of my tablet (as you can see I am writing this right now….) When I swipe my finger from out of the screen on the right inside the screen (or move the mouse to the upper right corner) this menu will appear. Next to settings and the start menu button we’ll find the Search and the Share charms. These are two ways that your app can share the information it contains with the rest of the world, or at least: the rest of your system. So don’t write a Search feature in your app. Don’t write a Share feature in your app. It’s here already. Users, once they are used to Windows 8, will use that feature and expect it to work. If it doesn’t, they won’t like your app and you can kiss you dreams of everlasting fame goodbye. So use these two. What are they? Well, simply they are parts of a contract. In your app you say somewhere in code that you are supporting Search and Share. So when the user selects Share the system will interrogate the current app in the foreground if it supports this feature. Your app will say “But why, yes, I do!” Then the system will ask the app “Ok then, wisecrack, then share!” and you will have to provide the system with some information about the format. Other applications have subscribed to be at the receiving end of the Share contract. They have told the system that they support Sharing (receiving) and which formats they understand. If one or more of them support the formats you specify, the user will see them. The user clicks / taps on the app of their choice and data is moved from your app to the new one. So if you say you support Facebook and Twitter users can post data from your app to these networks by selecting Share. The same applies to Search. Don’t make a “search” button in your app but use the contract to tell the system that you support search and use that instead. Users will be grateful (remember that bar with men/women/creatures that are waiting for you?) The more and more people get to know Windows 8, the more they will use this. And if you are one of the people who wrote an app that helped them learn the system, well, that’s even better. So. We don’t have a Share or a Search button. We do have other buttons. Most important: we probably need a “New Spot” button. And a “Filter” might be useful. Or someway to open the camera so you can add a picture to the spot. Where will be put those? The answer is the “Appbar” . This is a application / context aware menu that slides up from the bottom of the screen when you move your finger / mouse from below the screen into it. From above downwards works just as well. Here you see an example of the appbar from the People app. (click on it for a larger version). This appears whenever you slide your finger up from below of down from above. This is where you put your commands. Remember, this is context aware so this menu will change when you are in different parts of your app or when you have selected different items. There are a few conventions when you create this appbar. First, the items on the right are “General” items, meaning they have little to do with what is on the screen right now. I think this would be a great place to add our “New Spot” icon. On the far left are items associated with the current selected item or screen. So if you have a spot selected, the button for Add Photo should be visible here and on the left hand side. Not everything is as clear as this, but this is what you should strive for. Group items together. And please note: this is the only place in Metro design where we are allowed to use lines as separators. So when you want to separate a group of icons from another group, add a line. Also note the simplicity of the buttons. No colors, no lights or shadows, no 3D. After a couple of years of fancy almost realistic looking icons people have finally decided that hey, this is a virtual world: it’s ok to look virtual as well. So make things as readable and clear as possible and don’t try to duplicate nature. It’s all about the information, remember? (If you don’t remember I’d like to point you to a older blog post of mine about the what and why of Metro). So.. think about the buttons a bit and think about Share and Search. What will you put there? Remember: this is the way the users interact with your apps and while you shouldn’t judge a book by its covers when it comes to people, this isn’t entirely so when it comes to apps. People DO judge an app by its looks and the way it feels. Take advantage of that. History has learned that a crappy app with a GREAT user interface gets better reviews than a GREAT app with a lousy UI… I know: developers will find this extremely unfair but that’s the world we live in (No, I am not saying you should deliver rubbish apps). Next time: we’ll start by building the darn thing!

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• Does Test Driven Development (TDD) improve Quality and Correctness? (Part 1)

  - by David V. Corbin

  Since the dawn of the computer age, various methodologies have been introduced to improve quality and reduce cost. In this posting, I will by sharing my experiences with Test Driven Development; both its benefits and limitations. To start this topic, we need to agree on what TDD is. The first is to define each of the three words as used in this context. Test - An item or action which measures something in some quantifiable form. Driven - The primary motivation or focus of a series of activities (process) Development - All phases of a software project/product from concept through delivery. The above are very simple definitions that result in the following: "TDD is a process where the primary focus is on measuring and quantifying all aspects of the creation of a (software) product." There are many places where TDD is used outside of software development, even though it is not known by this name. Consider the (conventional) education process that most of us grew up on. The focus was to get the best grades as measured by different tests. Many of these tests measured rote memorization and not understanding of the subject matter. The result of this that many people graduated with high scores but without "quality and correctness" in their ability to utilize the subject matter (of course, the flip side is true where certain people DID understand the material but were not very good at taking this type of test). Returning to software development, let us look at some common scenarios. While these items are generally applicable regardless of platform, language and tools; the remainder of this post will utilize Microsoft Visual Studio and Team Foundation Server (TFS) for examples. It should be realized that everyone does at least some aspect of TDD. At the most rudimentary level, getting a program to compile involves a "pass/fail" measurement (is the syntax valid) that drives their ability to proceed further (run the program). Other developers may create "Unit Tests" in the belief that having a test for every method/property of a class and good code coverage is the goal of TDD. These items may be helpful and even important, but really only address a small aspect of the overall effort. To see TDD in a bigger view, lets identify the various activities that are part of the Software Development LifeCycle. These are going to be presented in a Waterfall style for simplicity, but each item also occurs within Iterative methodologies such as Agile/Scrum. the key ones here are: Requirements Gathering Architecture Design Implementation Quality Assurance Can each of these items be subjected to a process which establishes metrics (quantified metrics) that reflect both the quality and correctness of each item? It should be clear that conventional Unit Tests do not apply to all of these items; at best they can verify that a local aspect (e.g. a Class/Method) of implementation matches the (test writers perspective of) the appropriate design document. So what can we do? For each of area, the goal is to create tests that are quantifiable and durable. The ability to quantify the measurements (beyond a simple pass/fail) is critical to tracking progress(eventually measuring the level of success that has been achieved) and for providing clear information on what items need to be addressed (along with the appropriate time to address them - in varying levels of detail) . Durability is important so that the test can be reapplied (ideally in an automated fashion) over the entire cycle. Returning for a moment back to our "education example", one must also be careful of how the tests are organized and how the measurements are taken. If a test is in a multiple choice format, there is a significant statistical probability that a correct answer might be the result of a random guess. Also, in many situations, having the student simply provide a final answer can obscure many important elements. For example, on a math test, having the student simply provide a numeric answer (rather than showing the methodology) may result in a complete mismatch between the process and the result. It is hard to determine which is worse: The student who makes a simple arithmetric error at one step of a long process (resulting in a wrong answer) or The student who (without providing the "workflow") uses a completely invalid approach, yet still comes up with the right number. The "Wrong Process"/"Right Answer" is probably the single biggest problem in software development. Even very simple items can suffer from this. As an example consider the following code for a "straight line" calculation....Is it correct? (for Integral Points)         int Solve(int m, int b, int x) { return m * x + b; }   Most people would respond "Yes". But let's take the question one step further... Is it correct for all possible values of m,b,x??? (no fair if you cheated by being focused on the bolded text!)  Without additional information regarding constrains on "the possible values of m,b,x" the answer must be NO, there is the risk of overflow/wraparound that will produce an incorrect result! To properly answer this question (i.e. Test the Code), one MUST be able to backtrack from the implementation through the design, and architecture all the way back to the requirements. And the requirement itself must be tested against the stakeholder(s). It is only when the bounding conditions are defined that it is possible to determine if the code is "Correct" and has "Quality". Yet, how many of us (myself included) have written such code without even thinking about it. In many canses we (think we) "know" what the bounds are, and that the code will be correct. As we all know, requirements change, "code reuse" causes implementations to be applied to different scenarios, etc. This leads directly to the types of system failures that plague so many projects. This approach to TDD is much more holistic than ones which start by focusing on the details. The fundamental concepts still apply: Each item should be tested. The test should be defined/implemented before (or concurrent with) the definition/implementation of the actual item. We also add concepts that expand the scope and alter the style by recognizing: There are many things beside "lines of code" that benefit from testing (measuring/evaluating in a formal way) Correctness and Quality can not be solely measured by "correct results" In the future parts, we will examine in greater detail some of the techniques that can be applied to each of these areas....

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• Writing Unit Tests for an ASP.NET MVC Action Method that handles Ajax Request and Normal Request

  - by shiju

  In this blog post, I will demonstrate how to write unit tests for an ASP.NET MVC action method, which handles both Ajax request and normal HTTP Request. I will write a unit test for specifying the behavior of an Ajax request and will write another unit test for specifying the behavior of a normal HTTP request. Both Ajax request and normal request will be handled by a single action method. So the ASP.NET MVC action method will be execute HTTP Request object’s IsAjaxRequest method for identifying whether it is an Ajax request or not. So we have to create mock object for Request object and also have to make as a Ajax request from the unit test for verifying the behavior of an Ajax request. I have used NUnit and Moq for writing unit tests. Let me write a unit test for a Ajax request Code Snippet [Test] public void Index_AjaxRequest_Returns_Partial_With_Expense_List() {     // Arrange       Mock<HttpRequestBase> request = new Mock<HttpRequestBase>();     Mock<HttpResponseBase> response = new Mock<HttpResponseBase>();     Mock<HttpContextBase> context = new Mock<HttpContextBase>();       context.Setup(c => c.Request).Returns(request.Object);     context.Setup(c => c.Response).Returns(response.Object);     //Add XMLHttpRequest request header     request.Setup(req => req["X-Requested-With"]).         Returns("XMLHttpRequest");       IEnumerable<Expense> fakeExpenses = GetMockExpenses();     expenseRepository.Setup(x => x.GetMany(It.         IsAny<Expression<Func<Expense, bool>>>())).         Returns(fakeExpenses);     ExpenseController controller = new ExpenseController(         commandBus.Object, categoryRepository.Object,         expenseRepository.Object);     controller.ControllerContext = new ControllerContext(         context.Object, new RouteData(), controller);     // Act     var result = controller.Index(null, null) as PartialViewResult;     // Assert     Assert.AreEqual("_ExpenseList", result.ViewName);     Assert.IsNotNull(result, "View Result is null");     Assert.IsInstanceOf(typeof(IEnumerable<Expense>),             result.ViewData.Model, "Wrong View Model");     var expenses = result.ViewData.Model as IEnumerable<Expense>;     Assert.AreEqual(3, expenses.Count(),         "Got wrong number of Categories");         }   In the above unit test, we are calling Index action method of a controller named ExpenseController, which will returns a PartialView named _ExpenseList, if it is an Ajax request. We have created mock object for HTTPContextBase and setup XMLHttpRequest request header for Request object’s X-Requested-With for making it as a Ajax request. We have specified the ControllerContext property of the controller with mocked object HTTPContextBase. Code Snippet controller.ControllerContext = new ControllerContext(         context.Object, new RouteData(), controller); Let me write a unit test for a normal HTTP method Code Snippet [Test] public void Index_NormalRequest_Returns_Index_With_Expense_List() {     // Arrange               Mock<HttpRequestBase> request = new Mock<HttpRequestBase>();     Mock<HttpResponseBase> response = new Mock<HttpResponseBase>();     Mock<HttpContextBase> context = new Mock<HttpContextBase>();       context.Setup(c => c.Request).Returns(request.Object);     context.Setup(c => c.Response).Returns(response.Object);       IEnumerable<Expense> fakeExpenses = GetMockExpenses();       expenseRepository.Setup(x => x.GetMany(It.         IsAny<Expression<Func<Expense, bool>>>())).         Returns(fakeExpenses);     ExpenseController controller = new ExpenseController(         commandBus.Object, categoryRepository.Object,         expenseRepository.Object);     controller.ControllerContext = new ControllerContext(         context.Object, new RouteData(), controller);     // Act     var result = controller.Index(null, null) as ViewResult;     // Assert     Assert.AreEqual("Index", result.ViewName);     Assert.IsNotNull(result, "View Result is null");     Assert.IsInstanceOf(typeof(IEnumerable<Expense>),             result.ViewData.Model, "Wrong View Model");     var expenses = result.ViewData.Model         as IEnumerable<Expense>;     Assert.AreEqual(3, expenses.Count(),         "Got wrong number of Categories"); }   In the above unit test, we are not specifying the XMLHttpRequest request header for Request object’s X-Requested-With, so that it will be normal HTTP Request. If this is a normal request, the action method will return a ViewResult with a view template named Index. The below is the implementation of Index action method Code Snippet public ActionResult Index(DateTime? startDate, DateTime? endDate) {     //If date is not passed, take current month's first and last date     DateTime dtNow;     dtNow = DateTime.Today;     if (!startDate.HasValue)     {         startDate = new DateTime(dtNow.Year, dtNow.Month, 1);         endDate = startDate.Value.AddMonths(1).AddDays(-1);     }     //take last date of start date's month, if end date is not passed     if (startDate.HasValue && !endDate.HasValue)     {         endDate = (new DateTime(startDate.Value.Year,             startDate.Value.Month, 1)).AddMonths(1).AddDays(-1);     }     var expenses = expenseRepository.GetMany(         exp => exp.Date >= startDate && exp.Date <= endDate);     //if request is Ajax will return partial view     if (Request.IsAjaxRequest())     {         return PartialView("_ExpenseList", expenses);     }     //set start date and end date to ViewBag dictionary     ViewBag.StartDate = startDate.Value.ToShortDateString();     ViewBag.EndDate = endDate.Value.ToShortDateString();     //if request is not ajax     return View("Index",expenses); }   The index action method will returns a PartialView named _ExpenseList, if it is an Ajax request and will returns a View named Index if it is a normal request. Source Code The source code has been taken from my EFMVC app which can download from here

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• SSIS: Deploying OLAP cubes using C# script tasks and AMO

  - by DrJohn

  As part of the continuing series on Building dynamic OLAP data marts on-the-fly, this blog entry will focus on how to automate the deployment of OLAP cubes using SQL Server Integration Services (SSIS) and Analysis Services Management Objects (AMO). OLAP cube deployment is usually done using the Analysis Services Deployment Wizard. However, this option was dismissed for a variety of reasons. Firstly, invoking external processes from SSIS is fraught with problems as (a) it is not always possible to ensure SSIS waits for the external program to terminate; (b) we cannot log the outcome properly and (c) it is not always possible to control the server's configuration to ensure the executable works correctly. Another reason for rejecting the Deployment Wizard is that it requires the 'answers' to be written into four XML files. These XML files record the three things we need to change: the name of the server, the name of the OLAP database and the connection string to the data mart. Although it would be reasonably straight forward to change the content of the XML files programmatically, this adds another set of complication and level of obscurity to the overall process. When I first investigated the possibility of using C# to deploy a cube, I was surprised to find that there are no other blog entries about the topic. I can only assume everyone else is happy with the Deployment Wizard! SSIS "forgets" assembly references If you build your script task from scratch, you will have to remember how to overcome one of the major annoyances of working with SSIS script tasks: the forgetful nature of SSIS when it comes to assembly references. Basically, you can go through the process of adding an assembly reference using the Add Reference dialog, but when you close the script window, SSIS "forgets" the assembly reference so the script will not compile. After repeating the operation several times, you will find that SSIS only remembers the assembly reference when you specifically press the Save All icon in the script window. This problem is not unique to the AMO assembly and has certainly been a "feature" since SQL Server 2005, so I am not amazed it is still present in SQL Server 2008 R2! Sample Package So let's take a look at the sample SSIS package I have provided which can be downloaded from here: DeployOlapCubeExample.zip  Below is a screenshot after a successful run. Connection Managers The package has three connection managers: AsDatabaseDefinitionFile is a file connection manager pointing to the .asdatabase file you wish to deploy. Note that this can be found in the bin directory of you OLAP database project once you have clicked the "Build" button in Visual Studio TargetOlapServerCS is an Analysis Services connection manager which identifies both the deployment server and the target database name. SourceDataMart is an OLEDB connection manager pointing to the data mart which is to act as the source of data for your cube. This will be used to replace the connection string found in your .asdatabase file Once you have configured the connection managers, the sample should run and deploy your OLAP database in a few seconds. Of course, in a production environment, these connection managers would be associated with package configurations or set at runtime. When you run the sample, you should see that the script logs its activity to the output screen (see screenshot above). If you configure logging for the package, then these messages will also appear in your SSIS logging. Sample Code Walkthrough Next let's walk through the code. The first step is to parse the connection string provided by the TargetOlapServerCS connection manager and obtain the name of both the target OLAP server and also the name of the OLAP database. Note that the target database does not have to exist to be referenced in an AS connection manager, so I am using this as a convenient way to define both properties. We now connect to the server and check for the existence of the OLAP database. If it exists, we drop the database so we can re-deploy. svr.Connect(olapServerName); if (svr.Connected) { // Drop the OLAP database if it already exists Database db = svr.Databases.FindByName(olapDatabaseName); if (db != null) { db.Drop(); } // rest of script } Next we start building the XMLA command that will actually perform the deployment. Basically this is a small chuck of XML which we need to wrap around the large .asdatabase file generated by the Visual Studio build process. // Start generating the main part of the XMLA command XmlDocument xmlaCommand = new XmlDocument(); xmlaCommand.LoadXml(string.Format("<Batch Transaction='false' xmlns='http://schemas.microsoft.com/analysisservices/2003/engine'><Alter AllowCreate='true' ObjectExpansion='ExpandFull'><Object><DatabaseID>{0}</DatabaseID></Object><ObjectDefinition/></Alter></Batch>", olapDatabaseName));  Next we need to merge two XML files which we can do by simply using setting the InnerXml property of the ObjectDefinition node as follows: // load OLAP Database definition from .asdatabase file identified by connection manager XmlDocument olapCubeDef = new XmlDocument(); olapCubeDef.Load(Dts.Connections["AsDatabaseDefinitionFile"].ConnectionString); // merge the two XML files by obtain a reference to the ObjectDefinition node oaRootNode.InnerXml = olapCubeDef.InnerXml;   One hurdle I had to overcome was removing detritus from the .asdabase file left by the Visual Studio build. Through an iterative process, I found I needed to remove several nodes as they caused the deployment to fail. The XMLA error message read "Cannot set read-only node: CreatedTimestamp" or similar. In comparing the XMLA generated with by the Deployment Wizard with that generated by my code, these read-only nodes were missing, so clearly I just needed to strip them out. This was easily achieved using XPath to find the relevant XML nodes, of which I show one example below: foreach (XmlNode node in rootNode.SelectNodes("//ns1:CreatedTimestamp", nsManager)) { node.ParentNode.RemoveChild(node); } Now we need to change the database name in both the ID and Name nodes using code such as: XmlNode databaseID = xmlaCommand.SelectSingleNode("//ns1:Database/ns1:ID", nsManager); if (databaseID != null) databaseID.InnerText = olapDatabaseName; Finally we need to change the connection string to point at the relevant data mart. Again this is easily achieved using XPath to search for the relevant nodes and then replace the content of the node with the new name or connection string. XmlNode connectionStringNode = xmlaCommand.SelectSingleNode("//ns1:DataSources/ns1:DataSource/ns1:ConnectionString", nsManager); if (connectionStringNode != null) { connectionStringNode.InnerText = Dts.Connections["SourceDataMart"].ConnectionString; } Finally we need to perform the deployment using the Execute XMLA command and check the returned XmlaResultCollection for errors before setting the Dts.TaskResult. XmlaResultCollection oResults = svr.Execute(xmlaCommand.InnerXml);  // check for errors during deployment foreach (Microsoft.AnalysisServices.XmlaResult oResult in oResults) { foreach (Microsoft.AnalysisServices.XmlaMessage oMessage in oResult.Messages) { if ((oMessage.GetType().Name == "XmlaError")) { FireError(oMessage.Description); HadError = true; } } } If you are not familiar with XML programming, all this may all seem a bit daunting, but perceiver as the sample code is pretty short. If you would like the script to process the OLAP database, simply uncomment the lines in the vicinity of Process method. Of course, you can extend the script to perform your own custom processing and to even synchronize the database to a front-end server. Personally, I like to keep the deployment and processing separate as the code can become overly complex for support staff.If you want to know more, come see my session at the forthcoming SQLBits conference.

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• Anatomy of a .NET Assembly - Custom attribute encoding

  - by Simon Cooper

  In my previous post, I covered how field, method, and other types of signatures are encoded in a .NET assembly. Custom attribute signatures differ quite a bit from these, which consequently affects attribute specifications in C#. Custom attribute specifications In C#, you can apply a custom attribute to a type or type member, specifying a constructor as well as the values of fields or properties on the attribute type: public class ExampleAttribute : Attribute { public ExampleAttribute(int ctorArg1, string ctorArg2) { ... } public Type ExampleType { get; set; } } [Example(5, "6", ExampleType = typeof(string))] public class C { ... } How does this specification actually get encoded and stored in an assembly? Specification blob values Custom attribute specification signatures use the same building blocks as other types of signatures; the ELEMENT_TYPE structure. However, they significantly differ from other types of signatures, in that the actual parameter values need to be stored along with type information. There are two types of specification arguments in a signature blob; fixed args and named args. Fixed args are the arguments to the attribute type constructor, named arguments are specified after the constructor arguments to provide a value to a field or property on the constructed attribute type (PropertyName = propValue) Values in an attribute blob are limited to one of the basic types (one of the number types, character, or boolean), a reference to a type, an enum (which, in .NET, has to use one of the integer types as a base representation), or arrays of any of those. Enums and the basic types are easy to store in a blob - you simply store the binary representation. Strings are stored starting with a compressed integer indicating the length of the string, followed by the UTF8 characters. Array values start with an integer indicating the number of elements in the array, then the item values concatentated together. Rather than using a coded token, Type values are stored using a string representing the type name and fully qualified assembly name (for example, MyNs.MyType, MyAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0123456789abcdef). If the type is in the current assembly or mscorlib then just the type name can be used. This is probably done to prevent direct references between assemblies solely because of attribute specification arguments; assemblies can be loaded in the reflection-only context and attribute arguments still processed, without loading the entire assembly. Fixed and named arguments Each entry in the CustomAttribute metadata table contains a reference to the object the attribute is applied to, the attribute constructor, and the specification blob. The number and type of arguments to the constructor (the fixed args) can be worked out by the method signature referenced by the attribute constructor, and so the fixed args can simply be concatenated together in the blob without any extra type information. Named args are different. These specify the value to assign to a field or property once the attribute type has been constructed. In the CLR, fields and properties can be overloaded just on their type; different fields and properties can have the same name. Therefore, to uniquely identify a field or property you need: Whether it's a field or property (indicated using byte values 0x53 and 0x54, respectively) The field or property type The field or property name After the fixed arg values is a 2-byte number specifying the number of named args in the blob. Each named argument has the above information concatenated together, mostly using the basic ELEMENT_TYPE values, in the same way as a method or field signature. A Type argument is represented using the byte 0x50, and an enum argument is represented using the byte 0x55 followed by a string specifying the name and assembly of the enum type. The named argument property information is followed by the argument value, using the same encoding as fixed args. Boxed objects This would be all very well, were it not for object and object[]. Arguments and properties of type object allow a value of any allowed argument type to be specified. As a result, more information needs to be specified in the blob to interpret the argument bytes as the correct type. So, the argument value is simple prepended with the type of the value by specifying the ELEMENT_TYPE or name of the enum the value represents. For named arguments, a field or property of type object is represented using the byte 0x51, with the actual type specified in the argument value. Some examples... All property signatures start with the 2-byte value 0x0001. Similar to my previous post in the series, names in capitals correspond to a particular byte value in the ELEMENT_TYPE structure. For strings, I'll simply give the string value, rather than the length and UTF8 encoding in the actual blob. I'll be using the following enum and attribute types to demonstrate specification encodings: class AttrAttribute : Attribute { public AttrAttribute() {} public AttrAttribute(Type[] tArray) {} public AttrAttribute(object o) {} public AttrAttribute(MyEnum e) {} public AttrAttribute(ushort x, int y) {} public AttrAttribute(string str, Type type1, Type type2) {} public int Prop1 { get; set; } public object Prop2 { get; set; } public object[] ObjectArray; } enum MyEnum : int { Val1 = 1, Val2 = 2 } Now, some examples: Here, the the specification binds to the (ushort, int) attribute constructor, with fixed args only. The specification blob starts off with a prolog, followed by the two constructor arguments, then the number of named arguments (zero): [Attr(42, 84)] 0x0001 0x002a 0x00000054 0x0000 An example of string and type encoding: [Attr("MyString", typeof(Array), typeof(System.Windows.Forms.Form))] 0x0001 "MyString" "System.Array" "System.Windows.Forms.Form, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" 0x0000 As you can see, the full assembly specification of a type is only needed if the type isn't in the current assembly or mscorlib. Note, however, that the C# compiler currently chooses to fully-qualify mscorlib types anyway. An object argument (this binds to the object attribute constructor), and two named arguments (a null string is represented by 0xff and the empty string by 0x00) [Attr((ushort)40, Prop1 = 12, Prop2 = "")] 0x0001 U2 0x0028 0x0002 0x54 I4 "Prop1" 0x0000000c 0x54 0x51 "Prop2" STRING 0x00 Right, more complicated now. A type array as a fixed argument: [Attr(new[] { typeof(string), typeof(object) })] 0x0001 0x00000002 // the number of elements "System.String" "System.Object" 0x0000 An enum value, which is simply represented using the underlying value. The CLR works out that it's an enum using information in the attribute constructor signature: [Attr(MyEnum.Val1)] 0x0001 0x00000001 0x0000 And finally, a null array, and an object array as a named argument: [Attr((Type[])null, ObjectArray = new object[] { (byte)2, typeof(decimal), null, MyEnum.Val2 })] 0x0001 0xffffffff 0x0001 0x53 SZARRAY 0x51 "ObjectArray" 0x00000004 U1 0x02 0x50 "System.Decimal" STRING 0xff 0x55 "MyEnum" 0x00000002 As you'll notice, a null object is encoded as a null string value, and a null array is represented using a length of -1 (0xffffffff). How does this affect C#? So, we can now explain why the limits on attribute arguments are so strict in C#. Attribute specification blobs are limited to basic numbers, enums, types, and arrays. As you can see, this is because the raw CLR encoding can only accommodate those types. Special byte patterns have to be used to indicate object, string, Type, or enum values in named arguments; you can't specify an arbitary object type, as there isn't a generalised way of encoding the resulting value in the specification blob. In particular, decimal values can't be encoded, as it isn't a 'built-in' CLR type that has a native representation (you'll notice that decimal constants in C# programs are compiled as several integer arguments to DecimalConstantAttribute). Jagged arrays also aren't natively supported, although you can get around it by using an array as a value to an object argument: [Attr(new object[] { new object[] { new Type[] { typeof(string) } }, 42 })] Finally... Phew! That was a bit longer than I thought it would be. Custom attribute encodings are complicated! Hopefully this series has been an informative look at what exactly goes on inside a .NET assembly. In the next blog posts, I'll be carrying on with the 'Inside Red Gate' series.

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• Sliding collision response

  - by dbostream

  I have been reading plenty of tutorials about sliding collision responses yet I am not able to implement it properly in my project. What I want to do is make a puck slide along the rounded corner boards of a hockey rink. In my latest attempt the puck does slide along the boards but there are some strange velocity behaviors. First of all the puck slows down a lot pretty much right away and then it slides for awhile and stops before exiting the corner. Even if I double the speed I get a similar behavior and the puck does not make it out of the corner. I used some ideas from this document http://www.peroxide.dk/papers/collision/collision.pdf. This is what I have: Update method called from the game loop when it is time to update the puck (I removed some irrelevant parts). I use two states (current, previous) which are used to interpolate the position during rendering. public override void Update(double fixedTimeStep) { /* Acceleration is set to 0 for now. */ Acceleration.Zero(); PreviousState = CurrentState; _collisionRecursionDepth = 0; CurrentState.Position = SlidingCollision(CurrentState.Position, CurrentState.Velocity * fixedTimeStep + 0.5 * Acceleration * fixedTimeStep * fixedTimeStep); /* Should not this be affected by a sliding collision? and not only the position. */ CurrentState.Velocity = CurrentState.Velocity + Acceleration * fixedTimeStep; Heading = Vector2.NormalizeRet(CurrentState.Velocity); } private Vector2 SlidingCollision(Vector2 position, Vector2 velocity) { if(_collisionRecursionDepth > 5) return position; bool collisionFound = false; Vector2 futurePosition = position + velocity; Vector2 intersectionPoint = new Vector2(); Vector2 intersectionPointNormal = new Vector2(); /* I did not include the collision detection code, if a collision is detected the intersection point and normal in that point is returned. */ if(!collisionFound) return futurePosition; /* If no collision was detected it is safe to move to the future position. */ /* It is not exactly the intersection point, but slightly before. */ Vector2 newPosition = intersectionPoint; /* oldVelocity is set to the distance from the newPosition(intersection point) to the position it had moved to had it not collided. */ Vector2 oldVelocity = futurePosition - newPosition; /* Project the distance left to move along the intersection normal. */ Vector2 newVelocity = oldVelocity - intersectionPointNormal * oldVelocity.DotProduct(intersectionPointNormal); if(newVelocity.LengthSq() < 0.001) return newPosition; /* If almost no speed, no need to continue. */ _collisionRecursionDepth++; return SlidingCollision(newPosition, newVelocity); } What am I doing wrong with the velocity? I have been staring at this for very long so I have gone blind. I have tried different values of recursion depth but it does not seem to make it better. Let me know if you need more information. I appreciate any help. EDIT: A combination of Patrick Hughes' and teodron's answers solved the velocity problem (I think), thanks a lot! This is the new code: I decided to use a separate recursion method now too since I don't want to recalculate the acceleration in each recursion. public override void Update(double fixedTimeStep) { Acceleration.Zero();// = CalculateAcceleration(fixedTimeStep); PreviousState = new MovingEntityState(CurrentState.Position, CurrentState.Velocity); CurrentState = SlidingCollision(CurrentState, fixedTimeStep); Heading = Vector2.NormalizeRet(CurrentState.Velocity); } private MovingEntityState SlidingCollision(MovingEntityState state, double timeStep) { bool collisionFound = false; /* Calculate the next position given no detected collision. */ Vector2 futurePosition = state.Position + state.Velocity * timeStep; Vector2 intersectionPoint = new Vector2(); Vector2 intersectionPointNormal = new Vector2(); /* I did not include the collision detection code, if a collision is detected the intersection point and normal in that point is returned. */ /* If no collision was detected it is safe to move to the future position. */ if (!collisionFound) return new MovingEntityState(futurePosition, state.Velocity); /* Set new position to the intersection point (slightly before). */ Vector2 newPosition = intersectionPoint; /* Project the new velocity along the intersection normal. */ Vector2 newVelocity = state.Velocity - 1.90 * intersectionPointNormal * state.Velocity.DotProduct(intersectionPointNormal); /* Calculate the time of collision. */ double timeOfCollision = Math.Sqrt((newPosition - state.Position).LengthSq() / (futurePosition - state.Position).LengthSq()); /* Calculate new time step, remaining time of full step after the collision * current time step. */ double newTimeStep = timeStep * (1 - timeOfCollision); return SlidingCollision(new MovingEntityState(newPosition, newVelocity), newTimeStep); } Even though the code above seems to slide the puck correctly please have a look at it. I have a few questions, if I don't multiply by 1.90 in the newVelocity calculation it doesn't work (I get a stack overflow when the puck enters the corner because the timeStep decreases very slowly - a collision is found early in every recursion), why is that? what does 1.90 really do and why 1.90? Also I have a new problem, the puck does not move parallell to the short side after exiting the curve; to be more exact it moves outside the rink (I am not checking for any collisions with the short side at the moment). When I perform the collision detection I first check that the puck is in the correct quadrant. For example bottom-right corner is quadrant four i.e. circleCenter.X < puck.X && circleCenter.Y puck.Y is this a problem? or should the short side of the rink be the one to make the puck go parallell to it and not the last collision in the corner? EDIT2: This is the code I use for collision detection, maybe it has something to do with the fact that I can't make the puck slide (-1.0) but only reflect (-2.0): /* Point is the current position (not the predicted one) and quadrant is 4 for the bottom-right corner for example. */ if (GeometryHelper.PointInCircleQuadrant(circleCenter, circleRadius, state.Position, quadrant)) { /* The line is: from = state.Position, to = futurePosition. So a collision is detected when from is inside the circle and to is outside. */ if (GeometryHelper.LineCircleIntersection2d(state.Position, futurePosition, circleCenter, circleRadius, intersectionPoint, quadrant)) { collisionFound = true; /* Set the intersection point to slightly before the real intersection point (I read somewhere this was good to do because of floting point precision, not sure exactly how much though). */ intersectionPoint = intersectionPoint - Vector2.NormalizeRet(state.Velocity) * 0.001; /* Normal at the intersection point. */ intersectionPointNormal = Vector2.NormalizeRet(circleCenter - intersectionPoint) } } When I set the intersection point, if I for example use 0.1 instead of 0.001 the puck travels further before it gets stuck, but for all values I have tried (including 0 - the real intersection point) it gets stuck somewhere (but I necessarily not get a stack overflow). Can something in this part be the cause of my problem? I can see why I get the stack overflow when using -1.0 when calculating the new velocity vector; but not how to solve it. I traced the time steps used in the recursion (initial time step is always 1/60 ~ 0.01666): Recursion depth Time step next recursive call [Start recursion, time step ~ 0.016666] 0 0,000985806527246773 [No collision, stop recursion] [Start recursion, time step ~ 0.016666] 0 0,0149596704364629 1 0,0144883449376379 2 0,0143155612984837 3 0,014224925727213 4 0,0141673917461608 5 0,0141265435314026 6 0,0140953966184117 7 0,0140704653746625 ...and so on. As you can see the collision is detected early in every recursive call which means the next time step decreases very slowly thus the recursion depth gets very big - stack overflow.

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• SQL SERVER – Weekly Series – Memory Lane – #034

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 UDF – User Defined Function to Strip HTML – Parse HTML – No Regular Expression The UDF used in the blog does fantastic task – it scans entire HTML text and removes all the HTML tags. It keeps only valid text data without HTML task. This is one of the quite commonly requested tasks many developers have to face everyday. De-fragmentation of Database at Operating System to Improve Performance Operating system skips MDF file while defragging the entire filesystem of the operating system. It is absolutely fine and there is no impact of the same on performance. Read the entire blog post for my conversation with our network engineers. Delay Function – WAITFOR clause – Delay Execution of Commands How do you delay execution of the commands in SQL Server – ofcourse by using WAITFOR keyword. In this blog post, I explain the same with the help of T-SQL script. Find Length of Text Field To measure the length of TEXT fields the function is DATALENGTH(textfield). Len will not work for text field. As of SQL Server 2005, developers should migrate all the text fields to VARCHAR(MAX) as that is the way forward. Retrieve Current Date Time in SQL Server CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} There are three ways to retrieve the current datetime in SQL SERVER. CURRENT_TIMESTAMP, GETDATE(), {fn NOW()} Explanation and Comparison of NULLIF and ISNULL An interesting observation is NULLIF returns null if it comparison is successful, whereas ISNULL returns not null if its comparison is successful. In one way they are opposite to each other. Here is my question to you - How to create infinite loop using NULLIF and ISNULL? If this is even possible? 2008 Introduction to SERVERPROPERTY and example SERVERPROPERTY is a very interesting system function. It returns many of the system values. I use it very frequently to get different server values like Server Collation, Server Name etc. SQL Server Start Time We can use DMV to find out what is the start time of SQL Server in 2008 and later version. In this blog you can see how you can do the same. Find Current Identity of Table Many times we need to know what is the current identity of the column. I have found one of my developers using aggregated function MAX () to find the current identity. However, I prefer following DBCC command to figure out current identity. Create Check Constraint on Column Some time we just need to create a simple constraint over the table but I have noticed that developers do many different things to make table column follow rules than just creating constraint. I suggest constraint is a very useful concept and every SQL Developer should pay good attention to this subject. 2009 List Schema Name and Table Name for Database This is one of the blog post where I straight forward display script. One of the kind of blog posts, which I still love to read and write. Clustered Index on Separate Drive From Table Location A table devoid of primary key index is called heap, and here data is not arranged in a particular order, which gives rise to issues that adversely affect performance. Data must be stored in some kind of order. If we put clustered index on it then the order will be forced by that index and the data will be stored in that particular order. Understanding Table Hints with Examples Hints are options and strong suggestions specified for enforcement by the SQL Server query processor on DML statements. The hints override any execution plan the query optimizer might select for a query. 2010 Data Pages in Buffer Pool – Data Stored in Memory Cache One of my earlier year article, which I still read it many times and point developers to read it again. It is clear from the Resultset that when more than one index is used, datapages related to both or all of the indexes are stored in Memory Cache separately. TRANSACTION, DML and Schema Locks Can you create a situation where you can see Schema Lock? Well, this is a very simple question, however during the interview I notice over 50 candidates failed to come up with the scenario. In this blog post, I have demonstrated the situation where we can see the schema lock in database. 2011 Solution – Puzzle – Statistics are not updated but are Created Once In this example I have created following situation: Create Table Insert 1000 Records Check the Statistics Now insert 10 times more 10,000 indexes Check the Statistics – it will be NOT updated Auto Update Statistics and Auto Create Statistics for database is TRUE Now I have requested two things in the example 1) Why this is happening? 2) How to fix this issue? Selecting Domain from Email Address This is a straight to script blog post where I explain how to select only domain name from entire email address. Solution – Generating Zero Without using Any Numbers in T-SQL How to get zero digit without using any digit? This is indeed a very interesting question and the answer is even interesting. Try to come up with answer in next 10 minutes and if you can’t come up with the answer the blog post read this post for solution. 2012 Simple Explanation and Puzzle with SOUNDEX Function and DIFFERENCE Function In simple words - SOUNDEX converts an alphanumeric string to a four-character code to find similar-sounding words or names. DIFFERENCE function returns an integer value. The  integer returned is the number of characters in the SOUNDEX values that are the same. Read Only Files and SQL Server Management Studio (SSMS) I have come across a very interesting feature in SSMS related to “Read Only” files. I believe it is a little unknown feature as well so decided to write a blog about the same. Identifying Column Data Type of uniqueidentifier without Querying System Tables How do I know if any table has a uniqueidentifier column and what is its value without using any DMV or System Catalogues? Only information you know is the table name and you are allowed to return any kind of error if the table does not have uniqueidentifier column. Read the blog post to find the answer. Solution – User Not Able to See Any User Created Object in Tables – Security and Permissions Issue Interesting question – “When I try to connect to SQL Server, it lets me connect just fine as well let me open and explore the database. I noticed that I do not see any user created instances but when my colleague attempts to connect to the server, he is able to explore the database as well see all the user created tables and other objects. Can you help me fix it?” Importing CSV File Into Database – SQL in Sixty Seconds #018 – Video Here is interesting small 60 second video on how to import CSV file into Database. ColumnStore Index – Batch Mode vs Row Mode Here is the logic behind when Columnstore Index uses Batch Mode and when it uses Row Mode. A batch typically represents about 1000 rows of data. Batch mode processing also uses algorithms that are optimized for the multicore CPUs and increased memory throughput. Follow up – Usage of $rowguid and $IDENTITY This is an excellent follow up blog post of my earlier blog post where I explain where to use $rowguid and $identity.  If you do not know the difference between them, this is a blog with a script example. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• xml file save/read error (making a highscore system for XNA game)

  - by Eddy

  i get an error after i write player name to the file for second or third time (An unhandled exception of type 'System.InvalidOperationException' occurred in System.Xml.dll Additional information: There is an error in XML document (18, 17).) (in highscores load method In data = (HighScoreData)serializer.Deserialize(stream); it stops) the problem is that some how it adds additional "" at the end of my .dat file could anyone tell me how to fix this? the file before save looks: <?xml version="1.0"?> <HighScoreData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <PlayerName> <string>neil</string> <string>shawn</string> <string>mark</string> <string>cindy</string> <string>sam</string> </PlayerName> <Score> <int>200</int> <int>180</int> <int>150</int> <int>100</int> <int>50</int> </Score> <Count>5</Count> </HighScoreData> the file after save looks: <?xml version="1.0"?> <HighScoreData xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <PlayerName> <string>Nick</string> <string>Nick</string> <string>neil</string> <string>shawn</string> <string>mark</string> </PlayerName> <Score> <int>210</int> <int>210</int> <int>200</int> <int>180</int> <int>150</int> </Score> <Count>5</Count> </HighScoreData>> the part of my code that does all of save load to xml is: DECLARATIONS PART [Serializable] public struct HighScoreData { public string[] PlayerName; public int[] Score; public int Count; public HighScoreData(int count) { PlayerName = new string[count]; Score = new int[count]; Count = count; } } IAsyncResult result = null; bool inputName; HighScoreData data; int Score = 0; public string NAME; public string HighScoresFilename = "highscores.dat"; Game1 constructor public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; Width = graphics.PreferredBackBufferWidth = 960; Height = graphics.PreferredBackBufferHeight =640; GamerServicesComponent GSC = new GamerServicesComponent(this); Components.Add(GSC); } Inicialize function (end of it) protected override void Initialize() { //other game code base.Initialize(); string fullpath =Path.Combine(HighScoresFilename); if (!File.Exists(fullpath)) { //If the file doesn't exist, make a fake one... // Create the data to save data = new HighScoreData(5); data.PlayerName[0] = "neil"; data.Score[0] = 200; data.PlayerName[1] = "shawn"; data.Score[1] = 180; data.PlayerName[2] = "mark"; data.Score[2] = 150; data.PlayerName[3] = "cindy"; data.Score[3] = 100; data.PlayerName[4] = "sam"; data.Score[4] = 50; SaveHighScores(data, HighScoresFilename); } } all methods for loading saving and output public static void SaveHighScores(HighScoreData data, string filename) { // Get the path of the save game string fullpath = Path.Combine("highscores.dat"); // Open the file, creating it if necessary FileStream stream = File.Open(fullpath, FileMode.OpenOrCreate); try { // Convert the object to XML data and put it in the stream XmlSerializer serializer = new XmlSerializer(typeof(HighScoreData)); serializer.Serialize(stream, data); } finally { // Close the file stream.Close(); } } /* Load highscores */ public static HighScoreData LoadHighScores(string filename) { HighScoreData data; // Get the path of the save game string fullpath = Path.Combine("highscores.dat"); // Open the file FileStream stream = File.Open(fullpath, FileMode.OpenOrCreate, FileAccess.Read); try { // Read the data from the file XmlSerializer serializer = new XmlSerializer(typeof(HighScoreData)); data = (HighScoreData)serializer.Deserialize(stream);//this is the line // where program gives an error } finally { // Close the file stream.Close(); } return (data); } /* Save player highscore when game ends */ private void SaveHighScore() { // Create the data to saved HighScoreData data = LoadHighScores(HighScoresFilename); int scoreIndex = -1; for (int i = 0; i < data.Count ; i++) { if (Score > data.Score[i]) { scoreIndex = i; break; } } if (scoreIndex > -1) { //New high score found ... do swaps for (int i = data.Count - 1; i > scoreIndex; i--) { data.PlayerName[i] = data.PlayerName[i - 1]; data.Score[i] = data.Score[i - 1]; } data.PlayerName[scoreIndex] = NAME; //Retrieve User Name Here data.Score[scoreIndex] = Score; // Retrieve score here SaveHighScores(data, HighScoresFilename); } } /* Iterate through data if highscore is called and make the string to be saved*/ public string makeHighScoreString() { // Create the data to save HighScoreData data2 = LoadHighScores(HighScoresFilename); // Create scoreBoardString string scoreBoardString = "Highscores:\n\n"; for (int i = 0; i<5;i++) { scoreBoardString = scoreBoardString + data2.PlayerName[i] + "-" + data2.Score[i] + "\n"; } return scoreBoardString; } when ill make this work i will start this code when i call game over (now i start it when i press some buttons, so i could test it faster) public void InputYourName() { if (result == null && !Guide.IsVisible) { string title = "Name"; string description = "Write your name in order to save your Score"; string defaultText = "Nick"; PlayerIndex playerIndex = new PlayerIndex(); result= Guide.BeginShowKeyboardInput(playerIndex, title, description, defaultText, null, null); // NAME = result.ToString(); } if (result != null && result.IsCompleted) { NAME = Guide.EndShowKeyboardInput(result); result = null; inputName = false; SaveHighScore(); } } this where i call output to the screen (ill call this in highscores meniu section when i am done with debugging) spriteBatch.DrawString(Font1, "" + makeHighScoreString(),new Vector2(500,200), Color.White); }

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• Developing with Fluid UI – The Fluid Home Page

  - by Dave Bain

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} The first place to start with Fluid UI is with the Fluid Home Page. Sometimes it’s referred to as the landing page, but it’s formally called the Fluid Home Page. It’s delivered with PeopleTools 8.54, and the nice thing about it is, it’s a component. That’s one thing you’ll discover with Fluid UI. Fluid UI is built int PeopleTools with Fluid UI. The Home Page is a component, the tiles or grouplets are group boxes, and the search and prompt pages are just pages. It makes it easy to find things, customize and brand the applications (and of course to see what’s going on) when you can open it in AppDesigner. To see what makes a component fluid, let’s start with the Fluid Home Page. It’s a component called PT_LANDINGPAGE. You can open it in AppDesigner and see what’s unique and different about Fluid UI. If you open the Component Properties dialog, you’ll see a new tab called Fluid On the Component Properties Fluid tab you’ll see the most important checkbox of all, Fluid Mode. That is the one flag that will tell PeopleSoft if the component is Fluid (responsive, dynamic layout) or classic (pixel perfect). Now that you know it’s a single flag, you know that a component can’t be both Fluid UI and Classic at the same time, it’s one or the other. There are some other interesting fields on this page. The Small Form Factor Optimized field tells us whether or not to display this on a small device (think smarphone). Header Toolbar Actions offer standard options that are set at the component level so you have complete control of the components header bar. You’ll notice that the PT_LANDINGPAGE has got some PostBuild PeopleCode. That’s to build the grouplets that are used to launch Fluid UI Pages (more about those later). Probably not a good idea to mess with that code! The next thing to look at is the Page Definition for the PT_LANDINGPAGE component. When you open the page PT_LANDINGPAGE it will look different than anything you’ve ever seen. You’re probably thinking “What’s up with all the group boxes”? That is where Fluid UI is so different. In classic PeopleSoft, you put a button, field, group, any control on a page and that’s where it shows up, no questions asked. With Fluid UI, everything is positioned relative to something else. That’s why there are so many containers (you know them as group boxes). They are UI objects that are used for dynamic positioning. The Fluid Home Page has some special behavior and special settings. The first is in the Web Profile Configuration settings (Main Menu->PeopleTools->Web Profile->Web Profile Configuration from the main menu). There are two checkboxes that control the behavior of Fluid UI. Disable Fluid Mode and Disable Fluid On Desktop. Disable Fluid Mode prevents any Fluid UI component from being run from this installation. This is a web profile setting for users that want to run later versions of PeopleTools but only want to run Classic PeopleSoft pages. The second setting, Disable Fluid On Desktop allows the Fluid UI to be run on mobile devices such as smartphones and tablets, but prevents Fluid UI from running on a desktop computer. Fluid UI settings are also make in My Personalizations (Main Menu->My Personalizations from the Main Menu), in the General Options section. In that section, each user has the choice to determine the home page for their desktop and for tablets. Now that you know the Fluid UI landing page is just a component, and the profile and personalization settings, you should be able to launch one. It’s pretty easy to add a menu using Structure and Content, just make sure the proper security is set up. You’ll have to run a Fluid UI supported browser in order to see it. Latest versions of Chrome, Firefox and IE will do. Check the certification page on MOS for all the details. When you open the first Fluid Landing Page, there’s not much there. Not to worry, we’ll get some content on it soon. Take a moment to navigate around and look at some of the header actions that were set up from the component properties. The home button takes you back to the classic system. You won’t see any notifications and the personalization doesn’t have any content to add. The NavBar icon on the top right has a lot of content, including a Navigator and Classic home. Spend some time looking through what’s available. Stay tuned for more. Next up is adding some content. Normal 0 false false false false EN-US X-NONE X-NONE /* 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-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0in; line-height:107%; 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:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Anatomy of a .NET Assembly - CLR metadata 1

  - by Simon Cooper

  Before we look at the bytes comprising the CLR-specific data inside an assembly, we first need to understand the logical format of the metadata (For this post I only be looking at simple pure-IL assemblies; mixed-mode assemblies & other things complicates things quite a bit). Metadata streams Most of the CLR-specific data inside an assembly is inside one of 5 streams, which are analogous to the sections in a PE file. The name of each section in a PE file starts with a ., and the name of each stream in the CLR metadata starts with a #. All but one of the streams are heaps, which store unstructured binary data. The predefined streams are: #~ Also called the metadata stream, this stream stores all the information on the types, methods, fields, properties and events in the assembly. Unlike the other streams, the metadata stream has predefined contents & structure. #Strings This heap is where all the namespace, type & member names are stored. It is referenced extensively from the #~ stream, as we'll be looking at later. #US Also known as the user string heap, this stream stores all the strings used in code directly. All the strings you embed in your source code end up in here. This stream is only referenced from method bodies. #GUID This heap exclusively stores GUIDs used throughout the assembly. #Blob This heap is for storing pure binary data - method signatures, generic instantiations, that sort of thing. Items inside the heaps (#Strings, #US, #GUID and #Blob) are indexed using a simple binary offset from the start of the heap. At that offset is a coded integer giving the length of that item, then the item's bytes immediately follow. The #GUID stream is slightly different, in that GUIDs are all 16 bytes long, so a length isn't required. Metadata tables The #~ stream contains all the assembly metadata. The metadata is organised into 45 tables, which are binary arrays of predefined structures containing information on various aspects of the metadata. Each entry in a table is called a row, and the rows are simply concatentated together in the file on disk. For example, each row in the TypeRef table contains: A reference to where the type is defined (most of the time, a row in the AssemblyRef table). An offset into the #Strings heap with the name of the type An offset into the #Strings heap with the namespace of the type. in that order. The important tables are (with their table number in hex): 0x2: TypeDef 0x4: FieldDef 0x6: MethodDef 0x14: EventDef 0x17: PropertyDef Contains basic information on all the types, fields, methods, events and properties defined in the assembly. 0x1: TypeRef The details of all the referenced types defined in other assemblies. 0xa: MemberRef The details of all the referenced members of types defined in other assemblies. 0x9: InterfaceImpl Links the types defined in the assembly with the interfaces that type implements. 0xc: CustomAttribute Contains information on all the attributes applied to elements in this assembly, from method parameters to the assembly itself. 0x18: MethodSemantics Links properties and events with the methods that comprise the get/set or add/remove methods of the property or method. 0x1b: TypeSpec 0x2b: MethodSpec These tables provide instantiations of generic types and methods for each usage within the assembly. There are several ways to reference a single row within a table. The simplest is to simply specify the 1-based row index (RID). The indexes are 1-based so a value of 0 can represent 'null'. In this case, which table the row index refers to is inferred from the context. If the table can't be determined from the context, then a particular row is specified using a token. This is a 4-byte value with the most significant byte specifying the table, and the other 3 specifying the 1-based RID within that table. This is generally how a metadata table row is referenced from the instruction stream in method bodies. The third way is to use a coded token, which we will look at in the next post. So, back to the bytes Now we've got a rough idea of how the metadata is logically arranged, we can now look at the bytes comprising the start of the CLR data within an assembly: The first 8 bytes of the .text section are used by the CLR loader stub. After that, the CLR-specific data starts with the CLI header. I've highlighted the important bytes in the diagram. In order, they are: The size of the header. As the header is a fixed size, this is always 0x48. The CLR major version. This is always 2, even for .NET 4 assemblies. The CLR minor version. This is always 5, even for .NET 4 assemblies, and seems to be ignored by the runtime. The RVA and size of the metadata header. In the diagram, the RVA 0x20e4 corresponds to the file offset 0x2e4 Various flags specifying if this assembly is pure-IL, whether it is strong name signed, and whether it should be run as 32-bit (this is how the CLR differentiates between x86 and AnyCPU assemblies). A token pointing to the entrypoint of the assembly. In this case, 06 (the last byte) refers to the MethodDef table, and 01 00 00 refers to to the first row in that table. (after a gap) RVA of the strong name signature hash, which comes straight after the CLI header. The RVA 0x2050 corresponds to file offset 0x250. The rest of the CLI header is mainly used in mixed-mode assemblies, and so is zeroed in this pure-IL assembly. After the CLI header comes the strong name hash, which is a SHA-1 hash of the assembly using the strong name key. After that comes the bodies of all the methods in the assembly concatentated together. Each method body starts off with a header, which I'll be looking at later. As you can see, this is a very small assembly with only 2 methods (an instance constructor and a Main method). After that, near the end of the .text section, comes the metadata, containing a metadata header and the 5 streams discussed above. We'll be looking at this in the next post. Conclusion The CLI header data doesn't have much to it, but we've covered some concepts that will be important in later posts - the logical structure of the CLR metadata and the overall layout of CLR data within the .text section. Next, I'll have a look at the contents of the #~ stream, and how the table data is arranged on disk.

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• I have 6 updates that won't install on Ubuntu 12.04?

  - by Taylor

  I'm an Ubuntu novice, so any help here is greatly appreciated! I'm running Ubuntu 12.04, and I have six updates that just won't install. I've tried Update Manger, sudo apt-get upgrade, and sudo apt-get update. Nothing has worked so far. Here are the details I get from Update Manager: installArchives() failed: Setting up linux-image-3.2.0-24-generic-pae (3.2.0-24.37) ... Running depmod. sh: 1: /usr/sbin/update-initramfs: not found Failed to create initrd image. dpkg: error processing linux-image-3.2.0-24-generic-pae (--configure): subprocess installed post-installation script returned error exit status 2 Setting up linux-image-3.2.0-27-generic-pae (3.2.0-27.43) ... No apport report written because MaxReports is reached already Running depmod. sh: 1: /usr/sbin/update-initramfs: not found Failed to create initrd image. dpkg: error processing linux-image-3.2.0-27-generic-pae (--configure): subprocess installed post-installation script returned error exit status 2 No apport report written because MaxReports is reached already Setting up linux-image-3.2.0-29-generic-pae (3.2.0-29.46) ... Running depmod. sh: 1: /usr/sbin/update-initramfs: not found Failed to create initrd image. dpkg: error processing linux-image-3.2.0-29-generic-pae (--configure): subprocess installed post-installation script returned error exit status 2 No apport report written because MaxReports is reached already Setting up udev (175-0ubuntu9.1) ... udev stop/waiting udev start/running, process 3685 /var/lib/dpkg/info/udev.postinst: 87: /var/lib/dpkg/info/udev.postinst: update-initramfs: not found dpkg: error processing udev (--configure): subprocess installed post-installation script returned error exit status 127 No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of xserver-xorg-core: xserver-xorg-core depends on udev (= 149); however: Package udev is not configured yet. dpkg: error processing xserver-xorg-core (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of fglrx: fglrx depends on xserver-xorg-core; however: Package xserver-xorg-core is not configured yet. dpkg: error processing fglrx (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of fglrx-amdcccle: fglrx-amdcccle depends on fglrx; however: Package fglrx is not configured yet. dpkg: error processing fglrx-amdcccle (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of linux-image-generic-pae: linux-image-generic-pae depends on linux-image-3.2.0-24-generic-pae; however: Package linux-image-3.2.0-24-generic-pae is not configured yet. dpkg: error processing linux-image-generic-pae (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of linux-generic-pae: linux-generic-pae depends on linux-image-generic-pae (= 3.2.0.24.26); however: Package linux-image-generic-pae is not configured yet. dpkg: error processing linux-generic-pae (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of xserver-xorg-video-intel: xserver-xorg-video-intel depends on xorg-video-abi-11; however: Package xorg-video-abi-11 is not installed. Package xserver-xorg-core which provides xorg-video-abi-11 is not configured yet. xserver-xorg-video-intel depends on xserver-xorg-core (= 2:1.10.99.901); however: Package xserver-xorg-core is not configured yet. dpkg: error processing xserver-xorg-video-intel (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of fglrx-dev:No apport report written because MaxReports is reached already fglrx-dev depends on fglrx; however: Package fglrx is not configured yet. dpkg: error processing fglrx-dev (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already Errors were encountered while processing: linux-image-3.2.0-24-generic-pae linux-image-3.2.0-27-generic-pae linux-image-3.2.0-29-generic-pae udev xserver-xorg-core fglrx fglrx-amdcccle linux-image-generic-pae linux-generic-pae xserver-xorg-video-intel fglrx-dev Error in function: Setting up linux-image-3.2.0-24-generic-pae (3.2.0-24.37) ... Running depmod. sh: 1: /usr/sbin/update-initramfs: not found Failed to create initrd image. dpkg: error processing linux-image-3.2.0-24-generic-pae (--configure): subprocess installed post-installation script returned error exit status 2 Setting up linux-image-3.2.0-29-generic-pae (3.2.0-29.46) ... Running depmod. sh: 1: /usr/sbin/update-initramfs: not found Failed to create initrd image. dpkg: error processing linux-image-3.2.0-29-generic-pae (--configure): subprocess installed post-installation script returned error exit status 2 Setting up linux-image-3.2.0-27-generic-pae (3.2.0-27.43) ... Running depmod. sh: 1: /usr/sbin/update-initramfs: not found Failed to create initrd image. dpkg: error processing linux-image-3.2.0-27-generic-pae (--configure): subprocess installed post-installation script returned error exit status 2 Setting up udev (175-0ubuntu9.1) ... udev stop/waiting udev start/running, process 3782 /var/lib/dpkg/info/udev.postinst: 87: /var/lib/dpkg/info/udev.postinst: update-initramfs: not found dpkg: error processing udev (--configure): subprocess installed post-installation script returned error exit status 127 dpkg: dependency problems prevent configuration of linux-image-generic-pae: linux-image-generic-pae depends on linux-image-3.2.0-24-generic-pae; however: Package linux-image-3.2.0-24-generic-pae is not configured yet. dpkg: error processing linux-image-generic-pae (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of xserver-xorg-core: xserver-xorg-core depends on udev (= 149); however: Package udev is not configured yet. dpkg: error processing xserver-xorg-core (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of fglrx: fglrx depends on xserver-xorg-core; however: Package xserver-xorg-core is not configured yet. dpkg: error processing fglrx (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of linux-generic-pae: linux-generic-pae depends on linux-image-generic-pae (= 3.2.0.24.26); however: Package linux-image-generic-pae is not configured yet. dpkg: error processing linux-generic-pae (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of xserver-xorg-video-intel: xserver-xorg-video-intel depends on xorg-video-abi-11; however: Package xorg-video-abi-11 is not installed. Package xserver-xorg-core which provides xorg-video-abi-11 is not configured yet. xserver-xorg-video-intel depends on xserver-xorg-core (= 2:1.10.99.901); however: Package xserver-xorg-core is not configured yet. dpkg: error processing xserver-xorg-video-intel (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of fglrx-amdcccle: fglrx-amdcccle depends on fglrx; however: Package fglrx is not configured yet. dpkg: error processing fglrx-amdcccle (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of fglrx-dev: fglrx-dev depends on fglrx; however: Package fglrx is not configured yet. dpkg: error processing fglrx-dev (--configure): dependency problems - leaving unconfigured

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• Dell Studio 1737 Overheating

  - by Sean

  I am using a Dell Studio 1737 laptop. I have been running Linux and have ran Windows recently for a very long time. I upgraded to the 10.10 distribution and since that distro, it seems that for some reason all Linuxes want to push my laptop to extremes. I have recently upgraded to Ubuntu 12.04 since I heart that it contains kernel fixes for overheating issues. 12.04 will actually eventually cool the system, but that is after the fans run to the point it sounds like a jet aircraft taking off and the laptop makes my hands sweat. In trying to combat the heat problems I have done the following: I installed the propriatery driver for my ATI Mobility HD 3600. I have tried both the one in the Additional Drivers and also tried ATI's latest greatest version. If I don't install this my laptop will overheat and shut off in minutes. Both seem to perform similarly, but the heat problem remains. I have tried limiting the CPU by installing the CPUFreq Indicator. This does help keep the machine from shutting off, but the heat is still uncomfortable to be around the machine. I usually run in power saver mode or run the cpu at 1.6 GHZ just to error on safety. I ran sensors-detect and here are the results: sean@sean-Studio-1737:~$ sudo sensors-detect # sensors-detect revision 5984 (2011-07-10 21:22:53 +0200) # System: Dell Inc. Studio 1737 (laptop) # Board: Dell Inc. 0F237N This program will help you determine which kernel modules you need to load to use lm_sensors most effectively. It is generally safe and recommended to accept the default answers to all questions, unless you know what you're doing. Some south bridges, CPUs or memory controllers contain embedded sensors. Do you want to scan for them? This is totally safe. (YES/no): y Module cpuid loaded successfully. Silicon Integrated Systems SIS5595... No VIA VT82C686 Integrated Sensors... No VIA VT8231 Integrated Sensors... No AMD K8 thermal sensors... No AMD Family 10h thermal sensors... No AMD Family 11h thermal sensors... No AMD Family 12h and 14h thermal sensors... No AMD Family 15h thermal sensors... No AMD Family 15h power sensors... No Intel digital thermal sensor... Success! (driver `coretemp') Intel AMB FB-DIMM thermal sensor... No VIA C7 thermal sensor... No VIA Nano thermal sensor... No Some Super I/O chips contain embedded sensors. We have to write to standard I/O ports to probe them. This is usually safe. Do you want to scan for Super I/O sensors? (YES/no): y Probing for Super-I/O at 0x2e/0x2f Trying family `National Semiconductor/ITE'... No Trying family `SMSC'... No Trying family `VIA/Winbond/Nuvoton/Fintek'... No Trying family `ITE'... No Probing for Super-I/O at 0x4e/0x4f Trying family `National Semiconductor/ITE'... Yes Found `ITE IT8512E/F/G Super IO' (but not activated) Some hardware monitoring chips are accessible through the ISA I/O ports. We have to write to arbitrary I/O ports to probe them. This is usually safe though. Yes, you do have ISA I/O ports even if you do not have any ISA slots! Do you want to scan the ISA I/O ports? (YES/no): y Probing for `National Semiconductor LM78' at 0x290... No Probing for `National Semiconductor LM79' at 0x290... No Probing for `Winbond W83781D' at 0x290... No Probing for `Winbond W83782D' at 0x290... No Lastly, we can probe the I2C/SMBus adapters for connected hardware monitoring devices. This is the most risky part, and while it works reasonably well on most systems, it has been reported to cause trouble on some systems. Do you want to probe the I2C/SMBus adapters now? (YES/no): y Using driver `i2c-i801' for device 0000:00:1f.3: Intel ICH9 Module i2c-i801 loaded successfully. Module i2c-dev loaded successfully. Now follows a summary of the probes I have just done. Just press ENTER to continue: Driver `coretemp': * Chip `Intel digital thermal sensor' (confidence: 9) To load everything that is needed, add this to /etc/modules: #----cut here---- # Chip drivers coretemp #----cut here---- If you have some drivers built into your kernel, the list above will contain too many modules. Skip the appropriate ones! Do you want to add these lines automatically to /etc/modules? (yes/NO)y Successful! Monitoring programs won't work until the needed modules are loaded. You may want to run 'service module-init-tools start' to load them. Unloading i2c-dev... OK Unloading i2c-i801... OK Unloading cpuid... OK sean@sean-Studio-1737:~$ sudo service module-init-tools start module-init-tools stop/waiting I also tried installing i8k but that didn't work since it didn't seem to be able to communicate with the hardware (probably for different kind of device). Also I ran acpi -V and here are the results: Battery 0: Full, 100% Battery 0: design capacity 613 mAh, last full capacity 260 mAh = 42% Adapter 0: on-line Thermal 0: ok, 49.0 degrees C Thermal 0: trip point 0 switches to mode critical at temperature 100.0 degrees C Thermal 1: ok, 48.0 degrees C Thermal 1: trip point 0 switches to mode critical at temperature 100.0 degrees C Thermal 2: ok, 51.0 degrees C Thermal 2: trip point 0 switches to mode critical at temperature 100.0 degrees C Cooling 0: LCD 0 of 15 Cooling 1: Processor 0 of 10 Cooling 2: Processor 0 of 10 I have hit a wall and don't know what to do now. Any advice is appreciated.

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