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  • Apache Alias subfolder and starting with dot

    - by MauricioOtta
    I have a multi purpose server running ArchLinux that currently serves multiple virtual hosts from /var/www/domains/EXAMPLE.COM/html /var/www/domains/EXAMPLE2.COM/html I deploy those websites (mostly using Kohana framework) using a Jenkins job by checking out the project, removes the .git folder and ssh-copy the tar.gz to /var/www/domains/ on the server and untars it. Since I don't want to have to re-install phpMyAdmin after each deploy, I decided to use an alias. I would like the alias to be something like /.tools/phpMyAdmin/ so I could have more "tools" later if I wanted to. I have tried just changing the default httpd-phpmyadmin.conf that was installed by following the official WIKI: https://wiki.archlinux.org/index.php/Phpmyadmin Alias /.tools/phpMyAdmin/ "/usr/share/webapps/phpMyAdmin" <Directory "/usr/share/webapps/phpMyAdmin"> AllowOverride All Options FollowSymlinks Order allow,deny Allow from all php_admin_value open_basedir "/var/www/:/tmp/:/usr/share/webapps/:/etc/webapps:/usr/share/pear/" </Directory> Changing only that, doesn't seem to work with my current setup on the server, and apache forwards the request to the framework which 404s (as there's no route to handle /.tools/phpAdmin). I have Mass Virtual hosting enable and setup like this: # # Use name-based virtual hosting. # NameVirtualHost *:8000 # get the server name from the Host: header UseCanonicalName On # splittable logs LogFormat "%{Host}i %h %l %u %t \"%r\" %s %b" vcommon CustomLog logs/access_log vcommon <Directory /var/www/domains> # ExecCGI is needed here because we can't force # CGI execution in the way that ScriptAlias does Options FollowSymLinks ExecCGI AllowOverride All Order allow,deny Allow from all </Directory> RewriteEngine On # a ServerName derived from a Host: header may be any case at all RewriteMap lowercase int:tolower ## deal with normal documents first: # allow Alias /icons/ to work - repeat for other aliases RewriteCond %{REQUEST_URI} !^/icons/ # allow CGIs to work RewriteCond %{REQUEST_URI} !^/cgi-bin/ # do the magic RewriteCond %{SERVER_NAME} ^(www\.|)(.*) RewriteRule ^/(.*)$ /var/www/domains/${lowercase:%2}/html/$1 ## and now deal with CGIs - we have to force a MIME type RewriteCond %{REQUEST_URI} ^/cgi-bin/ RewriteRule ^/(.*)$ /var/www/domains/${lowercase:%{SERVER_NAME}}/cgi-bin/$1 [T=application/x-httpd-cgi] There is also nginx running on this server on port 80 as a reverse proxy for Apache: location ~ \.php$ { proxy_pass http://127.0.0.1:8000; } Everything else was setup by following the official WIKI so I don't think those would cause trouble. Do I need to have the alias for phpMyAdmin setup along the mass virtual hosting or can it be in a separate include file for that alias to work?

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  • How to generate and encode (for use in GA), random, strict, binary rooted trees with N leaves?

    - by Peter Simon
    First, I am an engineer, not a computer scientist, so I apologize in advance for any misuse of nomenclature and general ignorance of CS background. Here is the motivational background for my question: I am contemplating writing a genetic algorithm optimizer to aid in designing a power divider network (also called a beam forming network, or BFN for short). The BFN is intended to distribute power to each of N radiating elements in an array of antennas. The fraction of the total input power to be delivered to each radiating element has been specified. Topologically speaking, a BFN is a strictly binary, rooted tree. Each of the (N-1) interior nodes of the tree represents the input port of an unequal, binary power splitter. The N leaves of the tree are the power divider outputs. Given a particular power divider topology, one is still free to map the power divider outputs to the array inputs in an arbitrary order. There are N! such permutations of the outputs. There are several considerations in choosing the desired ordering: 1) The power ratio for each binary coupler should be within a specified range of values. 2) The ordering should be chosen to simplify the mechanical routing of the transmission lines connecting the power divider. The number of ouputs N of the BFN may range from, say, 6 to 22. I have already written a genetic algorithm optimizer that, given a particular BFN topology and desired array input power distribution, will search through the N! permutations of the BFN outputs to generate a design with compliant power ratios and good mechanical routing. I would now like to generalize my program to automatically generate and search through the space of possible BFN topologies. As I understand it, for N outputs (leaves of the binary tree), there are $C_{N-1}$ different topologies that can be constructed, where $C_N$ is the Catalan number. I would like to know how to encode an arbitrary tree having N leaves in a way that is consistent with a chromosomal description for use in a genetic algorithm. Also associated with this is the need to generate random instances for filling the initial population, and to implement crossover and mutations operators for this type of chromosome. Any suggestions will be welcome. Please minimize the amount of CS lingo in your reply, since I am not likely to be acquainted with it. Thanks in advance, Peter

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  • Transient network dropout for Xen DomU's

    - by Stephen C
    We've got a CentOS server running a cluster of virtuals. Occasionally the cluster's internal network drops out for a minute or so ... and then comes back. The problem is somehow related to the actual network traffic, but it is not a simple load issue. (The system is generally lightly loaded, and the problem occurs irrespective of actual load.) The setup: CentOS 5.6 on Dom0, various CentOS on the DomU's Hardware - a Dell R710 with a BroadCom NextXpress 2 NIC (sigh) using the latest drivers for the NIC from BroadCom Xen configured to use network-bridge and vif-bridge Some iptable tweaks to route an unrelated port to one of the virtuals. The system has one externally visible IP address, and Dom0 runs an Apache httpd configured with a number of virtual hosts each of which reverse proxies to web servers running on the virtuals. (The virtuals have to be NAT'ed, primarily because we don't have enough allocated public IP addresses.) The symptoms: Works fine most of the time. When someone tries to UPLOAD a large file to one virtuals, the internal network drops out ... for all virtuals: The Dom0 httpd sees a network timeout talking to the backend server on the virtual and reports a 502. A previously established ssh connection from Dom0 to any of the DomU's freezes. Our monitoring shows ping failures for traffic between virtuals. The Xen consoles to the DomU's do not freeze. No log messages in any log files that I can see, on either Dom0 or the DomU's ... apart from the Dom0 httpd logs. After a minute or so, the problem clears by itself. This is 100% reproducible. What we've tried: Downloading, building and installing the latest BNX2 driver on Dom0 Turning off MSI on the NIC - adding "options bnx2 disable_msi=1" to /etc/modprobe.conf Turning off tcp segmentation offload - "ethtool -K eth0 tso off". Sacrificing a black rooster at midnight. I've exhausted all my options apart from switching to KVM ... or slaughtering more roosters. Any suggestions?

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  • How to obtain a pointer out of a C++ vtable?

    - by Josh Haberman
    Say you have a C++ class like: class Foo { public: virtual ~Foo() {} virtual DoSomething() = 0; }; The C++ compiler translates a call into a vtable lookup: Foo* foo; // Translated by C++ to: // foo->vtable->DoSomething(foo); foo->DoSomething(); Suppose I was writing a JIT compiler and I wanted to obtain the address of the DoSomething() function for a particular instance of class Foo, so I can generate code that jumps to it directly instead of doing a table lookup and an indirect branch. My questions are: Is there any standard C++ way to do this (I'm almost sure the answer is no, but wanted to ask for the sake of completeness). Is there any remotely compiler-independent way of doing this, like a library someone has implemented that provides an API for accessing a vtable? I'm open to completely hacks, if they will work. For example, if I created my own derived class and could determine the address of its DoSomething method, I could assume that the vtable is the first (hidden) member of Foo and search through its vtable until I find my pointer value. However, I don't know a way of getting this address: if I write &DerivedFoo::DoSomething I get a pointer-to-member, which is something totally different. Maybe I could turn the pointer-to-member into the vtable offset. When I compile the following: class Foo { public: virtual ~Foo() {} virtual void DoSomething() = 0; }; void foo(Foo *f, void (Foo::*member)()) { (f->*member)(); } On GCC/x86-64, I get this assembly output: Disassembly of section .text: 0000000000000000 <_Z3fooP3FooMS_FvvE>: 0: 40 f6 c6 01 test sil,0x1 4: 48 89 74 24 e8 mov QWORD PTR [rsp-0x18],rsi 9: 48 89 54 24 f0 mov QWORD PTR [rsp-0x10],rdx e: 74 10 je 20 <_Z3fooP3FooMS_FvvE+0x20> 10: 48 01 d7 add rdi,rdx 13: 48 8b 07 mov rax,QWORD PTR [rdi] 16: 48 8b 74 30 ff mov rsi,QWORD PTR [rax+rsi*1-0x1] 1b: ff e6 jmp rsi 1d: 0f 1f 00 nop DWORD PTR [rax] 20: 48 01 d7 add rdi,rdx 23: ff e6 jmp rsi I don't fully understand what's going on here, but if I could reverse-engineer this or use an ABI spec I could generate a fragment like the above for each separate platform, as a way of obtaining a pointer out of a vtable.

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  • Recommendations or advice for shared computer control

    - by Telemachus
    Basic scenario: we are a school (overwhelmingly Mac, some Windows machines via BootCamp), and we are considering using DeepFreeze to guard the state of our shared machines. We have roughly 250 machines that are either shared laptops (which move around quite a bit) or common desktops in public spaces. Obviously, we spend a lot of time maintaining the machines and trying to reverse the inevitable drift as people make changes to the computers. We would like to control the integrity of the build we initially put onto the machines without handcuffing users and especially without using Mac's Parental Control software. (We've had nothing but bad experiences with it.) We've been testing DeepFreeze, and so far it's very impressive. But I'm curious to hear if people who have used DeepFreeze or any similar software have any advice or tips. To get things started, I will post my own pros and cons. Pros: The state of the machine is frozen in our chosen state. All changes made to the machine after that disappear upon restart. (This frozen state really appears to cover everything. I have yet to do something to a test machine that isn't instantly healed.) Tons of trivial but time-consuming maintenance is gone in an instant. Also, lots of not-so-trivial breakage should be avoided. There are good options, however, that allow you to create storage spaces either globally or per user. (Otherwise, stored files disappear upon reboot. For some machines, this is a good option itself. Simply warn people: save externally or else; this machine is a kiosk, not your storage space.) Cons: Anytime we actually need to make a change (upgrade basic software, add a printer or an airport permanently, add new software), the process is a bit more complex. Reboot into a special mode (thaw state), make changes, reboot back into frozen mode. If (when?) we forget this, we will end up making changes that disappear after the next reboot. Users will forget to save files correctly (in the right place or externally), and we will have loud, unpleasant conversations explaining that we can't recover the document they worked on all afternoon yesterday. The machine rebooted. The file is gone. These are my initial thoughts, but I would love to hear from other people who have experience with DeepFreeze or any similar software. What should we be careful about? Do the pros outweigh the cons? What gains or problems am I not seeing? Thanks.

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  • Why can host and nslookup resolve a name but dig cannot?

    - by musashiXXX
    Can anyone tell me why this is happening? I can resolve a hostname using host and/or nslookup but forward lookups do not work with dig; reverse lookups do: musashixxx@box:~$ host someserver someserver.somenet.internal has address 192.168.0.252 musashixxx@box:~$ host 192.168.0.252 252.0.168.192.in-addr.arpa domain name pointer someserver.somenet.internal. musashixxx@box:~$ nslookup someserver Server: 192.168.0.253 Address: 192.168.0.253#53 Name: someserver.somenet.internal Address: 192.168.0.252 musashixxx@box:~$ nslookup 192.168.0.252 Server: 192.168.0.253 Address: 192.168.0.253#53 252.0.168.192.in-addr.arpa name = someserver.somenet.internal. musashixxx@box:~$ dig someserver ; <<>> DiG 9.8.1-P1 <<>> someserver ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 55306 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;someserver. IN A ;; Query time: 0 msec ;; SERVER: 192.168.0.253#53(192.168.0.253) ;; WHEN: Wed Oct 3 15:47:38 2012 ;; MSG SIZE rcvd: 27 musashixxx@box:~$ dig -x 192.168.0.252 ; <<>> DiG 9.8.1-P1 <<>> -x 192.168.0.252 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28126 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;252.0.168.192.in-addr.arpa. IN PTR ;; ANSWER SECTION: 252.0.168.192.in-addr.arpa. 3600 IN PTR someserver.somenet.internal. ;; Query time: 0 msec ;; SERVER: 192.168.0.253#53(192.168.0.253) ;; WHEN: Wed Oct 3 15:49:11 2012 ;; MSG SIZE rcvd: 86 Here's what my resolv.conf looks like: nameserver 192.168.0.253 search somenet.internal Is this behavior normal? Any thoughts?

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  • What the best way to achieve RPO of zero and lowest possible RTO (less than 15 minutes) with SQL 2008 R2?

    - by Adrian Hope-Bailie
    We are running a payments (EFT transaction processing) application which is processing high volumes of transactions 24/7 and are currently investigating a better way of doing DB replication to our disaster recovery site. Our current and previous strategies have included using both DoubleTake and Redgate to replicate data to a warm stand-by. DoubleTake is the supported solution from the payments software vendor however their (DoubleTake's) support in South Africa is very poor. We had a few issues and simply couldn't ever resolve them so we had to give up on DoubleTake. We have been using Redgate to manually read the data from the primary site (via queries) and write to the DR site but this is: A bad solution Getting the software vendor hot and bothered whenever we have support issues as it has a tendency to interfere with the payment application which is very DB intensive. We recently upgraded the whole system to run on SQL 2008 R2 Enterprise which means we should probably be looking at using some of the built-in replication features. The server has 2 fairly large databases with a mixture of tables containing highly volatile transactional data and pretty static configuration data. Replication would be done over a WAN link to a separate physical site and needs to achieve the following objectives. RPO: Zero loss - This is transactional data with financial impact so we can't lose anything. RTO: Tending to zero - The business depends on our ability to process transactions every minute we are down we are losing money I have looked at a few of the other questions/answers but none meet our case exactly: SQL Server 2008 failover strategy - Log shipping or replication? How to achieve the following RTO & RPO with logshipping only using SQL Server? What is the best of two approaches to achieve DB Replication? My current thinking is that we should use mirroring but I am concerned that for RPO:0 we will need to do delayed commits and this could impact the performance of the primary DB which is not an option. Our current DR process is to: Stop incoming traffic to the primary site and allow all in-flight transaction to complete. Allow the replication to DR to complete. Change network routing to route to DR site. Start all applications and services on the secondary site (Ideally we can change this to a warmer stand-by whereby the applications are already running but not processing any transactions). In other words the DR database needs to, as quickly as possible, catch up with primary and be ready for processing as the new primary. We would then need to be able to reverse this when we are ready to switch back. Is there a better option than mirroring (should we be doing log-shipping too) and can anyone suggest other considerations that we should keep in mind?

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  • Primary/secondary ethernet interfaces via NetworkManager in Ubuntu 9.10

    - by Josh
    I have an Ubuntu 9.10 machine with three ethernet interfaces, eth0, eth1 and eth2. eth2 is connected to a private network. eth0 and eth2 are connected to two different LANs. Either one will provide access to the internet. All three networks have DHCP servers. Using Ubuntu's the default settings (And Gnome), when I boot up all the interfaces are active and my system gets three IP addresses. However any attempt to access the internet results in connection timeouts and other weirdness. I suspect that traffic is going out on one NIC (like eth0) and coming back in on another (like eth1). I'm not sure what's going on. The only way I can access the internet at the moment is to bring two of the devices down with ifdown. How can I configure eth0 as my primary interface so all trafic goes out by default on that interface, while keeping the other two active? Also, I want to make sure Avahi broadcasts properly on all three IPs so that the computers on the LAN of eth1 can still connect to myHostname.local... EDIT: Here's my routing table: Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 172.16.151.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2 172.16.30.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.1.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 0.0.0.0 172.16.30.2 0.0.0.0 UG 0 0 0 eth0 0.0.0.0 10.1.0.1 0.0.0.0 UG 0 0 0 eth1 I want the 172.16.30.2 network to be the primary one and the 10.1.0.0 network to be the secondary one. EDIT2: My nameservers are also incorrect. It seems like Ubuntu is bringing the networks up in order, eth0, then 1, then 2, and the DHCP information from eth1 is overriding eth0, and eth2 is overriding eth1. How can I reverse this so the DHCP information from eth0 is the "master"? EDIT3: This seems to be an issue with Gnome's NetworkManager.

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  • Do You Really Know Your Programming Languages?

    - by Kristopher Johnson
    I am often amazed at how little some of my colleagues know or care about their craft. Something that constantly frustrates me is that people don't want to learn any more than they need to about the programming languages they use every day. Many programmers seem content to learn some pidgin sub-dialect, and stick with that. If they see a keyword or construct that they aren't familiar with, they'll complain that the code is "tricky." What would you think of a civil engineer who shied away from calculus because it had "all those tricky math symbols?" I'm not suggesting that we all need to become "language lawyers." But if you make your living as a programmer, and claim to be a competent user of language X, then I think at a minimum you should know the following: Do you know the keywords of the language and what they do? What are the valid syntactic forms? How are memory, files, and other operating system resources managed? Where is the official language specification and library reference for the language? The last one is the one that really gets me. Many programmers seem to have no idea that there is a "specification" or "standard" for any particular language. I still talk to people who think that Microsoft invented C++, and that if a program doesn't compile under VC6, it's not a valid C++ program. Programmers these days have it easy when it comes to obtaining specs. Newer languages like C#, Java, Python, Ruby, etc. all have their documentation available for free from the vendors' web sites. Older languages and platforms often have standards controlled by standards bodies that demand payment for specs, but even that shouldn't be a deterrent: the C++ standard is available from ISO for $30 (and why am I the only person I know who has a copy?). Programming is hard enough even when you do know the language. If you don't, I don't see how you have a chance. What do the rest of you think? Am I right, or should we all be content with the typical level of programming language expertise? Update: Several great comments here. Thanks. A couple of people hit on something that I didn't think about: What really irks me is not the lack of knowledge, but the lack of curiosity and willingness to learn. It seems some people don't have any time to hone their craft, but they have plenty of time to write lots of bad code. And I don't expect people to be able to recite a list of keywords or EBNF expressions, but I do expect that when they see some code, they should have some inkling of what it does. Few people have complete knowledge of every dark corner of their language or platform, but everyone should at least know enough that when they see something unfamiliar, they will know how to get whatever additional information they need to understand it.

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  • Squid on windows loadbalancing only to one server

    - by Martin L.
    After thousands of googles and trying days i cant get the load balancer/failover in squid on windows to work. Iam using squid 2.7. My webservers are 2 single NIC lighttpd and one dual nic lighttpd. server1 in this example is running squid on port 80 and lighttpd on port 8080 (just to test) Requirements: All 3 webservers running lighttpd should be balanced two option for load balancing: Best would be if server1 is busy server2 takes over, if server2 is busy server3 takes over, etc.. Round robin style evenly distributed load. Eg server1 takes first call, server2 second etc.. All requests should be treated the same way (no url rewriting or so on) Sent host headers have to be redirected to every server as http host header, speaking of "server1", "server1.company.internal" and "10.211.1.1". My approach: acl all src all acl manager proto cache_object http_port 80 accel defaultsite=server1.company.internal vhost #reverse proxy entries cache_peer 10.211.2.1 parent 8080 0 no-query originserver round-robin login=PASS name=server1_nic1 cache_peer 10.211.1.2 parent 80 0 no-query originserver round-robin login=PASS name=server2_nic1 cache_peer 10.211.2.3 parent 8080 0 no-query originserver round-robin login=PASS name=server3_nic1 cache_peer 10.211.2.4 parent 8080 0 no-query originserver round-robin login=PASS name=server3_nic2 #decl of names of squid host acl registered_name_hostdomain dstdomain server1.company.internal acl registered_name_host dstdomain server1 #ip of squid host acl registered_name_ip dstdomain 10.211.2.1 # access: redirects the correct squid hostname http_access allow registered_name_hostdomain http_access allow registered_name_host http_access allow registered_name_ip http_access deny all cache_peer_access server1_nic1 allow registered_name_hostdomain cache_peer_access server1_nic1 allow registered_name_host cache_peer_access server1_nic1 allow registered_name_ip cache_peer_access server2_nic1 allow registered_name_hostdomain cache_peer_access server2_nic1 allow registered_name_host cache_peer_access server2_nic1 allow registered_name_ip cache_peer_access server3_nic1 allow registered_name_hostdomain cache_peer_access server3_nic1 allow registered_name_host cache_peer_access server3_nic1 allow registered_name_ip cache_peer_access server3_nic2 allow registered_name_hostdomain cache_peer_access server3_nic2 allow registered_name_host cache_peer_access server3_nic2 allow registered_name_ip cache_peer_access server1_nic1 deny all cache_peer_access server2_nic1 deny all cache_peer_access server3_nic1 deny all cache_peer_access server3_nic2 deny all never_direct allow all Problems: Load balancer does not load balance other than to first server. Only if the first server is killed in any way the second will take over. I have seen the others working at some point, but definitely not as the intended load balancing described above. If the cache_peer_access is not defined sometimes the wrong hostname is sent to the backend webserver and this always depends on the defaultsite= parameter. Probably because the host header on the request to squid is not set and its replaced by defaultsite. Leaving out defaultsite didnt solve the problem. The only workaround i found for this is the current approach with cache_peer_access. Questions: Does the cache_peer_access influence the round-robin? Is there a better workaround to pass the host header to the backed webservers? Which parameters do increase the speed of load balancing or does anyone have a better approach? -Martin

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  • DNS Issue Windows 2003 AD-The server holding the PDC role is down

    - by Dave M
    Our network of Windows 2003 and Windows 2008 servers suddenly hasDNS issues. There are 7 DCs. Two at our main office and one each at branch sites (one branch has two a 2008R2 and WIN2K3) Only two are WIN2008R2 Running DCDIAG on the WIN2K3 at main site (DC1) reports no issues. Running at any branch site reports two issues All other test pass. The server DC1 can be PINGed by name from any site Starting test: frsevent There are warning or error events within the last 24 hours after the SYSVOL has been shared. Failing SYSVOL replication problems may cause Group Policy problems. Starting test: FsmoCheck Warning: DcGetDcName(PDC_REQUIRED) call failed, error 1355 A Primary Domain Controller could not be located. The server holding the PDC role is down. Netdom.exe /query DC reports the expected servers. netdom query fsmo This reports the server at the main office holds the following roles: * Schema owner Domain role owner PDC role RID pool manager Infrastructure owner In the DNS management snap-in, DC1 appears as DNS server but does not appear in _msdcs-dc-_sites-Default-First-Site-Name-_TCP There is no _ldap or –kerberos record pointing to DC1 Same issue msdcs-dc-_sites- -_TCP Again there is no _ldap or –kerberos record pointing to DC1 Under Domain DNS Zones there is no entry for the server. This is the case for any _tcp folder in the DNS. The server DC1 appears correctly as a name server in the Reverse Lookup Zone. There is a Host(A) record for DC1 but in the Forward Lookup Zone there is no (same as parent folder) Host(A) for the DC1 server but such an entry exists for the other DCs at branch sites and the other DC at the main office. We have tried stopping and starting the netlogon service, restarting DNS and also dcdiag /fix. Netdiag reports error: Trust relationship test. . . . . . : Failed [FATAL] Secure channel to domain 'XXX' is broken. [ERROR_NO_LOGON_SERVERS] [WARNING] Failed to query SPN registration on DC- One entry for each branch DC All braches lsit the problem server and it can be Pinged by name from any branch Fixing is number one priority but also would like to determine the casue.

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  • ntpdate works, but ntpd can't synchronize

    - by dafydd
    This is in RHEL 5.5. First, ntpdate to the remote host works: $ ntpdate XXX.YYY.4.21 24 Oct 16:01:17 ntpdate[5276]: adjust time server XXX.YYY.4.21 offset 0.027291 sec Second, here are the server lines in my /etc/ntp.conf. All restrict lines have been commented out for troubleshooting. server 127.127.1.0 server XXX.YYY.4.21 I execute service ntpd start and check with ntpq: $ ntpq ntpq> peer remote refid st t when poll reach delay offset jitter ============================================================================== *LOCAL(0) .LOCL. 5 l 36 64 377 0.000 0.000 0.001 timeserver.doma .LOCL. 1 u 39 128 377 0.489 51.261 58.975 ntpq> opeer remote local st t when poll reach delay offset disp ============================================================================== *LOCAL(0) 127.0.0.1 5 l 40 64 377 0.000 0.000 0.001 timeserver.doma XXX.YYY.22.169 1 u 43 128 377 0.489 51.261 58.975 XXX.YYY.22.169 is the address of the host I'm working on. A reverse lookup on the IP address in my ntp.conf file validates that the ntpq output is correctly naming the remote server. However, as you can see, it appears to just roll over to my .LOCL. time server. Also, ntptrace just returns the local time server, and ntptrace XXX.YYY.4.21 times out. $ ntptrace localhost.localdomain: stratum 6, offset 0.000000, synch distance 0.948181 $ ntptrace XXX.YYY.4.21 XXX.YYY.4.21: timed out, nothing received ***Request timed out This looks like my ntp daemon is just querying itself. I am thinking about the possibility that the router-I-don't-control between my test network timeserver and the corporate network timeserver is blocking on source port. (I think ntpdate sends on port 123, which gets it around that filter and is why I can't use it while ntpd is running.) I have email in to the network folks to check that. Finally, telnet XXX.YYY.4.21 123 never times out or completes a connection. The questions: What am I missing, here? What else can I check to try to figure out where this connection is failing? Would strace ntptrace XXX.YYY.4.21 show me the source port ntptrace is sending from? I can deconstruct most strace calls, but I can't figure out the location of that datum. If I can't directly examine the gateway router between my test network and the timeserver, how might I build evidence that it's responsible for these disconnections? Alternately, how might I rule it out?

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  • Htaccess strange behaviour with Nginx

    - by Termos
    I have a site running on Nginx (v1.0.14) serving as reverse proxy which proxies requests to Apache (v2.2.19). So Nginx runs on port 80, Apache is on 8080. Overall site works fine except that i cannot block access to certain directories with .htaccess file. For example i have 'my-protected-directory' on 'www.site.com' Inside it i have htaccess with following code: <Files *> order deny,allow deny from all allow from 1.2.3.4 <--- my ip address here </Files> When i try to access this page with my ip (1.2.3.4) i get 404 error which is not what i expect: http://www.site.com/my-protected-directory However everything works as expected when this page is served directly by Apache. I can see this page, everyone else can't. http://www.site.com:8080/my-protected-directory Update. Nginx config (7.1.3.7 is site ip.): user apache; worker_processes 4; error_log logs/error.log; pid logs/nginx.pid; events { worker_connections 1024; } http { include mime.types; default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; sendfile on; keepalive_timeout 65; gzip on; gzip_min_length 1024; gzip_http_version 1.1; gzip_proxied any; gzip_comp_level 5; gzip_types text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript image/x-icon; server { listen 80; server_name www.site.com site.com 7.1.3.7; access_log logs/host.access.log main; # serve static files location ~* ^.+.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|doc|xls|exe|pdf|ppt|txt|tar|mid|midi|wav|bmp|rtf|js)$ { root /var/www/vhosts/www.site.com/httpdocs; proxy_set_header Range ""; expires 30d; } # pass requests for dynamic content to Apache location / { proxy_redirect off; proxy_set_header X-Real-IP $remote_addr; proxy_set_header Host $http_host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Range ""; proxy_pass http://7.1.3.7:8080; } } Could please anyone tell me what is wrong and how this can be fixed ?

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  • I can't connect to mysql on a remote server

    - by eisaacson
    I'm trying to connect from an Ubuntu server to a RHEL6 server using mysql. I've tried telneting into the server as well as trying to connect with mysql. I've tried commenting out the bind-address but didn't have any success with that either. I don't get an error code or anything with telnet. It just fails after a minute or so. With mysql, I get this error code ERROR 2003 (HY000): Can't connect to MySQL server on 'SERVER_IP' (111). "SERVER_IP" is of course a placeholder where actual error gives that actual IP. I've included my my.cnf as well as well as my iptables from the destination server. On Destination Server... my.cnf: [mysqld] bind-address=0.0.0.0 tmp_table_size=512M max_heap_table_size=512M sort_buffer_size=32M read_buffer_size=128K read_rnd_buffer_size=256K table_cache=2048 key_buffer_size=512M thread_cache_size=50 query_cache_type=1 query_cache_size=256M query_cache_limit=24M #query_alloc_block_size=128 #query_cache_min_res_unit=128 innodb_log_buffer_size=16M innodb_flush_log_at_trx_commit=2 innodb_file_per_table innodb_log_files_in_group=2 innodb_buffer_pool_size=32G innodb_log_file_size=512M innodb_additional_mem_pool_size=20M join_buffer_size=128K max_allowed_packet=100M max_connections=256 wait_timeout=28800 interactive_timeout=3600 # modify isolation method for faster inserting. # Do not uncomment the line below unless you understand what this does. # transaction-isolation = READ-COMMITTED # do not reverse lookup clients skip-name-resolve #long_query_time=6 #log_slow_queries=/var/log/mysqld-slow.log #log_queries_not_using_indexes=On #log_slow_admin_statements=On datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 #Added by Magento ECG long_query_time=1 slow_query_log [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid iptables: :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT -A INPUT -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 225 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT -A INPUT -m state --state NEW -m tcp -p tcp -i eth1 --dport 11211 -j ACCEPT -A INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -j REJECT --reject-with icmp-host-prohibited COMMIT sudo netstat -ntpl Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:11211 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:2123 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:1581 0.0.0.0:* LISTEN - tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN - tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN - tcp 0 0 :::11211 :::* LISTEN - tcp 0 0 :::22 :::* LISTEN - tcp 0 0 :::225 :::* LISTEN -

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  • iotop for Linux kernel 2.6.18

    - by Lightsauce
    So it has to come to my attention that iotop isn't availalbe for 2.6.18 since it's less than 2.6.20 and requires Python 2.6+. I've done some research and came across this article: http://lserinol.blogspot.com/2009/09/io-usage-per-process-on-linux.html According to this, if these process have io stats in /proc/pid#/io (where pid# is the process #) it's doable regardless of the kernel version. So, in reality, I could upgrade Python to 2.6 and test out iotop. However, my flavor of Linux, CentOS release 5.5 (Final), only supports Python 2.4.3-44.el5 currently. If I were to do uninstall from yum, it doesn't look so pretty. It ends up wanting to uninstall 235 packages, most of which are very important! I read in one place, online (I forget the URL from yesterday), that you can install Python 2.6+ parallel to this one, and have the rpm install for iotop use that. Well, I didn't choose that route. I figured, what the heck, lets write iotop (not copying it, but reverse engineering it without actually looking at it's code/it in use) in bash. I thought it would just grab the /proc/pid#/io file and parse stats. So I wrote a script to grab the top 10 rchar, wchar, read_bytes, and write_bytes by collecting all these stats from all the /proc/pid#/io files, sorting them by each metric, then grabbing the top 10 highest values. The conclusion, the data seems completely useless. Does anybody know any resources for advanced Linux where I can figure out how to take these /proc/pid#/ directories and figure out what the heck they are doing with io on the disk? My main goal is to figure out what exactly is causing high load on my disk. I just know it's on the / partition (/dev/sda2 in this case), and I'm not really sure how to narrow it down without the help of iotop. If I run iostat to grab metrics for 1 minute, every second, the first result it gives me shows a high 'kB_read/s', so that makes me think, it's reading mostly. However, if I watch the update it gives me every second, it's actually just showing values for kB_wrtn/s. This makes me think the initial value iostat gives me is misleading.

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  • ssh, "Last Login", `last` and OS X

    - by allentown
    I have hit the googles as much as I can on this, being specific to OS X, I am not finding an answer. Nothing is wrong, but curiosity levels are high. $ssh [email protected] Password: Last login: Wed Apr 7 21:28:03 2010 from my-laptop.local ^lonely tylenol^ Line 1 is my command line 2 is the shell asking for the password line 3 is where my question comes from line 4 comes out of /etc/motd I can find nothing in ~/ of an of the .bash* files that contains the string "Last Login", and would like to alter it. It performs some type of hostname lookup, which I can not determine. If I ssh to another host: $ssh [email protected] Last login: Wed Apr 7 21:14:51 2010 from 123-234-321-123-some.cal.isp.net.example hi there, you are on box 456 line 1 is my command line 2 is again, where my question comes from line 3 is from /etc/motd *The dash'd IP address is not reversed On this remote host, I have ~/.ssh and it's corresponding keys set up, so there was no password request Where is the "Last Login:" coming from, where does the date stamp come from, and most importantly, where does the hostname come from? While on [email protected] (box 456) $echo hostname remote.location.example456.com Or with dig, to make sure I have rDNS/PTR set up, for which I am not authoritative, but my ISP has correctly set... $dig -x 123.234.321.123 PTR remote.location.example456.com or $dig PTR 123.321.234.123.in-addr.arpa. +short remote.location.example456.com. my previous hostname used to be 123-234-321-123-some.cal.isp.net.example, which I set with hostname -s remote.location.example456.com, because it was obnoxious to see such a long name. That solves the value of $echo hostname which now returns remote.location.example456.com. Mac OS X, 10.6 is this case, does seem to honor: touch ~/.hushlogin If leave that file empty, I get nothing on the shell when I login. I want to know what controls the host resolution of the IP, and how it is all working. For example, running last reports a huge list of my logins, which have obtusely long hostnames, when they would be preferable to just be remote.location.example456.com. More confusing to me, reading the man page for wtmp and lastlog, it looks like lastlog is not used on OS X, /var/log/lastlog does not exist. Actually, none of these exist on 10.5 or 10.6: /var/run/utmp The utmp file. /var/log/wtmp The wtmp file. /var/log/lastlog The lastlog file. If I am to assume that the system is doing some kind of reverse lookup, I certainly do not know what it is, as it is not an accurate one.

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  • Are there any modern GUI toolkits which implement a heirarchical menu buffer zone?

    - by scomar
    In Bruce Tognazzini's quiz on Fitt's Law, the question discussing the bottleneck in the hierarchical menu (as used in almost every modern desktop UI), talks about his design for the original Mac: The bottleneck is the passage between the first-level menu and the second-level menu. Users first slide the mouse pointer down to the category menu item. Then, they must carefully slide the mouse directly across (horizontally) in order to move the pointer into the secondary menu. The engineer who originally designed hierarchicals apparently had his forearm mounted on a track so that he could move it perfectly in a horizontal direction without any vertical component. Most of us, however, have our forarms mounted on a pivot we like to call our elbow. That means that moving our hand describes an arc, rather than a straight line. Demanding that pivoted people move a mouse pointer along in a straight line horizontally is just wrong. We are naturally going to slip downward even as we try to slide sideways. When we are not allowed to slip downward, the menu we're after is going to slam shut just before we get there. The Windows folks tried to overcome the pivot problem with a hack: If they see the user move down into range of the next item on the primary menu, they don't instantly close the second-level menu. Instead, they leave it open for around a half second, so, if users are really quick, they can be inaccurate but still get into the second-level menu before it slams shut. Unfortunately, people's reactions to heightened chance of error is to slow down, rather than speed up, a well-established phenomenon. Therefore, few users will ever figure out that moving faster could solve their problem. Microsoft's solution is exactly wrong. When I specified the Mac hierarchical menu algorthm in the mid-'80s, I called for a buffer zone shaped like a <, so that users could make an increasingly-greater error as they neared the hierarchical without fear of jumping to an unwanted menu. As long as the user's pointer was moving a few pixels over for every one down, on average, the menu stayed open, no matter how slow they moved. (Cancelling was still really easy; just deliberately move up or down.) This just blew me away! Such a simple idea which would result in a huge improvement in usability. I'm sure I'm not the only one who regularly has the next level of a menu slam shut because I don't move the mouse pointer in a perfectly horizontal line. So my question is: Are there any modern UI toolkits which implement this brilliant idea of a < shaped buffer zone in hierarchical menus? And if not, why not?!

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  • Creating packages in code – Execute SQL Task

    The Execute SQL Task is for obvious reasons very well used, so I thought if you are building packages in code the chances are you will be using it. Using the task basic features of the task are quite straightforward, add the task and set some properties, just like any other. When you start interacting with variables though it can be a little harder to grasp so these samples should see you through. Some of these more advanced features are explained in much more detail in our ever popular post The Execute SQL Task, here I’ll just be showing you how to implement them in code. The abbreviated code blocks below demonstrate the different features of the task. The complete code has been encapsulated into a sample class which you can download (ExecSqlPackage.cs). Each feature described has its own method in the sample class which is mentioned after the code block. This first sample just shows adding the task, setting the basic properties for a connection and of course an SQL statement. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Set required properties taskHost.Properties["Connection"].SetValue(taskHost, sqlConnection.ID); taskHost.Properties["SqlStatementSource"].SetValue(taskHost, "SELECT * FROM sysobjects"); For the full version of this code, see the CreatePackage method in the sample class. The AddSqlConnection method is a helper method that adds an OLE-DB connection to the package, it is of course in the sample class file too. Returning a single value with a Result Set The following sample takes a different approach, getting a reference to the ExecuteSQLTask object task itself, rather than just using the non-specific TaskHost as above. Whilst it means we need to add an extra reference to our project (Microsoft.SqlServer.SQLTask) it makes coding much easier as we have compile time validation of any property and types we use. For the more complex properties that is very valuable and saves a lot of time during development. The query has also been changed to return a single value, one row and one column. The sample shows how we can return that value into a variable, which we also add to our package in the code. To do this manually you would set the Result Set property on the General page to Single Row and map the variable on the Result Set page in the editor. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Add variable to hold result value package.Variables.Add("Variable", false, "User", 0); // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = 'sysrowsets'"; // Set single row result set task.ResultSetType = ResultSetType.ResultSetType_SingleRow; // Add result set binding, map the id column to variable task.ResultSetBindings.Add(); IDTSResultBinding resultBinding = task.ResultSetBindings.GetBinding(0); resultBinding.ResultName = "id"; resultBinding.DtsVariableName = "User::Variable"; For the full version of this code, see the CreatePackageResultVariable method in the sample class. The other types of Result Set behaviour are just a variation on this theme, set the property and map the result binding as required. Parameter Mapping for SQL Statements This final example uses a parameterised SQL statement, with the coming from a variable. The syntax varies slightly between connection types, as explained in the Working with Parameters and Return Codes in the Execute SQL Taskhelp topic, but OLE-DB is the most commonly used, for which a question mark is the parameter value placeholder. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, ".", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = ?"; // Add variable to hold parameter value package.Variables.Add("Variable", false, "User", "sysrowsets"); // Add input parameter binding task.ParameterBindings.Add(); IDTSParameterBinding parameterBinding = task.ParameterBindings.GetBinding(0); parameterBinding.DtsVariableName = "User::Variable"; parameterBinding.ParameterDirection = ParameterDirections.Input; parameterBinding.DataType = (int)OleDBDataTypes.VARCHAR; parameterBinding.ParameterName = "0"; parameterBinding.ParameterSize = 255; For the full version of this code, see the CreatePackageParameterVariable method in the sample class. You’ll notice the data type has to be specified for the parameter IDTSParameterBinding .DataType Property, and these type codes are connection specific too. My enumeration I wrote several years ago is shown below was probably done by reverse engineering a package and also the API header file, but I recently found a very handy post that covers more connections as well for exactly this, Setting the DataType of IDTSParameterBinding objects (Execute SQL Task). /// <summary> /// Enumeration of OLE-DB types, used when mapping OLE-DB parameters. /// </summary> private enum OleDBDataTypes { BYTE = 0x11, CURRENCY = 6, DATE = 7, DB_VARNUMERIC = 0x8b, DBDATE = 0x85, DBTIME = 0x86, DBTIMESTAMP = 0x87, DECIMAL = 14, DOUBLE = 5, FILETIME = 0x40, FLOAT = 4, GUID = 0x48, LARGE_INTEGER = 20, LONG = 3, NULL = 1, NUMERIC = 0x83, NVARCHAR = 130, SHORT = 2, SIGNEDCHAR = 0x10, ULARGE_INTEGER = 0x15, ULONG = 0x13, USHORT = 0x12, VARCHAR = 0x81, VARIANT_BOOL = 11 } Download Sample code ExecSqlPackage.cs (10KB)

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  • Issue 15: The Benefits of Oracle Exastack

    - by rituchhibber
         SOLUTIONS FOCUS The Benefits of Oracle Exastack Paul ThompsonDirector, Alliances and Solutions Partner ProgramsOracle EMEA Alliances & Channels RESOURCES -- Oracle PartnerNetwork (OPN) Oracle Exastack Program Oracle Exastack Ready Oracle Exastack Optimized Oracle Exastack Labs and Enablement Resources Oracle Exastack Labs Video Tour SUBSCRIBE FEEDBACK PREVIOUS ISSUES Exastack is a revolutionary programme supporting Oracle independent software vendor partners across the entire Oracle technology stack. Oracle's core strategy is to engineer software and hardware together, and our ISV strategy is the same. At Oracle we design engineered systems that are pre-integrated to reduce the cost and complexity of IT infrastructures while increasing productivity and performance. Oracle innovates and optimises performance at every layer of the stack to simplify business operations, drive down costs and accelerate business innovation. Our engineered systems are optimised to achieve enterprise performance levels that are unmatched in the industry. Faster time to production is achieved by implementing pre-engineered and pre-assembled hardware and software bundles. Our strategy of delivering a single-vendor stack simplifies and reduces costs associated with purchasing, deploying, and supporting IT environments for our customers and partners. In parallel to this core engineered systems strategy, the Oracle Exastack Program enables our Oracle ISV partners to leverage a scalable, integrated infrastructure that delivers their applications tuned, tested and optimised for high-performance. Specifically, the Oracle Exastack Program helps ISVs run their solutions on the Oracle Exadata Database Machine, Oracle Exalogic Elastic Cloud, and Oracle SPARC SuperCluster T4-4 - integrated systems products in which the software and hardware are engineered to work together. These products provide OPN members with a lower cost and high performance infrastructure for database and application workloads across on-premise and cloud based environments. Ready and Optimized Oracle Partners can now leverage our new Oracle Exastack Program to become Oracle Exastack Ready and Oracle Exastack Optimized. Partners can achieve Oracle Exastack Ready status through their support for Oracle Solaris, Oracle Linux, Oracle VM, Oracle Database, Oracle WebLogic Server, Oracle Exadata Database Machine, Oracle Exalogic Elastic Cloud, and Oracle SPARC SuperCluster T4-4. By doing this, partners can demonstrate to their customers that their applications are available on the latest major releases of these products. The Oracle Exastack Ready programme helps customers readily differentiate Oracle partners from lesser software developers, and identify applications that support Oracle engineered systems. Achieving Oracle Exastack Optimized status demonstrates that an OPN member has proven itself against goals for performance and scalability on Oracle integrated systems. This status enables end customers to readily identify Oracle partners that have tested and tuned their solutions for optimum performance on an Oracle Exadata Database Machine, Oracle Exalogic Elastic Cloud, and Oracle SPARC SuperCluster T4-4. These ISVs can display the Oracle Exadata Optimized, Oracle Exalogic Optimized or Oracle SPARC SuperCluster Optimized logos on websites and on all their collateral to show that they have tested and tuned their application for optimum performance. Deliver higher value to customers Oracle's investment in engineered systems enables ISV partners to deliver higher value to customer business processes. New innovations are enabled through extreme performance unachievable through traditional best-of-breed multi-vendor server/software approaches. Core product requirements can be launched faster, enabling ISVs to focus research and development investment on core competencies in order to bring value to market as quickly as possible. Through Exastack, partners no longer have to worry about the underlying product stack, which allows greater focus on the development of intellectual property above the stack. Partners are not burdened by platform issues and can concentrate simply on furthering their applications. The advantage to end customers is that partners can focus all efforts on business functionality, rather than bullet-proofing underlying technologies, and so will inevitably deliver application updates faster. Exastack provides ISVs with a number of flexible deployment options, such as on-premise or Cloud, while maintaining one single code base for applications regardless of customer deployment preference. Customers buying their solutions from Exastack ISVs can therefore be confident in deploying on their own networks, on private clouds or into a public cloud. The underlying platform will support all conceivable deployments, enabling a focus on the ISV's application itself that wouldn't be possible with other vendor partners. It stands to reason that Exastack accelerates time to value as well as lowering implementation costs all round. There is a big competitive advantage in partners being able to offer customers an optimised, pre-configured solution rather than an assortment of components and a suggested fit. Once a customer has decided to buy an Oracle Exastack Ready or Optimized partner solution, it will be up and running without any need for the customer to conduct testing of its own. Operational costs and complexity are also reduced, thanks to streamlined customer support through standardised configurations and pro-active monitoring. 'Engineered to Work Together' is a significant statement of Oracle strategy. It guarantees smoother deployment of a single vendor solution, clear ownership with no finger-pointing and the peace of mind of the Oracle Support Centre underpinning the entire product stack. Next steps Every OPN member with packaged applications must seriously consider taking steps to become Exastack Ready, or Exastack Optimized at the first opportunity. That first step down the track is to talk to an expert on the OPN Portal, at the Oracle Partner Business Center or to discuss the next steps with the closest Oracle account manager. Oracle Exastack lab environments and other technical enablement resources are available for OPN members wishing to further their knowledge of Oracle Exastack and qualify their applications for Oracle Exastack Optimized. New Boot Camps and Guided Learning Paths (GLPs), tailored specifically for ISVs, are available for Oracle Exadata Database Machine, Oracle Exalogic Elastic Cloud, Oracle Linux, Oracle Solaris, Oracle Database, and Oracle WebLogic Server. More information about these GLPs and Boot Camps (including delivery dates and locations) are posted on the OPN Competency Center and corresponding OPN Knowledge Zones. Learn more about Oracle Exastack labs and ISV specific enablement resources. "Oracle Specialized partners are of course front-and-centre, with potential customers clearly directed to those partners and to Exadata Ready partners as a matter of priority." --More OpenWorld 2011 highlights for Oracle partners and customers Oracle Application Testing Suite 9.3 application testing solution for Web, SOA and Oracle Applications Oracle Application Express Release 4.1 improving the development of database-centric Web 2.0 applications and reports Oracle Unified Directory 11g helping customers manage the critical identity information that drives their business applications Oracle SOA Suite for healthcare integration Oracle Enterprise Pack for Eclipse 11g demonstrating continued commitment to the developer and open source communities Oracle Coherence 3.7.1, the latest release of the industry's leading distributed in-memory data grid Oracle Process Accelerators helping to simplify and accelerate time-to-value for customers' business process management initiatives Oracle's JD Edwards EnterpriseOne on the iPad meeting the increasingly mobile demands of today's workforces Oracle CRM On Demand Release 19 Innovation Pack introducing industry-leading hosted call centre and enterprise-marketing capabilities designed to drive further revenue and productivity while reducing costs and improving the customer experience Oracle's Primavera Portfolio Management 9 for businesses delivering on project portfolio goals with increased versatility, transparency and accuracy Oracle's PeopleSoft Human Capital Management (HCM) 9.1 On Demand Standard Edition helping customers manage their long-term investment in enterprise-wide business applications New versions of Oracle FLEXCUBE Universal Banking and Oracle FLEXCUBE Investor Servicing for Financial Institutions, as well as Oracle Financial Services Enterprise Case Management, Oracle Financial Services Pricing Management, Oracle Financial Management Analytics and Oracle Tax Analytics Oracle Utilities Network Management System 1.11 offering new modelling and analysis features to improve distribution-grid management for electric utilities Oracle Communications Network Charging and Control 4.4 helping communications service providers (CSPs) offer their customers more flexible charging options Plus many, many more technology announcements, enhancements, momentum news and community updates -- Oracle OpenWorld 2012 A date has already been set for Oracle OpenWorld 2012. Held once again in San Francisco, exhibitors, partners, customers and Oracle people will gather from 30 September until 4 November to meet, network and learn together with the rest of the global Oracle community. Register now for Oracle OpenWorld 2012 and save $$$! We'll reward your early planning for Oracle OpenWorld 2012 with reduced rates. Super Saver deals are now available! -- Back to the welcome page

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  • Creating packages in code – Execute SQL Task

    The Execute SQL Task is for obvious reasons very well used, so I thought if you are building packages in code the chances are you will be using it. Using the task basic features of the task are quite straightforward, add the task and set some properties, just like any other. When you start interacting with variables though it can be a little harder to grasp so these samples should see you through. Some of these more advanced features are explained in much more detail in our ever popular post The Execute SQL Task, here I’ll just be showing you how to implement them in code. The abbreviated code blocks below demonstrate the different features of the task. The complete code has been encapsulated into a sample class which you can download (ExecSqlPackage.cs). Each feature described has its own method in the sample class which is mentioned after the code block. This first sample just shows adding the task, setting the basic properties for a connection and of course an SQL statement. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Set required properties taskHost.Properties["Connection"].SetValue(taskHost, sqlConnection.ID); taskHost.Properties["SqlStatementSource"].SetValue(taskHost, "SELECT * FROM sysobjects"); For the full version of this code, see the CreatePackage method in the sample class. The AddSqlConnection method is a helper method that adds an OLE-DB connection to the package, it is of course in the sample class file too. Returning a single value with a Result Set The following sample takes a different approach, getting a reference to the ExecuteSQLTask object task itself, rather than just using the non-specific TaskHost as above. Whilst it means we need to add an extra reference to our project (Microsoft.SqlServer.SQLTask) it makes coding much easier as we have compile time validation of any property and types we use. For the more complex properties that is very valuable and saves a lot of time during development. The query has also been changed to return a single value, one row and one column. The sample shows how we can return that value into a variable, which we also add to our package in the code. To do this manually you would set the Result Set property on the General page to Single Row and map the variable on the Result Set page in the editor. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Add variable to hold result value package.Variables.Add("Variable", false, "User", 0); // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = 'sysrowsets'"; // Set single row result set task.ResultSetType = ResultSetType.ResultSetType_SingleRow; // Add result set binding, map the id column to variable task.ResultSetBindings.Add(); IDTSResultBinding resultBinding = task.ResultSetBindings.GetBinding(0); resultBinding.ResultName = "id"; resultBinding.DtsVariableName = "User::Variable"; For the full version of this code, see the CreatePackageResultVariable method in the sample class. The other types of Result Set behaviour are just a variation on this theme, set the property and map the result binding as required. Parameter Mapping for SQL Statements This final example uses a parameterised SQL statement, with the coming from a variable. The syntax varies slightly between connection types, as explained in the Working with Parameters and Return Codes in the Execute SQL Taskhelp topic, but OLE-DB is the most commonly used, for which a question mark is the parameter value placeholder. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, ".", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = ?"; // Add variable to hold parameter value package.Variables.Add("Variable", false, "User", "sysrowsets"); // Add input parameter binding task.ParameterBindings.Add(); IDTSParameterBinding parameterBinding = task.ParameterBindings.GetBinding(0); parameterBinding.DtsVariableName = "User::Variable"; parameterBinding.ParameterDirection = ParameterDirections.Input; parameterBinding.DataType = (int)OleDBDataTypes.VARCHAR; parameterBinding.ParameterName = "0"; parameterBinding.ParameterSize = 255; For the full version of this code, see the CreatePackageParameterVariable method in the sample class. You’ll notice the data type has to be specified for the parameter IDTSParameterBinding .DataType Property, and these type codes are connection specific too. My enumeration I wrote several years ago is shown below was probably done by reverse engineering a package and also the API header file, but I recently found a very handy post that covers more connections as well for exactly this, Setting the DataType of IDTSParameterBinding objects (Execute SQL Task). /// <summary> /// Enumeration of OLE-DB types, used when mapping OLE-DB parameters. /// </summary> private enum OleDBDataTypes { BYTE = 0x11, CURRENCY = 6, DATE = 7, DB_VARNUMERIC = 0x8b, DBDATE = 0x85, DBTIME = 0x86, DBTIMESTAMP = 0x87, DECIMAL = 14, DOUBLE = 5, FILETIME = 0x40, FLOAT = 4, GUID = 0x48, LARGE_INTEGER = 20, LONG = 3, NULL = 1, NUMERIC = 0x83, NVARCHAR = 130, SHORT = 2, SIGNEDCHAR = 0x10, ULARGE_INTEGER = 0x15, ULONG = 0x13, USHORT = 0x12, VARCHAR = 0x81, VARIANT_BOOL = 11 } Download Sample code ExecSqlPackage.cs (10KB)

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  • ODI and OBIEE 11g Integration

    - by David Allan
    Here we will see some of the connectivity options to OBIEE 11g using the JDBC driver. You’ll see based upon some connection properties how the physical or presentation layers can be utilized. In the integrators guide for OBIEE 11g you will find a brief statement indicating that there actually is a JDBC driver for OBIEE. In OBIEE 11g its now possible to connect directly to the physical layer, Venkat has an informative post here on this topic. In ODI 11g the Oracle BI technology is shipped with the product along with KMs for reverse engineering, and using OBIEE models for a data source. When you install OBIEE in 11g a light weight demonstration application is preinstalled in the server, when you open this in the BI Administration tool we see the regular 3 panel view within the administration tool. To interrogate this system via JDBC (just like ODI does using the KMs) need a couple of things; the JDBC driver from OBIEE 11g, a java client program and the credentials. In my java client program I want to connect to the OBIEE system, when I connect I can interrogate what the JDBC driver presents for the metadata. The metadata projected via the JDBC connection’s DatabaseMetadata changes depending on whether the property NQ_SESSION.SELECTPHYSICAL is set when the java client connects. Let’s use the sample app to illustrate. I have a java client program here that will print out the tables in the DatabaseMetadata, it will also output the catalog and schema. For example if I execute without any special JDBC properties as follows; java -classpath .;%BIHOMEDIR%\clients\bijdbc.jar meta_jdbc oracle.bi.jdbc.AnaJdbcDriver jdbc:oraclebi://localhost:9703/ weblogic mypass Then I get the following returned representing the presentation layer, the sample I used is XML, and has no schema; Catalog Schema Table Sample Sales Lite null Base Facts Sample Sales Lite null Calculated Facts …     Sample Targets Lite null Base Facts …     Now if I execute with the only difference being the JDBC property NQ_SESSION.SELECTPHYSICAL with the value Yes, then I see a different set of values representing the physical layer in OBIEE; java -classpath .;%BIHOMEDIR%\clients\bijdbc.jar meta_jdbc oracle.bi.jdbc.AnaJdbcDriver jdbc:oraclebi://localhost:9703/ weblogic mypass NQ_SESSION.SELECTPHYSICAL=Yes The following is returned; Catalog Schema Table Sample App Lite Data null D01 Time Day Grain Sample App Lite Data null F10 Revenue Facts (Order grain) …     System DB (Update me)     …     If this was a database system such as Oracle, the catalog value would be the OBIEE database name and the schema would be the Oracle database schema. Other systems which have real catalog structure such as SQLServer would use its catalog value. Its this ‘Catalog’ and ‘Schema’ value that is important when integration OBIEE with ODI. For the demonstration application in OBIEE 11g, the following illustration shows how the information from OBIEE is related via the JDBC driver through to ODI. In the XML example above, within ODI’s physical schema definition on the right, we leave the schema blank since the XML data source has no schema. When I did this at first, I left the default value that ODI places in the Schema field since which was ‘<Undefined>’ (like image below) but this string is actually used in the RKM so ended up not finding any tables in this schema! Entering an empty string resolved this. Below we see a regular Oracle database example that has the database, schema, physical table structure, and how this is defined in ODI.   Remember back to the physical versus presentation layer usage when we passed the special property, well to do this in ODI, the data server has a panel for properties where you can define key/value pairs. So if you want to select physical objects from the OBIEE server, then you must set this property. An additional changed in ODI 11g is the OBIEE connection pool support, this has been implemented via a ‘Connection Pool’ flex field for the Oracle BI data server. So here you set the connection pool name from the OBIEE system that you specifically want to use and this is used by the Oracle BI to Oracle (DBLINK) LKM, so if you are using this you must set this flex field. Hopefully a useful insight into some of the mechanics of how this hangs together.

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  • EBS Techstack Sessions at OAUG/Collaborate 2010

    - by Steven Chan
    We have a large contingent of E-Business Suite Applications Technology Group staff rolling out to the OAUG/Collaborate 2010 conference in Las Vegas new week.  Our Applications Technology Group staff will be appearing as guest speakers or full-speakers at the following E-Business Suite technology stack related sessions:Database Special Interest GroupSunday, April 18, 11:00 AM, Breakers FSIG Leaders:  Michael Brown, Colibri; Sandra Vucinic, Vlad GroupGuest Speaker:  Steven ChanCovering database upcoming and past desupport dates, and database support policies as they apply to E-Business Suite environments, general Q&A E-Business Suite Technology Stack Special Interest GroupSunday, April 18, 3:00 PM, Breakers FSIG Leaders:  Elke Phelps, Paul Jackson, HumanaGuest Speaker:  Steven ChanCovering the latest EBS technology stack certifications, roadmap, desupport noticesupgrade options for Discoverer, OID, SSO, Portal, general Q&A E-Business Suite Applications Technology Roadmap & VisionMonday, April 19, 8:00 AM, South Seas GOracle Speaker:  Uma PrabhalaLatest developments for SOA, AOL, OAF, Web ADI, SES, AMP, ACMP, security, and other technologies Oracle E-Business Suite Applications Strategy and General Manager UpdateMonday, April 19, 2:30 PM, Mandalay Bay Ballroom DOracle Speaker:  Cliff GodwinUpdate on the entire Oracle E-Business Suite product line. The session covers the value delivered by the current release of Oracle E-Business Suite applications, the momentum, and how Oracle E-Business Suite applications integrate into Oracle's overall applications strategy 10 Things You Can Do Today to Prepare for the Next Generation ApplicationsTuesday, April 20, 8:00 AM, South Seas FOracle Speaker:  Nadia Bendjedou"Common sense" and "practical" steps that can be taken today to increase the value of your Oracle Applications (E-Business Suite, PeopleSoft, Siebel, and JDE) investments by using the latest Oracle solutions and technologiesReducing TCO using Oracle E-Business Suite Management PacksTuesday, April 20, 10:30 AM, South Seas EOracle Speaker:  Angelo RosadoLearn how you can reduce the Total Cost of Ownership by implementing Application Management Pack (AMP) and Application Change Management Pack (ACP) for E-Business Suite 11i, R12, R12.1. AMP is Oracle's next generation system manageability product offering that provides a centralized platform to manage and maintain EBS. ACP is Oracle's offering to monitor and manage E-Business Suite changes in the areas of E-Business Suite Customizations, Patches and Functional Setups. E-Business Suite Upgrade Special Interest GroupTuesday, April 20, 3:15 PM, South Seas ESIG Leaders:  John Stouffer; Sandra Vucinic, Vlad GroupGuest Speaker:  Steven ChanParticipating in general Q&A E-Business Suite Technology Essentials: Using the Latest Oracle Technologies with E-Business Suite Wednesday, April 21, 8:00 AM, South Seas HOracle Speaker:  Lisa ParekhOracle continues to build new functionality into the Oracle Database, Fusion Middleware, and Enterprise Manager. Come see how you can enhance the value of E-Business Suite for your users and lower your costs of ownership by utilizing the latest features of these Oracle technologies with E-Business Suite. Learn about the latest advanced E-Business Suite topologies and features, including new options for security, performance, third-party integration, SOA, virtualization, clouds, systems management, and much more How to Leverage the New E-Business Suite R12.1 Solutions Without Upgrading your 11.5.10 EnvironmentWednesday, April 21, 10:30 AMOracle Speaker:  Nadia Bendjedou, South Seas ELearn how you can use the latest E-Business Suite 12.1 standalone solutions without upgrading from your E-Business Suite 11.5.10 environment Web 2.0 User Experience and Oracle Fusion Middleware Integration with Oracle E-Business SuiteWednesday, April 21, 4:00 PM, South Seas FOracle Speaker:  Padmaprabodh AmbaleSee the next generation Oracle E-Business Suite OA framework improvements that will provide new rich interactions in components such as LOV, Tables and Attachments.  See  new components like the Rich Container that allows any Web 2.0 content like Flash or OBIEE to be embedded in OA Framework pages. Advanced Technology Deployment Architectures for E-Business Suite Wednesday, April 21, 2:15 PM, South Seas EOracle Speaker:  Steven ChanLearn how to take advantage of the latest version of Oracle Fusion Middleware with Oracle E-Business Suite. Learn how to utilize identity management systems and LDAP directories. In addition, come to this session for answers about advanced network deployments involving reverse proxy servers, load balancers, and DMZ's, and to see how you can take benefit from virtualization and new system management capabilities. Upgrading to Oracle E-Business Suite 12.1 - Best PracticesThursday, April 22, 11:00 AM, South Seas EOracle Speaker:  Lester Gutierrez, Udayan ParvateFundamental of upgrading to Release 12.1, which includes the technology stack components and differences, the upgrade path from various releases of Oracle E-Business Suite, upgrade steps, monitoring the upgrade, hints and tips for minimizing downtime and upgrade best practices for making the upgrade to Release 12.1 a success.  We look forward to seeing you there!

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  • How to get SQL Railroad Diagrams from MSDN BNF syntax notation.

    - by Phil Factor
    pre {margin-bottom:.0001pt; font-size:8.0pt; font-family:"Courier New"; margin-left: 0cm; margin-right: 0cm; margin-top: 0cm; } On SQL Server Books-On-Line, in the Transact-SQL Reference (database Engine), every SQL Statement has its syntax represented in  ‘Backus–Naur Form’ notation (BNF)  syntax. For a programmer in a hurry, this should be ideal because It is the only quick way to understand and appreciate all the permutations of the syntax. It is a great feature once you get your eye in. It isn’t the only way to get the information;  You can, of course, reverse-engineer an understanding of the syntax from the examples, but your understanding won’t be complete, and you’ll have wasted time doing it. BNF is a good start in representing the syntax:  Oracle and SQLite go one step further, and have proper railroad diagrams for their syntax, which is a far more accessible way of doing it. There are three problems with the BNF on MSDN. Firstly, it is isn’t a standard version of  BNF, but an ancient fork from EBNF, inherited from Sybase. Secondly, it is excruciatingly difficult to understand, and thirdly it has a number of syntactic and semantic errors. The page describing DML triggers, for example, currently has the absurd BNF error that makes it state that all statements in the body of the trigger must be separated by commas.  There are a few other detail problems too. Here is the offending syntax for a DML trigger, pasted from MSDN. Trigger on an INSERT, UPDATE, or DELETE statement to a table or view (DML Trigger) CREATE TRIGGER [ schema_name . ]trigger_name ON { table | view } [ WITH <dml_trigger_option> [ ,...n ] ] { FOR | AFTER | INSTEAD OF } { [ INSERT ] [ , ] [ UPDATE ] [ , ] [ DELETE ] } [ NOT FOR REPLICATION ] AS { sql_statement [ ; ] [ ,...n ] | EXTERNAL NAME <method specifier [ ; ] > }   <dml_trigger_option> ::=     [ ENCRYPTION ]     [ EXECUTE AS Clause ]   <method_specifier> ::=  This should, of course, be /* Trigger on an INSERT, UPDATE, or DELETE statement to a table or view (DML Trigger) */ CREATE TRIGGER [ schema_name . ]trigger_name ON { table | view } [ WITH <dml_trigger_option> [ ,...n ] ] { FOR | AFTER | INSTEAD OF } { [ INSERT ] [ , ] [ UPDATE ] [ , ] [ DELETE ] } [ NOT FOR REPLICATION ] AS { {sql_statement [ ; ]} [ ...n ] | EXTERNAL NAME <method_specifier> [ ; ] }   <dml_trigger_option> ::=     [ ENCRYPTION ]     [ EXECUTE AS CLAUSE ]   <method_specifier> ::=     assembly_name.class_name.method_name I’d love to tell Microsoft when I spot errors like this so they can correct them but I can’t. Obviously, there is a mechanism on MSDN to get errors corrected by using comments, but that doesn’t work for me (*Error occurred while saving your data.”), and when I report that the comment system doesn’t work to MSDN, I get no reply. I’ve been trying to create railroad diagrams for all the important SQL Server SQL statements, as good as you’d find for Oracle, and have so far published the CREATE TABLE and ALTER TABLE railroad diagrams based on the BNF. Although I’ve been aware of them, I’ve never realised until recently how many errors there are. Then, Colin Daley created a translator for the SQL Server dialect of  BNF which outputs standard EBNF notation used by the W3C. The example MSDN BNF for the trigger would be rendered as … /* Trigger on an INSERT, UPDATE, or DELETE statement to a table or view (DML Trigger) */ create_trigger ::= 'CREATE TRIGGER' ( schema_name '.' ) ? trigger_name 'ON' ( table | view ) ( 'WITH' dml_trigger_option ( ',' dml_trigger_option ) * ) ? ( 'FOR' | 'AFTER' | 'INSTEAD OF' ) ( ( 'INSERT' ) ? ( ',' ) ? ( 'UPDATE' ) ? ( ',' ) ? ( 'DELETE' ) ? ) ( 'NOT FOR REPLICATION' ) ? 'AS' ( ( sql_statement ( ';' ) ? ) + | 'EXTERNAL NAME' method_specifier ( ';' ) ? )   dml_trigger_option ::= ( 'ENCRYPTION' ) ? ( 'EXECUTE AS CLAUSE' ) ?   method_specifier ::= assembly_name '.' class_name '.' method_name Colin’s intention was to allow anyone to paste SQL Server’s BNF notation into his website-based parser, and from this generate classic railroad diagrams via Gunther Rademacher's Railroad Diagram Generator.  Colin's application does this for you: you're not aware that you are moving to a different site.  Because Colin's 'translator' it is a parser, it will pick up syntax errors. Once you’ve fixed the syntax errors, you will get the syntax in the form of a human-readable railroad diagram and, in this form, the semantic mistakes become flamingly obvious. Gunter’s Railroad Diagram Generator is brilliant. To be able, after correcting the MSDN dialect of BNF, to generate a standard EBNF, and from thence to create railroad diagrams for SQL Server’s syntax that are as good as Oracle’s, is a great boon, and many thanks to Colin for the idea. Here is the result of the W3C EBNF from Colin’s application then being run through the Railroad diagram generator. create_trigger: dml_trigger_option: method_specifier:   Now that’s much better, you’ll agree. This is pretty easy to understand, and at this point any error is immediately obvious. This should be seriously useful, and it is to me. However  there is that snag. The BNF is generally incorrect, and you can’t expect the average visitor to mess about with it. The answer is, of course, to correct the BNF on MSDN and maybe even add railroad diagrams for the syntax. Stop giggling! I agree it won’t happen. In the meantime, we need to collaboratively store and publish these corrected syntaxes ourselves as we do them. How? GitHub?  SQL Server Central?  Simple-Talk? What should those of us who use the system  do with our corrected EBNF so that anyone can use them without hassle?

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  • Big Data – Buzz Words: Importance of Relational Database in Big Data World – Day 9 of 21

    - by Pinal Dave
    In yesterday’s blog post we learned what is HDFS. In this article we will take a quick look at the importance of the Relational Database in Big Data world. A Big Question? Here are a few questions I often received since the beginning of the Big Data Series - Does the relational database have no space in the story of the Big Data? Does relational database is no longer relevant as Big Data is evolving? Is relational database not capable to handle Big Data? Is it true that one no longer has to learn about relational data if Big Data is the final destination? Well, every single time when I hear that one person wants to learn about Big Data and is no longer interested in learning about relational database, I find it as a bit far stretched. I am not here to give ambiguous answers of It Depends. I am personally very clear that one who is aspiring to become Big Data Scientist or Big Data Expert they should learn about relational database. NoSQL Movement The reason for the NoSQL Movement in recent time was because of the two important advantages of the NoSQL databases. Performance Flexible Schema In personal experience I have found that when I use NoSQL I have found both of the above listed advantages when I use NoSQL database. There are instances when I found relational database too much restrictive when my data is unstructured as well as they have in the datatype which my Relational Database does not support. It is the same case when I have found that NoSQL solution performing much better than relational databases. I must say that I am a big fan of NoSQL solutions in the recent times but I have also seen occasions and situations where relational database is still perfect fit even though the database is growing increasingly as well have all the symptoms of the big data. Situations in Relational Database Outperforms Adhoc reporting is the one of the most common scenarios where NoSQL is does not have optimal solution. For example reporting queries often needs to aggregate based on the columns which are not indexed as well are built while the report is running, in this kind of scenario NoSQL databases (document database stores, distributed key value stores) database often does not perform well. In the case of the ad-hoc reporting I have often found it is much easier to work with relational databases. SQL is the most popular computer language of all the time. I have been using it for almost over 10 years and I feel that I will be using it for a long time in future. There are plenty of the tools, connectors and awareness of the SQL language in the industry. Pretty much every programming language has a written drivers for the SQL language and most of the developers have learned this language during their school/college time. In many cases, writing query based on SQL is much easier than writing queries in NoSQL supported languages. I believe this is the current situation but in the future this situation can reverse when No SQL query languages are equally popular. ACID (Atomicity Consistency Isolation Durability) – Not all the NoSQL solutions offers ACID compliant language. There are always situations (for example banking transactions, eCommerce shopping carts etc.) where if there is no ACID the operations can be invalid as well database integrity can be at risk. Even though the data volume indeed qualify as a Big Data there are always operations in the application which absolutely needs ACID compliance matured language. The Mixed Bag I have often heard argument that all the big social media sites now a days have moved away from Relational Database. Actually this is not entirely true. While researching about Big Data and Relational Database, I have found that many of the popular social media sites uses Big Data solutions along with Relational Database. Many are using relational databases to deliver the results to end user on the run time and many still uses a relational database as their major backbone. Here are a few examples: Facebook uses MySQL to display the timeline. (Reference Link) Twitter uses MySQL. (Reference Link) Tumblr uses Sharded MySQL (Reference Link) Wikipedia uses MySQL for data storage. (Reference Link) There are many for prominent organizations which are running large scale applications uses relational database along with various Big Data frameworks to satisfy their various business needs. Summary I believe that RDBMS is like a vanilla ice cream. Everybody loves it and everybody has it. NoSQL and other solutions are like chocolate ice cream or custom ice cream – there is a huge base which loves them and wants them but not every ice cream maker can make it just right  for everyone’s taste. No matter how fancy an ice cream store is there is always plain vanilla ice cream available there. Just like the same, there are always cases and situations in the Big Data’s story where traditional relational database is the part of the whole story. In the real world scenarios there will be always the case when there will be need of the relational database concepts and its ideology. It is extremely important to accept relational database as one of the key components of the Big Data instead of treating it as a substandard technology. Ray of Hope – NewSQL In this module we discussed that there are places where we need ACID compliance from our Big Data application and NoSQL will not support that out of box. There is a new termed coined for the application/tool which supports most of the properties of the traditional RDBMS and supports Big Data infrastructure – NewSQL. Tomorrow In tomorrow’s blog post we will discuss about NewSQL. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • Software Architecture: Quality Attributes

    Quality is what all software engineers should strive for when building a new system or adding new functionality. Dictonary.com ambiguously defines quality as a grade of excellence. Unfortunately, quality must be defined within the context of a situation in that each engineer must extract quality attributes from a project’s requirements. Because quality is defined by project requirements the meaning of quality is constantly changing base on the project. Software architecture factors that indicate the relevance and effectiveness The relevance and effectiveness of architecture can vary based on the context in which it was conceived and the quality attributes that are required to meet. Typically when evaluating architecture for a specific system regarding relevance and effectiveness the following questions should be asked.   Architectural relevance and effectiveness questions: Does the architectural concept meet the needs of the system for which it was designed? Out of the competing architectures for a system, which one is the most suitable? If we look at the first question regarding meeting the needs of a system for which it was designed. A system that answers yes to this question must meet all of its quality goals. This means that it consistently meets or exceeds performance goals for the system. In addition, the system meets all the other required system attributers based on the systems requirements. The suitability of a system is based on several factors. In order for a project to be suitable the necessary resources must be available to complete the task. Standard Project Resources: Money Trained Staff Time Life cycle factors that affect the system and design The development life cycle used on a project can drastically affect how a system’s architecture is created as well as influence its design. In the case of using the software development life cycle (SDLC) each phase must be completed before the next can begin.  This waterfall approach does not allow for changes in a system’s architecture after that phase is completed. This can lead to major system issues when the architecture for the system is not as optimal because of missed quality attributes. This can occur when a project has poor requirements and makes misguided architectural decisions to name a few examples. Once the architectural phase is complete the concepts established in this phase must move on to the design phase that is bound to use the concepts and guidelines defined in the previous phase regardless of any missing quality attributes needed for the project. If any issues arise during this phase regarding the selected architectural concepts they cannot be corrected during the current project. This directly has an effect on the design of a system because the proper qualities required for the project where not used when the architectural concepts were approved. When this is identified nothing can be done to fix the architectural issues and system design must use the existing architectural concepts regardless of its missing quality properties because the architectural concepts for the project cannot be altered. The decisions made in the design phase then preceded to fall down to the implementation phase where the actual system is coded based on the approved architectural concepts established in the architecture phase regardless of its architectural quality. Conversely projects using more of an iterative or agile methodology to implement a system has more flexibility to correct architectural decisions based on missing quality attributes. This is due to each phase of the SDLC is executed more than once so any issues identified in architecture of a system can be corrected in the next architectural phase. Subsequently the corresponding changes will then be adjusted in the following design phase so that when the project is completed the optimal architectural and design decision are applied to the solution. Architecture factors that indicate functional suitability Systems that have function shortcomings do not have the proper functionality based on the project’s driving quality attributes. What this means in English is that the system does not live up to what is required of it by the stakeholders as identified by the missing quality attributes and requirements. One way to prevent functional shortcomings is to test the project’s architecture, design, and implementation against the project’s driving quality attributes to ensure that none of the attributes were missed in any of the phases. Another way to ensure a system has functional suitability is to certify that all its requirements are fully articulated so that there is no chance for misconceptions or misinterpretations by all stakeholders. This will help prevent any issues regarding interpreting the system requirements during the initial architectural concept phase, design phase and implementation phase. Consider the applicability of other architectural models When considering an architectural model for a project is also important to consider other alternative architectural models to ensure that the model that is selected will meet the systems required functionality and high quality attributes. Recently I can remember talking about a project that I was working on and a coworker suggested a different architectural approach that I had never considered. This new model will allow for the same functionally that is offered by the existing model but will allow for a higher quality project because it fulfills more quality attributes. It is always important to seek alternatives prior to committing to an architectural model. Factors used to identify high-risk components A high risk component can be defined as a component that fulfills 2 or more quality attributes for a system. An example of this can be seen in a web application that utilizes a remote database. One high-risk component in this system is the TCIP component because it allows for HTTP connections to handle by a web server and as well as allows for the server to also connect to a remote database server so that it can import data into the system. This component allows for the assurance of data quality attribute and the accessibility quality attribute because the system is available on the network. If for some reason the TCIP component was to fail the web application would fail on two quality attributes accessibility and data assurance in that the web site is not accessible and data cannot be update as needed. Summary As stated previously, quality is what all software engineers should strive for when building a new system or adding new functionality. The quality of a system can be directly determined by how closely it is implemented when compared to its desired quality attributes. One way to insure a higher quality system is to enforce that all project requirements are fully articulated so that no assumptions or misunderstandings can be made by any of the stakeholders. By doing this a system has a better chance of becoming a high quality system based on its quality attributes

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