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  • How to force a gtk tooltip to be shown?

    - by markuz
    I have an application and I want to show a tooltip every time a user set the focus on a entry widget. Do you know a way to force a gtk Tooltip to be shown?, because right now it only shows when the user puts the mouse pointer over the entry, but the application in production will have no mouse at all.

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  • Problem with user logins after db Restore

    - by JJgates
    I have two SQL 2005 instances that reside on different networks. I need to backup a database from instance A and restore it to a database in instance B on a weekly basis so that both databases hold the same data. After the restore, logins SIDS on database B are changed and therefore users can't log into database B and connection strings for the web application it supports are broken. Is there a work around for this? Thanks.

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  • serve static play2.x content from CDN

    - by Adam Lane
    In development mode I would like to have assets served locally and when deployed in production I would like them served from the CDN. Anyone using play2 and serving content from CDN be willing to share how they are doing it? // Thinking of something like this in the routes file... @if(play.Play.isDev()) { GET /assets/*file controllers.Assets.at(path="/public", file) } else { GET CDNPATH/assets/*file controllers.Assets.at(path="CDNPATH", file) } (Note: using 2.0.2 because of the headers fix https://github.com/playframework/Play20/pull/276)

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  • Why Create Mock Objects?

    - by Chris
    During a recent interview I was asked why one would want to create mock objects. My answer went something like, "Take a database--if you're writing test code, you may not want that test hooked up live to the production database where actual operations will be performed." Judging by response, my answer clearly was not what the interviewer was looking for. What's a better answer?

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  • Simple DB2 Query for connection validation

    - by Eric Tuttleman
    I'm looking for a simple DB2 query that can be used to test if a database connection in pool is still valid. It needs to be a generic query that would execute regardless of which databases exist. For other database servers, I've used something like 'SELECT 1' or 'SELECT version();' What would be an equivalent for DB2? Thanks!

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  • `export PS1='value'` does not propagate to (Korn) subshells for root?

    - by user319845
    Please consider the following /root/.profile: export PS1=value1 export x=value2 How come the login shell shows the expected prompt (and $x as value2), while the subshells keep showing $x as value2 but $PS1 as '#'? Just in case, I'm trying this under OpenBSD. [Yeah, I know... What on earth am I doing with OpenBSD if I don't know this? Just toying... in an isolated, most definitely non-production VM =).]

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  • Mysql without installer is not working

    - by yyy i 777
    I have downloaded MYSQL without installer suppourt in my windows 64 bit machine . I have followed the guidelines mentioned in this website http://dev.mysql.com/doc/refman/5.0/en/windows-install-archive.html i have installed it inside c: mysql directory . As first step i navigated to c:\mysql\binmysqld , as shown in picture below . This started the Database Then i opened another command Prompt Window and navigated to c:\mysql\bin and typed show databases; With this it it showing an Error in Command Prompt saying

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  • HTTP 500 Internal Server Error on IIS 7.5 with MVC3

    - by Tor Haugen
    I am trying to install an MVC3 application on our production server with no luck. The application is from a 3rd party (compiled), and so debugging is not available to me. Besides, I strongly suspect the error occurs before any code in the site has a chance to execute. Our staging server is - as far as I can determine - set up excactly like the production server. Both run Windows Server 2008 Standard R2, both also run a Sharepoint 2010 site (though this install doesn't touch that in any way). IIS is version 7.5, and .NET Framework 4.0 (required by the MVC app) is (recently) installed (by me, with a reboot after). The application is very small and simple and, as far as I can tell sticks to fairly standard functionality - including forms authentication (ie. it doesnt' pull any dirty tricks). The error message shown in the browser is very general: HTTP Error 500.0 - Internal Server Error An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. The bit about 'An error message detailing the cause' being in the application event log seems to be just speculation - a pious hope that whatever code actually caused the error will log it. Nothing useful is to be found in the event log (only the very same message, logged by IIS). Module: AspNetInitClrHostFailureModule Notification: BeginRequest Handler: StaticFile Error Code: 0x80070002 Requested URL: http://xxxxxx.xxxxxx.xx:80/ Physical Path: C:\Xxxxxxx\Prod\WebClient Logon Method: Not yet determined Logon User: Not yet determined Using Failed Request Tracing, I have been able to track the error (as also indicated above) to the AspNetInitClrHostFailureModule: 103. -NOTIFY_MODULE_START ModuleName AspNetInitClrHostFailureModule Notification 1 fIsPostNotification false Notification BEGIN_REQUEST 104. -SET_RESPONSE_ERROR_DESCRIPTION ErrorDescription An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. 105. -MODULE_SET_RESPONSE_ERROR_STATUS ModuleName AspNetInitClrHostFailureModule Notification 1 HttpStatus 500 HttpReason Internal Server Error HttpSubStatus 0 ErrorCode 2147942402 ConfigExceptionInfo Notification BEGIN_REQUEST ErrorCode The system cannot find the file specified. (0x80070002) So there you have it. Seemingly, the AspNetInitClrHostFailureModule fails to find some file. So some questions are: What is the AspNetInitClrHostFailureModule? It is not listed in the fairly exhausting list of modules configurable in IIS manager for the site. I have had no success googling it either. Maybe it's secret.. I access the root URL of the site. This is supposed to be redirected to /Account/LogOn by the FormsAuthenticationModule. Why then is the handler StaticFile? Is that a clue? I have tried removing the infamous system.webserver/modules/runAllManagedModulesForAllRequests attribute, and that makes the error go away (but MVC not actually working, of course). I am prepared to specify all necessary modules manually if that's what it takes, but if the AspNetInitClrHostFailureModule is actually needed, I will be just as stuck. Does anyone know, or can anyone direct me to someone who knows, exactly what modules a typical MVC3 application actually needs? This question might well be a duplicate of this one, but he didn't get any useful answer, and also asked less specific questions. So I'll have my own go. Hoping for some help here :) Edit: I have now tried setting up a trivial MVC 3 project on the server. I created a new project using the MVC Application template, compiled it and deployed it to the server. It behaves in exactly the same way. The server simply cannot run MVC 3 projects.

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  • Using Upstart to manage Unicorn w/ rbenv + bundler binstubs w/ ruby-local-exec shebang

    - by codykrieger
    Alright, this is melting my brain. It might have something to do with the fact that I don't understand Upstart as well as I should. Sorry in advance for the long question. I'm trying to use Upstart to manage a Rails app's Unicorn master process. Here is my current /etc/init/app.conf: description "app" start on runlevel [2] stop on runlevel [016] console owner # expect daemon script APP_ROOT=/home/deploy/app PATH=/home/deploy/.rbenv/shims:/home/deploy/.rbenv/bin:$PATH $APP_ROOT/bin/unicorn -c $APP_ROOT/config/unicorn.rb -E production # >> /tmp/upstart.log 2>&1 end script # respawn That works just fine - the Unicorns start up great. What's not great is that the PID detected is not of the Unicorn master, it's of an sh process. That in and of itself isn't so bad, either - if I wasn't using the automagical Unicorn zero-downtime deployment strategy. Because shortly after I send -USR2 to my Unicorn master, a new master spawns up, and the old one dies...and so does the sh process. So Upstart thinks my job has died, and I can no longer restart it with restart or stop it with stop if I want. I've played around with the config file, trying to add -D to the Unicorn line (like this: $APP_ROOT/bin/unicorn -c $APP_ROOT/config/unicorn.rb -E production -D) to daemonize Unicorn, and I added the expect daemon line, but that didn't work either. I've tried expect fork as well. Various combinations of all of those things can cause start and stop to hang, and then Upstart gets really confused about the state of the job. Then I have to restart the machine to fix it. I think Upstart is having problems detecting when/if Unicorn is forking because I'm using rbenv + the ruby-local-exec shebang in my $APP_ROOT/bin/unicorn script. Here it is: #!/usr/bin/env ruby-local-exec # # This file was generated by Bundler. # # The application 'unicorn' is installed as part of a gem, and # this file is here to facilitate running it. # require 'pathname' ENV['BUNDLE_GEMFILE'] ||= File.expand_path("../../Gemfile", Pathname.new(__FILE__).realpath) require 'rubygems' require 'bundler/setup' load Gem.bin_path('unicorn', 'unicorn') Additionally, the ruby-local-exec script looks like this: #!/usr/bin/env bash # # `ruby-local-exec` is a drop-in replacement for the standard Ruby # shebang line: # # #!/usr/bin/env ruby-local-exec # # Use it for scripts inside a project with an `.rbenv-version` # file. When you run the scripts, they'll use the project-specified # Ruby version, regardless of what directory they're run from. Useful # for e.g. running project tasks in cron scripts without needing to # `cd` into the project first. set -e export RBENV_DIR="${1%/*}" exec ruby "$@" So there's an exec in there that I'm worried about. It fires up a Ruby process, which fires up Unicorn, which may or may not daemonize itself, which all happens from an sh process in the first place...which makes me seriously doubt the ability of Upstart to track all of this nonsense. Is what I'm trying to do even possible? From what I understand, the expect stanza in Upstart can only be told (via daemon or fork) to expect a maximum of two forks.

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  • what is the best mid/high-end class audio/music creation audio sound card?

    - by Chris
    Hello, I have a computershop myself, and I repair computers. But one of the things I really don't know (yet) is the performace od audio cards for music creation with midi. I have searched and searched and came up with some good reviews, but after browsing for a couple of hours I could't see the trees trough the forrest :-D (it's a dutch expression) At one moment I thought the M-Audio - Delta 1010LT would be a good PCIe card, later on I read that this card was released years ago. (but that could be false information) Also any personal expierence would be great, but not necessairy. I have searched a few cards, and I hope someone can help me make a choice for a friend of mine. He's buget is between $100 and $350 I know there are audio cards from $ 500 - $1850,- this is just too expensive. The following specs are crucial: ASIO Midi Mic in minimal 5.1, 7.1 recommended it's not for airplay, but just to compose music at home. using Ableton and midi keyboard. 1. M-Audio - Delta 1010LT: 8 x 8 analog I/O 2 mic preamps or line inputs S/PDIF digital I/O (coaxial) with 2-channel PCM SCMS copy protection control digital I/O supports surround-encoded AC-3 and DTS pass-through 1 x 1 MIDI I/O directly drive up to 7.1 surround (bass management software included) software controlled 36-bit internal DSP digital mixing/routing +4dbu/-10dBV operation individually switched in software word clock I/O for sample accurate device synchronization 2. RME HDSP 9632: * Stereo Analog Ein- und Ausgang, symmetrisch*, 24-Bit/192kHz, > 110 dB SNR * Optionale Erweiterungsboards mit je 4 symmetrischen Ein- und Ausgängen * Alle analogen I/Os voll 192 kHz-fähig, also keine Reduzierung der Kanalzahl * 1 x ADAT Digital In/Out, 96 kHz-fähig (S/MUX) * 1 x SPDIF Digital In/Out, 192 kHz-fähig * 1 x Breakout Kabel für koaxialen SPDIF-Betrieb* * Also bis zu 16 Ein-und Ausgänge gleichzeitig nutzbar! * 1 x Stereo Kopfhörerausgang, parallel zum analogen Ausgang, aber eigene Pegelanpassung * 1 x MIDI I/O für 16 Kanäle Hi-Speed MIDI über Breakout Kabel * DIGICheck, RMEs einzigartiges Meter- und Analysetool mit Spectral Analyser, Professionelle Level Meter 2/8/16-Kanalig, Vector Audio Scope und diversen weiteren Analysefunktionen * HDSP Meter Bridge: Frei skalierbare Levelmeter mit Peak- und RMS Berechnung in Hardware * TotalMix: 512-Kanal Mischer mit 40 Bit interner Auflösung 3. EMU 1212M (1212 M) PCIe: * Top kwaliteit convertors 24-bit/192kHz convertors. * Hardware gestuurde effecten. * DSP zero-latency hardware mixen en monitoring. * Analoge en digitale I/O plus MIDI. * EMU Production Tools Software Bundle - Cakewalk SONAR , Steinberg Cubase LE, Ableton Live E-MU Edition **EMU 1212M PCI-e inputs/outputs:** * 2 balanced jack inputs. * 2 balanced jack outputs. * 24-bit/192kHz ADAT I/O. * 24-bit/192kHz Coaxiale S/PDif I/O switchable to AES/EBU. * MIDI I/O. 4. M-Audio Audiophile 192: - Up to 24-bit/192kHz audio - 2 balanced analog inputs (1/4” TRS) - 2 balanced analog outputs (1/4” TRS) - S/PDIF digital I/O (coaxial RCA connectors) with 2-channel PCM - SCMS copy protection control - Digital I/O supports surround-encoded AC-3 and DTS pass-through - Direct hardware input monitoring via separate balanced 1/4” TRS monitor outputs - Software routing of inputs and outputs - Digital I/O can be routed to/from external effects - 16-channel MIDI I/O - ASIO, WDM, GSIF 2 and Core Audio driver support for compatibility with most applications - 64-bit driver support for Windows - PCI 2.2 compatibility - Apple G5 compatible - Incompatible exceptions - Includes Ableton Live Lite music production software, so you can make music right away - Works with other Delta cards Technical Specifcations: - Compatibility - ASIO - WDM - GSIF 2 - Core Audio

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  • DRBD not syncing between my nodes when IP is reset

    - by ramdaz
    I am trying to setup DRBD by following the article at http://www.howtoforge.com/setting-up-network-raid1-with-drbd-on-ubuntu-11.10-p2 I am using Ubuntu 10.04 DRBD - 8.3.11 In the first run I had everything working perfectly and when shifting the systems to a production environment I decided to restart the Meta Data creation part and start from scratch. The IPs had changed entirely in the production environment. Issuing drdbadm create-md r0 in both the servers runs successfully. But when I do "drbdadm -- --overwrite-data-of-peer primary all" on the primary it fails to start the re sync. My config file is as given below resource r0 { protocol C; syncer { rate 50M; } startup { wfc-timeout 15; degr-wfc-timeout 60; } net { cram-hmac-alg sha1; shared-secret "aklsadkjlhdbskjndsf8738734jkfkjfkjf"; } on primaryds { device /dev/drbd0; disk /dev/md2; address 172.16.7.1:7788; meta-disk internal; } on secondaryds { device /dev/drbd0; disk /dev/md2; address 172.16.7.3:7788; meta-disk internal; } } Status on primary root at primaryds:~# cat /proc/drbd version: 8.3.7 (api:88/proto:86-91) GIT-hash: ea9e28dbff98e331a62bcbcc63a6135808fe2917 build by root at primaryds, 2012-05-12 15:08:01 0: cs:WFBitMapS ro:Primary/Secondary ds:UpToDate/Inconsistent C r---- ns:0 nr:0 dw:0 dr:200 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5690352828 Status on secondary root at secondaryds:/etc/drbd.d# cat /proc/drbd version: 8.3.7 (api:88/proto:86-91) GIT-hash: ea9e28dbff98e331a62bcbcc63a6135808fe2917 build by root at secondaryds, 2012-05-12 15:25:25 0: cs:WFBitMapT ro:Secondary/Primary ds:Inconsistent/UpToDate C r---- ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5690352828 Log of Primary May 30 13:42:23 primaryds kernel: [ 1584.057076] block drbd0: role( Secondary -> Primary ) disk( Inconsistent -> UpToDate ) May 30 13:42:23 primaryds kernel: [ 1584.086264] block drbd0: Forced to consider local data as UpToDate! May 30 13:42:23 primaryds kernel: [ 1584.086303] block drbd0: Creating new current UUID May 30 13:42:26 primaryds kernel: [ 1586.405551] block drbd0: drbd_sync_handshake: May 30 13:42:26 primaryds kernel: [ 1586.405564] block drbd0: self E8A075F378173D4B:0000000000000004:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:26 primaryds kernel: [ 1586.405574] block drbd0: peer 0000000000000004:0000000000000000:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:26 primaryds kernel: [ 1586.405582] block drbd0: uuid_compare()=2 by rule 30 May 30 13:42:26 primaryds kernel: [ 1586.405587] block drbd0: Becoming sync source due to disk states. May 30 13:42:26 primaryds kernel: [ 1586.405592] block drbd0: Writing the whole bitmap, full sync required after drbd_sync_handshake. May 30 13:42:27 primaryds kernel: [ 1588.171638] block drbd0: 5427 GB (1422588207 bits) marked out-of-sync by on disk bit-map. May 30 13:42:27 primaryds kernel: [ 1588.172769] block drbd0: conn( Connected -> WFBitMapS ) Log in Secondary May 30 13:42:24 secondaryds kernel: [ 1563.304894] block drbd0: peer( Secondary - Primary ) pdsk( Inconsistent - UpToDate ) May 30 13:42:24 secondaryds kernel: [ 1563.339674] block drbd0: drbd_sync_handshake: May 30 13:42:24 secondaryds kernel: [ 1563.339685] block drbd0: self 0000000000000004:0000000000000000:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:24 secondaryds kernel: [ 1563.339695] block drbd0: peer E8A075F378173D4B:0000000000000004:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:24 secondaryds kernel: [ 1563.339703] block drbd0: uuid_compare()=-2 by rule 20 May 30 13:42:24 secondaryds kernel: [ 1563.339709] block drbd0: Becoming sync target due to disk states. May 30 13:42:24 secondaryds kernel: [ 1563.339714] block drbd0: Writing the whole bitmap, full sync required after drbd_sync_handshake. May 30 13:42:26 secondaryds kernel: [ 1565.652342] block drbd0: 5427 GB (1422588207 bits) marked out-of-sync by on disk bit-map. May 30 13:42:26 secondaryds kernel: [ 1565.652965] block drbd0: conn( Connected - WFBitMapT ) The serves are not responding once it reaches this stage. Tried redoing it couple of time but noting happens. Why could the resync not be taking place? I would like some advice? Directions?

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  • Putting indexes in separate filegroup kills our queries

    - by womp
    Can anyone shed some light on this? On our dev boxes, our database resides entirely in the PRIMARY filegroup, and everything works fine. On one of our production servers, recently upgraded from 2005 to 2008, we noticed it was performing slower than it should. On this machine, there are two filegroups - PRIMARY and INDEXES. Both filegroups contain 1 file per logical volume, one logical volume per CPU, (and each logical volume is a RAID 10 of 4 physical disks). We isolated a few queries that were performing fast on the dev boxes and slow (up to 40x slower) on the production machine. Turned out these queries were using the non-clustered indexes that resided in the INDEXES filegroup. Tweaking some of the queries to only use clustered indexes that were in the PRIMARY filegroup dropped their times back to normal. As a final confirmation, we redeployed the same database on the same machine to have everything in PRIMARY, and things went back to normal! Here's the statistics output of one of the queries, run identically on the machine with different filegroup configurations (table names changed to protect the innocent): FAST (everything in PRIMARY filegroup): (3 row(s) affected) Table '0'. Scan count 2, logical reads 14, ... Table '1'. Scan count 0, logical reads 0, ... Table '1'. Scan count 0, logical reads 0, ... Table '2'. Scan count 2, logical reads 7, ... Table '3'. Scan count 2, logical reads 1012, ... Table '4'. Scan count 1, logical reads 3, ... SQL Server Execution Times: CPU time = 437 ms, elapsed time = 445 ms. SLOW (indexes split into their own filegroup): (3 row(s) affected) Table '0'. Scan count 209, logical reads 428, ... Table '1'. Scan count 0, logical reads 0,... Table '2'. Scan count 1021, logical reads 9043,.... Table '3'. Scan count 209, logical reads 105754, .... Table '4'. Scan count 0, logical reads 0, .... Table '5'. Scan count 1, logical reads 695, ... **Table '#46DA8CA9'. Scan count 205, logical reads 205, ...** Table '6'. Scan count 6, logical reads 436, ... Table '7'. Scan count 1, logical reads 12,.... SQL Server Execution Times: CPU time = 17581 ms, elapsed time = 17595 ms. Notice the weird temp table and extra tables involved in the slow query. It seems clear that having a second file group is making SQL Server batty with choosing an execution plan. What the heck is going on?

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  • Cloud MBaaS : The Next Big Thing in Enterprise Mobility

    - by shiju
    In this blog post, I will take a look at Cloud Mobile Backend as a Service (MBaaS) and how we can leverage Cloud based Mobile Backend as a Service for building enterprise mobile apps. Today, mobile apps are incredibly significant in both consumer and enterprise space and the demand for the mobile apps is unbelievably increasing in day to day business. An enterprise can’t survive in business without a proper mobility strategy. A better mobility strategy and faster delivery of your mobile apps will give you an extra mileage for your business and IT strategy. So organizations and mobile developers are looking for different strategy for meeting this demand and adopting different development strategy for their mobile apps. Some developers are adopting hybrid mobile app development platforms, for delivering their products for multiple platforms, for fast time-to-market. Others are adopting a Mobile enterprise application platform (MEAP) such as Kony for their enterprise mobile apps for fast time-to-market and better business integration. The Challenges of Enterprise Mobility The real challenge of enterprise mobile apps, is not about creating the front-end environment or developing front-end for multiple platforms. The most important thing of enterprise mobile apps is to expose your enterprise data to mobile devices where the real pain is your business data might be residing in lot of different systems including legacy systems, ERP systems etc., and these systems will be deployed with lot of security restrictions. Exposing your data from the on-premises servers, is not a easy thing for most of the business organizations. Many organizations are spending too much time for their front-end development strategy, but they are really lacking for building a strategy on their back-end for exposing the business data to mobile apps. So building a REST services layer and mobile back-end services, on the top of legacy systems and existing middleware systems, is the key part of most of the enterprise mobile apps, where multiple mobile platforms can easily consume these REST services and other mobile back-end services for building mobile apps. For some mobile apps, we can’t predict its user base, especially for products where customers can gradually increase at any time. And for today’s mobile apps, faster time-to-market is very critical so that spending too much time for mobile app’s scalability, will not be worth. The real power of Cloud is the agility and on-demand scalability, where we can scale-up and scale-down our applications very easily. It would be great if we could use the power of Cloud to mobile apps. So using Cloud for mobile apps is a natural fit, where we can use Cloud as the storage for mobile apps and hosting mechanism for mobile back-end services, where we can enjoy the full power of Cloud with greater level of on-demand scalability and operational agility. So Cloud based Mobile Backend as a Service is great choice for building enterprise mobile apps, where enterprises can enjoy the massive scalability power of their mobile apps, provided by public cloud vendors such as Microsoft Windows Azure. Mobile Backend as a Service (MBaaS) We have discussed the key challenges of enterprise mobile apps and how we can leverage Cloud for hosting mobile backend services. MBaaS is a set of cloud-based, server-side mobile services for multiple mobile platforms and HTML5 platform, which can be used as a backend for your mobile apps with the scalability power of Cloud. The information below provides the key features of a typical MBaaS platform: Cloud based storage for your application data. Automatic REST API services on the application data, for CRUD operations. Native push notification services with massive scalability power. User management services for authenticate users. User authentication via Social accounts such as Facebook, Google, Microsoft, and Twitter. Scheduler services for periodically sending data to mobile devices. Native SDKs for multiple mobile platforms such as Windows Phone and Windows Store, Android, Apple iOS, and HTML5, for easily accessing the mobile services from mobile apps, with better security.  Typically, a MBaaS platform will provide native SDKs for multiple mobile platforms so that we can easily consume the server-side mobile services. MBaaS based REST APIs can use for integrating to enterprise backend systems. We can use the same mobile services for multiple platform so hat we can reuse the application logic to multiple mobile platforms. Public cloud vendors are building the mobile services on the top of their PaaS offerings. Windows Azure Mobile Services is a great platform for a MBaaS offering that is leveraging Windows Azure Cloud platform’s PaaS capabilities. Hybrid mobile development platform Titanium provides their own MBaaS services. LoopBack is a new MBaaS service provided by Node.js consulting firm StrongLoop, which can be hosted on multiple cloud platforms and also for on-premises servers. The Challenges of MBaaS Solutions If you are building your mobile apps with a new data storage, it will be very easy, since there is not any integration challenges you have to face. But most of the use cases, you have to extract your application data in which stored in on-premises servers which might be under VPNs and firewalls. So exposing these data to your MBaaS solution with a proper security would be a big challenge. The capability of your MBaaS vendor is very important as you have to interact with your legacy systems for many enterprise mobile apps. So you should be very careful about choosing for MBaaS vendor. At the same time, you should have a proper strategy for mobilizing your application data which stored in on-premises legacy systems, where your solution architecture and strategy is more important than platforms and tools.  Windows Azure Mobile Services Windows Azure Mobile Services is an MBaaS offerings from Windows Azure cloud platform. IMHO, Microsoft Windows Azure is the best PaaS platform in the Cloud space. Windows Azure Mobile Services extends the PaaS capabilities of Windows Azure, to mobile devices, which can be used as a cloud backend for your mobile apps, which will provide global availability and reach for your mobile apps. Windows Azure Mobile Services provides storage services, user management with social network integration, push notification services and scheduler services and provides native SDKs for all major mobile platforms and HTML5. In Windows Azure Mobile Services, you can write server-side scripts in Node.js where you can enjoy the full power of Node.js including the use of NPM modules for your server-side scripts. In the previous section, we had discussed some challenges of MBaaS solutions. You can leverage Windows Azure Cloud platform for solving many challenges regarding with enterprise mobility. The entire Windows Azure platform can play a key role for working as the backend for your mobile apps where you can leverage the entire Windows Azure platform for your mobile apps. With Windows Azure, you can easily connect to your on-premises systems which is a key thing for mobile backend solutions. Another key point is that Windows Azure provides better integration with services like Active Directory, which makes Windows Azure as the de facto platform for enterprise mobility, for enterprises, who have been leveraging Microsoft ecosystem for their application and IT infrastructure. Windows Azure Mobile Services  is going to next evolution where you can expect some exciting features in near future. One area, where Windows Azure Mobile Services should definitely need an improvement, is about the default storage mechanism in which currently it is depends on SQL Server. IMHO, developers should be able to choose multiple default storage option when creating a new mobile service instance. Let’s say, there should be a different storage providers such as SQL Server storage provider and Table storage provider where developers should be able to choose their choice of storage provider when creating a new mobile services project. I have been used Windows Azure and Windows Azure Mobile Services as the backend for production apps for mobile, where it performed very well. MBaaS Over MEAP Recently, many larger enterprises has been adopted Mobile enterprise application platform (MEAP) for their mobile apps. I haven’t worked on any production MEAP solution, but I heard that developers are really struggling with MEAP in different way. The learning curve for a proprietary MEAP platform is very high. I am completely against for using larger proprietary ecosystem for mobile apps. For enterprise mobile apps, I highly recommend to use native iOS/Android/Windows Phone or HTML5  for front-end with a cloud hosted MBaaS solution as the middleware. A MBaaS service can be consumed from multiple mobile apps where REST APIs are using to integrating with enterprise backend systems. Enterprise mobility should start with exposing REST APIs on the enterprise backend systems and these REST APIs can host on Cloud where we can enjoy the power of Cloud for our services. If you are having REST APIs for your enterprise data, then you can easily build mobile frontends for multiple platforms.   You can follow me on Twitter @shijucv

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  • SQL Monitor’s data repository

    - by Chris Lambrou
    As one of the developers of SQL Monitor, I often get requests passed on by our support people from customers who are looking to dip into SQL Monitor’s own data repository, in order to pull out bits of information that they’re interested in. Since there’s clearly interest out there in playing around directly with the data repository, I thought I’d write some blog posts to start to describe how it all works. The hardest part for me is knowing where to begin, since the schema of the data repository is pretty big. Hmmm… I guess it’s tricky for anyone to write anything but the most trivial of queries against the data repository without understanding the hierarchy of monitored objects, so perhaps my first post should start there. I always imagine that whenever a customer fires up SSMS and starts to explore their SQL Monitor data repository database, they become immediately bewildered by the schema – that was certainly my experience when I did so for the first time. The following query shows the number of different object types in the data repository schema: SELECT type_desc, COUNT(*) AS [count] FROM sys.objects GROUP BY type_desc ORDER BY type_desc;  type_desccount 1DEFAULT_CONSTRAINT63 2FOREIGN_KEY_CONSTRAINT181 3INTERNAL_TABLE3 4PRIMARY_KEY_CONSTRAINT190 5SERVICE_QUEUE3 6SQL_INLINE_TABLE_VALUED_FUNCTION381 7SQL_SCALAR_FUNCTION2 8SQL_STORED_PROCEDURE100 9SYSTEM_TABLE41 10UNIQUE_CONSTRAINT54 11USER_TABLE193 12VIEW124 With 193 tables, 124 views, 100 stored procedures and 381 table valued functions, that’s quite a hefty schema, and when you browse through it using SSMS, it can be a bit daunting at first. So, where to begin? Well, let’s narrow things down a bit and only look at the tables belonging to the data schema. That’s where all of the collected monitoring data is stored by SQL Monitor. The following query gives us the names of those tables: SELECT sch.name + '.' + obj.name AS [name] FROM sys.objects obj JOIN sys.schemas sch ON sch.schema_id = obj.schema_id WHERE obj.type_desc = 'USER_TABLE' AND sch.name = 'data' ORDER BY sch.name, obj.name; This query still returns 110 tables. I won’t show them all here, but let’s have a look at the first few of them:  name 1data.Cluster_Keys 2data.Cluster_Machine_ClockSkew_UnstableSamples 3data.Cluster_Machine_Cluster_StableSamples 4data.Cluster_Machine_Keys 5data.Cluster_Machine_LogicalDisk_Capacity_StableSamples 6data.Cluster_Machine_LogicalDisk_Keys 7data.Cluster_Machine_LogicalDisk_Sightings 8data.Cluster_Machine_LogicalDisk_UnstableSamples 9data.Cluster_Machine_LogicalDisk_Volume_StableSamples 10data.Cluster_Machine_Memory_Capacity_StableSamples 11data.Cluster_Machine_Memory_UnstableSamples 12data.Cluster_Machine_Network_Capacity_StableSamples 13data.Cluster_Machine_Network_Keys 14data.Cluster_Machine_Network_Sightings 15data.Cluster_Machine_Network_UnstableSamples 16data.Cluster_Machine_OperatingSystem_StableSamples 17data.Cluster_Machine_Ping_UnstableSamples 18data.Cluster_Machine_Process_Instances 19data.Cluster_Machine_Process_Keys 20data.Cluster_Machine_Process_Owner_Instances 21data.Cluster_Machine_Process_Sightings 22data.Cluster_Machine_Process_UnstableSamples 23… There are two things I want to draw your attention to: The table names describe a hierarchy of the different types of object that are monitored by SQL Monitor (e.g. clusters, machines and disks). For each object type in the hierarchy, there are multiple tables, ending in the suffixes _Keys, _Sightings, _StableSamples and _UnstableSamples. Not every object type has a table for every suffix, but the _Keys suffix is especially important and a _Keys table does indeed exist for every object type. In fact, if we limit the query to return only those tables ending in _Keys, we reveal the full object hierarchy: SELECT sch.name + '.' + obj.name AS [name] FROM sys.objects obj JOIN sys.schemas sch ON sch.schema_id = obj.schema_id WHERE obj.type_desc = 'USER_TABLE' AND sch.name = 'data' AND obj.name LIKE '%_Keys' ORDER BY sch.name, obj.name;  name 1data.Cluster_Keys 2data.Cluster_Machine_Keys 3data.Cluster_Machine_LogicalDisk_Keys 4data.Cluster_Machine_Network_Keys 5data.Cluster_Machine_Process_Keys 6data.Cluster_Machine_Services_Keys 7data.Cluster_ResourceGroup_Keys 8data.Cluster_ResourceGroup_Resource_Keys 9data.Cluster_SqlServer_Agent_Job_History_Keys 10data.Cluster_SqlServer_Agent_Job_Keys 11data.Cluster_SqlServer_Database_BackupType_Backup_Keys 12data.Cluster_SqlServer_Database_BackupType_Keys 13data.Cluster_SqlServer_Database_CustomMetric_Keys 14data.Cluster_SqlServer_Database_File_Keys 15data.Cluster_SqlServer_Database_Keys 16data.Cluster_SqlServer_Database_Table_Index_Keys 17data.Cluster_SqlServer_Database_Table_Keys 18data.Cluster_SqlServer_Error_Keys 19data.Cluster_SqlServer_Keys 20data.Cluster_SqlServer_Services_Keys 21data.Cluster_SqlServer_SqlProcess_Keys 22data.Cluster_SqlServer_TopQueries_Keys 23data.Cluster_SqlServer_Trace_Keys 24data.Group_Keys The full object type hierarchy looks like this: Cluster Machine LogicalDisk Network Process Services ResourceGroup Resource SqlServer Agent Job History Database BackupType Backup CustomMetric File Table Index Error Services SqlProcess TopQueries Trace Group Okay, but what about the individual objects themselves represented at each level in this hierarchy? Well that’s what the _Keys tables are for. This is probably best illustrated by way of a simple example – how can I query my own data repository to find the databases on my own PC for which monitoring data has been collected? Like this: SELECT clstr._Name AS cluster_name, srvr._Name AS instance_name, db._Name AS database_name FROM data.Cluster_SqlServer_Database_Keys db JOIN data.Cluster_SqlServer_Keys srvr ON db.ParentId = srvr.Id -- Note here how the parent of a Database is a Server JOIN data.Cluster_Keys clstr ON srvr.ParentId = clstr.Id -- Note here how the parent of a Server is a Cluster WHERE clstr._Name = 'dev-chrisl2' -- This is the hostname of my own PC ORDER BY clstr._Name, srvr._Name, db._Name;  cluster_nameinstance_namedatabase_name 1dev-chrisl2SqlMonitorData 2dev-chrisl2master 3dev-chrisl2model 4dev-chrisl2msdb 5dev-chrisl2mssqlsystemresource 6dev-chrisl2tempdb 7dev-chrisl2sql2005SqlMonitorData 8dev-chrisl2sql2005TestDatabase 9dev-chrisl2sql2005master 10dev-chrisl2sql2005model 11dev-chrisl2sql2005msdb 12dev-chrisl2sql2005mssqlsystemresource 13dev-chrisl2sql2005tempdb 14dev-chrisl2sql2008SqlMonitorData 15dev-chrisl2sql2008master 16dev-chrisl2sql2008model 17dev-chrisl2sql2008msdb 18dev-chrisl2sql2008mssqlsystemresource 19dev-chrisl2sql2008tempdb These results show that I have three SQL Server instances on my machine (a default instance, one named sql2005 and one named sql2008), and each instance has the usual set of system databases, along with a database named SqlMonitorData. Basically, this is where I test SQL Monitor on different versions of SQL Server, when I’m developing. There are a few important things we can learn from this query: Each _Keys table has a column named Id. This is the primary key. Each _Keys table has a column named ParentId. A foreign key relationship is defined between each _Keys table and its parent _Keys table in the hierarchy. There are two exceptions to this, Cluster_Keys and Group_Keys, because clusters and groups live at the root level of the object hierarchy. Each _Keys table has a column named _Name. This is used to uniquely identify objects in the table within the scope of the same shared parent object. Actually, that last item isn’t always true. In some cases, the _Name column is actually called something else. For example, the data.Cluster_Machine_Services_Keys table has a column named _ServiceName instead of _Name (sorry for the inconsistency). In other cases, a name isn’t sufficient to uniquely identify an object. For example, right now my PC has multiple processes running, all sharing the same name, Chrome (one for each tab open in my web-browser). In such cases, multiple columns are used to uniquely identify an object within the scope of the same shared parent object. Well, that’s it for now. I’ve given you enough information for you to explore the _Keys tables to see how objects are stored in your own data repositories. In a future post, I’ll try to explain how monitoring data is stored for each object, using the _StableSamples and _UnstableSamples tables. If you have any questions about this post, or suggestions for future posts, just submit them in the comments section below.

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  • Now Available &ndash; Windows Azure SDK 1.6

    - by Shaun
    Microsoft has just announced the Windows Azure SDK 1.6 and the Windows Azure Tools for Visual Studio 1.6. Now people can download the latest product through the WebPI. After you downloaded and installed the SDK you will find that The SDK 1.6 can be stayed side by side with the SDK 1.5, which means you can still using the 1.5 assemblies. But the Visual Studio Tools would be upgraded to 1.6. Different from the previous SDK, in this version it includes 4 components: Windows Azure Authoring Tools, Windows Azure Emulators, Windows Azure Libraries for .NET 1.6 and the Windows Azure Tools for Microsoft Visual Studio 2010. There are some significant upgrades in this version, which are Publishing Enhancement: More easily connect to the Windows Azure when publish your application by retrieving a publish setting file. It will let you configure some settings of the deployment, without getting back to the developer portal. Multi-profiles: The publish settings, cloud configuration files, etc. will be stored in one or more MSBuild files. It will be much easier to switch the settings between vary build environments. MSBuild Command-line Build Support. In-Place Upgrade Support.   Publishing Enhancement So let’s have a look about the new features of the publishing. Just create a new Windows Azure project in Visual Studio 2010 with a MVC 3 Web Role, and right-click the Windows Azure project node in the solution explorer, then select Publish, we will find the new publish dialog. In this version the first thing we need to do is to connect to our Windows Azure subscription. Click the “Sign in to download credentials” link, we will be navigated to the login page to provide the Live ID. The Windows Azure Tool will generate a certificate file and uploaded to the subscriptions those belong to us. Then we will download a PUBLISHSETTINGS file, which contains the credentials and subscriptions information. The Visual Studio Tool will generate a certificate and deployed to the subscriptions you have as the Management Certificate. The VS Tool will use this certificate to connect to the subscription in the next step. In the next step, I would back to the Visual Studio (the publish dialog should be stilling opened) and click the Import button, select the PUBLISHSETTINGS file I had just downloaded. Then all my subscriptions will be shown in the dropdown list. Select a subscription that I want the application to be published and press the Next button, then we can select the hosted service, environment, build configuration and service configuration shown in the dialog. In this version we can create a new hosted service directly here rather than go back to the developer portal. Just select the <Create New …> item in the hosted service. What we need to do is to provide the hosted service name and the location. Once clicked the OK, after several seconds the hosted service will be established. If we went to the developer portal we will find the new hosted service in my subscription. a) Currently we cannot select the Affinity Group when create a new hosted service through the Visual Studio Publish dialog. b) Although we can specify the hosted service name and DNS prefixing through the developer portal, we cannot do so from the VS Tool, which means the DNS prefixing would be the same as what we specified for the hosted service name. For example, we specified our hosted service name as “Sdk16Demo”, so the public URL would be http://sdk16demo.cloudapp.net/. After created a new hosted service we can select the cloud environment (production or staging), the build configuration (release or debug), and the service configuration (cloud or local). And we can set the Remote Desktop by check the related checkbox as well. One thing should be note is that, in this version when we set the Remote Desktop settings we don’t need to specify a certificate by default. This is because the Visual Studio will generate a new certificate for us by default. But we can still specify an existing certificate for RDC, by clicking the “More Options” button. Visual Studio Tool will create another certificate for the Remote Desktop connection. It will NOT use the certificate that managing the subscription. We also can select the “Advanced Settings” page to specify the deployment label, storage account, IntelliTrace and .NET profiling information, etc.. Press Next button, the dialog will display all settings I had just specified and it will save them as a new profile. The last step is to click the Publish button. Since we enabled the Remote Desktop feature, the first step of publishing was uploading the certificate. And then it will verify the storage account we specified and upload the package, then finally created the website in Windows Azure.   Multi-Profiles After published, if we back to the Visual Studio we can find a AZUREPUBXML file under the Profiles folder in the Azure project. It includes all settings we specified before. If we publish this project again, we can just use the current settings (hosted service, environment, RDC, etc.) from this profile without input them again. And this is very useful when we have more than one deployment settings. For example it would be able to have one AZUREPUBXML profile for deploying to testing environment (debug building, less roles with RDC and IntelliTrace) and one for production (release building, more roles but without IntelliTrace).   In-Place Upgrade Support Let’s change some codes in the MVC pages and click the Publish menu from the azure project node. No need to specify any settings,  here we can use the pervious settings by loading the azure profile file (AZUREPUBXML). After clicked the Publish button the VS Tool brought a dialog to us to indicate that there’s a deployment available in the hosted service environment, and prompt to REPLACE it or not. Notice that in this version, the dialog tool said “replace” rather than “delete”, which means by default the VS Tool will use In-Place Upgrade when we deploy to a hosted service that has a deployment already exist. After click Yes the VS Tool will upload the package and perform the In-Place Upgrade. If we back to the developer portal we can find that the status of the hosted service was turned to “Updating…”. But in the previous SDK, it will try to delete the whole deployment and publish a new one.   Summary When the Microsoft announced the features that allows the changing VM size via In-Place Upgrade, they also mentioned that in the next few versions the user experience of publishing the azure application would be improved. The target was trying to accomplish the whole publish experience in Visual Studio, which means no need to touch developer portal any more. In the SDK 1.6 we can see from the new publish dialog, as a developer we can do the whole process, includes creating hosted service, specifying the environment, configuration, remote desktop, etc. values without going back the the developer portal.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • A pseudo-listener for AlwaysOn Availability Groups for SQL Server virtual machines running in Azure

    - by MikeD
    I am involved in a project that is implementing SharePoint 2013 on virtual machines hosted in Azure. The back end data tier consists of two Azure VMs running SQL Server 2012, with the SharePoint databases contained in an AlwaysOn Availability Group. I used this "Tutorial: AlwaysOn Availability Groups in Windows Azure (GUI)" to help me implement this setup.Because Azure DHCP will not assign multiple unique IP addresses to the same VM, having an AG Listener in Azure is not currently supported.  I wanted to figure out another mechanism to support a "pseudo listener" of some sort. First, I created a CNAME (alias) record in the DNS zone with a short TTL (time to live) of 5 minutes (I may yet make this even shorter). The record represents a logical name (let's say the alias is SPSQL) of the server to connect to for the databases in the availability group (AG). When Server1 was hosting the primary replica of the AG, I would set the CNAME of SPSQL to be SERVER1. When the AG failed over to Server1, I wanted to set the CNAME to SERVER2. Seemed simple enough.(It's important to point out that the connection strings for my SharePoint services should use the CNAME alias, and not the actual server name. This whole thing falls apart otherwise.)To accomplish this, I created identical SQL Agent Jobs on Server1 and Server2, with two steps:1. Step 1: Determine if this server is hosting the primary replica.This is a TSQL step using this script:declare @agName sysname = 'AGTest'set nocount on declare @primaryReplica sysnameselect @primaryReplica = agState.primary_replicafrom sys.dm_hadr_availability_group_states agState   join sys.availability_groups ag on agstate.group_id = ag.group_id   where ag.name = @AGname if not exists(   select *    from sys.dm_hadr_availability_group_states agState   join sys.availability_groups ag on agstate.group_id = ag.group_id   where @@Servername = agstate.primary_replica    and ag.name = @AGname)begin   raiserror ('Primary replica of %s is not hosted on %s, it is hosted on %s',17,1,@Agname, @@Servername, @primaryReplica) endThis script determines if the primary replica value of the AG group is the same as the server name, which means that our server is hosting the current AG (you should update the value of the @AgName variable to the name of your AG). If this is true, I want the DNS alias to point to this server. If the current server is not hosting the primary replica, then the script raises an error. Also, if the script can't be executed because it cannot connect to the server, that also will generate an error. For the job step settings, I set the On Failure option to "Quit the job reporting success". The next step in the job will set the DNS alias to this server name, and I only want to do that if I know that it is the current primary replica, otherwise I don't want to do anything. I also include the step output in the job history so I can see the error message.Job Step 2: Update the CNAME entry in DNS with this server's name.I used a PowerShell script to accomplish this:$cname = "SPSQL.contoso.com"$query = "Select * from MicrosoftDNS_CNAMEType"$dns1 = "dc01.contoso.com"$dns2 = "dc02.contoso.com"if ((Test-Connection -ComputerName $dns1 -Count 1 -Quiet) -eq $true){    $dnsServer = $dns1}elseif ((Test-Connection -ComputerName $dns2 -Count 1 -Quiet) -eq $true) {   $dnsServer = $dns2}else{  $msg = "Unable to connect to DNS servers: " + $dns1 + ", " + $dns2   Throw $msg}$record = Get-WmiObject -Namespace "root\microsoftdns" -Query $query -ComputerName $dnsServer  | ? { $_.Ownername -match $cname }$thisServer = [System.Net.Dns]::GetHostEntry("LocalHost").HostName + "."$currentServer = $record.RecordData if ($currentServer -eq $thisServer ) {     $cname + " CNAME is up to date: " + $currentServer}else{    $cname + " CNAME is being updated to " + $thisServer + ". It was " + $currentServer    $record.RecordData = $thisServer    $record.put()}This script does a few things:finds a responsive domain controller (Test-Connection does a ping and returns a Boolean value if you specify the -Quiet parameter)makes a WMI call to the domain controller to get the current CNAME record value (Get-WmiObject)gets the FQDN of this server (GetHostEntry)checks if the CNAME record is correct and updates it if necessary(You should update the values of the variables $cname, $dns1 and $dns2 for your environment.)Since my domain controllers are also hosted in Azure VMs, either one of them could be down at any point in time, so I need to find a DC that is responsive before attempting the DNS call. The other little thing here is that the CNAME record contains the FQDN of a machine, plus it ends with a period. So the comparison of the CNAME record has to take the trailing period into account. When I tested this step, I was getting ACCESS DENIED responses from PowerShell for the Get-WmiObject cmdlet that does a remote lookup on the DC. This occurred because the SQL Agent service account was not a member of the Domain Admins group, so I decided to create a SQL Credential to store the credentials for a domain administrator account and use it as a PowerShell proxy (rather than give the service account Domain Admins membership).In SQL Management Studio, right click on the Credentials node (under the server's Security node), and choose New Credential...Then, under SQL Agent-->Proxies, right click on the PowerShell node and choose New Proxy...Finally, in the job step properties for the PowerShell step, select the new proxy in the Run As drop down.I created this two step Job on both nodes of the Availability Group, but if you had more than two nodes, just create the same job on all the servers. I set the schedule for the job to execute every minute.When the server that is hosting the primary replica is running the job, the job history looks like this:The job history on the secondary server looks like this: When a failover occurs, the SQL Agent job on the new primary replica will detect that the CNAME needs to be updated within a minute. Based on the TTL of the CNAME (which I said at the beginning was 5 minutes), the SharePoint servers will get the new alias within five minutes and should be able to reconnect. I may want to shorten up the TTL to reduce the time it takes for the client connections to use the new alias. Using a DNS CNAME and a SQL Agent Job on all servers hosting AG replicas, I was able to create a pseudo-listener to automatically change the name of the server that was hosting the primary replica, for a scenario where I cannot use a regular AG listener (in this case, because the servers are all hosted in Azure).    

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  • Replication Services as ETL extraction tool

    - by jorg
    In my last blog post I explained the principles of Replication Services and the possibilities it offers in a BI environment. One of the possibilities I described was the use of snapshot replication as an ETL extraction tool: “Snapshot Replication can also be useful in BI environments, if you don’t need a near real-time copy of the database, you can choose to use this form of replication. Next to an alternative for Transactional Replication it can be used to stage data so it can be transformed and moved into the data warehousing environment afterwards. In many solutions I have seen developers create multiple SSIS packages that simply copies data from one or more source systems to a staging database that figures as source for the ETL process. The creation of these packages takes a lot of (boring) time, while Replication Services can do the same in minutes. It is possible to filter out columns and/or records and it can even apply schema changes automatically so I think it offers enough features here. I don’t know how the performance will be and if it really works as good for this purpose as I expect, but I want to try this out soon!” Well I have tried it out and I must say it worked well. I was able to let replication services do work in a fraction of the time it would cost me to do the same in SSIS. What I did was the following: Configure snapshot replication for some Adventure Works tables, this was quite simple and straightforward. Create an SSIS package that executes the snapshot replication on demand and waits for its completion. This is something that you can’t do with out of the box functionality. While configuring the snapshot replication two SQL Agent Jobs are created, one for the creation of the snapshot and one for the distribution of the snapshot. Unfortunately these jobs are  asynchronous which means that if you execute them they immediately report back if the job started successfully or not, they do not wait for completion and report its result afterwards. So I had to create an SSIS package that executes the jobs and waits for their completion before the rest of the ETL process continues. Fortunately I was able to create the SSIS package with the desired functionality. I have made a step-by-step guide that will help you configure the snapshot replication and I have uploaded the SSIS package you need to execute it. Configure snapshot replication   The first step is to create a publication on the database you want to replicate. Connect to SQL Server Management Studio and right-click Replication, choose for New.. Publication…   The New Publication Wizard appears, click Next Choose your “source” database and click Next Choose Snapshot publication and click Next   You can now select tables and other objects that you want to publish Expand Tables and select the tables that are needed in your ETL process In the next screen you can add filters on the selected tables which can be very useful. Think about selecting only the last x days of data for example. Its possible to filter out rows and/or columns. In this example I did not apply any filters. Schedule the Snapshot Agent to run at a desired time, by doing this a SQL Agent Job is created which we need to execute from a SSIS package later on. Next you need to set the Security Settings for the Snapshot Agent. Click on the Security Settings button.   In this example I ran the Agent under the SQL Server Agent service account. This is not recommended as a security best practice. Fortunately there is an excellent article on TechNet which tells you exactly how to set up the security for replication services. Read it here and make sure you follow the guidelines!   On the next screen choose to create the publication at the end of the wizard Give the publication a name (SnapshotTest) and complete the wizard   The publication is created and the articles (tables in this case) are added Now the publication is created successfully its time to create a new subscription for this publication.   Expand the Replication folder in SSMS and right click Local Subscriptions, choose New Subscriptions   The New Subscription Wizard appears   Select the publisher on which you just created your publication and select the database and publication (SnapshotTest)   You can now choose where the Distribution Agent should run. If it runs at the distributor (push subscriptions) it causes extra processing overhead. If you use a separate server for your ETL process and databases choose to run each agent at its subscriber (pull subscriptions) to reduce the processing overhead at the distributor. Of course we need a database for the subscription and fortunately the Wizard can create it for you. Choose for New database   Give the database the desired name, set the desired options and click OK You can now add multiple SQL Server Subscribers which is not necessary in this case but can be very useful.   You now need to set the security settings for the Distribution Agent. Click on the …. button Again, in this example I ran the Agent under the SQL Server Agent service account. Read the security best practices here   Click Next   Make sure you create a synchronization job schedule again. This job is also necessary in the SSIS package later on. Initialize the subscription at first synchronization Select the first box to create the subscription when finishing this wizard Complete the wizard by clicking Finish The subscription will be created In SSMS you see a new database is created, the subscriber. There are no tables or other objects in the database available yet because the replication jobs did not ran yet. Now expand the SQL Server Agent, go to Jobs and search for the job that creates the snapshot:   Rename this job to “CreateSnapshot” Now search for the job that distributes the snapshot:   Rename this job to “DistributeSnapshot” Create an SSIS package that executes the snapshot replication We now need an SSIS package that will take care of the execution of both jobs. The CreateSnapshot job needs to execute and finish before the DistributeSnapshot job runs. After the DistributeSnapshot job has started the package needs to wait until its finished before the package execution finishes. The Execute SQL Server Agent Job Task is designed to execute SQL Agent Jobs from SSIS. Unfortunately this SSIS task only executes the job and reports back if the job started succesfully or not, it does not report if the job actually completed with success or failure. This is because these jobs are asynchronous. The SSIS package I’ve created does the following: It runs the CreateSnapshot job It checks every 5 seconds if the job is completed with a for loop When the CreateSnapshot job is completed it starts the DistributeSnapshot job And again it waits until the snapshot is delivered before the package will finish successfully Quite simple and the package is ready to use as standalone extract mechanism. After executing the package the replicated tables are added to the subscriber database and are filled with data:   Download the SSIS package here (SSIS 2008) Conclusion In this example I only replicated 5 tables, I could create a SSIS package that does the same in approximately the same amount of time. But if I replicated all the 70+ AdventureWorks tables I would save a lot of time and boring work! With replication services you also benefit from the feature that schema changes are applied automatically which means your entire extract phase wont break. Because a snapshot is created using the bcp utility (bulk copy) it’s also quite fast, so the performance will be quite good. Disadvantages of using snapshot replication as extraction tool is the limitation on source systems. You can only choose SQL Server or Oracle databases to act as a publisher. So if you plan to build an extract phase for your ETL process that will invoke a lot of tables think about replication services, it would save you a lot of time and thanks to the Extract SSIS package I’ve created you can perfectly fit it in your usual SSIS ETL process.

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

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

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  • CI Deployment Of Azure Web Roles Using TeamCity

    - by srkirkland
    After recently migrating an important new website to use Windows Azure “Web Roles” I wanted an easier way to deploy new versions to the Azure Staging environment as well as a reliable process to rollback deployments to a certain “known good” source control commit checkpoint.  By configuring our JetBrains’ TeamCity CI server to utilize Windows Azure PowerShell cmdlets to create new automated deployments, I’ll show you how to take control of your Azure publish process. Step 0: Configuring your Azure Project in Visual Studio Before we can start looking at automating the deployment, we should make sure manual deployments from Visual Studio are working properly.  Detailed information for setting up deployments can be found at http://msdn.microsoft.com/en-us/library/windowsazure/ff683672.aspx#PublishAzure or by doing some quick Googling, but the basics are as follows: Install the prerequisite Windows Azure SDK Create an Azure project by right-clicking on your web project and choosing “Add Windows Azure Cloud Service Project” (or by manually adding that project type) Configure your Role and Service Configuration/Definition as desired Right-click on your azure project and choose “Publish,” create a publish profile, and push to your web role You don’t actually have to do step #4 and create a publish profile, but it’s a good exercise to make sure everything is working properly.  Once your Windows Azure project is setup correctly, we are ready to move on to understanding the Azure Publish process. Understanding the Azure Publish Process The actual Windows Azure project is fairly simple at its core—it builds your dependent roles (in our case, a web role) against a specific service and build configuration, and outputs two files: ServiceConfiguration.Cloud.cscfg: This is just the file containing your package configuration info, for example Instance Count, OsFamily, ConnectionString and other Setting information. ProjectName.Azure.cspkg: This is the package file that contains the guts of your deployment, including all deployable files. When you package your Azure project, these two files will be created within the directory ./[ProjectName].Azure/bin/[ConfigName]/app.publish/.  If you want to build your Azure Project from the command line, it’s as simple as calling MSBuild on the “Publish” target: msbuild.exe /target:Publish Windows Azure PowerShell Cmdlets The last pieces of the puzzle that make CI automation possible are the Azure PowerShell Cmdlets (http://msdn.microsoft.com/en-us/library/windowsazure/jj156055.aspx).  These cmdlets are what will let us create deployments without Visual Studio or other user intervention. Preparing TeamCity for Azure Deployments Now we are ready to get our TeamCity server setup so it can build and deploy Windows Azure projects, which we now know requires the Azure SDK and the Windows Azure PowerShell Cmdlets. Installing the Azure SDK is easy enough, just go to https://www.windowsazure.com/en-us/develop/net/ and click “Install” Once this SDK is installed, I recommend running a test build to make sure your project is building correctly.  You’ll want to setup your build step using MSBuild with the “Publish” target against your solution file.  Mine looks like this: Assuming the build was successful, you will now have the two *.cspkg and *cscfg files within your build directory.  If the build was red (failed), take a look at the build logs and keep an eye out for “unsupported project type” or other build errors, which will need to be addressed before the CI deployment can be completed. With a successful build we are now ready to install and configure the Windows Azure PowerShell Cmdlets: Follow the instructions at http://msdn.microsoft.com/en-us/library/windowsazure/jj554332 to install the Cmdlets and configure PowerShell After installing the Cmdlets, you’ll need to get your Azure Subscription Info using the Get-AzurePublishSettingsFile command. Store the resulting *.publishsettings file somewhere you can get to easily, like C:\TeamCity, because you will need to reference it later from your deploy script. Scripting the CI Deploy Process Now that the cmdlets are installed on our TeamCity server, we are ready to script the actual deployment using a TeamCity “PowerShell” build runner.  Before we look at any code, here’s a breakdown of our deployment algorithm: Setup your variables, including the location of the *.cspkg and *cscfg files produced in the earlier MSBuild step (remember, the folder is something like [ProjectName].Azure/bin/[ConfigName]/app.publish/ Import the Windows Azure PowerShell Cmdlets Import and set your Azure Subscription information (this is basically your authentication/authorization step, so protect your settings file Now look for a current deployment, and if you find one Upgrade it, else Create a new deployment Pretty simple and straightforward.  Now let’s look at the code (also available as a gist here: https://gist.github.com/3694398): $subscription = "[Your Subscription Name]" $service = "[Your Azure Service Name]" $slot = "staging" #staging or production $package = "[ProjectName]\bin\[BuildConfigName]\app.publish\[ProjectName].cspkg" $configuration = "[ProjectName]\bin\[BuildConfigName]\app.publish\ServiceConfiguration.Cloud.cscfg" $timeStampFormat = "g" $deploymentLabel = "ContinuousDeploy to $service v%build.number%"   Write-Output "Running Azure Imports" Import-Module "C:\Program Files (x86)\Microsoft SDKs\Windows Azure\PowerShell\Azure\*.psd1" Import-AzurePublishSettingsFile "C:\TeamCity\[PSFileName].publishsettings" Set-AzureSubscription -CurrentStorageAccount $service -SubscriptionName $subscription   function Publish(){ $deployment = Get-AzureDeployment -ServiceName $service -Slot $slot -ErrorVariable a -ErrorAction silentlycontinue   if ($a[0] -ne $null) { Write-Output "$(Get-Date -f $timeStampFormat) - No deployment is detected. Creating a new deployment. " } if ($deployment.Name -ne $null) { #Update deployment inplace (usually faster, cheaper, won't destroy VIP) Write-Output "$(Get-Date -f $timeStampFormat) - Deployment exists in $servicename. Upgrading deployment." UpgradeDeployment } else { CreateNewDeployment } }   function CreateNewDeployment() { write-progress -id 3 -activity "Creating New Deployment" -Status "In progress" Write-Output "$(Get-Date -f $timeStampFormat) - Creating New Deployment: In progress"   $opstat = New-AzureDeployment -Slot $slot -Package $package -Configuration $configuration -label $deploymentLabel -ServiceName $service   $completeDeployment = Get-AzureDeployment -ServiceName $service -Slot $slot $completeDeploymentID = $completeDeployment.deploymentid   write-progress -id 3 -activity "Creating New Deployment" -completed -Status "Complete" Write-Output "$(Get-Date -f $timeStampFormat) - Creating New Deployment: Complete, Deployment ID: $completeDeploymentID" }   function UpgradeDeployment() { write-progress -id 3 -activity "Upgrading Deployment" -Status "In progress" Write-Output "$(Get-Date -f $timeStampFormat) - Upgrading Deployment: In progress"   # perform Update-Deployment $setdeployment = Set-AzureDeployment -Upgrade -Slot $slot -Package $package -Configuration $configuration -label $deploymentLabel -ServiceName $service -Force   $completeDeployment = Get-AzureDeployment -ServiceName $service -Slot $slot $completeDeploymentID = $completeDeployment.deploymentid   write-progress -id 3 -activity "Upgrading Deployment" -completed -Status "Complete" Write-Output "$(Get-Date -f $timeStampFormat) - Upgrading Deployment: Complete, Deployment ID: $completeDeploymentID" }   Write-Output "Create Azure Deployment" Publish   Creating the TeamCity Build Step The only thing left is to create a second build step, after your MSBuild “Publish” step, with the build runner type “PowerShell”.  Then set your script to “Source Code,” the script execution mode to “Put script into PowerShell stdin with “-Command” arguments” and then copy/paste in the above script (replacing the placeholder sections with your values).  This should look like the following:   Wrap Up After combining the MSBuild /target:Publish step (which creates the necessary Windows Azure *.cspkg and *.cscfg files) and a PowerShell script step which utilizes the Azure PowerShell Cmdlets, we have a fully deployable build configuration in TeamCity.  You can configure this step to run whenever you’d like using build triggers – for example, you could even deploy whenever a new master branch deploy comes in and passes all required tests. In the script I’ve hardcoded that every deployment goes to the Staging environment on Azure, but you could deploy straight to Production if you want to, or even setup a deployment configuration variable and set it as desired. After your TeamCity Build Configuration is complete, you’ll see something that looks like this: Whenever you click the “Run” button, all of your code will be compiled, published, and deployed to Windows Azure! One additional enormous benefit of automating the process this way is that you can easily deploy any specific source control changeset by clicking the little ellipsis button next to "Run.”  This will bring up a dialog like the one below, where you can select the last change to use for your deployment.  Since Azure Web Role deployments don’t have any rollback functionality, this is a critical feature.   Enjoy!

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  • SQL SERVER – Core Concepts – Elasticity, Scalability and ACID Properties – Exploring NuoDB an Elastically Scalable Database System

    - by pinaldave
    I have been recently exploring Elasticity and Scalability attributes of databases. You can see that in my earlier blog posts about NuoDB where I wanted to look at Elasticity and Scalability concepts. The concepts are very interesting, and intriguing as well. I have discussed these concepts with my friend Joyti M and together we have come up with this interesting read. The goal of this article is to answer following simple questions What is Elasticity? What is Scalability? How ACID properties vary from NOSQL Concepts? What are the prevailing problems in the current database system architectures? Why is NuoDB  an innovative and welcome change in database paradigm? Elasticity This word’s original form is used in many different ways and honestly it does do a decent job in holding things together over the years as a person grows and contracts. Within the tech world, and specifically related to software systems (database, application servers), it has come to mean a few things - allow stretching of resources without reaching the breaking point (on demand). What are resources in this context? Resources are the usual suspects – RAM/CPU/IO/Bandwidth in the form of a container (a process or bunch of processes combined as modules). When it is about increasing resources the simplest idea which comes to mind is the addition of another container. Another container means adding a brand new physical node. When it is about adding a new node there are two questions which comes to mind. 1) Can we add another node to our software system? 2) If yes, does adding new node cause downtime for the system? Let us assume we have added new node, let us see what the new needs of the system are when a new node is added. Balancing incoming requests to multiple nodes Synchronization of a shared state across multiple nodes Identification of “downstate” and resolution action to bring it to “upstate” Well, adding a new node has its advantages as well. Here are few of the positive points Throughput can increase nearly horizontally across the node throughout the system Response times of application will increase as in-between layer interactions will be improved Now, Let us put the above concepts in the perspective of a Database. When we mention the term “running out of resources” or “application is bound to resources” the resources can be CPU, Memory or Bandwidth. The regular approach to “gain scalability” in the database is to look around for bottlenecks and increase the bottlenecked resource. When we have memory as a bottleneck we look at the data buffers, locks, query plans or indexes. After a point even this is not enough as there needs to be an efficient way of managing such large workload on a “single machine” across memory and CPU bound (right kind of scheduling)  workload. We next move on to either read/write separation of the workload or functionality-based sharing so that we still have control of the individual. But this requires lots of planning and change in client systems in terms of knowing where to go/update/read and for reporting applications to “aggregate the data” in an intelligent way. What we ideally need is an intelligent layer which allows us to do these things without us getting into managing, monitoring and distributing the workload. Scalability In the context of database/applications, scalability means three main things Ability to handle normal loads without pressure E.g. X users at the Y utilization of resources (CPU, Memory, Bandwidth) on the Z kind of hardware (4 processor, 32 GB machine with 15000 RPM SATA drives and 1 GHz Network switch) with T throughput Ability to scale up to expected peak load which is greater than normal load with acceptable response times Ability to provide acceptable response times across the system E.g. Response time in S milliseconds (or agreed upon unit of measure) – 90% of the time The Issue – Need of Scale In normal cases one can plan for the load testing to test out normal, peak, and stress scenarios to ensure specific hardware meets the needs. With help from Hardware and Software partners and best practices, bottlenecks can be identified and requisite resources added to the system. Unfortunately this vertical scale is expensive and difficult to achieve and most of the operational people need the ability to scale horizontally. This helps in getting better throughput as there are physical limits in terms of adding resources (Memory, CPU, Bandwidth and Storage) indefinitely. Today we have different options to achieve scalability: Read & Write Separation The idea here is to do actual writes to one store and configure slaves receiving the latest data with acceptable delays. Slaves can be used for balancing out reads. We can also explore functional separation or sharing as well. We can separate data operations by a specific identifier (e.g. region, year, month) and consolidate it for reporting purposes. For functional separation the major disadvantage is when schema changes or workload pattern changes. As the requirement grows one still needs to deal with scale need in manual ways by providing an abstraction in the middle tier code. Using NOSQL solutions The idea is to flatten out the structures in general to keep all values which are retrieved together at the same store and provide flexible schema. The issue with the stores is that they are compromising on mostly consistency (no ACID guarantees) and one has to use NON-SQL dialect to work with the store. The other major issue is about education with NOSQL solutions. Would one really want to make these compromises on the ability to connect and retrieve in simple SQL manner and learn other skill sets? Or for that matter give up on ACID guarantee and start dealing with consistency issues? Hybrid Deployment – Mac, Linux, Cloud, and Windows One of the challenges today that we see across On-premise vs Cloud infrastructure is a difference in abilities. Take for example SQL Azure – it is wonderful in its concepts of throttling (as it is shared deployment) of resources and ability to scale using federation. However, the same abilities are not available on premise. This is not a mistake, mind you – but a compromise of the sweet spot of workloads, customer requirements and operational SLAs which can be supported by the team. In today’s world it is imperative that databases are available across operating systems – which are a commodity and used by developers of all hues. An Ideal Database Ability List A system which allows a linear scale of the system (increase in throughput with reasonable response time) with the addition of resources A system which does not compromise on the ACID guarantees and require developers to learn new paradigms A system which does not force fit a new way interacting with database by learning Non-SQL dialect A system which does not force fit its mechanisms for providing availability across its various modules. Well NuoDB is the first database which has all of the above abilities and much more. In future articles I will cover my hands-on experience with it. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: NuoDB

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