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  • Determining Azure SQL Database requirements

    - by Gerald
    I'm looking into moving an SQL Server database project to the cloud using Azure SQL Database. I'm just wondering what metrics I can use from SQL Server to help determine what my needs will be on Azure. The size of the database is around 150GB, so I understand what my needs are in terms of storage, I'm just not sure what metrics I can use to translate my database usage to the DTU benchmark metrics that the various service tiers on Azure SQL use.

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  • How to conditionally exclude features from "FeaturesDlg" in WiX 3.0 from a managed Custom Action (DT

    - by Gerald
    I am trying to put together an installer using WiX 3.0 and I'm unsure about one thing. I would like to use the FeaturesDlg dialog to allow the users to select features to install, but I need to be able to conditionally exclude some features from the list based on some input previously received, preferably from a managed Custom Action. I see that if I set the "Display" attribute of a Feature to "hidden" in the .wxs file that it does what I want, but I can't figure out a way to change that attribute at runtime. Any pointers would be great.

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  • ABC PDF - create 256 color images

    - by Gerald Ferreira
    I am using ABCpdf7 to create pdf documents on the fly - Here is something that I do not understand. When I create the pdf document from a url - the images in the pdf document seems to be 256 colors. Does anyone know how I can set ABCpdf to create full color images. If I spesify the image url - the image gets created at full color - but then I cannot crab a page in one go

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  • What can cause throughput to become really slow when an ISAPI filter implements SF_NOTIFY_SEND_RAW_D

    - by Gerald
    I have an ISAPI filter for IIS6 that I've been developing for a while, but I just noticed something disturbing. Anytime I have the filter installed and I download a file, the file download becomes really slow. From a remote machine I'm getting ~120kb per second without the filter installed, and ~45kb per second with the filter installed. This seems to be related to the SF_NOTIFY_SEND_RAW_DATA callback. Whenever I register for this callback, I get the slow downloads, when I don't register for it, everything is fine. Even if I make my HttpFilterProc function just return immediately, like this: DWORD WINAPI HttpFilterProc( PHTTP_FILTER_CONTEXT pfc, DWORD notificationType, LPVOID pvNotification ) { return SF_STATUS_REQ_NEXT_NOTIFICATION; } I've also tried returning SF_STATUS_REQ_HANDLED_NOTIFICATION with the same result. Is it possible that I have some build setting on my DLL that is causing a slow execution of the callback function, or is this just the way it's going to be with ISAPI?

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  • What are interesting ideas for experimenting with Artificial Neural Networks?

    - by Gerald Kaszuba
    I'm after a list of possible neural network implementations that one can do to learn how to use it. What other possibilities are there? Here's the list so far: Games tic-tac-toe Connect 4 Chess Go Visual recognition Character recognition (typefaces, letters, numbers, etc) Facial recognition Audio recognition Language detection Male vs female Word recognition Language detection (natural, programming)

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  • IE7 - visited links revert to unvisted after page refresh

    - by Gerald
    Hello, A number of our users have just upgraded from IE6 to IE7. the upgreaded users are reporting an issue with visited links reverting to their unvisited color after a page refresh. This only happens to links that are using javascript instead of a hard coded URL: <script lang="JavaScript"> <!-- function LoadGoogle() { var LoadGoogle = window.open('http://www.google.com'); } --> </script> <a href="javascript:LoadGoogle()">Google using javascript</a> <a href="#" OnClick="javascript:LoadGoogle()">Google using javascript OnClick</a> The above links will revert back to the unvisited color whenever the page is refreshed. It doesn't matter if the page is refreshed because of a post back, manually hitting the refresh or f5 button, or from an auto-refresh function. Please note, the above code is an over simplification of what is actually happening, but I believe it illustrates the issue well enough. This is causing a problem for our users because we are providing them with a list of items that are all opened into new windows via javascript when they are clicked; and refresh the parent page when the users are finished with them. Each time the parent page is refreshed all of these links revert back to their unvisited color, so our users are losing track of which items they've worked on. I've been digging around and it looks like this is intended behavior. IE7 doesn't register these links with the browsers history. Does anyone know a work around that will allow us to keep these javascript links in the visited state without having to do a major overhaul of the apps code? Thank you.

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  • Regex to match last space character

    - by Gerald Ferreira
    Hi There I need some help I am looking for a regex that would match the last space character in a string. I am using Javascript and Classic ASP If there is someone that could maybe point me in the right direction I have a long string of text which I trim to 100 characters. I would like to remove the last character to avoid a spelling mistake if the trim cuts a word due to the 100 characters limit regex.replace(/[ ]$.*?/ig, ''); Anybody with ideas? Thanks

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  • Is it possible to add a New Project Wizard with a VSPackage?

    - by Gerald
    I have a VSPackage for Visual Studio 2008 that I created for adding some editor and custom language functionality. I also have a need to add a new project/solution wizard to create a new Solution and a complex series of C++ projects to the solution. I know I can do this using a "Custom Wizard", but I would be much happier if I can implement this within my VSPackage using C# instead. So I guess the main question is, is it possible to add an entry to the Project Types dialogs in Visual Studio from a VSPackage? Or is the "Custom Wizard" and JScript my only option here? And if it's possible, where can I find information and/or samples on how to accomplish this?

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  • Assembly reference from ASP.NET App_Code directory

    - by Gerald Schneider
    I have trouble getting a custom ObjectDataSource for an asp:ListView control to work. I have the class for the DataSource in the App_Code directory of the web application (as required by the asp:ListView control). using System; using System.Collections.Generic; using System.ComponentModel; using System.Configuration; using System.Data; using System.Data.Common; using System.Web; using System.DirectoryServices; [DataObject] public class UsersDAL { [DataObjectMethod(DataObjectMethodType.Select)] public List<User> LoadAll(int startIndex, int maxRows, string sortedBy) { List<User> users = new List<User>(); DirectoryEntry entry; return users; } } As soon as I add using System.DirectoryServices; the page crashes with this message: Compiler Error Message: CS0234: The type or namespace name 'DirectoryServices' does not exist in the namespace 'System' (are you missing an assembly reference?) Without the usage of System.DirectoryServices the page loads without problems. The reference is there, it is working in classes outside the App_Code directory.

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  • Use PHP to create a DOC file on a Unix Box based on an HTML webform selection

    - by Gerald Oakham
    Hello, I have an HTML file which contains a webform with multiple questions which have a YES / NO responses. If the question has a YES answer, I would like a predefined ( per question ) section of text to be written to a DOC file on the server, but only AFTER the submit button has been pressed ( this way, if the user changes their mind and changes an answer form YES to NO, I won't have to re-write the doc ). When the user has clicked Submit, The file should be presented as a download. Any Ideas

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  • Location redirect - is tracking possible ?

    - by Gerald Ferreira
    Hi there, I was wondering if someone can help me, I have the following script that redirect users to an affiliate link when they click on a banner. <?php $targets = array( 'site1' => 'http://www.site1.com/', 'site2' => 'http://www.site2.com/', 'site3' => 'http://www.site3.com/', 'site4' => 'http://www.site4.com/', ); if (isset($targets[$_GET['id']])) { header('Location: '.$targets[$_GET['id']]); exit; } ?> Is it possible to track when a user hits the banner telling me the referer site as well as the ip address of the person clicking on the banner. hmmmm something like pixel tracking? I have tried to add an iframe that does the tracking but it creates an error Hope it makes sense Thanks! This is more or less how I would have done it in asp <% var Command1 = Server.CreateObject ("ADODB.Command"); Command1.ActiveConnection = MM_cs_stats_STRING; Command1.CommandText = "INSERT INTO stats.g_stats (g_stats_ip, g_stats_referer) VALUES (?, ? ) "; Command1.Parameters.Append(Command1.CreateParameter("varg_stats_ip", 200, 1, 20, (String(Request.ServerVariables("REMOTE_ADDR")) != "undefined" && String(Request.ServerVariables("REMOTE_ADDR")) != "") ? String(Request.ServerVariables("REMOTE_ADDR")) : String(Command1__varg_stats_ip))); Command1.Parameters.Append(Command1.CreateParameter("varg_stats_referer", 200, 1, 255, (String(Request.ServerVariables("HTTP_REFERER")) != "undefined" && String(Request.ServerVariables("HTTP_REFERER")) != "") ? String(Request.ServerVariables("HTTP_REFERER")) : String(Command1__varg_stats_referer))); Command1.CommandType = 1; Command1.CommandTimeout = 0; Command1.Prepared = true; Command1.Execute(); %> I am not sure how to do it in php - unfortunately for me the hosting is only supporting php so I am more or less clueless on how to do it in php I was thinking if I can somehow call a picture I can do it with pixel tracking in anoter asp page, on another server. Hope this makes better sense

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  • redirecting to multiple virtual subdomains using htaccess

    - by Gerald Ferreira
    Hi Everyone I am trying to create subdomains via htaccess. The code below does exactly want I want It takes http://domain.com and redirect it to http://www.domain.com Options -Indexes DirectoryIndex index.html index.htm index.asp index.php ErrorDocument 401 http://www.domain.com ErrorDocument 403 http://www.domain.com ErrorDocument 404 http://www.domain.com ErrorDocument 500 http://www.domain.com ErrorDocument 507 http://www.domain.com RewriteEngine On RewriteCond %{HTTP_HOST} ^domain.com$ RewriteRule ^(.*) http://www.domain.com/$1 [QSA,L,R=301] AddType text/html .html .htm .asp This is the part I am not to sure of: RewriteCond %{HTTP_HOST} ^domain.com/nl$ RewriteRule ^(.*) http://nl.domain.com/$1 [QSA,L,R=301] How can I create virtual subdomains so that if someone goes to http://nl.domain.com it would stay on http://nl.domain.com if someone types http://www.nl.domain.com it would take out the http://www.nl.domain.com and make it http://nl.domain.com also the directory structure for the subdomain would be http://www.domain.com/nl (This is where the actual files will be sitting). so if someone goes to http://www.domain.com/nl it should also redirect to http://nl.domain.com. Thanks in advance for any advice and pointers

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  • How to unmangle exported symbols from C++ in dynamic libraries in XCode on OSX

    - by Gerald
    I've been trying to develop a dynamic library in C++ that can be run-time loaded in an application. I finally got it working, but it's a little ugly. I have a function that takes a pointer to a C++ class as an argument, which looks like this: bool registerGrindPlugin( Grind::PluginManager* mgr ); But of course it's being exported as: _Z19registerGrindPluginPN5Grind13PluginManagerE I tried a .c file with a simple function and it exported fine as "registerGrindPlugin", but of course I can't pass a C++ class as the argument that way. Soo... my question is, is there a way to unmangle or alias the exported symbol so that I don't have to use a monstrosity like Z19registerGrindPluginPN5Grind13PluginManagerE in my dlsym call? I did see something about -alias_list as a linker option, but I haven't quite figured out how to use it in XCode. If that is the solution, can somebody provide some more details on how to use this?

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  • Aligning multiple images into one image?

    - by Gerald Kaszuba
    What is a good method to align images together that may have different rotations, exposures, etc, but have the same background or other fixed reference? Adobe Photoshop can do this with its "Photomerge" feature. How can I do this programatically? Is there an Open Source application that does it?

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  • C++ associative array with arbitrary types for values

    - by Gerald Kaszuba
    What is the best way to have an associative array with arbitrary value types for each key in C++? Currently my plan is to create a "value" class with member variables of the types I will be expecting. For example: class Value { int iValue; Value(int v) { iValue = v; } std::string sValue; Value(std::string v) { sValue = v; } SomeClass *cValue; Value(SomeClass *v) { cValue = c; } }; std::map<std::string, Value> table; A downside with this is you have to know the type when accessing the "Value". i.e.: table["something"] = Value(5); SomeClass *s = table["something"].cValue; // broken pointer Also the more types that are put in Value, the more bloated the array will be. Any better suggestions?

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  • need to print 5 column list in alpha order, vertically

    - by Brad
    Have a webpage that will be viewed by mainly IE users, so CSS3 is out of the question. I want it to list like: A D G B E H C F I Here is the function that currently lists like: A B C D E F G H I function listPhoneExtensions($group,$group_title) { $adldap = new adLDAP(); $group_membership = $adldap->group_members(strtoupper($group),FALSE); sort($group_membership); print " <a name=\"".strtolower($group_title)."\"></a> <h2>".$group_title."</h2> <ul class=\"phone-extensions\">"; foreach ($group_membership as $i => $username) { $userinfo = $adldap->user_info($username, array("givenname","sn","telephonenumber")); $displayname = "<span class=\"name\">".substr($userinfo[0]["sn"][0],0,9).", ".substr($userinfo[0]["givenname"][0],0,9)."</span><span class=\"ext\">".$userinfo[0]["telephonenumber"][0]."</span>"; if($userinfo[0]["sn"][0] != "" && $userinfo[0]["givenname"][0] != "" && $userinfo[0]["telephonenumber"][0] != "") { print "<li>".$displayname."</li>"; } } print "</ul><p class=\"clear-both\"><a href=\"#top\" class=\"link-to-top\">&uarr; top</a></p>"; } Example rendered html: <ul class="phone-extensions"> <li><span class="name">Barry Bonds</span><span class="ext">8281</span></li> <li><span class="name">Gerald Clark</span><span class="ext">8211</span></li> <li><span class="name">Juan Dixon</span><span class="ext">8282</span></li> <li><span class="name">Omar Ebbs</span><span class="ext">8252</span></li> <li><span class="name">Freddie Flank</span><span class="ext">2281</span></li> <li><span class="name">Jerry Gilmore</span><span class="ext">4231</span></li> <li><span class="name">Kim Moore</span><span class="ext">5767</span></li> <li><span class="name">Barry Bonds</span><span class="ext">8281</span></li> <li><span class="name">Gerald Clark</span><span class="ext">8211</span></li> <li><span class="name">Juan Dixon</span><span class="ext">8282</span></li> <li><span class="name">Omar Ebbs</span><span class="ext">8252</span></li> <li><span class="name">Freddie Flank</span><span class="ext">2281</span></li> <li><span class="name">Jerry Gilmore</span><span class="ext">4231</span></li> <li><span class="name">Kim Moore</span><span class="ext">5767</span></li> <li><span class="name">Barry Bonds</span><span class="ext">8281</span></li> <li><span class="name">Gerald Clark</span><span class="ext">8211</span></li> <li><span class="name">Juan Dixon</span><span class="ext">8282</span></li> <li><span class="name">Omar Ebbs</span><span class="ext">8252</span></li> <li><span class="name">Freddie Flank</span><span class="ext">2281</span></li> <li><span class="name">Jerry Gilmore</span><span class="ext">4231</span></li> <li><span class="name">Kim Moore</span><span class="ext">5767</span></li> </ul> Any help is appreciated to getting it to list alpha vertically.

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  • ArchBeat Link-o-Rama for 2012-03-16

    - by Bob Rhubart
    Applications Architecture | Roy Hunter and Brian Rasmussen www.oracle.com Roy Hunter and Brian Rasmussen examine the strategies three organizations applied to modernize their application architectures. Part of the Oracle Experiences in Enterprise Architecture article series. Public Sector Architecture | Jeremy Foreman and Hamza Jahangir www.oracle.com Jeremy Foreman and Hamza Jahangir examine the strategies used by two different organizations in deploying their respective future-state architectures. Part of the Oracle Experiences in Enterprise Architecture article series. XMLA vs BAPI | Sunil S. Ranka sranka.wordpress.com Oracle ACE Sunil Ranka's brief primer on the XMLA and BAPI standards. The Java EE 6 Example - Running Galleria on WebLogic 12 - Part 3 | Markus Eisele blog.eisele.net Oracle ACE Director Markus Eisele continues his series on working with Galleria. Oracle Linux Online Forum - March 27 event.on24.com Date: Tuesday, March 27, 2012 Time: 9:30 AM PT / 12:30 PM ET Hosts: Oracle Executives Edward Screven and Wim Coekaerts. Customer Presentation: How Oracle Helps Reduce Cost and Improve Performance of Database Applications at Progressive Insurance Speaker: John Dome What's New in Oracle Linux Speakers: Waseem Daher, Chris Mason, Elena Zannoni, Lenz Grimmer Get More Value from your Linux Vendor Speakers: Sergio Leunissen, Chris Mason, Monica Kumar JavaOne 2012 Call for Papers www.oracle.com Don't keep all that Java skill locked up in your overstuffed cranium. Submit your proposal for that killer paper now to share your experience at this year’s JavaOne. Running applications in the cloud are not designed for the cloud | Tom Laszewski blogs.oracle.com "The issue you face with moving client/server applications to the cloud via rehosting is 'where will the applications run?'" says Tom Laszewski. GlassFish 3.1.2 - Which Platform(s)? | The Aquarium blogs.oracle.com The Aquarium shares a list of GlassFish 3.1.2-supported operating systems and JVMs. IT Strategies from Oracle; Three Recipes for Oracle Service Bus 11g ; Stir Up Some SOA www.oracle.com Featured this week on the OTN Architect Portal, along with the latest events, product downloads, community social resources, articles on hot topics, and a whole lot more. Thought for the Day "No matter what the problem is, it's always a people problem." — Gerald M. Weinberg

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  • ArchBeat Link-o-Rama for 2012-08-29

    - by Bob Rhubart
    ORCLville: OOW 2012 - Crystal BallOracle ACE Director Floyd Teter cooks up some tongue-in-cheek predictions for news and announcements that might come out of Oracle OpenWorld 2012. What's your prediction? Oracle Optimized Solutions at Oracle OpenWorld 2012 | Oracle Hardware Hardware matters, too! The people behind the Oracle Hardware blog have put together a list of Oracle Openworld 2012 sessions focused Oracle Optimized Solutions, "designed, pre-tested, tuned and fully documented architectures for optimal performance and availability." Just plug the session ID numbers into Schedule Builder and you're good to go. AIX Checklist for stable OBIEE deployment | Dick Dunbar "OBIEE is a complicated system with many moving parts and connection points," according to Oracle Business Inteligence escalation engineer Dick Dunbar. "The purpose of this article is to provide a checklist to discuss OBIEE deployment with your systems administrators." Demo for OPN: Coherence Management with EM Cloud Control 12c Oracle Partner Network members can check out a new Coherence Management demo that showcases some of the key capabilities of Management Pack for Oracle Coherence and JVM Diagnostics. "The demo flow showcases the key enhancements made in Enterprise Manager 12c release which includes new customizable performance summary, cache data management and configuration management," according to the WebLogic Partner Community EMEA blog. The Pragmatic Architect: To Boldly Go Where No One Has Gone Before | Frank Buschmann "Many architects have technical knowledge that's both impressive and sound, which is indeed an inevitable basis for design success," says Frank Buschmann. "Yet, a lot of software projects fail or suffer due to severe challenges in their architecture. The key to mastery is how architects approach design, what they value, and where they focus their attention and work." As retail dies, whom will be the winners? | Peter Evans-Greenwood "The problem for many retailers is that how consumers shop has changed but the the retailers haven't adapted, " says Peter Evans-Greenwood. "Their sole virtue was to be the last step in a supply chain delivering somebody else's products to the consumer. However, being the last step in the supply chain is no longer a virtue when consumers skip across channels and can reach around the globe, no longer dependant on or limited to what they can find locally." Thought for the Day "Brains require stimulation. If you're locked into a pattern of work, work, and more work, your brain soon habituates - the same way that it lets you stop hearing a clock ticking. So, if you want to be more effective at work, you must, paradoxically, be less single-minded in your devotion to work. Anything you do—anything—that stimulates new segments of your brain will make you a more effective programmer or analyst. I promise, with a money-back guarantee." — Gerald M. Weinberg Source: SoftwareQuotes.com

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  • ArchBeat Link-o-Rama Top 10 for December 9-15, 2012

    - by Bob Rhubart
    You click, we listen. The following list reflects the Top 10 most popular items posted on the OTN ArchBeat Facefbook page for the week of December 9-15, 2012. DevOps Basics II: What is Listening on Open Ports and Files – WebLogic Essentials | Dr. Frank Munz "Can you easily find out which WebLogic servers are listening to which port numbers and addresses?" asks Dr. Frank Munz. The good doctor has an answer—and a tech tip. Using OBIEE against Transactional Schemas Part 4: Complex Dimensions | Stewart Bryson "Another important entity for reporting in the Customer Tracking application is the Contact entity," says Stewart Bryson. "At first glance, it might seem that we should simply build another dimension called Dim – Contact, and use analyses to combine our Customer and Contact dimensions along with our Activity fact table to analyze Customer and Contact behavior." SOA 11g Technology Adapters – ECID Propagation | Greg Mally "Many SOA Suite 11g deployments include the use of the technology adapters for various activities including integration with FTP, database, and files to name a few," says Oracle Fusion Middleware A-Team member Greg Mally. "Although the integrations with these adapters are easy and feature rich, there can be some challenges from the operations perspective." Greg's post focuses on technical tips for dealing with one of these challenges. Podcast: DevOps and Continuous Integration In Part 1 of a 3-part program, panelists Tim Hall (Senior Director of product management for Oracle Enterprise Repository and Oracle’s Application Integration Architecture), Robert Wunderlich (Principal Product Manager for Oracle’s Application Integration Architecture Foundation Pack) and Peter Belknap (Director of product management for Oracle SOA Integration) discuss why DevOps matters and how it changes development methodologies and organizational structure. Good To Know - Conflicting View Objects and Shared Entity | Andrejus Baranovskis Oracle ACE Director Andrejus Baranovskis shares his thoughts -- and a sample application -- dealing with an "interesting ADF behavior" encountered over the weekend. Cloud Deployment Models | B. R. Clouse Looking out for the cloud newbies... "As the cloud paradigm grows in depth and breadth, more readers are approaching the topic for the first time, or from a new perspective," says B. R. Clouse. "This blog is a basic review of cloud deployment models, to help orient newcomers and neophytes." Service governance morphs into cloud API management | David Linthicum "When building and using clouds, the ability to manage APIs or services is the single most important item you can provide to ensure the success of the project," says David Linthicum. "But most organizations driving a cloud project for the first time have no experience handling a service-based architecture and don't see the need for API management until after deployment. By then, it's too late." Oracle Fusion Middleware Security: Password Policy in OAM 11g R2 | Rob Otto Rob Otto continues the Oracle Fusion Middleware A-Team "Oracle Access Manager Academy" series with a detailed look at OAM's ability to support "a subset of password management processes without the need to use Oracle Identity Manager and LDAP Sync." Understanding the JSF Lifecycle and ADF Optimized Lifecycle | Steven Davelaar Could you call that a surprise ending? Oracle WebCenter & ADF Architecture Team (A-Team) member learned a lot more than he expected while creating a UKOUG presentation entitled "What you need to know about JSF to be succesful with ADF." Expanding on requestaudit - Tracing who is doing what...and for how long | Kyle Hatlestad "One of the most helpful tracing sections in WebCenter Content (and one that is on by default) is the requestaudit tracing," says Oracle Fusion Middleware A-Team architect Kyle Hatlestad. Get up close and technical in his post. Thought for the Day "There is no code so big, twisted, or complex that maintenance can't make it worse." — Gerald Weinberg Source: SoftwareQuotes.com

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  • Following the Thread in OSB

    - by Antony Reynolds
    Threading in OSB The Scenario I recently led an OSB POC where we needed to get high throughput from an OSB pipeline that had the following logic: 1. Receive Request 2. Send Request to External System 3. If Response has a particular value   3.1 Modify Request   3.2 Resend Request to External System 4. Send Response back to Requestor All looks very straightforward and no nasty wrinkles along the way.  The flow was implemented in OSB as follows (see diagram for more details): Proxy Service to Receive Request and Send Response Request Pipeline   Copies Original Request for use in step 3 Route Node   Sends Request to External System exposed as a Business Service Response Pipeline   Checks Response to Check If Request Needs to Be Resubmitted Modify Request Callout to External System (same Business Service as Route Node) The Proxy and the Business Service were each assigned their own Work Manager, effectively giving each of them their own thread pool. The Surprise Imagine our surprise when, on stressing the system we saw it lock up, with large numbers of blocked threads.  The reason for the lock up is due to some subtleties in the OSB thread model which is the topic of this post.   Basic Thread Model OSB goes to great lengths to avoid holding on to threads.  Lets start by looking at how how OSB deals with a simple request/response routing to a business service in a route node. Most Business Services are implemented by OSB in two parts.  The first part uses the request thread to send the request to the target.  In the diagram this is represented by the thread T1.  After sending the request to the target (the Business Service in our diagram) the request thread is released back to whatever pool it came from.  A multiplexor (muxer) is used to wait for the response.  When the response is received the muxer hands off the response to a new thread that is used to execute the response pipeline, this is represented in the diagram by T2. OSB allows you to assign different Work Managers and hence different thread pools to each Proxy Service and Business Service.  In out example we have the “Proxy Service Work Manager” assigned to the Proxy Service and the “Business Service Work Manager” assigned to the Business Service.  Note that the Business Service Work Manager is only used to assign the thread to process the response, it is never used to process the request. This architecture means that while waiting for a response from a business service there are no threads in use, which makes for better scalability in terms of thread usage. First Wrinkle Note that if the Proxy and the Business Service both use the same Work Manager then there is potential for starvation.  For example: Request Pipeline makes a blocking callout, say to perform a database read. Business Service response tries to allocate a thread from thread pool but all threads are blocked in the database read. New requests arrive and contend with responses arriving for the available threads. Similar problems can occur if the response pipeline blocks for some reason, maybe a database update for example. Solution The solution to this is to make sure that the Proxy and Business Service use different Work Managers so that they do not contend with each other for threads. Do Nothing Route Thread Model So what happens if there is no route node?  In this case OSB just echoes the Request message as a Response message, but what happens to the threads?  OSB still uses a separate thread for the response, but in this case the Work Manager used is the Default Work Manager. So this is really a special case of the Basic Thread Model discussed above, except that the response pipeline will always execute on the Default Work Manager.   Proxy Chaining Thread Model So what happens when the route node is actually calling a Proxy Service rather than a Business Service, does the second Proxy Service use its own Thread or does it re-use the thread of the original Request Pipeline? Well as you can see from the diagram when a route node calls another proxy service then the original Work Manager is used for both request pipelines.  Similarly the response pipeline uses the Work Manager associated with the ultimate Business Service invoked via a Route Node.  This actually fits in with the earlier description I gave about Business Services and by extension Route Nodes they “… uses the request thread to send the request to the target”. Call Out Threading Model So what happens when you make a Service Callout to a Business Service from within a pipeline.  The documentation says that “The pipeline processor will block the thread until the response arrives asynchronously” when using a Service Callout.  What this means is that the target Business Service is called using the pipeline thread but the response is also handled by the pipeline thread.  This implies that the pipeline thread blocks waiting for a response.  It is the handling of this response that behaves in an unexpected way. When a Business Service is called via a Service Callout, the calling thread is suspended after sending the request, but unlike the Route Node case the thread is not released, it waits for the response.  The muxer uses the Business Service Work Manager to allocate a thread to process the response, but in this case processing the response means getting the response and notifying the blocked pipeline thread that the response is available.  The original pipeline thread can then continue to process the response. Second Wrinkle This leads to an unfortunate wrinkle.  If the Business Service is using the same Work Manager as the Pipeline then it is possible for starvation or a deadlock to occur.  The scenario is as follows: Pipeline makes a Callout and the thread is suspended but still allocated Multiple Pipeline instances using the same Work Manager are in this state (common for a system under load) Response comes back but all Work Manager threads are allocated to blocked pipelines. Response cannot be processed and so pipeline threads never unblock – deadlock! Solution The solution to this is to make sure that any Business Services used by a Callout in a pipeline use a different Work Manager to the pipeline itself. The Solution to My Problem Looking back at my original workflow we see that the same Business Service is called twice, once in a Routing Node and once in a Response Pipeline Callout.  This was what was causing my problem because the response pipeline was using the Business Service Work Manager, but the Service Callout wanted to use the same Work Manager to handle the responses and so eventually my Response Pipeline hogged all the available threads so no responses could be processed. The solution was to create a second Business Service pointing to the same location as the original Business Service, the only difference was to assign a different Work Manager to this Business Service.  This ensured that when the Service Callout completed there were always threads available to process the response because the response processing from the Service Callout had its own dedicated Work Manager. Summary Request Pipeline Executes on Proxy Work Manager (WM) Thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. Route Node Request sent using Proxy WM Thread Proxy WM Thread is released before getting response Muxer is used to handle response Muxer hands off response to Business Service (BS) WM Response Pipeline Executes on Routed Business Service WM Thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. No Route Node (Echo functionality) Proxy WM thread released New thread from the default WM used for response pipeline Service Callout Request sent using proxy pipeline thread Proxy thread is suspended (not released) until the response comes back Notification of response handled by BS WM thread so limited by setting of that WM.  If no WM specified then uses WLS default WM. Note this is a very short lived use of the thread After notification by callout BS WM thread that thread is released and execution continues on the original pipeline thread. Route/Callout to Proxy Service Request Pipeline of callee executes on requestor thread Response Pipeline of caller executes on response thread of requested proxy Throttling Request message may be queued if limit reached. Requesting thread is released (route node) or suspended (callout) So what this means is that you may get deadlocks caused by thread starvation if you use the same thread pool for the business service in a route node and the business service in a callout from the response pipeline because the callout will need a notification thread from the same thread pool as the response pipeline.  This was the problem we were having. You get a similar problem if you use the same work manager for the proxy request pipeline and a business service callout from that request pipeline. It also means you may want to have different work managers for the proxy and business service in the route node. Basically you need to think carefully about how threading impacts your proxy services. References Thanks to Jay Kasi, Gerald Nunn and Deb Ayers for helping to explain this to me.  Any errors are my own and not theirs.  Also thanks to my colleagues Milind Pandit and Prasad Bopardikar who travelled this road with me. OSB Thread Model Great Blog Post on Thread Usage in OSB

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