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• top Tweets SOA Partner Community &ndash; June 2012

  - by JuergenKress

  Send your tweets @soacommunity #soacommunity and follow us at http://twitter.com/soacommunity Simone Geib Contact me directly for ideas how to improve http://bit.ly/advancedsoasuite and additional posts, presentations, white papers, #soasuite SOA CommunitySOA Community Newsletter May 2012 https://soacommunity.wordpress.com /2012/05/28/soa-community-newsletter-may-2012/ #soacommunity Simone Geib #soasuite advanced OTN page has become too cluttered. Broke it into separate pages to start with. http://bit.ly/advancedsoasuite SOA CommunitySOA Management with Enterprise Manager Cloud Control 12c and Business Transaction Management 12c Demo https://soacommunity.wordpress.com /2012/05/21/soa-management-with-enterprise-manager-cloud-control-12c-and-business-transaction-management-12c-demo/ #soacommunity OracleBlogs June Webcast: SOA Gateway Implementation and Troubleshooting (2 sessions) http://ow.ly/1kbRFA OTNArchBeatEvery cloud needs an SOA lining: analyst | @JoeMcKendrick http://zd.net/KTgMHk ServiceTechSymposium New session just posted to calendar: "NoSQL for Data Services, Data Virtualization & Big Data" by Guido Schmutz, Trivadis AG ://ow.ly/bjjOe OTNArchBeat?Every cloud needs an SOA lining: analyst | @JoeMcKendrick http://zd.net/KTgMHk Debra Lilley looks good - real proof people are using the apps ! RT @fteter:Very cool Fusion Applications Help site: http://bit.ly/L3nvOR #FusionApps OTNArchBeat How to Set JVM Parameters in Oracle SOA 11G | Francis Ip http://bit.ly/JBDYPj demed"rapid proliferation of cloud computing will drive convergence of SOA and cloud paradigms" http://ovum.com/2012/05/18/soa-paves-the-way-for-cloud/ SOA Community Sending out invitations to our advanced Fusion Middleware Summer Camps! Want to learn more register for the community http://www.oracle.com/goto/emea/soa SOA Community Middleware Oracle Excellence Awards 2012 - HAPPY NEW YEAR! https://soacommunity.wordpress.com/ 2012/05/31/middleware-oracle-excellence-awards-2012 happy-new-year/ #soacommunity #opn #opnaward #specialization #oracle Simone Geib #oraclesoa performance tuning resources. All in one: docs, blogs, WPs, ppts: http://bit.ly/soa_resources OracleBlogs Middleware Oracle Excellence Awards 2012 - HAPPY NEW YEAR! http://ow.ly/1k9ri0 ServiceTechSymposiumNew session just posted to Symposium calendar: "Service Modeling & BPM Business Value Patterns" by Jürgen Kress, Oracle http://www.servicetechsymposium.com/ agenda2012.php #service_modeling_and_bpm _business_value_patterns SOA Community Happy New Year #soacommunity thanks for the business! Time for a drink ;-) http://pic.twitter.com/zkK08KWB Jan van ZoggelUsing execute-sql() function for Name-Value pair lookups in Oracle Service Bus http://wp.me/p1H430-jZ SOA Community Middleware Oracle Excellence Awards 2012&ndash;HAPPY NEW YEAR! http://wp.me/p10C8u-q4 orclateamsoa A-Team Blog #ateam: BPM 11g Deployment & Instance Migration - I have seen a number of request lately asking how to http://ow.ly/1jZ0h8 OTNArchBeat Who should ‘own’ the Enterprise Architecture? | Michael Glas http://bit.ly/K0ge0Q Oracle UPK & Tutor TOMORROW! (June 23rd) - UPK Professional Webinar at Noon ET: Discover why user adoption is a key factor for the http://bit.ly/LjZjdx Sabine Leitner Finance Event im Design-Hotel beim Barbeque: 21. Juni FRA mit Kunden SV Informatik, Schufa, LBBW http://bit.ly/JtwE3v #Oracle @itevent OracleEnterpriseMgr SOA Management with Enterprise Manager Cloud Control 12c and Business Transaction Management 12c Demo http://ow.ly/b3WP1 #em12c ServiceTechSymposium New session just posted to Symposium calendar: "Elastic SOA in the Cloud" by Steve Millidge, C2B2 Consulting http://www.servicetechsymposium.com /agenda2012.php #elastic_soa_in_the_cloud OTNArchBeat Securing Heterogeneous Systems Using Oracle Web Services Manager by @rluttikhuizen & Jens Peters http://bit.ly/KjShFi Oracleteamsoa A-Team Blog #ateam: How to Set JVM Parameters in Oracle SOA 11G http://ow.ly/1k2cnl SOA Community Oracle Service Registry in an automated (Maven) SOA/BPM build http://redstack.wordpress.com /2012/05/22/using-oracle-service-registry-in-an-automated-maven-soabpm-build/ #soacommunity #redstack #soa #osr #opn SOA CommunityHigh demand for advanced Fusion Middleware Summer Camps! Want to learn more register for the #soacommunity http://www.oracle.com/goto/emea/soa OracleBlogs? How to Set JVM Parameters in Oracle SOA 11G http://ow.ly/1k1UTv SOA Community top Tweets SOA Partner Community &ndash; May 2012 http://wp.me/p10C8u-pP ServiceTechSymposium New session just posted to Symposium calendar: "SOA Governance at EDP: A Global Energy Company" by Manuel Rosa, Link http://www.servicetechsymposium.com/ agenda2012.php #soa_governance_at_edp For regular information on Oracle SOA Suite become a member in the SOA Partner Community for registration please visit  www.oracle.com/goto/emea/soa (OPN account required) Blog Twitter LinkedIn Mix Forum Technorati Tags: soacommunity,twitter,Oracle,SOA Community,Jürgen Kress,OPN,SOA,BPM

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• Should I break contract early?

  - by cbang

  About 7 months ago I made the switch from a 5 year permie role (as a support developer in C#) to a contract role. I did this because I was stagnating in my old role. The extra cash contracting is really helping too. Unfortunately my team leader has taken a dislike to me from day 1. He regularly tells me I went out contracting too early, and frequently remarks that people in their 20's have no idea what they are talking about (I am 29). I was recently given the task of configuring our reports via our in house reporting library. It works off of a database driven criteria base, with controls being loaded as needed. The configs can get fairly complex, with controls having various levels of dependency on each other. I had a short time frame to get 50 reports working, and I was told to just get the basic configuration done, after which they will be handed over to the reporting team for fine tuning, then the test team. Our updated system was deployed 2 weeks ago, and it turned out that about 15 reports had issues causing incorrect data to be returned. Upon investigation I discovered that the reporting team hadn't even looked at them, and the test team hadn't bothered to test the reports. In spite of this, my team leader has told me that it is 100% my fault. As a result, our help desk got hit hard. I worked back until 2am that night to fix the highest priority issues (on my wedding anniversary!). The next day I arrive at work at 7:45 am to continue with the fixes. I got no thanks, but keep getting repeatedly told by my manager that "I fucked up" and "this is all my fault". I told my team leader I would spend part of my weekend working to fix the remaining issues. His response was "so you fucking should! you fucked it all up!" in front of the rest of the team. I responded "No worries." and left. I spent a decent chunk of my weekend working on it. Within 2 business days of finding out about the issues, I had all the medium and high priority issues fixed. The only comments my team leader has made to me in the last 2 weeks is to tell me how I have caused a big mess, and to tell me it was all my fault. I get this multiple times a day. If I make any jokes to anyone else in the team, I get told not to be a smartass... even though the rest of the team jokes throughout the day. Apart from that, all I get is angry looks any time I am anywhere near the guy. I don't give any response other than "alright" or silence when he starts giving me a hard time. Today we found out that the pilot release for the next stage has been pushed back. My team leader has said this was caused by me (but the higher ups said no such thing). He also said I have "no understanding of the ramifications of my actions". My question is, should I break contract (I am contracted until June 30) and find another role? No one else in my team will speak up in my favour, as they are contractors too and have no interest in rocking the boat. I could complain to my team leaders boss, but I can't see that helping, as I will still be stuck in the same team. As this is my first contract, I imagine getting the next one will be hard without a reference. I can't figure out if this guy is trying to get me fired up to provoke a confrontation (the guy loves conflict), or if he is just venting anger, or what. Copping this blame day after day is really wearing me down and making me depressed... especially since I have a wife and kid to support).

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• You Probably Already Have a “Private Cloud”

  - by BuckWoody

  I’ve mentioned before that I’m not a fan of the word “Cloud”. It’s too marketing-oriented, gimmicky and non-specific. A better definition (in many cases) is “Distributed Computing”. That means that some or all of the computing functions are handled somewhere other than under your specific control. But there is a current use of the word “Cloud” that does not necessarily mean that the computing is done somewhere else. In fact, it’s a vector of Cloud Computing that can better be termed “Utility Computing”. This has to do with the provisioning of a computing resource. That means the setup, configuration, management, balancing and so on that is needed so that a user – which might actually be a developer – can do some computing work. To that person, the resource is just “there” and works like they expect, like the phone system or any other utility. The interesting thing is, you can do this yourself. In fact, you probably already have been, or are now. It’s got a cool new trendy term – “Private Cloud”, but the fact is, if you have your setup automated, the HA and DR handled, balancing and performance tuning done, and a process wrapped around it all, you can call yourself a “Cloud Provider”. A good example here is your E-Mail system. your users – pretty much your whole company – just logs into e-mail and expects it to work. To them, you are the “Cloud” provider. On your side, the more you automate and provision the system, the more you act like a Cloud Provider. Another example is a database server. In this case, the “end user” is usually the development team, or perhaps your SharePoint group and so on. The data professionals configure, monitor, tune and balance the system all the time. The more this is automated, the more you’re acting like a Cloud Provider. Lots of companies help you do this in your own data centers, from VMWare to IBM and many others. Microsoft's offering in this is based around System Center – they have a “cloud in a box” provisioning system that’s actually pretty slick. The most difficult part of operating a Private Cloud is probably the scale factor. In the case of Windows and SQL Azure, we handle this in multiple ways – and we're happy to share how we do it. It’s not magic, and the algorithms for balancing (like the one we started with called Paxos) are well known. The key is the knowledge, infrastructure and people. Sure, you can do this yourself, and in many cases such as top-secret or private systems, you probably should. But there are times where you should evaluate using Azure or other vendors, or even multiple vendors to spread your risk. All of this should be based on client need, not on what you know how to do already. So congrats on your new role as a “Cloud Provider”. If you have an E-mail system or a database platform, you can just put that right on your resume.

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• SQL SERVER – Last Two Days to Get FREE Book – Joes 2 Pros Certification 70-433

  - by pinaldave

  Earlier this week we announced that we will be giving away FREE SQL Wait Stats book to everybody who will get SQL Server Joes 2 Pros Combo Kit. We had a fantastic response to the contest. We got an overwhelming response to the offer. We knew there would be a great response but we want to honestly say thank you to all of you for making it happen. Rick and I want to make sure that we express our special thanks to all of you who are reading our books. The offer is still on and there are two more days to avail this offer. We want to make sure that everybody who buys our most selling combo kits, we will send our other most popular SQL Wait Stats book. Please read all the details of the offer here. The books are great resources for anyone who wants to learn SQL Server from fundamentals and eventually go on the certification path of 70-433. Exam 70-433 contains following important subject and the book covers the subject of fundamental. If you are taking the exam or not taking the exam – this book is for every SQL Developer to learn the subject from fundamentals.  Create and alter tables. Create and alter views. Create and alter indexes. Create and modify constraints. Implement data types. Implement partitioning solutions. Create and alter stored procedures. Create and alter user-defined functions (UDFs). Create and alter DML triggers. Create and alter DDL triggers. Create and deploy CLR-based objects. Implement error handling. Manage transactions. Query data by using SELECT statements. Modify data by using INSERT, UPDATE, and DELETE statements. Return data by using the OUTPUT clause. Modify data by using MERGE statements. Implement aggregate queries. Combine datasets. INTERSECT, EXCEPT Implement subqueries. Implement CTE (common table expression) queries. Apply ranking functions. Control execution plans. Manage international considerations. Integrate Database Mail. Implement full-text search. Implement scripts by using Windows PowerShell and SQL Server Management Objects (SMOs). Implement Service Broker solutions. Track data changes. Data capture Retrieve relational data as XML. Transform XML data into relational data. Manage XML data. Capture execution plans. Collect output from the Database Engine Tuning Advisor. Collect information from system metadata. Availability of Book USA - Amazon | India - Flipkart | Indiaplaza Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• ArchBeat Link-o-Rama Top 10 for October 2012

  - by Bob Rhubart

  The Top 10 most popular items shared on the OTN ArchBeat Facebook Page for October 2012. OAM/OVD JVM Tuning | @FusionSecExpert Vinay from the Oracle Fusion Middleware Architecture Group (known as the A-Team) shares a process for analyzing and improving performance in Oracle Virtual Directory and Oracle Access Manager. SOA Galore: New Books for Technical Eyes Only Shake up up your technical skills with this trio of new technical books from community members covering SOA and BPM. Clustering ODI11g for High-Availability Part 1: Introduction and Architecture | Richard Yeardley "JEE agents can be deployed alongside, or instead of, standalone agents," says Rittman Meade's Richard Yeardley. "But there is one key advantage in using JEE agents and WebLogic – when you deploy JEE agents as part of a WebLogic cluster they can be configured together to form a high availability cluster." Learn more in Yeardley's extensive post. Solving Big Problems in Our 21st Century Information Society | Irving Wladawsky-Berger "I believe that the kind of extensive collaboration between the private sector, academia and government represented by the Internet revolution will be the way we will generally tackle big problems in the 21st century. Just as with the Internet, governments have a major role to play as the catalyst for many of the big projects that the private sector will then take forward and exploit. The need for high bandwidth, robust national broadband infrastructures is but one such example." -- Irving Wladawsky-Berger Eventually, 90% of tech budgets will be outside IT departments | ZDNet Another interesting post from ZDNet blogger Joe McKendrick about changing roles in IT. ADF Mobile - Login Functionality | Andrejus Baranovskis "The new ADF Mobile approach with native deployment is cool when you want to access phone functionality (camera, email, sms and etc.), also when you want to build mobile applications with advanced UI," reports Oracle ACE Director Andrejus Baranovskis. Podcast: Are You Future Proof? - Part 2 In Part 2, practicing architects and Oracle ACE Directors Ron Batra (AT&T), Basheer Khan (Innowave Technology), and Ronald van Luttikhuizen (Vennster) discuss re-tooling one’s skill set to reflect changes in enterprise IT, including the knowledge to steer stakeholders around the hype to what's truly valuable. ADF Mobile Custom Javascript — iFrame Injection | John Brunswick The ADF Mobile Framework provides a range of out of the box components to add within your AMX pages, according to John Brunswick. But what happens when "an out of the box component does not directly fulfill your development need? What options are available to extend your application interface?" John has an answer. Oracle Solaris 11.1 update focuses on database integration, cloud | Mark Fontecchio TechTarget editor Mark Fontecchio reports on the recent Oracle Solaris 11.1 release, with comments from IDC's Al Gillen. Architects Matter: Making sense of the people who make sense of enterprise IT Why do architects matter? Oracle Enterprise Architect Eric Stephens suggests that you ask yourself this question the next time you take the elevator to the Oracle offices on the 45th floor of the Willis Tower in Chicago, Illinois (or any other skyscraper, for that matter). If you had to take the stairs to get to those offices, who would you blame? "You get the picture," he says. "Architecture is essential for any necessarily complex structure, be it a building or an enterprise." (Read the article) Thought for the Day "I will contend that conceptual integrity is the most important consideration in system design. It is better to have a system omit certain anomalous features and improvements, but to reflect one set of design ideas, than to have one that contains many good but independent and uncoordinated ideas." — Frederick P. Brooks Source: SoftwareQuotes.com

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• Heterogeneous Datacenter Management with Enterprise Manager 12c

  - by Joe Diemer

  The following is a Guest Blog, contributed by Bryce Kaiser, Product Manager at Blue MedoraWhen I envision a perfect datacenter, it would consist of technologies acquired from a single vendor across the entire server, middleware, application, network, and storage stack - Apps to Disk - that meets your organization’s every IT requirement with absolute best-of-breed solutions in every category.   To quote a familiar motto, your datacenter would consist of "Hardware and Software, Engineered to Work Together".  In almost all cases, practical realities dictate something far less than the IT Utopia mentioned above.   You may wish to leverage multiple vendors to keep licensing costs down, a single vendor may not have an offering in the IT category you need, or your preferred vendor may quite simply not have the solution that meets your needs.    In other words, your IT needs dictate a heterogeneous IT environment.  Heterogeneity, however, comes with additional complexity. The following are two pretty typical challenges:1) No End-to-End Visibility into the Enterprise Wide Application Deployment. Each vendor solution which is added to an infrastructure may bring its own tooling creating different consoles for different vendor applications and platforms.2) No Visibility into Performance Bottlenecks. When multiple management tools operate independently, you lose diagnostic capabilities including identifying cross-tier issues with database, hung-requests, slowness, memory leaks and hardware errors/failures causing DB/MW issues. As adoption of Oracle Enterprise Manager (EM) has increased, especially since the release of Enterprise Manager 12c, Oracle has seen an increase in the number of customers who want to leverage their investments in EM to manage non-Oracle workloads.  Enterprise Manager provides a single pane of glass view into their entire datacenter.  By creating a highly extensible framework via the Oracle EM Extensibility Development Kit (EDK), Oracle has provided the tooling for business partners such as my company Blue Medora as well as customers to easily fill gaps in the ecosystem and enhance existing solutions.  As mentioned in the previous post on the Enterprise Manager Extensibility Exchange, customers have access to an assortment of Oracle and Partner provided solutions through this Exchange, which is accessed at http://www.oracle.com/goto/emextensibility.  Currently, there are over 80 Oracle and partner provided plug-ins across the EM 11g and EM 12c versions.  Blue Medora is one of those contributing partners, for which you will find 3 of our solutions including our flagship plugin for VMware.  Let's look at Blue Medora’s VMware plug-in as an example to what I'm trying to convey.  Here is a common situation solved by true visibility into your entire stack:Symptoms•    My database is bogging down, however the database appears okay internally.  Maybe it’s starved for resources?•    My OS tooling is showing everything is “OK”.  Something doesn’t add up. Root cause•    Through the VMware plugin we can see the problem is actually on the virtualization layer Solution•    From within Enterprise Manager  -- the same tool you use for all of your database tuning -- we can overlay the data of the database target, host target, and virtual machine target for a true picture of the true root cause. Here is the console view: Perhaps your monitoring conditions are more specific to your environment.  No worries, Enterprise Manager still has you covered.  With Metric Extensions you have the “Next Generation” of User-Defined Metrics, which easily bring the power of your existing management scripts into a single console while leveraging the proven Enterprise Manager framework. Simply put, Oracle Enterprise manager boasts a growing ecosystem that provides the single pane of glass for your entire datacenter from the database and beyond.  Bryce can be contacted at [email protected]

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• SQL Server Optimizer Malfunction?

  - by Tony Davis

  There was a sharp intake of breath from the audience when Adam Machanic declared the SQL Server optimizer to be essentially "stuck in 1997". It was during his fascinating "Query Tuning Mastery: Manhandling Parallelism" session at the recent PASS SQL Summit. Paraphrasing somewhat, Adam (blog | @AdamMachanic) offered a convincing argument that the optimizer often delivers flawed plans based on assumptions that are no longer valid with today’s hardware. In 1997, when Microsoft engineers re-designed the database engine for SQL Server 7.0, SQL Server got its initial implementation of a cost-based optimizer. Up to SQL Server 2000, the developer often had to deploy a steady stream of hints in SQL statements to combat the occasionally wilful plan choices made by the optimizer. However, with each successive release, the optimizer has evolved and improved in its decision-making. It is still prone to the occasional stumble when we tackle difficult problems, join large numbers of tables, perform complex aggregations, and so on, but for most of us, most of the time, the optimizer purrs along efficiently in the background. Adam, however, challenged further any assumption that the current optimizer is competent at providing the most efficient plans for our more complex analytical queries, and in particular of offering up correctly parallelized plans. He painted a picture of a present where complex analytical queries have become ever more prevalent; where disk IO is ever faster so that reads from disk come into buffer cache faster than ever; where the improving RAM-to-data ratio means that we have a better chance of finding our data in cache. Most importantly, we have more CPUs at our disposal than ever before. To get these queries to perform, we not only need to have the right indexes, but also to be able to split the data up into subsets and spread its processing evenly across all these available CPUs. Improvements such as support for ColumnStore indexes are taking things in the right direction, but, unfortunately, deficiencies in the current Optimizer mean that SQL Server is yet to be able to exploit properly all those extra CPUs. Adam’s contention was that the current optimizer uses essentially the same costing model for many of its core operations as it did back in the days of SQL Server 7, based on assumptions that are no longer valid. One example he gave was a "slow disk" bias that may have been valid back in 1997 but certainly is not on modern disk systems. Essentially, the optimizer assesses the relative cost of serial versus parallel plans based on the assumption that there is no IO cost benefit from parallelization, only CPU. It assumes that a single request will saturate the IO channel, and so a query would not run any faster if we parallelized IO because the disk system simply wouldn’t be able to handle the extra pressure. As such, the optimizer often decides that a serial plan is lower cost, often in cases where a parallel plan would improve performance dramatically. It was challenging and thought provoking stuff, as were his techniques for driving parallelism through query logic based on subsets of rows that define the "grain" of the query. I highly recommend you catch the session if you missed it. I’m interested to hear though, when and how often people feel the force of the optimizer’s shortcomings. Barring mistakes, such as stale statistics, how often do you feel the Optimizer fails to find the plan you think it should, and what are the most common causes? Is it fighting to induce it toward parallelism? Combating unexpected plans, arising from table partitioning? Something altogether more prosaic? Cheers, Tony.

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• Call For Papers Tips and Tricks

  - by speakjava

  This year's JavaOne session review has just been completed and by now everyone who submitted papers should know whether they were successful or not.  I had the pleasure again this year of leading the review of the 'JavaFX and Rich User Experiences' track.  I thought it would be useful to write up a few comments to help people in future when submitting session proposals, not just for JavaOne, but for any of the many developer conferences that run around the world throughout the year.  This also draws on conversations I recently had with various Java User Group leaders at the Oracle User Group summit in Riga.  Many of these leaders run some of the biggest and most successful Java conferences in Europe. Try to think of a title which will sound interesting.  For example, "Experiences of performance tuning embedded Java for an ARM architecture based single board computer" probably isn't going to get as much attention as "Do you like coffee with your dessert? Java on the Raspberry Pi".  When thinking of the subject and title for your talk try to steer clear of sessions that might be too generic (and so get lost in a group of similar sessions).  Introductory talks are great when the audience is new to a subject, but beware of providing sessions that are too basic when the technology has been around for a while and there are lots of tutorials already available on the web. JavaOne, like many other conferences has a number of fields that need to be filled in when submitting a paper.  Many of these are selected from pull-down lists (like which track the session is applicable to).  Check these lists carefully.  A number of sessions we had needed to be shuffled between tracks when it was thought that the one selected was not appropriate.  We didn't count this against any sessions, but it's always a good idea to try and get the right one from the start, just in case. JavaOne, again like many other conferences, has two fields that describe the session being submitted: abstract and summary.  These are the most critical to a successful submission.  The two fields have different names and that is significant; a frequent mistake people make is to write an abstract for a session and then duplicate it for the summary.  The abstract (at least in the case of JavaOne) is what gets printed in the show guide and is typically what will be used by attendees when deciding what sessions to attend.  This is where you need to sell your session, not just to the reviewers, but also the people who you want in your audience.  Submitting a one line abstract (unless it's a really good one line) is not usually enough to decide whether this is worth investing an hour of conference time.  The abstract typically has a limit of a few hundred characters.  Try to use as many of them as possible to get as much information about your session across.  The summary should be different from the abstract (and don't leave it blank as some people do).  This field is where you can give the reviewers more detail about things like the structure of the talk, possible demonstrations and so on.  As a reviewer I look to this section to help me decide whether the hard-sell of the title and abstract will actually be reflected in the final content.  Try to make this comprehensive, but don't make it excessively long.  When you have to review possibly hundreds of sessions a certain level of conciseness can make life easier for reviewers and help the cause of your session. If you've not made many submissions for talks in the past, or if this is your first, try to give reviewers places to find background on you as a presenter.  Having an active blog and Twitter handle can also help reviewers if they're not sure what your level of expertise is.  Many call-for-papers have places for you to include this type of information.  It's always good to have new and original presenters and presentations for conferences.  Hopefully these tips will help you be successful when you answer the next call-for-papers.

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• What Counts for a DBA: Skill

  - by drsql

  “Practice makes perfect:” right? Well, not exactly. The reality of it all is that this saying is an untrustworthy aphorism. I discovered this in my “younger” days when I was a passionate tennis player, practicing and playing 20+ hours a week. No matter what my passion level was, without some serious coaching (and perhaps a change in dietary habits), my skill level was never going to rise to a level where I could make any money at the sport that involved something other than selling tennis balls at a sporting goods store. My game may have improved with all that practice but I had too many bad practices to overcome. Practice by itself merely reinforces what we know and what we can figure out naturally. The truth is actually closer to the expression used by Vince Lombardi: “Perfect practice makes perfect.” So how do you get to become skilled as a DBA if practice alone isn’t sufficient? Hit the Internet and start searching for SQL training and you can find 100 different sites. There are also hundreds of blogs, magazines, books, conferences both onsite and virtual. But then how do you know who is good? Unfortunately often the worst guide can be to find out the experience level of the writer. Some of the best DBAs are frighteningly young, and some got their start back when databases were stored on stacks of paper with little holes in it. As a programmer, is it really so hard to understand normalization? Set based theory? Query optimization? Indexing and performance tuning? The biggest barrier often is previous knowledge, particularly programming skills cultivated before you get started with SQL. In the world of technology, it is pretty rare that a fresh programmer will gravitate to database programming. Database programming is very unsexy work, because without a UI all you have are a bunch of text strings that you could never impress anyone with. Newbies spend most of their time building UIs or apps with procedural code in C# or VB scoring obvious interesting wins. Making matters worse is that SQL programming requires mastery of a much different toolset than most any mainstream programming skill. Instead of controlling everything yourself, most of the really difficult work is done by the internals of the engine (written by other non-relational programmers…we just can’t get away from them.) So is there a golden road to achieving a high skill level? Sadly, with tennis, I am pretty sure I’ll never discover it. However, with programming it seems to boil down to practice in applying the appropriate techniques for whatever type of programming you are doing. Can a C# programmer build a great database? As long as they don’t treat SQL like C#, absolutely. Same goes for a DBA writing C# code. None of this stuff is rocket science, as long as you learn to understand that different types of programming require different skill sets and you as a programmer must recognize the difference between one of the procedural languages and SQL and treat them differently. Skill comes from practicing doing things the right way and making “right” a habit.

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• Application Logging needs work

  Application Logging Application logging is the act of logging events that occur within an application much like how a court report documents what happens in court case. Application logs can be useful for several reasons, but the most common use for logs is to recreate steps to find the root cause of applications errors. Other uses can include the detection of Fraud, verification of user activity, or provide audits on user/data interactions. “Logs can contain different kinds of data. The selection of the data used is normally affected by the motivation leading to the logging. “ (OWASP, 2009) OWASP also stats that logging include applicable debugging information like the event date time, responsible process, and a description of the event. “There are many reasons why a logging system is a necessary part of delivering a distributed application. One of the most important is the ability to track exactly how many users are using the application during different time periods.” (Hatton, 2000) Hatton also states that application logging helps system designers determine whether parts of an application aren't being used as designed. He implies that low usage can be used to identify if users like or do not like aspects of a system based on user usage of the application. This enables application designers to extract why users don't like aspects of an application so that changes can be made to increase its usefulness and effectiveness. “Logging memory usage can also assist you in tuning up the internals of your application. If you're experiencing a randomly occurring problem, being able to match activities performed with the memory status at the time may enable you to discover the cause of the problem. It also gives you a good indication of the health of the distributed server machine at the time any activity is performed. “ (Hatton, 2000) Commonly Logged Application Events (Defined by OWASP) Access of Data Creation of Data Modification of Data in any form Administrative Functions  Configuration Changes Debugging Information(Application Events)  Authorization Attempts  Data Deletion Network Communication  Authentication Events  Errors/Exceptions Application Error Logging The functionality associated with application error logging is actually the combination of proper error handling and applications logging.  If we look back at Figure 4 and Figure 5, these code examples allow developers to handle various types of errors that occur within the life cycle of an application’s execution. Application logging can be applied within the Catch section of the TryCatch statement allowing for the errors to be logged when they occur. By placing the logging within the Catch section specific error details can be accessed that help identify the source of the error, the path to the error, what caused the error and definition of the error that occurred. This can then be logged and reviewed at a later date in order recreate the error that was received based data found in the application log. By allowing applications to log errors developers IT staff can use them to recreate errors that are encountered by end-users or other dependent systems.

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• Faster Memory Allocation Using vmtasks

  - by Steve Sistare

  You may have noticed a new system process called "vmtasks" on Solaris 11 systems: % pgrep vmtasks 8 % prstat -p 8 PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP 8 root 0K 0K sleep 99 -20 9:10:59 0.0% vmtasks/32 What is vmtasks, and why should you care? In a nutshell, vmtasks accelerates creation, locking, and destruction of pages in shared memory segments. This is particularly helpful for locked memory, as creating a page of physical memory is much more expensive than creating a page of virtual memory. For example, an ISM segment (shmflag & SHM_SHARE_MMU) is locked in memory on the first shmat() call, and a DISM segment (shmflg & SHM_PAGEABLE) is locked using mlock() or memcntl(). Segment operations such as creation and locking are typically single threaded, performed by the thread making the system call. In many applications, the size of a shared memory segment is a large fraction of total physical memory, and the single-threaded initialization is a scalability bottleneck which increases application startup time. To break the bottleneck, we apply parallel processing, harnessing the power of the additional CPUs that are always present on modern platforms. For sufficiently large segments, as many of 16 threads of vmtasks are employed to assist an application thread during creation, locking, and destruction operations. The segment is implicitly divided at page boundaries, and each thread is given a chunk of pages to process. The per-page processing time can vary, so for dynamic load balancing, the number of chunks is greater than the number of threads, and threads grab chunks dynamically as they finish their work. Because the threads modify a single application address space in compressed time interval, contention on locks protecting VM data structures locks was a problem, and we had to re-scale a number of VM locks to get good parallel efficiency. The vmtasks process has 1 thread per CPU and may accelerate multiple segment operations simultaneously, but each operation gets at most 16 helper threads to avoid monopolizing CPU resources. We may reconsider this limit in the future. Acceleration using vmtasks is enabled out of the box, with no tuning required, and works for all Solaris platform architectures (SPARC sun4u, SPARC sun4v, x86). The following tables show the time to create + lock + destroy a large segment, normalized as milliseconds per gigabyte, before and after the introduction of vmtasks: ISM system ncpu before after speedup ------ ---- ------ ----- ------- x4600 32 1386 245 6X X7560 64 1016 153 7X M9000 512 1196 206 6X T5240 128 2506 234 11X T4-2 128 1197 107 11x DISM system ncpu before after speedup ------ ---- ------ ----- ------- x4600 32 1582 265 6X X7560 64 1116 158 7X M9000 512 1165 152 8X T5240 128 2796 198 14X (I am missing the data for T4 DISM, for no good reason; it works fine). The following table separates the creation and destruction times: ISM, T4-2 before after ------ ----- create 702 64 destroy 495 43 To put this in perspective, consider creating a 512 GB ISM segment on T4-2. Creating the segment would take 6 minutes with the old code, and only 33 seconds with the new. If this is your Oracle SGA, you save over 5 minutes when starting the database, and you also save when shutting it down prior to a restart. Those minutes go directly to your bottom line for service availability.

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• Why do GPUs overheat?

  - by JAD

  About a year ago, I added a 9800GT (1 GB version) and a Corsair CX500 PSU to an HP M8000N computer. A few weeks ago, the HDD overheated and I decided to transfer the GPU & PSU to a new build, which consists of: i3 @ 3.3Ghz Gigabyte H61 Micro ATX Mobo 4GB RAM 500GB WD HDD DVD RW Drive Cooler Master Elite 430 Tower Once I had Win7 up and running, I installed all the essential drivers that came with the Gigabyte Mobo CD. However, whenever I tried installing the Graphics Media Accelerator driver, the computer would crash and enter an endless boot sequence on the next startup. I skipped installing this driver and installed the CD driver for the 9800GT, which by now is a year old. Everything was working fine, WEI rated my GPU at 6.6 graphics & aero performance. However, after updating my Nvidia drivers to the latest, the WEI dropped my rating to 3.3 for Aero, and 4.7 for graphics performance. Just to make sure that everything was ok, I ran Bad Company 2 on medium settings. The first few minutes ran just fine at a smooth framerate, so I dismissed this as Windows being Windows. About 6 hours later, I ran BC2 again. This time I averaged anywhere from 2-5 FPS. I checked the GPU temperature through GPU-Z, and it came back as 120C. The problem with this, is that the computer was on for six hours up to that point. Wouldn't the card have experienced a reactor core meltdown a lot sooner than that? Granted, the computer was "sleeping" some of the time, but still... The next day I took out a temperature gun and ran some tests. I would point the laser at a very specific area on the reverse side of the card (not the fan or "front"), and compare the temp reading with GPU-Z. After leaving the system on idle on idle for a few minutes, I ran BC2 twice. Here are the results: GPU-Z Reading / Temp Gun Reading / Time Null / 22.3°C / Comp is Off 53°C / 33.5°C / 1:49 78°C / 46°C / 1:53 - (First BC2 run; good framerate) 102°C / 64.6°C / 2:01 - (System is again on idle) 113°C / 64.8°C / 2:10 119°C / 71.8°C / 2:17 - (Second BC2 run; poor framerate) I should also mention that I also took a temp recording of another part of the GPU from 2:01-2:17. The temp in this area jumped from 75°C to 82.9°C in that time frame. This pretty much confirms that GPU-Z is reporting the temperature accurately, and the card is overheating. But I'd like to know why; the cars is doing nothing and still the temperature climbs at a steady rate. I thoroughly cleaned the GPU and PSU when I salvaged them from the old HP M8000N computer with a can of compressed air, dust cant be the issue. Similarly, the rest of the computer is brand new. I installed various Nvidia drivers, but no luck. It seems strange to me that a year-old card is suddenly failing on me; aren't they supposed to last at least two years? Could this be a driver issue? Is the motherboard faulty? Could the PSU be overfeeding the card on voltage? Neither case seems likely, as the CPU, RAM and otherwise the rest of the comp has worked flawlessly and has stayed well within respectable temp ranges (the i3 lingers around 50C, the HDD stays at 30C, so does the PSU). How can I pinpoint the issue?

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• SATA drive problems with two SIL RAID cards

  - by Jon Topper

  I've just put a second SiI 3114 SATARaid card in my home server so that I could add another pair of SATA drives and increase my storage space. Annoyingly, it doesn't seem to work: [ 32.816030] ata5: lost interrupt (Status 0x0) [ 32.816072] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen [ 32.816091] ata5.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in [ 32.816094] res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) [ 32.816101] ata5.00: status: { DRDY } [ 32.816117] ata5: hard resetting link [ 33.136082] ata5: SATA link down (SStatus 0 SControl 0) [ 36.060940] irq 18: nobody cared (try booting with the "irqpoll" option) [ 36.060949] Pid: 0, comm: swapper Not tainted 2.6.31-20-generic #58-Ubuntu [ 36.060954] Call Trace: [ 36.060977] [] ? printk+0x18/0x1c [ 36.060997] [] __report_bad_irq+0x27/0x90 [ 36.061005] [] note_interrupt+0x150/0x190 [ 36.061011] [] handle_fasteoi_irq+0xac/0xd0 [ 36.061023] [] handle_irq+0x18/0x30 [ 36.061029] [] do_IRQ+0x47/0xc0 [ 36.061042] [] ? irq_exit+0x50/0x70 [ 36.061058] [] ? smp_apic_timer_interrupt+0x57/0x90 [ 36.061065] [] common_interrupt+0x30/0x40 [ 36.061075] [] ? native_safe_halt+0x5/0x10 [ 36.061082] [] default_idle+0x46/0xd0 [ 36.061088] [] cpu_idle+0x8c/0xd0 [ 36.061103] [] rest_init+0x55/0x60 [ 36.061111] [] start_kernel+0x2e6/0x2ec [ 36.061117] [] ? unknown_bootoption+0x0/0x19e [ 36.061133] [] i386_start_kernel+0x7c/0x83 [ 36.061137] handlers: [ 36.061139] [] (sil_interrupt+0x0/0xb0) [ 36.061151] Disabling IRQ #18 [ 38.136014] ata5: hard resetting link [ 38.456022] ata5: SATA link down (SStatus 0 SControl 0) [ 43.456013] ata5: hard resetting link [ 43.776022] ata5: SATA link down (SStatus 0 SControl 0) [ 43.776035] ata5.00: disabled [ 43.776055] ata5.00: device reported invalid CHS sector 0 [ 43.776074] sd 4:0:0:0: [sde] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 43.776082] sd 4:0:0:0: [sde] Sense Key : Aborted Command [current] [descriptor] [ 43.776092] Descriptor sense data with sense descriptors (in hex): [ 43.776097] 72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00 [ 43.776112] 00 00 00 00 [ 43.776118] sd 4:0:0:0: [sde] Add. Sense: No additional sense information [ 43.776127] end_request: I/O error, dev sde, sector 0 [ 43.776136] Buffer I/O error on device sde, logical block 0 [ 43.776170] ata5: EH complete [ 43.776187] ata5.00: detaching (SCSI 4:0:0:0) root@core:~# cat /proc/interrupts CPU0 0: 47 IO-APIC-edge timer 1: 8 IO-APIC-edge i8042 6: 3 IO-APIC-edge floppy 7: 0 IO-APIC-edge parport0 8: 0 IO-APIC-edge rtc0 9: 0 IO-APIC-fasteoi acpi 14: 53069 IO-APIC-edge pata_sis 15: 53004 IO-APIC-edge pata_sis 17: 112265 IO-APIC-fasteoi sata_sil 18: 200002 IO-APIC-fasteoi sata_sil, SiS SI7012 19: 111140 IO-APIC-fasteoi eth0 20: 0 IO-APIC-fasteoi ohci_hcd:usb2 21: 0 IO-APIC-fasteoi ohci_hcd:usb3 23: 0 IO-APIC-fasteoi ehci_hcd:usb1 NMI: 0 Non-maskable interrupts LOC: 6650492 Local timer interrupts SPU: 0 Spurious interrupts CNT: 0 Performance counter interrupts PND: 0 Performance pending work RES: 0 Rescheduling interrupts CAL: 0 Function call interrupts TLB: 0 TLB shootdowns TRM: 0 Thermal event interrupts THR: 0 Threshold APIC interrupts MCE: 0 Machine check exceptions MCP: 160 Machine check polls ERR: 0 MIS: 0 root@core:~# lspci | grep Raid 00:09.0 RAID bus controller: Silicon Image, Inc. SiI 3114 [SATALink/SATARaid] Serial ATA Controller (rev 02) 00:0a.0 RAID bus controller: Silicon Image, Inc. SiI 3114 [SATALink/SATARaid] Serial ATA Controller (rev 02) root@core:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 9.10 Release: 9.10 Codename: karmic root@core:~# uname -a Linux core.topper.me.uk 2.6.31-20-generic #58-Ubuntu SMP Fri Mar 12 05:23:09 UTC 2010 i686 GNU/Linux I've tried a combination of different kernel options (irqpoll, noapic, noacpi, pci=noapic) all to no avail. Does anyone have any bright ideas about how I can go about making this work? Swapping PCI cards around isn't an option as there are only two slots in this motherboard (an ASRock K7S41GX). The BIOS doesn't look to have too much in the way of configuration options regarding IRQ usage. Plan B is to ditch this server completely and buy a new QNAP for these drives to go in, but I was hoping to avoid doing this right now.

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• What Apache/PHP configurations do you know and how good are they?

  - by FractalizeR

  Hello. I wanted to ask you about PHP/Apache configuration methods you know, their pros and cons. I will start myself: ---------------- PHP as Apache module---------------- Pros: good speed since you don't need to start exe every time especially in mpm-worker mode. You can also use various PHP accelerators in this mode like APC or eAccelerator. Cons: if you are running apache in mpm-worker mode, you may face stability issues because every glitch in any php script will lead to unstability to the whole thread pool of that apache process. Also in this mode all scripts are executed on behalf of apache user. This is bad for security. mpm-worker configuration requires PHP compiled in thread-safe mode. At least CentOS and RedHat default repositories doesn't have thread-safe PHP version so on these OSes you need to compile at least PHP yourself (there is a way to activate worker mpm on Apache). The use of thread-safe PHP binaries is considered experimental and unstable. Plus, many PHP extensions does not support thread-safe mode or were not well-tested in thread-safe mode. ---------------- PHP as CGI ---------------- This seems to be the slowest default configuration which seems to be a "con" itself ;) ---------------- PHP as CGI via mod_suphp ---------------- Pros: suphp allows you to execute php scipts on behalf of the script file owner. This way you can securely separate different sites on the same machine. Also, suphp allows to use different php.ini files per virtual host. Cons: PHP in CGI mode means less performance. In this mode you can't use php accelerators like APC because each time new process is spawned to handle script rendering the cache of previous process useless. BTW, do you know the way to apply some accelerator in this config? I heard something about using shm for php bytecode cache. Also, you cannot configure PHP via .htaccess files in this mode. You will need to install PECL htscanner for this if you need to set various per-script options via .htaccess (php_value / php_flag directives) ---------------- PHP as CGI via suexec ---------------- This configuration looks the same as with suphp, but I heard, that it's slower and less safe. Almost same pros and cons apply. ---------------- PHP as FastCGI ---------------- Pros: FastCGI standard allows single php process to handle several scripts before php process is killed. This way you gain performance since no need to spin up new php process for each script. You can also use PHP accelerators in this configuration (see cons section for comment). Also, FCGI almost like suphp also allows php processes to be executed on behalf of some user. mod_fcgid seems to have the most complete fcgi support and flexibility for apache. Cons: The use of php accelerator in fastcgi mode will lead to high memory consumption because each PHP process will have his own bytecode cache (unless there is some accelerator that can use shared memory for bytecode cache. Is there such?). FastCGI is also a little bit complex to configure. You need to create various configuration files and make some configuration modifications. It seems, that fastcgi is the most stable, secure, fast and flexible PHP configuration, however, a bit difficult to be configured. But, may be, I missed something? Comments are welcome!

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• register_globals error in php

  - by user145862

  I was stuck up with the error directive 'register_globals' is no longer available in PHP in unknown on line 0 when tried to check the php version using "php -v" after enabling register_globals in php.ini file. I am not getting any php version info by doing so. Instead it throws the above mentioned error.After turning off this option, php info works quite well. It is very essential for me to have register_globals to be turned on.How can I have this corrected. my php.ini is as follows: ; Default Value: None ; Development Value: "GP" ; Production Value: "GP" ; http://php.net/request-order request_order = "GP" ; Whether or not to register the EGPCS variables as global variables. You may ; want to turn this off if you don't want to clutter your scripts' global scope ; with user data. ; You should do your best to write your scripts so that they do not require ; register_globals to be on; Using form variables as globals can easily lead ; to possible security problems, if the code is not very well thought of. ; register_globals = On ; Determines whether the deprecated long $HTTP_*_VARS type predefined variables ; are registered by PHP or not. As they are deprecated, we obviously don't ; recommend you use them. They are on by default for compatibility reasons but ; they are not recommended on production servers. ; Default Value: On ; Development Value: Off ; Production Value: Off ; register_long_arrays = Off ; This directive determines whether PHP registers $argv & $argc each time it ; runs. $argv contains an array of all the arguments passed to PHP when a script ; is invoked. $argc contains an integer representing the number of arguments ; that were passed when the script was invoked. These arrays are extremely ; useful when running scripts from the command line. When this directive is ; enabled, registering these variables consumes CPU cycles and memory each time ; a script is executed. For performance reasons, this feature should be disabled ; on production servers. ; Note: This directive is hardcoded to On for the CLI SAPI ; Default Value: On ; Development Value: Off ; Production Value: Off ; register_argc_argv = Off ; When enabled, the SERVER and ENV variables are created when they're first ; used (Just In Time) instead of when the script starts. If these variables ; are not used within a script, having this directive on will result in a ; performance gain. The PHP directives register_globals, register_long_arrays, ; and register_argc_argv must be disabled for this directive to have any affect. ; auto_globals_jit = On

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• Troubleshooting Website problems within the local network

  - by HaydnWVN

  Have an external website which opens fine on some PC's, yet seems to time out (or symptoms of timing out, but never actually does) on others. Seems to only affect (some) of our newer HP Pro 3305 MT Workstations. All of which are running Win7 32bit SP1 with all updates. Older PC's (Win7 32bit SP1 & WinXP) are unaffected. Using Google Chrome & Firefox makes no difference. Opening the website in IE9 Compatibility Mode has exactly the same symptoms. All PC's are on the same local network (Workgroup) using the same DNS server & gateway (inhouse) on the same internet connection, on the same subnet. There is no proxy server, no content filtering, no load balancing etc etc. Only group policy in effect (locally) is for Update scheduling. Local firewalls are all the same (Kaspersky WP4) and our external facing firewall has no IP specific settings. I have no control over the external website, traceroute shows the same destination on all PC's. It is a fairly popular website in our industry (Horticulture) and i'm not aware of any other people (even other sites within our sister companies) with the same problem. Update: Used Fiddler2 to monitor the HTTP request, seems its not getting fulfilled for some reason?! Request sent: GET http://www.rhs.org.uk/ HTTP/1.1 Host: www.rhs.org.uk Connection: keep-alive User-Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Encoding: gzip,deflate,sdch Accept-Language: en-GB,en-US;q=0.8,en;q=0.6 Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3 Log from Fiddler 2 of the request: This session is not yet complete. Press F5 to refresh when session is complete for updated statistics. Request Count: 1 Bytes Sent: 567 (headers:567; body:0) Bytes Received: 0 (headers:0; body:0) ACTUAL PERFORMANCE -------------- ClientConnected: 17:02:33.720 ClientBeginRequest: 17:02:39.118 GotRequestHeaders: 17:02:39.118 ClientDoneRequest: 17:02:39.118 Determine Gateway: 0ms DNS Lookup: 0ms TCP/IP Connect: 46ms HTTPS Handshake: 0ms ServerConnected: 17:02:39.165 FiddlerBeginRequest: 17:02:39.165 ServerGotRequest: 17:02:39.165 ServerBeginResponse: 00:00:00.000 GotResponseHeaders: 00:00:00.000 ServerDoneResponse: 00:00:00.000 ClientBeginResponse: 00:00:00.000 ClientDoneResponse: 00:00:00.000 RESPONSE BYTES (by Content-Type) -------------- ~headers~: 0 Log of a successful request from a working PC (done this morning, excuse the timestamps being different from above): Request Count: 1 Bytes Sent: 493 (headers:493; body:0) Bytes Received: 20,413 (headers:525; body:19,888) ACTUAL PERFORMANCE -------------- ClientConnected: 08:22:47.766 ClientBeginRequest: 08:22:47.766 GotRequestHeaders: 08:22:47.766 ClientDoneRequest: 08:22:47.766 Determine Gateway: 0ms DNS Lookup: 26ms TCP/IP Connect: 30ms HTTPS Handshake: 0ms ServerConnected: 08:22:47.828 FiddlerBeginRequest: 08:22:47.828 ServerGotRequest: 08:22:47.828 ServerBeginResponse: 08:22:48.905 GotResponseHeaders: 08:22:48.905 ServerDoneResponse: 08:22:48.905 ClientBeginResponse: 08:22:48.905 ClientDoneResponse: 08:22:48.905 Overall Elapsed: 00:00:01.1388020 RESPONSE BYTES (by Content-Type) -------------- text/html: 19,888 ~headers~: 525 So my question has evolved into: What is the difference between the 2 requests and how do I determine why 1 PC is not getting a reply to it's GET request?

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• Thoughts on home NAS server

  - by user826955

  I currently have a NAS with a 2x2TB HDD 1x16GB SSD layout on a mini-itx atom board. The NAS is in a Lian Li PC-Q07 case. On this system I was running freebsd 8 with a gmirror raid 1 setup, which was enough for my needs. So far I was using the NAS for: Fileserver with AFP protocol (only mac clients used) SVN server hosting all my source trees of my projects JIRA (performance was okay-ish) Timemachine backup for the macs The power consumption was about 38W, although I did not put HDDs asleep when unused (I think this is not possible in a raid setup). I liked the NAS because: the performance was good through gigabit LAN (enough for my needs) power consumption was good its a pretty small case and fits in one of my cupboards I disliked the NAS a bit because: it was a bit noisy, the Q07 case vibrated a good amount because of the HDDs. I switched the NAS off every evening I do not have a real backup of the data on the NAS, only the internal raid 1 as safety. I really dont want to loose my source trees under no circumstances, so I would really be sleeping better if I knew I had regular backups somewhere. Recently, the board seemed to have died, I can't boot anymore. Thus, I was thinking about a redesign of my NAS (I still have to find out what parts are broken, I probably need to replace the mainboard and SSD. HDDs seem to be okay). First of all, I was wondering what other users have as backup for their NAS? Are you actually using a second NAS, and regularly copying over the data to have it safe? Or is there any better solution to this? I was thinking about getting a cheap NAS like the synology DS112j with only one disk, and use rsync or something similar to regularly copy data over to the second NAS (wake the second NAS upon start, shut it down after copy). Although this approach seems somewhat weird, It would have the benefit (?) that I could use a single disk instead of raid in the main NAS, and put the disk asleep when idle, and have the NAS running 24/7 with low energy consumption (I found no way to do this with a gmirror setup). Is there any recommended backup solution for a small NAS? Then I was thinking about a different raid setup. Since I have to buy a new mainboard as well as SSD, I might as well switch over to a i3 board with more ram, and also switch to ZFS. I am not familar with ZFS, I've never used it, but I read and hear much about it. Would it be viable to set up a ZFS storage with only 2 disks? Can I easily extend this storage with more disks, once I choose to add some? I could maybe get a new case like the Fractal Design Array R2 which has more 3,5" slots. I could as well get another 2 disks, but I would prefer sticking with the existing 2 for enegery/heat/noise reasons. Should I go for a ZFS storage or stick to my gmirror setup? I would also like to keep freebsd as operating system, and also I dont need any web gui or something (that is, I dont need/want to use FreeNAS or Openfiler etc). Does anyone maybe have a sample setup in use so I can compare energy consumption/noise/software setup? Any guidance towards the NAS of my dreams (silent, low energy, safe w/ backups) much appreciated.

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• CPU Utilization LAMP stack

  - by Max

  We've got an ec2 m2.4xlarge running Magento (centos 5.6, httpd 2.2, php 5.2.17 with eaccelerator 0.9.5.3, mysql 5.1.52). Right now we're getting a large traffic spike, and our top looks like this: top - 09:41:29 up 31 days, 1:12, 1 user, load average: 120.01, 129.03, 113.23 Tasks: 1190 total, 18 running, 1172 sleeping, 0 stopped, 0 zombie Cpu(s): 97.3%us, 1.8%sy, 0.0%ni, 0.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.4%st Mem: 71687720k total, 36898928k used, 34788792k free, 49692k buffers Swap: 880737784k total, 0k used, 880737784k free, 1586524k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2433 mysql 15 0 23.6g 4.5g 7112 S 564.7 6.6 33607:34 mysqld 24046 apache 16 0 411m 65m 28m S 26.4 0.1 0:09.05 httpd 24360 apache 15 0 410m 60m 25m S 26.4 0.1 0:03.65 httpd 24993 apache 16 0 410m 57m 21m S 26.1 0.1 0:01.41 httpd 24838 apache 16 0 428m 74m 20m S 24.8 0.1 0:02.37 httpd 24359 apache 16 0 411m 62m 26m R 22.3 0.1 0:08.12 httpd 23850 apache 15 0 411m 64m 27m S 16.8 0.1 0:14.54 httpd 25229 apache 16 0 404m 46m 17m R 10.2 0.1 0:00.71 httpd 14594 apache 15 0 404m 63m 34m S 8.4 0.1 1:10.26 httpd 24955 apache 16 0 404m 50m 21m R 8.4 0.1 0:01.66 httpd 24313 apache 16 0 399m 46m 22m R 8.1 0.1 0:02.30 httpd 25119 apache 16 0 411m 59m 23m S 6.8 0.1 0:01.45 httpd Questions: Would giving msyqld more memory help it cache queries and react faster? If so, how? Other than splitting mysql and php to separate servers (which we're about to do) is there anything else we could/should be doing? Thanks! UPDATE: Here's our my.cnf along with the output of mysqltuner. It looks like a cache problem. Thanks again! # cat /etc/my.cnf [client] port = **** socket = /var/lib/mysql/mysql.sock [mysqld] datadir=/mnt/persistent/mysql port=**** socket=/var/lib/mysql/mysql.sock key_buffer = 512M max_allowed_packet = 64M table_cache = 1024 sort_buffer_size = 8M read_buffer_size = 4M read_rnd_buffer_size = 2M myisam_sort_buffer_size = 64M thread_cache_size = 128M tmp_table_size = 128M join_buffer_size = 1M query_cache_limit = 2M query_cache_size= 64M query_cache_type = 1 max_connections = 1000 thread_stack = 128K thread_concurrency = 48 log-bin=mysql-bin server-id = 1 wait_timeout = 300 innodb_data_home_dir = /mnt/persistent/mysql/ innodb_data_file_path = ibdata1:10M:autoextend innodb_buffer_pool_size = 20G innodb_additional_mem_pool_size = 20M innodb_log_file_size = 64M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 innodb_thread_concurrency = 48 ft_min_word_len=3 [myisamchk] ft_min_word_len=3 key_buffer = 128M sort_buffer_size = 128M read_buffer = 2M write_buffer = 2M # ./mysqltuner.pl >> MySQLTuner 1.2.0 - Major Hayden <[email protected]> >> Bug reports, feature requests, and downloads at http://mysqltuner.com/ >> Run with '--help' for additional options and output filtering -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.1.52-log [OK] Operating on 64-bit architecture -------- Storage Engine Statistics ------------------------------------------- [--] Status: +Archive -BDB +Federated +InnoDB -ISAM -NDBCluster [--] Data in MyISAM tables: 2G (Tables: 26) [--] Data in InnoDB tables: 749M (Tables: 250) [!!] Total fragmented tables: 262 -------- Security Recommendations ------------------------------------------- -------- Performance Metrics ------------------------------------------------- [--] Up for: 31d 2h 30m 38s (680M q [253.371 qps], 2M conn, TX: 4825B, RX: 236B) [--] Reads / Writes: 89% / 11% [--] Total buffers: 20.6G global + 15.1M per thread (1000 max threads) [OK] Maximum possible memory usage: 35.4G (51% of installed RAM) [OK] Slow queries: 0% (35K/680M) [OK] Highest usage of available connections: 53% (537/1000) [OK] Key buffer size / total MyISAM indexes: 512.0M/457.2M [OK] Key buffer hit rate: 100.0% (9B cached / 264K reads) [OK] Query cache efficiency: 42.3% (260M cached / 615M selects) [!!] Query cache prunes per day: 4384652 [OK] Sorts requiring temporary tables: 0% (1K temp sorts / 38M sorts) [!!] Joins performed without indexes: 100404 [OK] Temporary tables created on disk: 17% (7M on disk / 45M total) [OK] Thread cache hit rate: 99% (537 created / 2M connections) [!!] Table cache hit rate: 0% (1K open / 946K opened) [OK] Open file limit used: 9% (453/5K) [OK] Table locks acquired immediately: 99% (758M immediate / 758M locks) [OK] InnoDB data size / buffer pool: 749.3M/20.0G -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance Enable the slow query log to troubleshoot bad queries Adjust your join queries to always utilize indexes Increase table_cache gradually to avoid file descriptor limits Variables to adjust: query_cache_size (> 64M) join_buffer_size (> 1.0M, or always use indexes with joins) table_cache (> 1024)

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• Using different SSDs types (not only SATA based) as system drive

  - by Hubert Kario

  Currently I have a Thinkpad X61s and want to make it both a bit faster and a bit more power efficient. For that reason I thought that adding SSD drive would make most sense. Unfortunately, because of financial reasons, buying SSD of over 200GB capacity is out of reach for me (not only it would be worth more than the rest of the laptop, but also I currently have a 500GB drive in it, so even such a drive would be kind of a downgrade for me). During preliminary testing with a cheap Transcend 4GB Class 6 (14MiB/s streaming, 9MiB/s random read) card I experienced boot times to be reduced by half so putting the OS only on it would already would be an improvement. Unfortunately, my system now is about 11GiB in size so anything less than 16GB would be constraining. In this laptop I can connect additional drives on at least 5 different ways: using SATA-ATA converter caddy in the X6 Ultrabase using internal mini PCIe slot using integrated SDHC slot using CardBus (a.k.a PCMCIA or PC Card) slot using USB Thankfully, because I use only Linux on this PC the bootability of them is irrelevant as I can put the /boot partition on internal HDD and / on any of the above mentioned Flash memories (as I already did for the SDHC test). From what I was able to research and from my own experience those options come with rather big downsides or other problems: SATA-ATA caddy It has three downsides: I have to carry the Ultrabse with me at all times (it's not really inconvenient, but those grams do add) and couldn't disconnect it when I want to disconnect the battery It makes the bay unusable for the optical drive and occasional quick access to other hard drives the only caddies I could buy have rather flaky controllers in them so putting my OS on it would hamper its stability Internal mini PCIe slot This would be an ideal solution, if only I could find real PCIe SSDs, not only devices that could talk only SATA or ATA over PCIe mechanical connection (the ones used in Dell Mini or Asus EEE). Theoretically Samsung did release such devices but I couldn't find them in retail anywhere. Integrated SDHC slot It's a nice solution with a single drawback: the fastest 16GB SDHC card on the market can only do around 35MiB/s read and 15MiB/s write while still costing like a normal 40GB SATA SSD that's 10 times faster. Not really cost-effective. CardBus (a.k.a PCMCIA or PC Card) slot Those cards are much faster than the SDHC option (there are ones that can do well over 50MiB/s read in benchmarks) and from what I could find the PCMCIA controller in my laptop does support UDMA so it should be able to deliver comparable speeds. They still cost similarly to SD cards but at least they provide streaming performance comparable to my current HDD. USB That's the worst option. Not only is it limited to 20-30MiB/s by the interface itself the drive would stick out of the laptop so it's a big no no. The question As such I think that going the "CF in a CardBus adapter" route will be the best option. My question is: did anyone try using CF cards in CardBus adapters as system drives with Linux on Thinkpad laptops? Laptops in general? What was the real-world performance? I don't have any CF cards so I can't check how well does it work with suspend/resume, or whatever it's easy to make it work in initramfs (I'm using ArchLinux and SD card was trivial — add 3 modules in single config line and rebuilding initramfs) so any tips/gotchas on this are welcome as well.

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• Rosewill RSV-S5 and it's transferespeeds

  - by DoomStone

  I have just bought a Rosewill RSV-S5, I have installed 5x1,5Tb Western Digital Green disks in it. After that have I created a Raid5 on them all with the software that followed with the hardware. Not the raid it self works fine, but it is SLOW, I can only obtain a maximum of 25 MB/s, and if SABnzbd+ is downloading with 5 MB/s is it having a hard time streaming a normal DIVX (700 mb) movie. Is this normal or is there something wrong? Edit: should be able to handle 3 Gbps = 384 megabytes / second Edit 2: As you can see am I only downloading with 3,76 MB/s and I'm trying to watch V s02e08 (720p), but it is completely unwatchable, as I can see 30 sec, and the it buffers for 20 sec. Edit: Other information there might be required I'm running Windows Server 2008 R2, optimized for program performance. Windows is installed on a 60GB SSD. I have a 50 Mb/s internet connection and a 1 Gb/s LAN, all connected with Cat6 Ethernet cables. The MCE is using a Gigabyte EP35C-DS3R motherboard with 2 GB DDR2 ram. Edit 3: I have used chunk sizes for 128 KB Edit 4: I found this on newegg Pros: Enclosure for 5x2TB hard drive is fine. This is basically a rebranded San Digital TR5M-B product. For support Rosewill tells you to contact San Digital. No direct support from Silicon Image for the computer raid card. Cons: Includes computer Silicon Image 3132 raid card, extremely slow raid 5 write (our tests ~10MB/s). Compare to regular internal local drive write 30-60MB/s. We basically dumped the Sil3132 card and replaced with High Point RocketRaid 622 card for extra $69.99. Note for RR622, turn off ECRC (end to end CRC check) for card to work on IBM xserver. What took 12hrs to copy now took 2-3hrs. San Digital realized the problem and has the newer model TR5M-BP TowerRaid Plus that comes with High Point RocketRaid 622 card. Rosewill should discontinue this product and go with TR5M-BP. Could not get Silicon Image raid management software to work with complicated 2008R2 server with 10 NICs, application doesn't know how to talk to localhost port with all those NICs. No updates from Silicon Image and support from San Digital ignored. Gave up on Sil3132 card. Save yourself from a lot of headaches, get the RR622 card too if you are going to buy this product. Other Thoughts: The newer model is TR5M-BP TowerRaid Plus, comes with High Point RocketRaid 622 raid card for the PC instead of Silicon Image Sil3132. According to San Digital, raid 5 performance for Sil3132 read 80MB/s write 19MB/s, and RR622 read 154MB/s write 149MB/s. Our RR622 tests gave (8TB raid 5) write ~80-110MB/s copying 40GB file took 8mins. So I have now ordered a HighPoint RocketRAID 622 2P ext SATA III and hopes that it will solve my problems.

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• Network config / gear question

  - by mcgee1234

  I have been tasked with setting up a fairly straightforward rack in a data center (we do not even need a whole rack, but this is the smallest allotment available). In a nutshell, 4 to 6 servers need to be able to reach 2 (maybe 3) vendors. The servers needs to be reachable over the internet. A little more detail - the networks the servers need to reach are inside of the data center, and are "trusted". Connections to these networks will be achieved through intra data center cross connects. It is kind of like a manufacturing line where we receive data from one vendor (burst-able up to 200 Mbits), churn through it on the servers, and then send out data to another vendor (bursts up to 20 Mbits). This series of events is very latency sensitive, so much so that it is common practice not to use NAT or a firewall on these segments (or so I hear). To reach the servers over the internet, I plan to use a site to site VPN. (This part is only relevant as far as hardware selection goes). I have 2 configurations in mind: Cisco 2911 (2921) (with the additional wan ports module) and a layer 2 switch - in this scenario, I would use the router also for VPN. Cisco 3560 layer 3 switch to interconnect the networks inside of the data center and an ASA 5510 (which is total overkill, but the 5505 is not rack mountable) as a firewall for the Wan side (internet) and VPN. I envision the setup to be as follows: Internet - ASA - 3560 Vendors - 3560 - Servers The general idea is that the ASA acts as a firewall and VPN device and the 3560 does all the heavy lifting. The first is a fairly traditional setup but my concern is performance. The second is somewhat unorthodox in that the vendors are directly connected to the layer 3 switch without passing through a firewall. Based on my understanding however, a layer 3 switch will perform substantially better as it will do hardware (ASIC) vs. software switching. (Note that number 2 is a little over the budget, but not unworkable (double negative, ugh)) Since this is my first time dealing with a data center, I am not sure what the IP space is going to look like. I suspect I will retain a block(s) of public IPs, vlan them to individual interfaces for the vendor connections and the servers (which will not reachable from the wan side of course) and setup routing on the switch. So here are my questionss: Is there a substantial performance difference between 1 and 2, i.e. hardware based switching on a layer 3 vs a software base on the 2911? I have trolled the internet and found a lot of Cisco literature, but nothing that I could really use to get a good handle. The vendors we connect to are secure and trusted (famous last words) and as I understand it, it is common practice not to NAT or firewall these connections (because of the aforementioned latency sensitivity). But what what kind of latency are we really talking about if I push the data through a router (or even ASA for that matter)? For our purposes, 5 ms will not kill us, 20 or 30 can be very costly. Others measure in microseconds, but they are out of our league. Is there any issues with using public IPs on a layer 3 switch? I am certainly not married to either of these configs, and I am totally open to any ideas. My knowledge (and I use the term loosely) is largely from books so I welcome any advice / insight. Thanks in advance.

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• ActiveX component can't create Object Error? Check 64 bit Status

  - by Rick Strahl

  If you're running on IIS 7 and a 64 bit operating system you might run into the following error using ASP classic or ASP.NET with COM interop. In classic ASP applications the error will show up as: ActiveX component can't create object   (Error 429) (actually without error handling the error just shows up as 500 error page) In my case the code that's been giving me problems has been a FoxPro COM object I'd been using to serve banner ads to some of my pages. The code basically looks up banners from a database table and displays them at random. The ASP classic code that uses it looks like this: <% Set banner = Server.CreateObject("wwBanner.aspBanner") banner.BannerFile = "wwsitebanners" Response.Write(banner.GetBanner(-1)) %> Originally this code had no specific error checking as above so the ASP pages just failed with 500 error pages from the Web server. To find out what the problem is this code is more useful at least for debugging: <% ON ERROR RESUME NEXT Set banner = Server.CreateObject("wwBanner.aspBanner") Response.Write(err.Number & " - " & err.Description) banner.BannerFile = "wwsitebanners" Response.Write(banner.GetBanner(-1)) %> which results in: 429 - ActiveX component can't create object which at least gives you a slight clue. In ASP.NET invoking the same COM object with code like this: <% dynamic banner = wwUtils.CreateComInstance("wwBanner.aspBanner") as dynamic; banner.cBANNERFILE = "wwsitebanners"; Response.Write(banner.getBanner(-1)); %> results in: Retrieving the COM class factory for component with CLSID {B5DCBB81-D5F5-11D2-B85E-00600889F23B} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)). The class is in fact registered though and the COM server loads fine from a command prompt or other COM client. This error can be caused by a COM server that doesn't load. It looks like a COM registration error. There are a number of traditional reasons why this error can crop up of course. The server isn't registered (run regserver32 to register a DLL server or /regserver on an EXE server) Access permissions aren't set on the COM server (Web account has to be able to read the DLL ie. Network service) The COM server fails to load during initialization ie. failing during startup One thing I always do to check for COM errors fire up the server in a COM client outside of IIS and ensure that it works there first - it's almost always easier to debug a server outside of the Web environment. In my case I tried the server in Visual FoxPro on the server with: loBanners = CREATEOBJECT("wwBanner.aspBanner") loBanners.cBannerFile = "wwsitebanners" ? loBanners.GetBanner(-1) and it worked just fine. If you don't have a full dev environment on the server you can also use VBScript do the same thing and run the .vbs file from the command prompt: Set banner = Server.CreateObject("wwBanner.aspBanner") banner.BannerFile = "wwsitebanners" MsgBox(banner.getBanner(-1)) Since this both works it tells me the server is registered and working properly. This leaves startup failures or permissions as the problem. I double checked permissions for the Application Pool and the permissions of the folder where the DLL lives and both are properly set to allow access by the Application Pool impersonated user. Just to be sure I assigned an Admin user to the Application Pool but still no go. So now what? 64 bit Servers Ahoy A couple of weeks back I had set up a few of my Application pools to 64 bit mode. My server is Server 2008 64 bit and by default Application Pools run 64 bit. Originally when I installed the server I set up most of my Application Pools to 32 bit mainly for backwards compatibility. But as more of my code migrates to 64 bit OS's I figured it'd be a good idea to see how well code runs under 64 bit code. The transition has been mostly painless. Until today when I noticed the problem with the code above when scrolling to my IIS logs and noticing a lot of 500 errors on many of my ASP classic pages. The code in question in most of these pages deals with this single simple COM object. It took a while to figure out that the problem is caused by the Application Pool running in 64 bit mode. The issue is that 32 bit COM objects (ie. my old Visual FoxPro COM component) cannot be loaded in a 64 bit Application Pool. The ASP pages using this COM component broke on the day I switched my main Application Pool into 64 bit mode but I didn't find the problem until I searched my logs for errors by pure chance. To fix this is easy enough once you know what the problem is by switching the Application Pool to Enable 32-bit Applications: Once this is done the COM objects started working correctly again. 64 bit ASP and ASP.NET with DCOM Servers This is kind of off topic, but incidentally it's possible to load 32 bit DCOM (out of process) servers from ASP.NET and ASP classic even if those applications run in 64 bit application pools. In fact, in West Wind Web Connection I use this capability to run a 64 bit ASP.NET handler that talks to a 32 bit FoxPro COM server which allows West Wind Web Connection to run in native 64 bit mode without custom configuration (which is actually quite useful). It's probably not a common usage scenario but it's good to know that you can actually access 32 bit COM objects this way from ASP.NET. For West Wind Web Connection this works out well as the DCOM interface only makes one non-chatty call to the backend server that handles all the rest of the request processing. Application Pool Isolation is your Friend For me the recent incident of failure in the classic ASP pages has just been another reminder to be very careful with moving applications to 64 bit operation. There are many little traps when switching to 64 bit that are very difficult to track and test for. I described one issue I had a couple of months ago where one of the default ASP.NET filters was loading the wrong version (32bit instead of 64bit) which was extremely difficult to track down and was caused by a very sneaky configuration switch error (basically 3 different entries for the same ISAPI filter all with different bitness settings). It took me almost a full day to track this down). Recently I've been taken to isolate individual applications into separate Application Pools rather than my past practice of combining many apps into shared AppPools. This is a good practice assuming you have enough memory to make this work. Application Pool isolate provides more modularity and allows me to selectively move applications to 64 bit. The error above came about precisely because I moved one of my most populous app pools to 64 bit and forgot about the minimal COM object use in some of my old pages. It's easy to forget. To 64bit or Not Is it worth it to move to 64 bit? Currently I'd say -not really. In my - admittedly limited - testing I don't see any significant performance increases. In fact 64 bit apps just seem to consume considerably more memory (30-50% more in my pools on average) and performance is minimally improved (less than 5% at the very best) in the load testing I've performed on a couple of sites in both modes. The only real incentive for 64 bit would be applications that require huge data spaces that exceed the 32 bit 4 gigabyte memory limit. However I have a hard time imagining an application that needs 4 gigs of memory in a single Application Pool :-). Curious to hear other opinions on benefits of 64 bit operation. © Rick Strahl, West Wind Technologies, 2005-2011Posted in COM   ASP.NET  FoxPro  

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• Parallelism in .NET – Part 5, Partitioning of Work

  - by Reed

  When parallelizing any routine, we start by decomposing the problem.  Once the problem is understood, we need to break our work into separate tasks, so each task can be run on a different processing element.  This process is called partitioning. Partitioning our tasks is a challenging feat.  There are opposing forces at work here: too many partitions adds overhead, too few partitions leaves processors idle.  Trying to work the perfect balance between the two extremes is the goal for which we should aim.  Luckily, the Task Parallel Library automatically handles much of this process.  However, there are situations where the default partitioning may not be appropriate, and knowledge of our routines may allow us to guide the framework to making better decisions. First off, I’d like to say that this is a more advanced topic.  It is perfectly acceptable to use the parallel constructs in the framework without considering the partitioning taking place.  The default behavior in the Task Parallel Library is very well-behaved, even for unusual work loads, and should rarely be adjusted.  I have found few situations where the default partitioning behavior in the TPL is not as good or better than my own hand-written partitioning routines, and recommend using the defaults unless there is a strong, measured, and profiled reason to avoid using them.  However, understanding partitioning, and how the TPL partitions your data, helps in understanding the proper usage of the TPL. I indirectly mentioned partitioning while discussing aggregation.  Typically, our systems will have a limited number of Processing Elements (PE), which is the terminology used for hardware capable of processing a stream of instructions.  For example, in a standard Intel i7 system, there are four processor cores, each of which has two potential hardware threads due to Hyperthreading.  This gives us a total of 8 PEs – theoretically, we can have up to eight operations occurring concurrently within our system. In order to fully exploit this power, we need to partition our work into Tasks.  A task is a simple set of instructions that can be run on a PE.  Ideally, we want to have at least one task per PE in the system, since fewer tasks means that some of our processing power will be sitting idle.  A naive implementation would be to just take our data, and partition it with one element in our collection being treated as one task.  When we loop through our collection in parallel, using this approach, we’d just process one item at a time, then reuse that thread to process the next, etc.  There’s a flaw in this approach, however.  It will tend to be slower than necessary, often slower than processing the data serially. The problem is that there is overhead associated with each task.  When we take a simple foreach loop body and implement it using the TPL, we add overhead.  First, we change the body from a simple statement to a delegate, which must be invoked.  In order to invoke the delegate on a separate thread, the delegate gets added to the ThreadPool’s current work queue, and the ThreadPool must pull this off the queue, assign it to a free thread, then execute it.  If our collection had one million elements, the overhead of trying to spawn one million tasks would destroy our performance. The answer, here, is to partition our collection into groups, and have each group of elements treated as a single task.  By adding a partitioning step, we can break our total work into small enough tasks to keep our processors busy, but large enough tasks to avoid overburdening the ThreadPool.  There are two clear, opposing goals here: Always try to keep each processor working, but also try to keep the individual partitions as large as possible. When using Parallel.For, the partitioning is always handled automatically.  At first, partitioning here seems simple.  A naive implementation would merely split the total element count up by the number of PEs in the system, and assign a chunk of data to each processor.  Many hand-written partitioning schemes work in this exactly manner.  This perfectly balanced, static partitioning scheme works very well if the amount of work is constant for each element.  However, this is rarely the case.  Often, the length of time required to process an element grows as we progress through the collection, especially if we’re doing numerical computations.  In this case, the first PEs will finish early, and sit idle waiting on the last chunks to finish.  Sometimes, work can decrease as we progress, since previous computations may be used to speed up later computations.  In this situation, the first chunks will be working far longer than the last chunks.  In order to balance the workload, many implementations create many small chunks, and reuse threads.  This adds overhead, but does provide better load balancing, which in turn improves performance. The Task Parallel Library handles this more elaborately.  Chunks are determined at runtime, and start small.  They grow slowly over time, getting larger and larger.  This tends to lead to a near optimum load balancing, even in odd cases such as increasing or decreasing workloads.  Parallel.ForEach is a bit more complicated, however. When working with a generic IEnumerable<T>, the number of items required for processing is not known in advance, and must be discovered at runtime.  In addition, since we don’t have direct access to each element, the scheduler must enumerate the collection to process it.  Since IEnumerable<T> is not thread safe, it must lock on elements as it enumerates, create temporary collections for each chunk to process, and schedule this out.  By default, it uses a partitioning method similar to the one described above.  We can see this directly by looking at the Visual Partitioning sample shipped by the Task Parallel Library team, and available as part of the Samples for Parallel Programming.  When we run the sample, with four cores and the default, Load Balancing partitioning scheme, we see this: The colored bands represent each processing core.  You can see that, when we started (at the top), we begin with very small bands of color.  As the routine progresses through the Parallel.ForEach, the chunks get larger and larger (seen by larger and larger stripes). Most of the time, this is fantastic behavior, and most likely will out perform any custom written partitioning.  However, if your routine is not scaling well, it may be due to a failure in the default partitioning to handle your specific case.  With prior knowledge about your work, it may be possible to partition data more meaningfully than the default Partitioner. There is the option to use an overload of Parallel.ForEach which takes a Partitioner<T> instance.  The Partitioner<T> class is an abstract class which allows for both static and dynamic partitioning.  By overriding Partitioner<T>.SupportsDynamicPartitions, you can specify whether a dynamic approach is available.  If not, your custom Partitioner<T> subclass would override GetPartitions(int), which returns a list of IEnumerator<T> instances.  These are then used by the Parallel class to split work up amongst processors.  When dynamic partitioning is available, GetDynamicPartitions() is used, which returns an IEnumerable<T> for each partition.  If you do decide to implement your own Partitioner<T>, keep in mind the goals and tradeoffs of different partitioning strategies, and design appropriately. The Samples for Parallel Programming project includes a ChunkPartitioner class in the ParallelExtensionsExtras project.  This provides example code for implementing your own, custom allocation strategies, including a static allocator of a given chunk size.  Although implementing your own Partitioner<T> is possible, as I mentioned above, this is rarely required or useful in practice.  The default behavior of the TPL is very good, often better than any hand written partitioning strategy.

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• Conversation as User Assistance

  - by ultan o'broin

  Applications User Experience members (Erika Web, Laurie Pattison, and I) attended the User Assistance Europe Conference in Stockholm, Sweden. We were impressed with the thought leadership and practical application of ideas in Anne Gentle's keynote address "Social Web Strategies for Documentation". After the conference, we spoke with Anne to explore the ideas further. Anne Gentle (left) with Applications User Experience Senior Director Laurie Pattison In Anne's book called Conversation and Community: The Social Web for Documentation, she explains how user assistance is undergoing a seismic shift. The direction is away from the old print manuals and online help concept towards a web-based, user community-driven solution using social media tools. User experience professionals now have a vast range of such tools to start and nurture this "conversation": blogs, wikis, forums, social networking sites, microblogging systems, image and video sharing sites, virtual worlds, podcasts, instant messaging, mashups, and so on. That user communities are a rich source of user assistance is not a surprise, but the extent of available assistance is. For example, we know from the Consortium for Service Innovation that there has been an 'explosion' of user-generated content on the web. User-initiated community conversations provide as much as 30 times the number of official help desk solutions for consortium members! The growing reliance on user community solutions is clearly a user experience issue. Anne says that user assistance as conversation "means getting closer to users and helping them perform well. User-centered design has been touted as one of the most important ideas developed in the last 20 years of workplace writing. Now writers can take the idea of user-centered design a step further by starting conversations with users and enabling user assistance in interactions." Some of Anne's favorite examples of this paradigm shift from the world of traditional documentation to community conversation include: Writer Bob Bringhurst's blog about Adobe InDesign and InCopy products and Adobe's community help The Microsoft Development Network Community Center ·The former Sun (now Oracle) OpenDS wiki, NetBeans Ruby and other community approaches to engage diverse audiences using screencasts, wikis, and blogs. Cisco's customer support wiki, EMC's community, as well as Symantec and Intuit's approaches The efforts of Ubuntu, Mozilla, and the FLOSS community generally Adobe Writer Bob Bringhurst's Blog Oracle is not without a user community conversation too. Besides the community discussions and blogs around documentation offerings, we have the My Oracle Support Community forums, Oracle Technology Network (OTN) communities, wiki, blogs, and so on. We have the great work done by our user groups and customer councils. Employees like David Haimes reach out, and enthusiastic non-employee gurus like Chet Justice (OracleNerd), Floyd Teter and Eddie Awad provide great "how-to" information too. But what does this paradigm shift mean for existing technical writers as users turn away from the traditional printable PDF manual deliverables? We asked Anne after the conference. The writer role becomes one of conversation initiator or enabler. The role evolves, along with the process, as the users define their concept of user assistance and terms of engagement with the product instead of having it pre-determined. It is largely a case now of "inventing the job while you're doing it, instead of being hired for it" Anne said. There is less emphasis on formal titles. Anne mentions that her own title "Content Stacker" at OpenStack; others use titles such as "Content Curator" or "Community Lead". However, the role remains one essentially about communications, "but of a new type--interacting with users, moderating, curating content, instead of sitting down to write a manual from start to finish." Clearly then, this role is open to more than professional technical writers. Product managers who write blogs, developers who moderate forums, support professionals who update wikis, rock star programmers with a penchant for YouTube are ideal. Anyone with the product knowledge, empathy for the user, and flair for relationships on the social web can join in. Some even perform these roles already but do not realize it. Anne feels the technical communicator space will move from hiring new community conversation professionals (who are already active in the space through blogging, tweets, wikis, and so on) to retraining some existing writers over time. Our own research reveals that the established proponents of community user assistance even set employee performance objectives for internal content curators about the amount of community content delivered by people outside the organization! To take advantage of the conversations on the web as user assistance, enterprises must first establish where on the spectrum their community lies. "What is the line between community willingness to contribute and the enterprise objectives?" Anne asked. "The relationship with users must be managed and also measured." Anne believes that the process can start with a "just do it" approach. Begin by reaching out to existing user groups, individual bloggers and tweeters, forum posters, early adopter program participants, conference attendees, customer advisory board members, and so on. Use analytical tools to measure the level of conversation about your products and services to show a return on investment (ROI), winning management support. Anne emphasized that success with the community model is dependent on lowering the technical and motivational barriers so that users can readily contribute to the conversation. Simple tools must be provided, and guidelines, if any, must be straightforward but not mandatory. The conversational approach is one where traditional style and branding guides do not necessarily apply. Tools and infrastructure help users to create content easily, to search and find the information online, read it, rate it, translate it, and participate further in the content's evolution. Recognizing contributors by using ratings on forums, giving out Twitter kudos, conference invitations, visits to headquarters, free products, preview releases, and so on, also encourages the adoption of the conversation model. The move to conversation as user assistance is not free, but there is a business ROI. The conversational model means that customer service is enhanced, as user experience moves from a functional to a valued, emotional level. Studies show a positive correlation between loyalty and financial performance (Consortium for Service Innovation, 2010), and as customer experience and loyalty become key differentiators, user experience professionals cannot explore the model's possibilities. The digital universe (measured at 1.2 million petabytes in 2010) is doubling every 12 to 18 months, and 70 percent of that universe consists of user-generated content (IDC, 2010). Conversation as user assistance cannot be ignored but must be embraced. It is a time to manage for abundance, not scarcity. Besides, the conversation approach certainly sounds more interesting, rewarding, and fun than the traditional model! I would like to thank Anne for her time and thoughts, and recommend that all user assistance professionals read her book. You can follow Anne on Twitter at: http://www.twitter.com/annegentle. Oracle's Acrolinx IQ deployment was used to author this article.

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• SQL SERVER – Developer Training Resources and Summary Roundup

  - by pinaldave

  It is always pleasure for any author when other renowned authors in the industry write about you. Earlier I wrote a five part blog series on Developer Training and I have received a phenomenal response to the series. I have received plenty of comments, questions and feedback. I thought it would be nice to sum up the whole series as well answer a few of the questions received. Quick Recap Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. There are companies that pay for 100% of the expenses and there are employees who opt for training on their own expense during their personal time. Training is often looked at as vacation by employee and employers and we need to change this mind-set. One of the ways is to report back the learning to your manager and implement newly learned knowledge in day-to-day work. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. The manager often feels pressure to accommodate every single employee for training even though his training budget is limited. It is indeed the responsibility of the developer to get maximum advantage from the training. Training immediately helps organizations but stays as a part of an employee’s knowledge forever. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. The common element between both the methods is “learning material”. Learning material can be of any format – videos, books, paper notes or just a plain black board. Instructor-led training is a very effective mode but not possible every single time. During the course of the developer’s career, one has to learn lots of new technology and it is almost impossible to have a quality trainer available on that subject at that time. Books are most effective and proven methods, however, it always helps if someone explains the concepts of the book with a demonstration. In recent times I have started to believe in online trainings which leads to a hybrid experience. Online trainings take the best part of the books and the best part of the instructor-led training and gives effective training in a matter of hours. Developer Training – A Conclusive Summary- Part 5 In this part, I shared what I was continuously thinking about developer training. There is no better teacher than oneself. There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. Once someone overcomes them, life is much easier. I believe that proper and appropriate high quality training can help to address the burning issues. Opinion of Friends I invited a few of my friends to express their opinion about developer training and here are their opinions. I am listing them here in the order of the blog post publishing date. Nakul Vachhrajani - Developer Trainings-Importance, Benefits, Tips and follow-up Nakul’s sums of many of the concepts which are complementary to my blog posts. Nakul addresses the burning question of developer training with different angles. I am personally very impressed by his following statement - “Being skilled does not mean having just a stack of certifications, but it also means having an understanding about the internals of the products that you are working on – and using that knowledge to improve the efficiency & productivity at the workplace in turn resulting in better products, better consulting abilities and a happier self.” Nakul also suggests the online training options of Pluralsight. Vinod Kumar - Training–a necessity or bonus Vinod Kumar comes up with excellent follow up on developer training. Vinod is known for his inspirational writing about SQL Server. Vinod starts with a story of a student who is extremely eager to learn the wisdom of life from a monk but the monk does not accept him as a disciple for a long time. The conversation between student and monk is indeed an essence of all learning. We all want to learn quickly and be successful but the most important thing in life is to have the right attitude towards learning and more so towards life. The blog post end with a very important thought about how to avoid the famous excuse – “I don’t have enough time.” Ritesh Shah - Training – useful or useless? Ritesh brings up very important concept related to training. Ritesh in his meticulous style explains why training is an important and lifelong process. Training must not stop at any age but should continue forever. The moment training stops, progress stops along with. Paras Doshi - Professional Development Resource Paras is known for his to–the-point writing, and has summarized the five part series very precisely. He read the five part series and created a digest summary of the blog post. If you are in a rush and have no time to read my five series – I suggest you read his blog post. Training Resources I am often asked what the best resources for learning new technology are. This is the most difficult question EVER. There are plenty of good training resources available. When it is about training our needs are different, our preference of learning is different and we all have an opinion. Additionally, we all are located in different geographic locations worldwide and there is no way one solution will fit all. However, let me list a few of the training resources which I have built so far and you can consume them if you find it relevant to your need. SQL Server Books SQL Server Interview Questions and Answers SQL Wait Stats SQL Programming Joes 2 Pros SQL Server Video Tutorials SQL Server Questions and Answers SQL Server Performance: Indexing Basics SQL Server Performance: Introduction to Query Tuning SQL in Sixty Seconds Series of Sixty Seconds Learning Video on YouTube Trust me worldwide web is very big and there are plenty of high quality learning materials available worldwide – trainer-led as well online. I suggest you explore various options and make the best choice for yourself. Remember, training is your personal journey and it should never stop. Are you ready? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Developer Training, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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