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• Constructing mocks in unit tests

  - by Flynn1179

  Is there any way to have a mock constructed instead of a real instance when testing code that calls a constructor? For example: public class ClassToTest { public void MethodToTest() { MyObject foo = new MyObject(); Console.WriteLine(foo.ToString()); } } In this example, I need to create a unit test that confirms that calling MethodToTest on an instance of ClassToTest will indeed output whatever the result of the ToString() method of a newly created instance of MyObject. I can't see a way of realistically testing the 'ClassToTest' class in isolation; testing this method would actually test the 'myObject.ToString()' method as well as the MethodToTest method.

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• Best and safest Java Profiler for production use?

  - by Pete

  I'm looking for a Java Profiler for use in a very high demand production environment, either commercial or free, that meets all of the following requirements: Lightweight integration with code (no recompile with special options, no code hooks, etc). Dropping some profiler specific .jars alongside the application code is ok. Should be able to connect/disconnect to the JVM without restarting the application. When profiling is not active, no impact to performance When profiling is active, negligible impact to performance. Very slight degradation is acceptable. Must do all the 'expected' stuff a profiler does - time spent in each method to find hotspots, object allocation/memory profiling, etc. Essentially I need something that can sit dormant in production when everything is fine without anyone knowing or caring that it is there, but then be able to connect to it hassle (and performance degradation) free to pinpoint the hard to find problems like hotspots and synchronization issues.

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• Is there a faster way to draw text?

  - by mystify

  Shark complains about a big performance hit with this line, which takes like 80% of CPU time. I have a counter that is updated very frequently and performance seriously sucks. It's an custom UILabel subclass with -drawRect: implemented. Every time the counter value changes, this is used to draw the new text: [self.text drawInRect:textRect withFont:correctedFont lineBreakMode:self.lineBreakMode alignment:self.textAlignment]; When I comment this line out, performance rocks. Its smooth and fast. So Shark isn't wrong about this. But what could I do to improve this? Maybe go a level deeper? Does that make any sense? Probably drawing text is really so incredible heavy...?

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• What's a good way to set up a development environment on OS X for ruby, rails, and git?

  - by Ein2015

  I'm going to start development on a web app using ruby, rails, probably either postgres or mysql, and most likely apache. I'll be using a git repository with the master repo on another server. I've searched through stackoverflow and done some Googling... so here's what I have so far... What are your opinions on what's described on this page?: http://robots.thoughtbot.com/post/159805668/2009-rubyists-guide-to-a-mac-os-x-development What about this one?: http://www.buildingwebapps.com/articles/79197-setting-up-rails-on-leopard-mac I don't need helping finding an editor, there's plenty out there (TextMate, TextWrangler, MacVim), but I do need help to make sure I'm setting things up correctly to code, build, and run the web app from my mac. Here's a specific set of scenarios I could use some help on: Testing various versions of rails and/or ruby. Testing performance, vulnerabilities, monitoring queries, etc. Testing different versions of gems. Working on other projects on this same machine.

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• Namespacing technique in JavaScript, recommended? performant? issues to be aware of?

  - by Bjartr

  In a project I am working on I am structuring my code as follows MyLib = { AField:0, ASubNamespace:{ AnotherField:"value", AClass:function(param) { this.classField = param; this.classFunction = function(){ // stuff } } }, AnotherClass:function(param) { this.classField = param; this.classFunction = function(){ // stuff } } } and so on like that to do stuff like: var anInstance = new MyLib.ASubNamespace.AClass("A parameter."); Is this the right way to go about achieving namespacing? Are there performance hits, and if so, how drastic? Do performance degradations stack as I nest deeper? Are there any other issues I should be aware of when using this structure? I care about every little bit of performance because it's a library for realtime graphics, so I'm taking any overhead very seriously.

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• Django Project Done and Working. Now What?

  - by Rodrogo

  Hi, I just finished what I would call a small django project and pretty soon it's going live. It's only 6 models but a fairly complex view layer and a lot of records saving and retrieving. Of course, forgetting the obvious huge amount of bugs that will, probably, fill my inbox to the top, what would it be the next step towards a website with best performance. What could be tweaked? I'm using jmeter a lot recently and feel confident that I have a good baseline for future performance comparisons, but the thing is: I'm not sure what is the best start, since I'm a greedy bastard that wants to work the least possible and gather the best results. For instance, should I try an approach towards infrastructure, like a distributed database, or should I go with the code itself and in that case, is there something that specifically results in better performance? In your experience, whats pays off more? Personal anecdotes are welcome, but some fact based opinions are even more. :) Thanks very much.

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• Why does SQL Server consider N'????' and N'???' to be equal?

  - by Aidan Ryan

  We are testing our application for Unicode compatibility and have been selecting random characters outside the Latin character set for testing. On both Latin and Japanese-collated systems the following equality is true (U+3422): N'????' = N'???' but the following is not (U+30C1): N'????' = N'???' This was discovered when a test case using the first example (using U+3422) violated a unique index. Do we need to be more selective about the characters we use for testing? Obviously we don't know the semantic meaning of the above comparisons. Would this behavior be obvious to a native speaker?

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• More than 100,000 articles !

  - by developerit

  In one month, we already got more than 100,000, and we continue to crawl! We plan on hitting 250,000 total articles next month. Due to the large amount of data we are gathering, we are planning on updating our SQL stored procedure to improve performance. We may be migrating to SQL Server 2008 Entreprise, as we are currently running on SQL Server 2005 Express Edition… We are at 400 Mb of data, getting more and more close to the 2 Gb limit. Stay tune for more info and browse daily fresh articles about web development.

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• SQL SERVER – Retrieve and Explore Database Backup without Restoring Database – Idera virtual databas

  - by pinaldave

  I recently downloaded Idera’s SQL virtual database, and tested it. There are a few things about this tool which caught my attention. My Scenario It is quite common in real life that sometimes observing or retrieving older data is necessary; however, it had changed as time passed by. The full database backup was 40 GB in size, and, to restore it on our production server, it usually takes around 16 to 22 minutes, depending on the load server that is usually present. This range in time varies from one server to another as per the configuration of the computer. Some other issues we used to have are the following: When we try to restore a large 40-GB database, we needed at least that much space on our production server. Once in a while, we even had to make changes in the restored database, and use the said changed and restored database for our purpose, making it more time-consuming. My Solution I have heard a lot about the Idera’s SQL virtual database tool.. Well, right after we started to test this tool, we found out that it really delivers what it promises. Using this software was very easy and we were able to restore our database from backup in less than 2 minutes, sparing us from the usual longer time of 16–22 minutes. The needful was finished in a total of 10 minutes. Another interesting observation is that there is no need to have an additional space for restoring the database. For complete database restoration, the single additional MB on the drive is not required anymore. We can use the database in the same way as our regular database, and there is no need for any additional configuration and setup. Let us look at the most relevant points of this product based on my initial experience: Quick restoration of the database backup No additional space required for database restoration virtual database has no physical .MDF or .LDF The database which is restored is, in fact, the backup file converted in the virtual database. DDL and DML queries can be executed against this virtually restored database. Regular backup operation can be implemented against virtual database, creating a physical .bak file that can be used for future use. There was no observed degradation in performance on the original database as well the restored virtual database. Additional T-SQL queries can be let off on the virtual database. Well, this summarizes my quick review. And, as I was saying, I am very impressed with the product and I plan to explore it more. There are many features that I have noticed in this tool, which I think can be very useful if properly understood. I had taken a few screenshots using my demo database afterwards. Let us see what other things this tool can do besides the mentioned activities. I am surprised with its performance so I want to know how exactly this feature works, specifically in the matter of why it does not create any additional files and yet, it still allows update on the virtually restored database. I guess I will have to send an e-mail to the developers of Idera and try to figure this out from them. I think this tool is very useful, and it delivers a high level of performance way more than what I expected. Soon, I will write a review for additional uses of SQL virtual database.. If you are using SQL virtual database in your production environment, I am eager to learn more about it and your experience while using it. The ‘Virtual’ Part of virtual database When I set out to test this software, I thought virtual database had something to do with Hyper-V or visualization. In fact, the virtual database is a kind of database which shows up in your SQL Server Management Studio without actually restoring or even creating it. This tool creates a database in SSMS from the backup of the same database. The backup, however, works virtually the same way as original database. Potential Usage of virtual database: As soon as I described this tool to my teammate, I think his very first reaction was, “hey, if we have this then there is no need for log shipping.” I find his comment very interesting as log shipping is something where logs are moved to another server. In fact, there are no updates on the database from log; I would rather compare it with Snapshot Replication. In fact, whatever we use, snapshot replicated database can be similarly used and configured with virtual database. I totally believe that we can use it for reporting purpose. In fact, after this database was configured, I think the uses of this tool are unlimited. I will have to spend some more time studying it and will get back to you. Click on images to see larger images. virtual database Console Harddrive Space before virtual database Setup Attach Full Backup Screen Backup on Harddrive Attach Full Backup Screen with Settings virtual database Setup – less than 60 sec virtual database Setup – Online Harddrive Space after virtual database Setup Point in Time Recovery Option – Timeline View virtual database Summary No Performance Difference between Regular DB vs Virtual DB Please note that all SQL Server MVP gets free license of this software. Reference: Pinal Dave (http://blog.SQLAuthority.com), Idera (virtual database) Filed under: Database, Pinal Dave, SQL, SQL Add-On, SQL Authority, SQL Backup and Restore, SQL Data Storage, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, SQLAuthority News, T SQL, Technology Tagged: Idera

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• How to fix Monogame WP8 Touch Position bug?

  - by Moses Aprico

  Normally below code will result in X:Infinity, Y:Infinity TouchCollection touchState = TouchPanel.GetState(); foreach (TouchLocation t in touchState) { if (t.State == TouchLocationState.Pressed) { vb.ButtonTouched((int)t.Position.X, (int)t.Position.Y); } } Then, I followed this https://github.com/mono/MonoGame/issues/1046 and added below code at the first line in update method. (I still don't know how it's worked, but it fixed the problem) if (_firstUpdate) { typeof(Microsoft.Xna.Framework.Input.Touch.TouchPanel).GetField("_touchScale",System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static).SetValue(null, Vector2.One); _firstUpdate = false; } And then, when I randomly testing something, there are several area that won't read the user touch. The tile with the purple dude is the area which won't receive user input (It don't even detect "Pressed", the TouchCollection.Count = 0) Any idea how to fix this? UPDATE 1 : The second attempt in recompiling The difference is weird. Dunno why the consistent clickable area is just 2/3 area to the left UPDATE 2 : After trying to rotate to landscape and back to portrait to randomly testing, then the outcome become :

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• Managing Database Clusters - A Whole Lot Simpler

  - by mat.keep(at)oracle.com

  Clustered computing brings with it many benefits: high performance, high availability, scalable infrastructure, etc.  But it also brings with it more complexity.Why ?  Well, by its very nature, there are more "moving parts" to monitor and manage (from physical, virtual and logical hosts) to fault detection and failover software to redundant networking components - the list goes on.  And a cluster that isn't effectively provisioned and managed will cause more downtime than the standalone systems it is designed to improve upon.  Not so great....When it comes to the database industry, analysts already estimate that 50% of a typical database's Total Cost of Ownership is attributable to staffing and downtime costs.  These costs will only increase if a database cluster is to hard to properly administer.Over the past 9 months, monitoring and management has been a major focus in the development of the MySQL Cluster database, and on Tuesday 12th January, the product team will be presenting the output of that development in a new webinar.Even if you can't make the date, it is still worth registering so you will receive automatic notification when the on-demand replay is availableIn the webinar, the team will cover:    * NDBINFO: released with MySQL Cluster 7.1, NDBINFO presents real-time status and usage statistics, providing developers and DBAs with a simple means of pro-actively monitoring and optimizing database performance and availability.    * MySQL Cluster Manager (MCM): available as part of the commercial MySQL Cluster Carrier Grade Edition, MCM simplifies the creation and management of MySQL Cluster by automating common management tasks, delivering higher administration productivity and enhancing cluster agility. Tasks that used to take 46 commands can be reduced to just one!    * MySQL Cluster Advisors & Graphs: part of the MySQL Enterprise Monitor and available in the commercial MySQL Cluster Carrier Grade Edition, the Enterprise Advisor includes automated best practice rules that alert on key performance and availability metrics from MySQL Cluster data nodes.You'll also learn how you can get started evaluating and using all of these tools to simplify MySQL Cluster management.This session will last round an hour and will include interactive Q&A throughout. You can learn more about MySQL Cluster Manager from this whitepaper and on-line demonstration.  You can also download the packages from eDelivery (just select "MySQL Database" as the product pack, select your platform, click "Go" and then scroll down to get the software).While managing clusters will never be easy, the webinar will show hou how it just got a whole lot simpler !

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• EBS + 11g Database Upgrade Best Practices Whitepaper Available

  - by Steven Chan

  I returned from OAUG/Collaborate with a cold and multiple overlapping development crises.  Fun.  Now that those are (mostly) out of the way, it's time to get back to clearing out my article backlog.  Premier Support for the 10gR2 database ends in July 2010.  If you haven't already started planning your 11g database upgrade, we recommend that you start soon.  We have certified both the 11gR1 (11.1.0.7) and 11gR2 (11.2.0.1) databases with Oracle E-Business Suite; see this blog's Certification summary to links to articles with the details.Our Applications Performance Group has reminded me that they have a whitepaper loaded with practical tips intended to make your 11g database upgrade easier.  No vacuous marketing rhetoric here -- this is strictly written for DBAs.  A must-read if you haven't already upgraded to either 11gR1 or 11gR2, and highly recommended even if you have.  You can download this whitepaper here:Upgrade to 11g Performance Best Practices (PDF, 184K)

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• Slides of my HOL on MySQL Cluster

  - by user13819847

  Hi!Thanks everyone who attended my hands-on lab on MySQL Cluster at MySQL Connect last Saturday.The following are the links for the slides, the HOL instructions, and the code examples.I'll try to summarize my HOL below.Aim of the HOL was to help attendees to familiarize with MySQL Cluster. In particular, by learning: the basics of MySQL Cluster Architecture the basics of MySQL Cluster Configuration and Administration how to start a new Cluster for evaluation purposes and how to connect to it We started by introducing MySQL Cluster. MySQL Cluster is a proven technology that today is successfully servicing the most performance-intensive workloads. MySQL Cluster is deployed across telecom networks and is powering mission-critical web applications. Without trading off use of commodity hardware, transactional consistency and use of complex queries, MySQL Cluster provides: Web Scalability (web-scale performance on both reads and writes) Carrier Grade Availability (99.999%) Developer Agility (freedom to use SQL or NoSQL access methods) MySQL Cluster implements: an Auto-Sharding, Multi-Master, Shared-nothing Architecture, where independent nodes can scale horizontally on commodity hardware with no shared disks, no shared memory, no single point of failure In the architecture of MySQL Cluster it is possible to find three types of nodes: management nodes: responsible for reading the configuration files, maintaining logs, and providing an interface to the administration of the entire cluster data nodes: where data and indexes are stored api nodes: provide the external connectivity (e.g. the NDB engine of the MySQL Server, APIs, Connectors) MySQL Cluster is recommended in the situations where: it is crucial to reduce service downtime, because this produces a heavy impact on business sharding the database to scale write performance higly impacts development of application (in MySQL Cluster the sharding is automatic and transparent to the application) there are real time needs there are unpredictable scalability demands it is important to have data-access flexibility (SQL & NoSQL) MySQL Cluster is available in two Editions: Community Edition (Open Source, freely downloadable from mysql.com) Carrier Grade Edition (Commercial Edition, can be downloaded from eDelivery for evaluation purposes) MySQL Carrier Grade Edition adds on the top of the Community Edition: Commercial Extensions (MySQL Cluster Manager, MySQL Enterprise Monitor, MySQL Cluster Installer) Oracle's Premium Support Services (largest team of MySQL experts backed by MySQL developers, forward compatible hot fixes, multi-language support, and more) We concluded talking about the MySQL Cluster vision: MySQL Cluster is the default database for anyone deploying rapidly evolving, realtime transactional services at web-scale, where downtime is simply not an option. From a practical point of view the HOL's steps were: MySQL Cluster installation start & monitoring of the MySQL Cluster processes client connection to the Management Server and to an SQL Node connection using the NoSQL NDB API and the Connector J In the hope that this blog post can help you get started with MySQL Cluster, I take the opportunity to thank you for the questions you made both during the HOL and at the MySQL Cluster booth. Slides are also on SlideShares: Santo Leto - MySQL Connect 2012 - Getting Started with Mysql Cluster Happy Clustering!

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• Hekaton – SQL Server’s in-memory database engine

  - by Christian

  Microsoft have just gone public at the PASS Summit in Seattle about a new SQL Server engine that they’re working on which is optimized for high-memory servers – an in-memory OLTP database engine which is built-in to SQL Server rather than a separate entity.  This means that you can move just the performance critical parts of your database to Hekaton. The new engine really pushes the performance boundaries by eliminating as many instructions as possible: Main memory optimized tables which are decoupled from on-disk structures; Everything is lock and latch free; More work is pushed to compile time so your T-SQL code is compiled natively into low-level code. We’re already working with a customer on an early adoption program so expect to hear from us on what we learn about implementing it!   Christian Bolton - MCA, MCM, MVP Technical Director http://coeo.com - SQL Server Consulting & Managed Services

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• Data Masking Pack 12.1.0.3 Certified with E-Business Suite 12.1.3

  - by Elke Phelps (Oracle Development)

  I'm pleased to announce the certification of the E-Business Suite 12.1.3 Data Masking Template for the Data Masking Pack with Enterprise Manager Cloud Control 12.1.0.3. You can use the Oracle Data Masking Pack with Oracle Enterprise Manager Grid Control 12c to scramble sensitive data in cloned E-Business Suite environments.     You may scramble data in E-Business Suite cloned environments with EM12.1.0.3 using the following template: E-Business Suite 12.1.3 Data Masking Template for Data Masking Pack with EM12c (Patch 18462641) What does data masking do in E-Business Suite environments? Application data masking does the following: De-identify the data:  Scramble identifiers of individuals, also known as personally identifiable information or PII.  Examples include information such as name, account, address, location, and driver's license number. Mask sensitive data:  Mask data that, if associated with personally identifiable information (PII), would cause privacy concerns.  Examples include compensation, health and employment information.   Maintain data validity:  Provide a fully functional application.  How can EBS customers use data masking? The Oracle E-Business Suite Template for Data Masking Pack can be used in situations where confidential or regulated data needs to be shared with other non-production users who need access to some of the original data, but not necessarily every table.  Examples of non-production users include internal application developers or external business partners such as offshore testing companies, suppliers or customers.  Due to data dependencies, scrambling E-Business Suite data is not a trivial task.  The data needs to be scrubbed in such a way that allows the application to continue to function. The template works with the Oracle Data Masking Pack and Oracle Enterprise Manager to obscure sensitive E-Business Suite information that is copied from production to non-production environments.  The Oracle E-Business Suite Template for Data Masking Pack is applied to a non-production environment with the Enterprise Manager Grid Control Data Masking Pack.  When applied, the Oracle E-Business Suite Template for Data Masking Pack will create an irreversibly scrambled version of your production database for development and testing. Is there a charge for this? Yes. You must purchase licenses for the Oracle Data Masking Pack to use the Oracle E-Business Suite 12.1.3 template. The Oracle E-Business Suite 12.1.3 Template for the Data Masking Pack is included with the Oracle Data Masking Pack license.  You can contact your Oracle account manager for more details about licensing. References Additional details and requirements are provided in the following My Oracle Support Note: Using Oracle E-Business Suite Release 12.1.3 Template for the Data Masking Pack with Oracle Enterprise Manager 12.1 Data Masking Tool (Note 1481916.1) Masking Sensitive Data in the Oracle Database Real Application Testing User's Guide 11g Release 2 (11.2) Related Articles Scrambling Sensitive Data in E-Business Suite E-Business Suite 12.1.3 Data Masking Certified with Enterprise Manager 12c

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• DynaTrace Beefs Up Support for Microsoft Applications

  The application performance management vendor ups support for platforms such as SharePoint Server, Dynamics CRM, and Visual Studio 2010.

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• DynaTrace Beefs Up Support for Microsoft Applications

  The application performance management vendor ups support for platforms such as SharePoint Server, Dynamics CRM, and Visual Studio 2010.

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• DynaTrace Beefs Up Support for Microsoft Applications

  The application performance management vendor ups support for platforms such as SharePoint Server, Dynamics CRM, and Visual Studio 2010.

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• DynaTrace Beefs Up Support for Microsoft Applications

  The application performance management vendor ups support for platforms such as SharePoint Server, Dynamics CRM, and Visual Studio 2010.

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• What’s new in IIS8, Perf, Indexing Service-Week 49

  - by OWScott

  You can find this week’s video here. After some delays in the publishing process week 49 is finally live.  This week I'm taking Q&A from viewers, starting with what's new in IIS8, a question on enable32BitAppOnWin64, performance settings for asp.net, the ARR Helper, and Indexing Services. Starting this week for the remaining four weeks of the 52 week series I'll be taking questions and answers from the viewers. Already a number of questions have come in. This week we look at five topics. Pre-topic: We take a look at the new features in IIS8. Last week Internet Information Services (IIS) 8 Beta was released to the public. This week's video touches on the upcoming features in the next version of IIS. Here’s a link to the blog post which was mentioned in the video Question 1: In a number of places (http://learn.iis.net/page.aspx/201/32-bit-mode-worker-processes/, http://channel9.msdn.com/Events/MIX/MIX08/T06), I've saw that enable32BitAppOnWin64 is recommended for performance reasons. I'm guessing it has to do with memory usage... but I never could find detailed explanation on why this is recommended (even Microsoft books are vague on this topic - they just say - do it, but provide no reason why it should be done). Do you have any insight into this? (Predrag Tomasevic) Question 2: Do you have any recommendations on modifying aspnet.config and machine.config to deliver better performance when it comes to "high number of concurrent connections"? I've implemented recommendations for modifying machine.config from this article (http://www.codeproject.com/KB/aspnet/10ASPNetPerformance.aspx - ASP.NET Process Configuration Optimization section)... but I would gladly listen to more recommendations if you have them. (Predrag Tomasevic) Question 3: Could you share more of your experience with ARR Helper? I'm specifically interested in configuring ARR Helper (for example - how to only accept only X-Forwards-For from certain IPs (proxies you trust)). (Predrag Tomasevic) Question 4: What is the replacement for indexing service to use in coding web search pages on a Windows 2008R2 server? (Susan Williams) Here’s the link that was mentioned: http://technet.microsoft.com/en-us/library/ee692804.aspx This is now week 49 of a 52 week series for the web pro. You can view past and future weeks here: http://dotnetslackers.com/projects/LearnIIS7/ You can find this week’s video here.

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• SQL SERVER – Guest Posts – Feodor Georgiev – The Context of Our Database Environment – Going Beyond the Internal SQL Server Waits – Wait Type – Day 21 of 28

  - by pinaldave

  This guest post is submitted by Feodor. Feodor Georgiev is a SQL Server database specialist with extensive experience of thinking both within and outside the box. He has wide experience of different systems and solutions in the fields of architecture, scalability, performance, etc. Feodor has experience with SQL Server 2000 and later versions, and is certified in SQL Server 2008. In this article Feodor explains the server-client-server process, and concentrated on the mutual waits between client and SQL Server. This is essential in grasping the concept of waits in a ‘global’ application plan. Recently I was asked to write a blog post about the wait statistics in SQL Server and since I had been thinking about writing it for quite some time now, here it is. It is a wide-spread idea that the wait statistics in SQL Server will tell you everything about your performance. Well, almost. Or should I say – barely. The reason for this is that SQL Server is always a part of a bigger system – there are always other players in the game: whether it is a client application, web service, any other kind of data import/export process and so on. In short, the SQL Server surroundings look like this: This means that SQL Server, aside from its internal waits, also depends on external waits and settings. As we can see in the picture above, SQL Server needs to have an interface in order to communicate with the surrounding clients over the network. For this communication, SQL Server uses protocol interfaces. I will not go into detail about which protocols are best, but you can read this article. Also, review the information about the TDS (Tabular data stream). As we all know, our system is only as fast as its slowest component. This means that when we look at our environment as a whole, the SQL Server might be a victim of external pressure, no matter how well we have tuned our database server performance. Let’s dive into an example: let’s say that we have a web server, hosting a web application which is using data from our SQL Server, hosted on another server. The network card of the web server for some reason is malfunctioning (think of a hardware failure, driver failure, or just improper setup) and does not send/receive data faster than 10Mbs. On the other end, our SQL Server will not be able to send/receive data at a faster rate either. This means that the application users will notify the support team and will say: “My data is coming very slow.” Now, let’s move on to a bit more exciting example: imagine that there is a similar setup as the example above – one web server and one database server, and the application is not using any stored procedure calls, but instead for every user request the application is sending 80kb query over the network to the SQL Server. (I really thought this does not happen in real life until I saw it one day.) So, what happens in this case? To make things worse, let’s say that the 80kb query text is submitted from the application to the SQL Server at least 100 times per minute, and as often as 300 times per minute in peak times. Here is what happens: in order for this query to reach the SQL Server, it will have to be broken into a of number network packets (according to the packet size settings) – and will travel over the network. On the other side, our SQL Server network card will receive the packets, will pass them to our network layer, the packets will get assembled, and eventually SQL Server will start processing the query – parsing, allegorizing, generating the query execution plan and so on. So far, we have already had a serious network overhead by waiting for the packets to reach our Database Engine. There will certainly be some processing overhead – until the database engine deals with the 80kb query and its 20 subqueries. The waits you see in the DMVs are actually collected from the point the query reaches the SQL Server and the packets are assembled. Let’s say that our query is processed and it finally returns 15000 rows. These rows have a certain size as well, depending on the data types returned. This means that the data will have converted to packages (depending on the network size package settings) and will have to reach the application server. There will also be waits, however, this time you will be able to see a wait type in the DMVs called ASYNC_NETWORK_IO. What this wait type indicates is that the client is not consuming the data fast enough and the network buffers are filling up. Recently Pinal Dave posted a blog on Client Statistics. What Client Statistics does is captures the physical flow characteristics of the query between the client(Management Studio, in this case) and the server and back to the client. As you see in the image, there are three categories: Query Profile Statistics, Network Statistics and Time Statistics. Number of server roundtrips–a roundtrip consists of a request sent to the server and a reply from the server to the client. For example, if your query has three select statements, and they are separated by ‘GO’ command, then there will be three different roundtrips. TDS Packets sent from the client – TDS (tabular data stream) is the language which SQL Server speaks, and in order for applications to communicate with SQL Server, they need to pack the requests in TDS packets. TDS Packets sent from the client is the number of packets sent from the client; in case the request is large, then it may need more buffers, and eventually might even need more server roundtrips. TDS packets received from server –is the TDS packets sent by the server to the client during the query execution. Bytes sent from client – is the volume of the data set to our SQL Server, measured in bytes; i.e. how big of a query we have sent to the SQL Server. This is why it is best to use stored procedures, since the reusable code (which already exists as an object in the SQL Server) will only be called as a name of procedure + parameters, and this will minimize the network pressure. Bytes received from server – is the amount of data the SQL Server has sent to the client, measured in bytes. Depending on the number of rows and the datatypes involved, this number will vary. But still, think about the network load when you request data from SQL Server. Client processing time – is the amount of time spent in milliseconds between the first received response packet and the last received response packet by the client. Wait time on server replies – is the time in milliseconds between the last request packet which left the client and the first response packet which came back from the server to the client. Total execution time – is the sum of client processing time and wait time on server replies (the SQL Server internal processing time) Here is an illustration of the Client-server communication model which should help you understand the mutual waits in a client-server environment. Keep in mind that a query with a large ‘wait time on server replies’ means the server took a long time to produce the very first row. This is usual on queries that have operators that need the entire sub-query to evaluate before they proceed (for example, sort and top operators). However, a query with a very short ‘wait time on server replies’ means that the query was able to return the first row fast. However a long ‘client processing time’ does not necessarily imply the client spent a lot of time processing and the server was blocked waiting on the client. It can simply mean that the server continued to return rows from the result and this is how long it took until the very last row was returned. The bottom line is that developers and DBAs should work together and think carefully of the resource utilization in the client-server environment. From experience I can say that so far I have seen only cases when the application developers and the Database developers are on their own and do not ask questions about the other party’s world. I would recommend using the Client Statistics tool during new development to track the performance of the queries, and also to find a synchronous way of utilizing resources between the client – server – client. Here is another example: think about similar setup as above, but add another server to the game. Let’s say that we keep our media on a separate server, and together with the data from our SQL Server we need to display some images on the webpage requested by our user. No matter how simple or complicated the logic to get the images is, if the images are 500kb each our users will get the page slowly and they will still think that there is something wrong with our data. Anyway, I don’t mean to get carried away too far from SQL Server. Instead, what I would like to say is that DBAs should also be aware of ‘the big picture’. I wrote a blog post a while back on this topic, and if you are interested, you can read it here about the big picture. And finally, here are some guidelines for monitoring the network performance and improving it: Run a trace and outline all queries that return more than 1000 rows (in Profiler you can actually filter and sort the captured trace by number of returned rows). This is not a set number; it is more of a guideline. The general thought is that no application user can consume that many rows at once. Ask yourself and your fellow-developers: ‘why?’. Monitor your network counters in Perfmon: Network Interface:Output queue length, Redirector:Network errors/sec, TCPv4: Segments retransmitted/sec and so on. Make sure to establish a good friendship with your network administrator (buy them coffee, for example J ) and get into a conversation about the network settings. Have them explain to you how the network cards are setup – are they standalone, are they ‘teamed’, what are the settings – full duplex and so on. Find some time to read a bit about networking. In this short blog post I hope I have turned your attention to ‘the big picture’ and the fact that there are other factors affecting our SQL Server, aside from its internal workings. As a further reading I would still highly recommend the Wait Stats series on this blog, also I would recommend you have the coffee break conversation with your network admin as soon as possible. This guest post is written by Feodor Georgiev. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL

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• Helping Storage Keep Up With Server Virtualization

  If you virtualize your server environment without taking storage into consideration, your performance will likely suffer.

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• HTG Explains: Why You Shouldn’t Use a Task Killer On Android

  - by Chris Hoffman

  Some people think that task killers are important on Android. By closing apps running in the background, you’ll get improved performance and battery life – that’s the idea, anyway. In reality, task killers can reduce your performance and battery life. Task killers can force apps running in the background to quit, removing them from memory. Some task killers do this automatically. However, Android can intelligently manage processes on its own – it doesn’t need a task killer. How Hackers Can Disguise Malicious Programs With Fake File Extensions Can Dust Actually Damage My Computer? What To Do If You Get a Virus on Your Computer

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• BizTalk host throttling &ndash; Singleton pattern and High database size

  - by S.E.R.

  Originally posted on: http://geekswithblogs.net/SERivas/archive/2013/06/30/biztalk-host-throttling-ndash-singleton-pattern-and-high-database-size.aspxI have worked for some days around the singleton pattern (for those unfamiliar with it, read this post by Victor Fehlberg) and have come across a few very interesting posts, among which one dealt with performance issues (here, also by Victor Fehlberg). Simply put: if you have an orchestration which implements the singleton pattern, then performances will continuously decrease as the orchestration receives and consumes messages, and that behavior is more obvious when the orchestration never ends (ie : it keeps looping and never terminates or completes). As I experienced the same kind of problem (actually I was alerted by SCOM, which told me that the host was being throttled because of High database size), I thought it would be a good idea to dig a little bit a see what happens deep inside BizTalk and thus understand the reasons for this behavior. NOTE: in this article, I will focus on this High database size throttling condition. I will try and work on the other conditions in some not too distant future… Test conditions The singleton orchestration For the purpose of this study, I have created the following orchestration, which is a very basic implementation of a singleton that piles up incoming messages, then does something else when a certain timeout has been reached without receiving another message: Throttling settings I have two distinct hosts : one that hosts the receive port (basic FILE port) : Ports_ReceiveHostone that hosts the orchestration : ProcessingHost In order to emphasize the throttling mechanism, I have modified the throttling settings for each of these hosts are as follows (all other parameters are set to the default value): [Throttling thresholds] Message count in database: 500 (default value : 50000) Evolution of performance counters when submitting messages Since we are investigating the High database size throttling condition, here are the performance counter that we should take a look at (all of them are in the BizTalk:Message Agent performance object): Database sizeHigh database sizeMessage delivery throttling stateMessage publishing throttling stateMessage delivery delay (ms)Message publishing delay (ms)Message delivery throttling state durationMessage publishing throttling state duration (If you are not used to Perfmon, I strongly recommend that you start using it right now: it is a wonderful tool that allows you to open the hood and see what is going on inside BizTalk – and other systems) Database size It is quite obvious that we will start by watching the database size and high database size counters, just to see when the first reaches the configured threshold (500) and when the second rings the alarm. NOTE : During this test I submitted 600 messages, one message at a time every 10ms to see the evolution of the counters we have previously selected. It might not show very well on this screenshot, but here is what happened: From 15:46:50 to 15:47:50, the database size for the Ports_ReceiveHost host (blue line) kept growing until it reached a maximum of 504.At 15:47:50, the high database size alert fires At first I was surprised by this result: why is it the database size of the receiving host that keeps growing since it is the processing host that piles up messages? Actually, it makes total sense. This counter measures the size of the database queue that is being filled by the host, not consumed. Therefore, the high database size alert is raised on the host that fills the queue: Ports_ReceiveHost. More information is available on the Public MPWiki page. Now, looking at the Message publishing throttling state for the receiving host (green line), we can see that a throttling condition has been reached at 15:47:50: We can also see that the Message publishing delay(ms) (blue line) has begun growing slowly from this point. All of this explains why performances keep decreasing when a singleton keeps processing new messages: the database size grows and when it has exceeded the Message count in database threshold, the host is throttled and the publishing delay keeps increasing. Digging further So, what happens to the database queue then? Is it flushed some day or does it keep growing and growing indefinitely? The real question being: will the host be throttled forever because of this singleton? To answer this question, I set the Message count in database threshold to 20 (this value is very low in order not to wait for too long, otherwise I certainly would have fallen asleep in front of my screen) and I submitted 30 messages. The test was started at 18:26. At 18:56 (ie : exactly 30min later) the throttling was stopped and the database size was divided by 2. 30 min later again, the database size had dropped to almost zero: I guess I’ll have to find some documentation and do some more testing before I sort this out! My guess is that some maintenance job is at work here, though I cannot tell which one Digging even further If we take a look at the Message delivery throttling state counter for the processing host, we can see that this host was also throttled during the submission of the 600 documents: The value for the counter was 1, meaning that Message delivery incoming rate for the host instance exceeds the Message delivery outgoing rate * the specified Rate overdrive factor (percent) value. We will see this another day… :) A last word Let’s end this article with a warning: DO NOT CHANGE THE THROTTLING SETTINGS LIGHTLY! The temptation can be great to just bypass throttling by setting very high values for each parameter (or zero in some cases, which simply disables throttling). Nevertheless, always keep in mind that this mechanism is here for a very good reason: prevent your BizTalk infrastructure from exploding!! So whatever you do with those settings, do a lot of testing and benchmarking!

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• Information Indepth Newsletter - Linux Edition

  - by Paulo Folgado

  INFORMATION INDEPTH NEWSLETTERLinux Edition February 2011 Stay Connected:  NEWS Now Available: Oracle Linux 6 Get the latest release of Oracle Linux 6, which includes Unbreakable Enterprise Kernel.Download Oracle Linux 6 Read More Customers Succeed by Using Oracle Exadata with Oracle Linux Watch IT executives from Bank of America, Linkshare, and Johns Hopkins as they talk about the business challenges they faced and why they chose to use Oracle Linux along with Oracle Exadata as the solution. Watch Now Video Interview: Oracle Senior Vice President Wim Coekaerts Watch Wim Coekaerts, senior vice president, Linux and Virtualization Engineering, as he talks about use cases for Oracle VM Templates as well as the Unbreakable Enterprise Kernel for Linux.Watch Now Hot Off the Press: Migrate Your IBM AIX Environment to Oracle Linux This new white paper provides recommendations for planning and implementing the migration of applications from an IBM Power System running AIX to Oracle's Sun Fire X4800 Server with Intel Xeon 7560 Processor running Oracle Linux 5.5.Read More  Back to Top BLOGOSPHERE Just Launched: The Oracle Linux Blog Follow our new Oracle Linux blog  to hear the latest updates, product news, upcoming events, and all the latest happenings, directly from the Linux team at Oracle. Back to Top TECH DIVE NEW: Linux/Oracle Solaris CommandComparo Site from Oracle Technology NetworkThis site gives equivalent command syntax in Oracle Solaris 10 and Oracle Enterprise Linux 5 for common administrative tasks--focusing particularly on tasks that have tricky syntax or that you frequently need to double check. It acts as a quick reference for administrators who operate in these two OS environments. Free Download: Oracle Linux Release 5.6Did you know that by using Oracle Linux 5.5 or 5.6 along with the Unbreakable Enterprise Kernel, you can get all the benefits of Linux mainline kernel 2.6.32 and more, right now, without the need to reinstall or migrate to a new operating system such as RHEL6?Read Release NotesDownload Oracle Linux 5.6 LSB 4.0 Certification Completed for Oracle Linux 5.5Oracle Linux 5.5 with Unbreakable Enterprise Kernel successfully completed the LSB 4.0 certification.  Back to Top WEBCASTS Boost Your Linux Performance with Oracle's Enhancements in Infiniband and RDSRegister to hear Director of Kernel Engineering Chris Mason cover scalability and performance improvements in Linux environment. Get the Facts Oracle's Unbreakable Enterprise KernelSVP Wim Coekaerts and Senior Director Monica Kumar cover the facts about and benefits of using Unbreakable Enterprise Kernel.  View Other Webcasts on Demand   Back to Top EVENTS Collaborate 2011April 10-14 Orlando, Florida Cloud Summit Events, WorldwideVarious dates (check the city for date/time of event) Datacenter Efficiency Events WorldwideThese events include Linux and Oracle VM sessions.Various dates (check the city for date/time of event) Virtualization Events in North America Find an Oracle Event  Back to Top EDUCATION Get Oracle Linux Certified from Oracle University Oracle University offers courses in both Oracle Linux and the administration of Oracle Database on Linux.  Back to Top CUSTOMER SPOTLIGHT Pella Corporation Improves IT Performance and Efficiency with Oracle Linux and Oracle VM To improve IT performance and efficiency and lower operational costs, Pella Corporation, has standardized on Oracle VM and Oracle Linux. Read More Disney Store Deploys POS in 330 Stores and 7 Countries on Oracle Linux Disney Store is running 1,500 registers worldwide on a broad Oracle technology software stack including Oracle Database 11g, Oracle Fusion Middleware, and Oracle Linux. Read More Back to Top PARTNER SPOTLIGHT Emulex and Oracle Announce Data Integrity Features The Unbreakable Enterprise Kernel provides data integrity checking between Oracle Database applications and Emulex 8Gb/s LightPulse Fibre Channel Host Bus Adapters. Read More Dell Inc. Dell Inc. tested and validated configurations support Oracle Linux. Back to Top STAY IN TOUCH Follow @ORCL_Linux on Twitter for the latest penguin tweets Bookmark Oracle.com/Linux Read the Oracle Linux blog Back to Top  Oracle Information InDepth newsletters bring targeted news, articles, customer stories, and special offers to business people who want to find out how to streamline enterprise information management, measure results, improve business processes, and communicate a single truth to their constituents. Please send questions or comments to [email protected]. For answers to questions about subscribing, unsubscribing, and managing your Oracle e-mail communications preferences, please see the Oracle E-Mail Communications page. Copyright © 2011, Oracle Corporation and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor is it subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission. 

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