Performance Testing, LoadRunner Tips and TricksPerformance Testing, LoadRunner Tips and TricksThis page is dedicated to performance testing using LoadRunner. Current development also includes tuning on various technologies and business perspective in load testing and usage of other load testing tools. Articles
Monitors: The Other Way? II
2007-06-25 08:58:00 The organisation that I worked in have frequent port clearance to perform prior the load test and this is often a troublesome matter to do. As you know that for monitoring to be successful, it requires certain ports to be opened as described in the article titled, "Monitors : How does the monitoring work?". So for this requirement, port-clearance becomes part and parcel of the performance tester job (or for me in particular). This kind of situation exists for some other organisations too. With that, I introduce you to monitor in an alternative way by monitoring locally on the machine and logging the data. The monitoring fundamental for LoadRunner is almost the same for all monitors, as such, you can collect the performance on the machine locally then port it to Analysis to be imported. Analysis provide an import feature that allows external monitor to be ported into the results of the load test. The import feature is straight forward in the usage. More information (a short o... More About: The Other , The O
General: Maximum amount of Vusers generated by a single load generator
2007-06-19 16:34:00 How many vusers can a Load Gene rator generate?There is a straight forward answer in this KB article, KB 11808, "How many Vusers can run on a given computer" from Mercury/HP. Also, you can refer to the following article, KB 3629, "Recommended hardware and OS tuning for optimal Vuser performance" to get information of recommended hardware for vuser performance. As per metioned in the articles, the question of maximum load relates closely to the CPU and Memory on a given hardware. Before we dwell deeper into the technical details, it is best to ensure that common blunders are removed, such as, (1) the Controller have sufficient license to run the amount of vusers stated in the Scenario. (2) Furthermore, ensure that there are no limits enforced on the Load Generators with are configured in the Scenario Settings.To start with, we must understand what happens during a scenarion execution. Refer to General : Scenario Execution for an understanding of the scenarion execution. Further... More About: Single
Basics: Transaction Response TIme
2007-06-18 16:52:00 What is Tran saction Response Time ? Transaction Response Time represents the time taken for the application to complete a defined transaction or business process.Why is important to measure Transaction Response Time? The objective of a performance test is to ensure that the application is working perfectly under load. However, the definition of “perfectly” under load may vary with different systems.By defining an initial acceptable response time, we can benchmark the application if it is performing as anticipated. The importance of Transaction Response Time is that it gives the project team/ application team an idea of how the application is performing in the measurement of time. With this information, they can relate to the users/customers on the expected time when processing request or understanding how their application performed.What does Transaction Response Time encompass? The Transaction Response Time encompasses the time taken for the request made to the web server, there... More About: Basics , Ansa
Products: SiteScope
2007-06-17 09:26:00 SiteScope is another Mercury/HP product that provides agentless monitoring to the users. Agentless monitoring in this context means that there is no need to have additional installation of components to the target servers to perform monitoring.Similar to the LoadRunner Controller, SiteScope requires the designated server to be able to perform monitoring of its own which SiteScope will be able to draw data from it. Depending on the user, they have a choice of using SiteScope to perform the monitoring or use the Controller. Below is a list of links written by Charles Laudia that provides SiteScope-related information. What is SiteScope?What are SiteScope components?How does SiteScope work? How does the licensing work in SiteScope? SiteScope for Windows QuickStartRelated TopicsContent Page - Prod ucts More About: Tesco , Cope
Working with Web (HTTP/HTML) V: File Download/Export
2007-06-08 14:58:00 Frequently, I've observed that there are always questions relating to file download functionalities or file export not being recorded by Vugen for Web (HTTP/HTML) protocol in Web applications, such as clicking a link and the file will be downloaded. In this article, I will describe the possibilities of the problem based on my experiences. We will elaborate using a Winword file. When you click on the link or button to access the file, the file gets loaded in the browser. From here, the business process requires you to click on a link to export it or save it to the local machine. There are two possibilities that will happen. The Winword is either saved over the network or at the OS level. In the context of network level, the client makes a request to the server (as per norm) to download the file which translates to network traffic going to and fro between the client and server. This will be recorded. In the context of OS level, the client issues a OS command to "save-as" the... More About: Download , File , Http , Export , Load
General: Virtualization with LoadRunner
2007-06-06 11:14:00 There was the question posted in the Yahoo discussion group on the topic of virtualization with Load Runner. That is to use virtualization tools such as VmWare and its support and compatibility with LoadRunner.James Pulley who often posts in the group came together a list of recommendations with regards to his experience in such a topic here. The recommendations consist of what could be installed on the virtual machines. I personally appreciated that he put in these information.I believed that the recommendations will be very useful for individuals or organisations looking for some answers with the proliferation of the virtualization tools and therefore extracted the content of the discussion and publish here.The recommendation by James were in order of the least influenced to the most influenced by virtualization.AnalysisThe core issue associated with virtualization is the state of the virtualized system clock which is inconsistent in operation, so much so that time critical events ... More About: General , Virtualization , Gene , Virt
Protocols: Working with CORBA-Java
2007-06-01 08:52:00 The blog by Stuart Moncrieff has great resources on load testing and particularly one of them is CORBA-Java . It comes really handy with a downloadable document at the end of the article and when Java-related protocol resources are hard to find.The article "Tips for Load Testing CORBA Applications with LoadRunner" covers recording, replaying, workarounds and scripting. Click on the link here to be redirected. Related TopicsContent Page - Prot ocol s More About: Working , Toco
Products: Diagnostics
2007-05-31 06:17:00 The Mercury Diagnostic s Software is a standalone software of its own that is functional by itself. Its main functionality is to profile the J2EE, .NET or ERP/CRM application and allowing drill down of the modules to understand the actual problem cause (depending on what you’ve purchased and installed).If you would like to hear from the sales, click here.The discussion here will be specified to performance testing (LoadRunner/Performance Center) and J2EE.The Diagnostics setup comprises of the Probe/Profiler and the Server (Commander). Note that Probe and Profiler will be use interchangeably in this article. Previous version of Diagnostics, 4.2 and earlier have the Probe/Mediator/Commander however that was been incorporated into just the Probe and Commander. Note as of this writing, the latest Diagnostics is 6.5The Profiler/Probe is also able to function on its own by collecting data of the instrumented application server. This can be displayed via the browser via port 35000 by defa... More About: Products , Prod , Gnostic
General: Vugen/Controller Crash or Abnormal Behavior
2007-05-28 11:56:00 In the event that Vugen, Mercury/HP has provided a document that assists the user in troubleshooting the problem. The document, KB 31731 provided is rather old but still relevant.Download the document and follow the steps sequentially not to miss any of it. Do take note on the following three which you can start with which usually resolves the problem.1. Login as administrator2. Run the batch file3. Reinitializing the ini fileThe definition of administrator here is it is a default administrator on the OS without any changes to its roles or privileges.Similarly, for crashing or abnormal behavior of Control ler, you can refer to KB 12532. Take note that for both KB, you will need a valid login to the support website to access them.On top of the list of solutions provided by Mercury/HP, you may want to verify the following too.1. Ensure that there are no other Mercury/HP product (especially QTP or WinRunner). It is advisable to install only LoadRunner components on the machine. 2. Ensur... More About: General , Behavior , Genera , Crash
Scripts: Replay Failure – Use Full Extended Log!
2007-05-22 14:20:00 Usually after recording, you would like to replay the script to ensure that it is workable. More than ever, if it is Web Application (or other application) that have a login and DB connection mechanism, it will fail.The above can be caused by various problems that it will be difficult to list them all out in this article. But for a start, the most common for Web Applications are:1. Session ID2. Authentication (Basic, NTLM or Digest)3. CertificatesWhen the errors happened, amateur users of LoadRunner usually do not know how to follow up.My recommendation for newbie when such things happened is to turn on the Full Extended Log and trace the possible problem areas. The Full Extended Log provides information that you can trace what is happening to the data being sent by the client and responded from the server. In this way, you will be able to determine if the correct request (in web application context) is sent to the server and if a valid respond is been sent back from the server.Trac... More About: Scripts , Failure , Lure
Message: Change of WebSite Template
2007-05-21 15:39:00 Hi Visitor,If you are a returning visitor, you might have noticed that the layout of this blog have changed. Well not really a perfect one, but sufficient for you to navigate (with the search box and menu on the top). Feel free to comment or suggest a good template to contribute effort of improving this website with content and user interface.RegardsHs More About: Website , Change , Message , Template , Sage
Working with Java – Introduction
2007-05-20 10:34:00 LoadRunner provides the capability of load testing Java -related applications. In this article, we will provide a brief introduction to working with Java related applications in LoadRunner.[1]Before we start choosing Java-related protocols to perform recording, you will need to understand the protocol that the Java application is using to communicate with the server. It maybe the case where the Java application is communicating via HTTP rather than RMI-Java, etc… Refer to the concept in a previously written article, "Protocols: What Protocol to use?". Take note that it is the fundamental of using LoadRunner correctly.If you have identified that the application is communicating with a Java related protocol, you can safely proceed to choose the relevant Java protocol.[2]For Java related protocol, the recording works in the same way as .NET and COM/DCOM protocol. All of them share the same characteristics but I will specify to just Java and only Java recording. Pure Java scripting wil... More About: Introduction , Working , Intro , Workin
Protocols: Working with Winsock
2007-05-19 10:15:00 LoadTester have another article that discuss interestingly on the complex protocol Wins ock. Click here to download the article.The article give a brief run through of (1) what is Winsock protocol, (2) the workings of Winsock, (3) how is it being used under what situations and (4) some exercises.Although the article provides a brief description of the Winsock protocol, it at least helps to clarify some questions that Mercury/HP left out in their knowledge base and documentations.Related Topics:Content Page – Prot ocol s More About: Working , Toco
Monitors: MS SQL Server
2007-05-17 04:17:00 LoadTester also provides another white paper that discussed about the performance counters you can utilize for monitoring SQL Serve r . I've extracted the portion of it and paste it here which will be useful first-hand for anyone that requires to monitor SQL Server. The list they provided however, is a recommendation list and you may include more counters based on your requirements.Cache Hit Ratio (SQLServer: Cache Manager object): This is the % of time that a record was found in cache. The recommend cache hit ratio is 90% or more. For typical OLTP systems, the recommended value is 99%. This can be achieved by adding more RAM to the system and a value of 90% is considered a low number.In OLAP systems, this % can be much less due to the nature of how OLAP systems work. Hence, the recommended ratio of 90%.User Connections (SQLServer: General Statistics object): this is the value of number of users connected to this database. Note that this value is the total number of user connections ... More About: Monitors
Protocols: Working with Citrix II - Best Practices
2007-05-16 11:23:00 I’ve recently come across a white paper regarding load-testing Citrix , provided by LoadTester Incorporated. I believed that it is very useful for those that are having problems with the working with Citrix as it covers quite a few aspects in this area. The white paper covers the following best practices for the following. Display SettingsKeyboard Entry versus the MouseICA FilesRandomizing Information Debugging Vusers in the Controller Generate Snapshot on Error Continue on Error Scripting without the Citrix Agent Scripting with the Citrix Agent Click here to access the actual document.Related Topics: Content Page - Protocol s More About: Itri , Working , Toco
General: Scenario Execution
2007-05-16 03:56:00 What happens when the scenario is executed? Here, we will discuss the basic overview when the scenario starts execution, during and end. Prior to the scenario execution, the Load Gene ra tors, number of Vusers, the designated monitoring machine, the ramp up timing, so on so forth should be already defined, and we will skip the discussion for it.When the scenario starts executing, the Controller dispatches the Vusers (scripts) to the designated Load Generator for execution. The Vusers are then executed on the Load Generator with the pre-defined amount on behalf of the Controller. The data generated by the Load Generator prior Collation process (discussed later) is stored in its default temp directory. This can be configured before the execution under the Load Generator setup.Note that if your load test stretches a (1) long duration, (2) contain additional logs or (3) you foresee a large amount of data to be generated, it is advisable to ensure that you have sufficient space for the tem... More About: General , Scenario , Execution
General: Working with Web (HTTP/HTML) IV: Internet Explorer 7 Support
2007-05-14 15:07:00 IE 7 is supported by LoadRunner 8.1 FP4 with an additional patch. The patch can be downloaded from the Mercury/HP support site here.Internet Explorer 7 (IE 7) support for LoadRunner 8.1 Feature Pack 4As of today’s writing, the company has pointed out limitations on the following (taken from the support website)1. Some versions of JInitiator may cause IE to crash when recording the Oracle NCA protocol on IE 7 platforms.2. Cannot record the FTP protocol upload or download operations on IE 7 platforms.3. Does not support tabbed browsing. If you record using VuGen on IE 7 platforms, then Internet Explorer will open with this feature disabled.4. The current version of Mercury Diagnostics (4.2) does not support IE 7. Diagnostics version 6.5 will support IE 7.Take note that you need LoadRunner 8.1 installed with FP4 before you can apply the IE 7 patch. If not, the patch installation will not work.Related TopicsContent Page - Protocols More About: General , Support
General: Understanding Processor - Interrupt Processing
2007-05-14 11:40:00 Interrupts are subjected to priority. The interrupt priority scheme is hardware-determined, but in the interest of portability it is abstracted by the Windows HAL. During interrupt processing, interrupts from lower-priority interrupts are masked so that they remain pending until the current interrupt processing completes. Following interrupt processing during which interrupts themselves are disabled, the operation system returns to its normal operating mode with the processor reset once more to receive interrupt signals. The processor is once again enabled for interrupts. Strictly speaking, on an Intel processor, there is a class of interrupts used for switching between the user level and privileged OS code. Although this involves interrupt processing on the Intel microprocessor, we are not referring to that type of interrupts here. Switching privilege levels does not necessarily cause the executing thread to relinquish the processor. However, Windows does classify these OS supervis... More About: General , Processor , Proc , Gene , Esso
General: Understanding Processor - Ready Queue Management
2007-05-14 07:41:00 Think of priority scheduling as the set of rules for ordering the Ready Queue , which is the internal data, structure that points to the threads that are ready to execute. A ready tread (from IE or any other application) transitions directly to the running state, where it executes if no other higher-priority threads are running or waiting. If there is another thread, the Windows Scheduler selects the highest-priority thread in the Ready Queue to run. Once a thread is running, it executes continuously on the processor until one of the following events occurs: 1. An external interrupt occurs 2. The thread voluntarily relinquishes the processor, usually because it needs to perform I/O 3. The thread involuntarily relinquishes the processor because it incurred page fault, which requires the system to perform I/O on its behalf 4. A maximum uninterrupted execution time limit is reached Interrupts An interrupt is a signal from an external device to the processor. Hardware devices raise inter... More About: Management , General , Processor , Mana
General: Understanding Processor - Ready Queue
2007-05-13 16:30:00 Processor Ready Queue The Processor Queue Length counter in the System object is an extremely important indicator of processor performance. It is an instantaneous peek at the number of Ready threads that are currently waiting to run. Even though reporting processor utilization is much more popular, the Processor Queue Length is actually a more important indicator of a processor bottleneck. It shows that work is being delayed, and the delay is directly proportional to the length of the queue.Since there is one Scheduler Dispatch Queue that services all processors, the Queue Length counter is only measured at System level. The Thread State counter in the Thread object indicates precisely which threads are waiting for service at the processor(s). In other words, the Processor Queue Length counter indicates how many threads are waiting in the Scheduler dispatch Ready Queue, while the Thread State counter tells which thread are in the queue. A good working assumption is that when the proc... More About: General , Processor , Gene , Esso
General: Understanding Processor - Processor State
2007-05-13 16:29:00 Processor utilization can be further broken down into time spent executing in user mode (Intel Ring 3) or in privileged mode (Ring 0), two mutually exclusive states. Applications typically run in the more restricted user mode, while operating system functions run in privileged mode. Whenever, an application implicitly or explicitly calls an OS service (e.g. to allocate or free memory, or perform some operation on a file), a context switch occurs as the system transitions from user to privileged mode and back again. The portion of time that a tread is executing in user mode is captured as % User Time; privileged mode execution time is captured in the % Privileged Time counter.Processor time usage in Windows is broken out into two additional subcategories. % Interrupt Time represents processor cycles consumed in device driver interrupt service routines (ISRs), which process interrupts from attached peripherals such as the keyboard, mouse, disks, network interface card, etc. This is wo... More About: General , Processor , State , Genera , Proc
General: Understanding Processor - Thread State
2007-05-13 16:28:00 As we know, a multiprogramming OS switches the processor back and forth between all the program threads that are executing. When the current thread blocks, usually due to I/O, the Windows Scheduler finds another thread that is ready to run and schedules it for execution. If no threads are ready to run, Windows schedules a thread associated with the System Idle process to run instead. When an I/O operation completes, a blocked thread becomes eligible to run again. This scheme means that threads alternate back and forth between the two states: a ready state, where a thread is eligible to execute instructions, and a blocked state. A blocked thread is waiting for some system event that signals that the transition from waiting to ready can occur.Thread state Counter is an instantaneous counter that you will need to observe at very fine granularity to catch this behavior. The following tables described the thread states and reasons.Values for Thread State CounterValue: State0: Initializin... More About: General , Processor , Gene
Protocols: Working with Web (HTTP/HTML) III - NTLM Authentication
2007-05-13 10:10:00 LoadRunner supports recording and replaying of NTLM authentication. This is described in two main KB articles below. You can refer to the KBs for information on working with it. Take note that you require an account to login to the Mercury/HP support website to view the articles.Tips on NTLM authentication when working with Web VusersHow to record against web applications that go through NTLM authenticationIn additional to the above, take note that be it any authentication (Basic or NTLM), if it is running over HTTP, it will be captured as it is transmitting in pure text form (except of course the encrypted password).Therefore, whenever there is problem in the replay, look at the Replay Log. It will show you the transmission sequence of the script. For NTLM, you will be able to see the 4-way authentication process in the Authentication header of the HTTP message. Trace through the sequence of the authentication in the header. If you are unfamiliar with NTLM authentication, it would ... More About: Http , Html , Working , Protocol
Products: LoadRunner
2007-05-13 09:09:00 LoadRunner is a load testing tool that allows load testing against various technologies (or protocols to be specified). The load testing is by done generating load of emulated real users in the form of scripts or in the LoadRunner terminology, Vusers. While load generating, monitoring is applied to the SUT (System Under Test) or servers and collected at the end of the load testing. This data, is then been analyzed to determine the next course of action (depending on the objective of the load test, i.e. benchmarking, SLA, stress testing, etc.) such as tuning, scaling, or defining a new SLA, etc.If you like to know more on the sales talk (again), feel free to explore the HP Software website here.LoadRunner have a couple of components that makes up the whole product, namely, the Vugen, Controller, Load Generator and Analysis. Take note that Diagnostics and SiteScope is a separate product by itself although it comes along with every LoadRunner CD. It would deserve more description than ... More About: Products , Load , Prod
Monitors: Unix System Resource
2007-05-13 07:49:00 Before we start off, a general understanding of how monitoring works in LoadRunner can be found in "Monitors : How does the monitoring work?"will be useful.Generally, LoadRunner is drawing data from rstatd daemon. For this, before you connect to the Unix box, ensure that rstatd is configured properly and running. This information can be found in the Monitor Reference with every installation of LoadRunner.To configure rstatd, ensure that you have (1) root account or someone who has root account to assist you and (2) someone who is Unix-trained to assist as much of the configuration is done on the Unix box. Verify rstatd DaemonTo verify if rstatd is configured, run rup command in the following syntax in the console.>rup hostYou can also use lr_host_monitor and see if it returns any relevant statistics. If the command returns meaningful statistics, the rstatd daemon is already configured and activated. If not, or if you receive an error message, the rstatd daemon is not configured.Confi... More About: System , Resource , Stem
Products: Performance Center
2007-05-11 07:33:00 Performance Center is an enterprise version of LoadRunner (LR) where it allows concurrent runs in an organization by managing a pool of Controllers and Load generators build on a web interface. The design is for suitable for organizations that require running multiple load test projects throughout the organization. If you like to know more on the sales talk from the company, you can click here.To put it simply, PC can run multiple load test while LR can run a single load test.Performance Center tends to design in a way that load tests are managed in the concept of projects. And through these projects, you will be able to trace the number of runs pertaining to each individual.Privileges are also introduced with the hindsight of projects where there is a difference in the roles. Administrator role maintains the PC setup as a whole, while privileges for users such as Consultant, Tester or Manager can be defined depending on the organization requirements.The administrator has the rights... More About: Products , Performance , Enter , Form
Scripts: Set Debug Mode in Script
2007-05-11 05:22:00 Sometimes there is a need to know what is the data being transmitted in the Replay Log or performing troubleshooting of the scripts. When the usual options are configured. Parameter substitution, Advance Trace and Data Returned by Server are turned on, it’s going to generate a big chunk of data. And in circumstances, you need to know only a certain portion of script to ensure that it is working perfectly, you have to wait through the replay, waiting for it to complete. As such, below is a faster way of generating the Replay Log in a shorter format. This, of course is not effective. So, how do we reduce the information generated to the Replay Log? You can use the lr_set_debug_message to display only a certain portion of the log generated. Place the lr_set_debug_message before the codes that you want the replay log to receive and close it again as per your requirement. The syntax is as below and more information can be consulted in the Function Reference.lr_set_debug_message(LR_MSG_... More About: Scripts , Mode , Script , Debug
Scripts: Remove Think Time
2007-05-11 04:42:00 Yesterday, my team got a requirement to randomize the think time and subtract the think time to reflect the actual response time of the transactions of the load test.To achieve the two requirements, (1) randomize think time and (2) subtract the think time from the transaction response time, two KBs were used.Randomize the think time with a random parameter described in KB 3448, "How to generate a random think time". Proceed to complete enhancing the script and port it over to the Controller. Run the scenario as per normOnce the scenario completes and anaylsis graph generated, filter the think time in the Analysis graph to get the processing time. Use KB 13748, "How to exclude think time from transaction timings in the Analysis graphs" to filter out the think time.Hope this little piece of information is useful. More About: Time , Scripts
Content Page - Products
2007-05-11 03:03:00 Performance CenterLoadRunner More About: Products , Page , Content , Prod , Tent
Content Page - Message Board
More articles from this author:2007-05-11 03:03:00 Message: Change of WebSite TemplateMessage: Some enhancements! Message: Thank you & Content Page Welcome!! More About: Board , Message , Sage 1, 2, 3 |
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