SLB test troubleshooting (from msdn)

Load Test troubleshooting

Visual Studio team system Load Test troubleshooting

 

Updated: February 1, November 2007

This topic lists the following Frequently asked questions that occur when you use a load test in Visual Studio team system test edition.

Unable to use SQL tracking

An error occurred while running the test. (Computer XYZ) failed to access the result Repository: the object name "loadtestrun" is invalid

Loadtestcounternotfoundexception Error

Loadtestresultscollectorslowexception

Loadtesterrorlimitexceededexception Error

No proxy computer that matches the selection criteria

Unable to access the load test result Repository

An error occurred while generating the expected load.

Limits on Load generation for multi-core computers

Unable to use SQL tracking

When you run the load test locally when SQL tracking is enabled, you may receive the following message:

An error occurred while running the test. Failed to start SQL tracking: You do not have permission to run "sp_trace_create"

To use SQL tracking in a local load test running on a computer running Windows Vista, you mustSysAdminA member of a role. To solve this problem, the SQL server administrator must add youSysAdminRole.

An error occurred while running the test. (Computer XYZ) failed to access the result Repository: the object name "loadtestrun" is invalid

This error indicates that no Server Load balancer database architecture has been created. You can use the query analyzer to run the loadtestresultsrepository. SQL file in <Visual Studio installation folder> \ common7 \ ide \ To create a database.

If you are using SQL Express, you can run "sqlcmd-S. \ sqlexpress-I loadtestresultsrepository. SQL" at the command prompt in the previously listed directory ".

Warning:
The parameters are case sensitive. You must enter uppercase S and lowercase I.

For more information, see How to: use SQL to create a result repository.

Loadtestcounternotfoundexception Error

This error occurs when the performance counters in a counter set contained in the load test cannot be found in the performance counter category that contains the counter set. If the counter has been added to the counter set, the name of the performance counter may be misspelled. It may also be that the performance counter no longer exists in the category, because the performance counter has been deleted from the software components that define its newer versions. You can remove it from the counter set to correct this error without losing any useful data.

Loadtestresultscollectorslowexception Error

This error indicates that the controller cannot collect performance counters of all computers at the specified sampling rate for the load test. This error may occur when the counter set ing in the load test specifies to collect multiple performance counters from multiple different computers. This error also occurs when the server Load balancer and the controller are running on the same computer. This error may be corrected by increasing the sampling rate of the load test.

Loadtestlimitexceededexception Error

This error occurs when there are 1000 or more errors of the same type. This error usually indicates that the test running under the load test has a problem. For example, if a web test sends a request to a URL that cannot be found, correct the web test to fix the error.

No proxy computer that matches the selection criteria

When running a test on a remote test unit (RIG), you may receive the following message:

No proxy computer that matches the selection criteria

When running a test on a remote test unit (RIG), you can specify the selection criteria for the proxy computer connected to the Controller. For example, you can specify that only agents with specific operating systems can be used for testing. If no conditions are specified, all proxies connected to the controller are used to run the test. If no proxy matches the selected condition, the test is not run.

To resolve the problem that no proxy computer matches the selection criteria, follow these steps:

1. On the "test" menu, point to "edit test run configuration", and then click the configuration of the current activity.

   Note:
   To find the configuration of the current activity, point to "select activity test run configuration" in the "test" menu ". There will be a selected tag before the activity configuration.

2. Click controller and proxy in the list box ".

3. In the "Name and value" grid, delete the condition that will be used to run the test proxy exclusion.

4. After that, click "application" and then click "OK ".

Unable to access the load test result Repository

When running a load test, you may receive the following message:

Failed to access the load test result Repository

One possible cause of this error is that an incorrect case is specified for the parameter name when you use the sqlcmd command line utility to set the load test result repository. The following code sets the load test result repository on a server named contososerver1:

Sqlcmd-s contososerver1-u <User Name>-P <password>-I loadtestresultsrepository. SQL

Warning:
The parameters are case sensitive. Uppercase S, U, P, and lowercase I must be entered.

For more information, see How to: use SQL to create a result repository.

An error occurred while generating the expected load.

A common problem that occurs when running a load test is that the expected load cannot be generated. The following table lists the possible causes:

The maximum load is limited by the thinking time or number of virtual users.	If you start the thinking time, it limits the Request Rate of each virtual user. For example, if the thinking time for each request is 5 seconds, each virtual user can have up to 0.2 requests per second. You can try one of the following changes in the preferred order: Increase the number of virtual users to generate more real loads. Increasing the number of virtual users usually requires more memory. Shorten thinking time. Turn off the thinking time to generate the maximum load. Warning: Closing the thinking time will have a great impact on the test engine. If you disable thinking time, reduce the number of virtual users.
Set the proxy attribute for Web Testing to "default ".	It is convenient to use "default" as the proxy settings in Web Testing because it can enable automatic Proxy Server Detection. However, using "default" as a proxy will cause performance problems in the load test and greatly reduce the maximum throughput. When running a load test, it is best not to use a proxy server. If you need a proxy server, specify the name of the proxy server to replace "default ".
Application bottleneck.	Remember, the role of the load testing tool is to identify bottlenecks in the application. If the response time of a page is too long due to a database or CPU bottleneck, it limits the number of requests sent by each virtual user per second. Start with a small amount of load and ensure a reasonable response time when the load increases slowly. You can use the "response time objective" attribute to set the expected maximum response time for each request.
The CPU, memory, or network size of the Web server exceeds the limit.	If the CPU, memory, or network of the Web server exceeds the limit, the expected load may not be generated. You may have found the server load limit. It can increase the CPU, memory, or network of the Web server.
The CPU memory or network of the computer that generates the load exceeds the limit.	More powerful computers or more proxy computers may be required to generate the required load.
The CPU, memory, or network size of the database server (if applicable) exceeds the upper limit.	If the CPU, memory, or network of the database server exceeds the limit, the expected load may not be generated. You may have found the load limit for the database server. It can increase the CPU, memory, or network of the database server.

Limits on Load generation for multi-core computers

When running a load test on a multi-core computer, load generation has the following restrictions:

• If the computer is running Visual Studio team system test edition or Visual Studio team system, the load generation is limited to single-core.

• If the computer runs the Visual Studio team system test load agent, the load generation is not limited and runs on all kernels and processors.

See

Task test edition troubleshooting Web Test troubleshooting controller, proxy, and Remote Test Unit (RIG) troubleshooting how: use SQL to create result repository concepts considerations for large load testing controllers, proxies, and remote test units (RIG) to analyze load test error analysis threshold rule conflicts other resource Load Test Result Repositories