How find the memory leaks and how to fix them?

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Permalink Reply by Siddiq on July 4, 2011 at 12:56am

Load Test the application or special tools to uncover memory leaks are available. Google you shall be able to find.

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Permalink Reply by Bijay Kumar Thakur on July 13, 2011 at 4:05pm

Hi,

There are two types of counter which you have to select in windows resource graph through "add measurement" column. simply right click on graph select "add measurement" then write your machine name (localhost by default) and select counters:

Pool Nonpaged bytes and Private bytes

Pool Nonpaged Bytes is the size, in bytes, of the nonpaged pool, an area of system memory (physical memory used by the operating system) for objects that cannot be written to disk, but must remain in physical memory as long as they are allocated.  Memory\\Pool Nonpaged Bytes is calculated differently than Process\\Pool Nonpaged Bytes, so it might not equal.

 

Private bytes

Private Bytes is the current size, in bytes, of memory that this process has allocated that cannot be shared with other processes.

 

when you run your scenario you can get the  Pool Nonpaged bytes (in %) in avg trasaction response time graph.

Now compare the % values with "matching correlation" in graph legend (bottom).

condition: 1. If  Pool Nonpaged bytes (in %) > 70% of matching correlation (100%)

It means the transaction which you performing needs more memory.

I hope you got the ans :)

Thanks

Bijay Kumar Thakur

voice: 09608466149

 

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Permalink Reply by priya on December 23, 2011 at 5:03am

Hi,
Can you please explain me with some more details.

Thanks.

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Permalink Reply by GSK Guptha on April 30, 2012 at 8:26am

Solution:

 * Create LoadRunner VuGen script for your application (Web server in my script)

* Create LoadRunner Controller scenario for your application using the VuGen scripts.

* The next step is to add measurement monitors which are quantitative indicators of resources being monitored (for example, memory usage, CPU usage, handle and thread count, and so on).
For that, on "Run" tab in the LoadRunner Controller, drag "Windows Resources" item from the "Available Graphs" tree and drop it to graphs area.

* Then right-click on the just added graph ("Windows Resources") and select "Add Measurements" from the pop-up menu.

* Add the name of server where the application (Web server in my case) will be run. This server can be a remote one. In this case, you have to make sure that LoadRunner will have an access to get info from the remote computer. Usually, I provide administrator rights for user which executes LR scripts.

* select the following counters:

• % User Time for two processes (RService & tomcat5) and the whole system (_Total)
• Available bytes in the system
• Handle counts
• Thread counts
• Working Sets

Also you may wish to add "Private Bytes" counter. Description for each counter is available on "Windows Resources" dialog. Obviously that the set of counters depends on the requirements and software to be tested.

* We have to run the scenario against a number of concurrent users (I user 30 users) and observe the graph displaying info on memory, CPU, handles and so on...

* Pay attention to the yellow dotted line (memory usage of "RService" process) and the brown dotted line (habdle count counsumed by "RService" process) trends. They grow constantly during ~ 4.5 hours. I marked them out with red lines.
So, this graph provides proofs that the application, I tested, contains memory leaks in the "RService" process.

* So, now Dev team has to fix the problem in the "RService" process..

 

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