DevTest Agent Stops or Losses Connection Because of Garbage Collector Thrashing

Document ID : KB000008501
Last Modified Date : 14/02/2018
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The agent stops almost immediately or intermediately losses connection to the broker.

In the agent logs are lines similar to:
Max handles limit (921 ) approaching - forcing GC...

All supported DevTest platforms.Unix/Linux Operating Systems

When the agent starts, it attempts to get the number of file descriptor available from the OS.
If there are any problems reading this value, the agent uses a default value.
Many times this default value is too low.


First you must determine if the file descriptors are set too low or the agent is having trouble reading the value.

Find/Adjust values:
Open a terminal and log into the OS as the user that starts the application server where the agent is installed.
Run the following two commands:
ulimit -n -H
ulimit -n -S

If either of these values is at or below 4096, have your system admin adjust the values.
DevTest recommends 32,000 or higher.

Agent cannot read values:
Also if lines similar to these are present at the beginning of the agent's log, you will need to adjust the rules.xml in the agent directory.
Note: if the rules.xml file is not present, copy the rules.xml from the DevTest Install directory.
exec (/bin/sh -c "ulimit -n -H"): java.iio.IOException: error=2, No such file or directory
Please set the property HANDLES_MAX to the value of ulimit -n -H on this machine

Add this line to the "Default" agent section:
<property comment="Keeps track of max file descriptors on Unix - set to -1 for discovery (ulimit) or manually if ulimit is not accessible" key="lisa.agent.handles.max" value="-1"/>

Note: Change the -1 to the correct number of file descriptors.

Restart the application server.

Additional Information:

If you need assistance with the above or have additional issues, please open a support ticket.