DevTest Agent Stops or Losses Connection Because of Garbage Collector Thrashing

Document ID : KB000008501
Last Modified Date : 14/02/2018
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Issue:

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...

Environment:
All supported DevTest platforms.Unix/Linux Operating Systems
Cause:

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.

Resolution:

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: java.io.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.