Prediction Engine Stops Processing messages until restarted.

Document ID : KB000004720
Last Modified Date : 14/02/2018
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Issue:

The prediction_engine probe may stop processing messages over time.  The probe will be seen in Task Manager to be using 100% of the allocated RAM.  The prediction_engine queue will be seen to grow without reducing, until the probe is restarted, which will cause processing to resume again for a time.

Cause:

This is caused by a combination of RAM settings and Java Garbage Collection.

Resolution:

To resolve this issue, we will increase the amount of RAM allocated to the probe, and change the garbage collection method.

To do this, edit the prediction_engine.cfg and look for this section:

 

<startup>

   <opt>

      java_mem_init = -Xms64m

      java_mem_max = -Xmx512m

      java_opts = -XX:+UseConcMarkSweepGC -XX:+ScavengeBeforeFullGC -XX:+UseParNewGC

   </opt>

 

Change it to look like this:

 

<startup>

   <opt>

      java_mem_init = -Xms64m

      java_mem_max = -Xmx4096m

      java_opts = -XX:+UseG1GC 

   </opt>

 

Deactivate and re-activate the probe to accept the new settings.