Question
I.T. Co.
RU
Last activity: 22 Aug 2019 7:29 EDT
How to fix OutOfMemoryError?
Hello Pega Community.
Hello Pega Community.
Sometimes I see the OutOfMemoryError(GC overhead limit exceeded) error on our Pega environment. Unfortunantelly it is impossible to understand what is the root cause of this. So I decided to perform investigation of java memory dump when our Pega application works good and when it crashes.
So I have some questions - could you please provide the answers?
Q1: Which tools do you use to analize the memory dump for Pega Application? I started the investigation of the memory dump using Eclipse Memory Analyzer.
Q2: Do you have the common instruction how to analize the crash memory dump for Pega application? How to undestand which pages or objects take a lot of memory? How to separate Data Pages, Caches and unneeded ClipboardPages?
Q3: Is it possible to understand which thread / activity causes OutOfMemoryError?
Q4: Is it possible to see the content of Pega Clipboard? Which java classes store it?
Q5: Could you please provide the description and java sources for the following Pega classes: com.pega.pegarules.bootstrap.loader.PRAppLoader, com.pega.pegarules.priv.collections.map.ConcurrentMostRecentlyUsedMap, com.pega.pegarules.session.internal.mgmt.PRNodeImpl, com.pega.pegarules.session.internal.mgmt.PRThreadImpl, com.pega.pegarules.session.internal.mgmt.PRRequestorImpl, com.pega.pegarules.data.internal.clipboard.ClipboardPageImpl?
Q6: When Pega application works good, 2 objects(com.pega.pegarules.bootstrap.loader.PRAppLoader and com.pega.pegarules.priv.collections.map.ConcurrentMostRecentlyUsedMap) take about 45% of heap. Is it normal?
Thank you in advance.
***Edited by Moderator Marissa to update platform capability tags****
Pegasystems Inc.
IN
Some answers:
Answer1- any tool can be used to analyze memory dumps ( Memory Analyzer, IBM heap dump analyzer etc)
Answer3-For this, you need to review caused by of OOM error trace, review PegaALerts for events occuring that time, also PDC for better understanding of all events on that node.
Pegasystems Inc.
IN
Hi,
You might want to check the GC logs and see how much memory is being claimed after full GC.
If full GC is able to reclaim memory or is it reclaiming very less memory.
Also you can check in the Pega-ALERT for PEGA0028.
If the above are the scenarios then you might need to increase your heap size.
Otherwise using any memory analyzer you need to check the heap dump.
Also please let us know which Pega version you are using and are you having the minimum required Heap based on the installation guidline or not.
Regards,
Vikash
I.T. Co.
RU
Hello,
There are no any PEGA0028 alerts in logs. I have thread dump created when OutOfMemoryError appears. So I started investigated it using Eclipse Memory Analyzer tool. May be you know the sequence of actions to find OutOfMemoryError root cause?
The used Pega version is 7.2.1