Recommendation to fine tune the metaspace size

Hello Rakesh!

 In today's report, eventhough we are not able to see the ideal improvement that we wanted to see, but performance is improving than the previous run.

 In the previous run (i.e. https://answers.ycrash.io/question/performance-tunning-recommendation-for-old-gc?q=255), average pause time and max pause time of Last ditch and Metadata GC events are very high 15 seconds and 17 seconds.

Fig: Previous GC causes

 Whereas in today's run Last ditch and Metadata GC events are better (6 seconds and 7 seconds) than pervious run. GC duration has improved by 50% than previous run.

Fig: Recent GC causes

So we should continue to increase the '-XX:MetaspaceSize'. Let's increase it's size from 256m to 500m i.e. '-XX:MetaspaceSize=500m'. In the previous run we were setting this value to be: '-XX:MetaspaceSize=256m'

Let's study the GC behaviour with this new setting.

Thanks Ram for quick response. Today report was only 22 hour period because we have restarted the system after making the GC changes yesterday. I will continue monitor the system today and will share the GC report again by tomorrow evening so That we will have three days GC data to do the investigation.

Regards

Rakesh

Hi Ram,

I again pull the GC logs today and generated the GC report . 

https://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMjEvMDIvMy8tLWdjX2xvZ18zZmViMTcxNF80LmxvZy0tNi0xNi00MQ==&channel=WEB

In this report again GC duration is very high.

Can you please go through this report and share your analysis.

Regards

Rakesh