What is recommended value for JVM young generation ratio on Jira

[Phill Fox]

I assume that your reason for asking the question is because you are experiencing some performance issues.

The optimal JVM settings differ for each install but it is worth reviewing the resources at https://confluence.atlassian.com/display/JIRAKB/Crashes+and+Performance+Issues+Troubleshooting as these will help you with troubleshooting your settings.

[GillesCM]

Hello Phill,

Our performances with JIRA are not really bad, but I want to know if  better settings can improve them. It seems to have read than Atlassian recommands to adjust XX:NewSize between 30% and 40% of Xmx.

In fact, why define 12Go for Xmx if only 5 is used ?

Regards,

[Phill Fox]

Hi Gilles, 

yes it does seem a little perverse at times the allocation of memory. 

I would look at the page <yourhost>/secure/admin/ViewMemoryInfo.jspa for any particular pain points. But be aware that a 100% usage is not always a bad thing.

If you have a monitoring tool in place it is a good idea to benchmark some changes so that you can see what your normal performance is and then what difference a small change makes to that performance. Typically you should capture this information over a reasonable (~1 week) period unless the performance degradation is very obvious.