How to choose optimal Initial and Maximum Memory Pool

[Pierre Cattin]

What's the best practice to set Inital and Maximum Memory Pool? What will happen if I allocate too much memory to Jira?

I found some information here. But i's not written how to choose Initial Memory Pool. Should both values be equal?

Our server (Windows server 2008 64 bits) has 8GB of RAM, and it is only used to host Jira (6.1) and its database (Oracle 11g).

Our Jira instance has 6 projects, 55'962 issues, 44 custom fields and 120 active users.

Pierre

[Radu Dumitriu · Accepted solution]

Well, tough question. There's no way we can answer that, there's a process of trial and error here.

Q1: Initial heap size and maximal heap size should be the same on *stable* systems. This means that you measured the spikes in memory usage over a long period.

Q2: The more memory you have extra, the more you delay full GC (well, you can control that, via some params). When that finally occurs, it will need to clear up a huge collection of non-used objects, making your entire server unresponsive. Getting the balance right between the time spent in GC and doing real stuff is that process of trial and error ...

You also need to make sure that the total allocated quantity *at the operating system level* is not pushing your machine in swap.

Fortunately, your machine seems a bit oversized for the given quantity of data, so I guess 1 - 1.5 - 2 Gb of heap allocated to JIRA would suffice (that depends on the CF types, btw).

[Pierre Cattin]

Thanks a lot for your explanations.