How to tune neo4j 2.1.5 in HA

Question

So we have are setup with 3 servers all running SSD storage and 8 vCPUs and 16GB of ram. We have installed everything performance wise as the defaults.

I have taken a look around but I'm still not exactly sure what I should be changing on the server in order to get the most optimal performance.

We have noticed some issues where our queries are acting sporadic. We can call one query and a few seconds call the same exact query and sometimes it will be quick and others it can take 5 - 10 seconds.

Any help would be appreciated. If you need more info on my setup just let me know and I can get it to you.

Answer 1

This sounds like you're suffering from lengthy GC pauses. Tracking down these is not a trivial task. If you're not experienced with these kind of issues I strongly recommend to read http://www.amazon.com/Java-Performance-Charlie-Hunt/dp/0137142528 or engange a skilled consultant.

Side note: if you've commercially licensed Neo4j, Neo Technology offers help for these kind of problems as part of the support offering.

The rough guideline is to first try to configure the mapped memory area large enough to fully cover your graph. From the remaining memory subtract 1-2 GB for OS and assign the rest to JVM's -Xmx and -Xms setting.

You might fine tune object cache as well.

On some deployments I've had good results switching to G1 garbage collector instead of CMS (which is the default). However this is not a general purpose advice.