GRAILS 2, memory issues

Question

We have an application built using Grails 2.0.1 and MongoDB. And as our userbase have grown and we did some performance research, we noticed that for each typical request grails eats about 150Mb of RAM, and when RAM is about to reach maximum it performs GC. We've put singleton mode for controllers, and non-transactional for Services. We use JRockit.

I'd like to know if it can be considered normal for grails app or no. Our website is nothing more than a usual website, no extra memory usages, just a user management system and the code itself seems to be OK.

Here are the plugins we use:

app.grails.version=2.0.1,
app.servlet.version=2.4,
app.version=0.1,
plugins.cache-headers=1.1.3,
plugins.code-coverage=1.2.5,
plugins.codenarc=0.12,
plugins.crypto=2.0,
plugins.gsp-arse=1.3
plugins.jaxrs=0.6,
plugins.mongodb=1.0.0.RC5,
plugins.navigation=1.2,
plugins.quartz=0.4.2,
plugins.redis=1.0.0.M9,
plugins.rendering=0.4.3,
plugins.selenium=0.8,
plugins.selenium-rc=1.0.2,
plugins.spring-security-core=1.2.7.2,
plugins.springcache=1.3.1,
plugins.svn=1.0.1,
plugins.tomcat=2.0.1,
plugins.ui-performance=1.2.2

Answer 1

On a Sun JDK, fire up jvisualvm (or the jrockit equivalent, if there is one. Otherwise get yourself a proper profiler that works with jrockit), attach it to your running server, start the profiler and analyze the output. This will give you an idea on where to look.

Maybe you are actually loading that much information from the backend storage. but that's just a guess.