Matthew W. wrote:
This is what I’ve been trying to research… I’m pulling these from
the default System Monitor tool that ships with Red Hat… And it
appears all Java instances are consuming a ton of memory but in the
grand scheme of things, only around 1.2GB of 7GB of memory are being
consumed, which is much less that if you add up what the “Totals” are
from the monitor.
Ok, then the Total size is really the virtual size…the space that the
JVM has “expressed an interest in” but has not actually used yet. I
believe virtual size for most processes is typically far larger than
what they’re actually consuming. In this case, it’s probably that large
because JRuby sets the “max heap size” to around 512MB by default, and
JVM itself probably adds on a bunch of extra for 64 bit and for JVM
internal memory use. So RSS: is probably your actual “commit size”.
Again, still large, but much more reasonably than the “Total” size.
Yes, the first example is a single Rails App (2.1) under JRuby 1.1.2
running Mongrel 1.1.5. Development mode. Though I just ran it in
production mode and the numbers remain just about th same.
Server has been running for well over an hour and things are still
floating around those values, so it’s not necessarily startup or
warmup it seems.
Is it possible to run under MRI to see if it’s a case where we’re
consuming considerably more than we should?
You could also try forcing less memory use to see if this is all actually
needed. JVM can sometimes be a little eager to grab more memory. -J-Xmx###M
for ### MB max.
This probably won’t make a difference since it appear your actual “in
use” size is far below the default 512MB setting. You could try someting
like 128MB but it probably wouldn’t even be able to start up.
Thanks for the response, I’m really enjoying the JRuby project and it
was a pleasure to get a chance to see you talk at Acts_as_conference
in Orlando a few months back and seeing all of the headway JRuby is
Is anyone else able to throw out some benchmarks on memory consumption
for a production server? I’m going to go ahead and fire up an
application I’ve got running on a Windows server (yuck) and see how it
I don’t, but I’m sure there are others around who have some metrics for
To unsubscribe from this list, please visit: