Hi,
We are facing certain memory issues with Jruby on Rails application.
1.We have a 7GB server out of which 4 GB is tomcat(2 tomcat instances
each of 2Gb) heap space and rest 3 GB memory is free for the server.
However it is noticed when server is idle through the weekend, the
memory drops down to 300 MB. However while monitoring jvm memory through
tomcat manager that seems to be fine and heap space memory is free.
However the server memory drops down.
- Also we have a call to java class file from ruby class. The java
class basically does xml unmarshalling. When memory becomes low this
particular operation takes loads of time. We monitored the same through
http watch.
We monitored the free memory using vmstat and top command.
We have set min jruby runtimes to 25 and max also to the same value.
Jruby 1.5.0
tomcat 6.0.26
Red hat Linux 32 bit (virtual machine)
Any ideas?
Hi,
Refering to the above post, PFA the vmstat output
The simplest answer is that the OS is pre-emptively swapping unused
pages of memory out (which all OS’s like to do) and then when you
start using it on Monday you are swapping in Gigs worth of pages
memory. Your graphic’s si column is showing this.
This problem is basic to any large memory application that becomes
idle for an extended period of time. I am not sure what the state of
art is for dealing with this, but you can have a client hit your
server periodically to make sure all relevant pages stay in memory.
There may be a better way, but I have not been on the management of a
server side of the fence in a long time.
-Tom
On Mon, Jan 3, 2011 at 11:33 AM, Prachi T. [email protected]
wrote:
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