db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Katherine Marsden <kmarsdende...@sbcglobal.net>
Subject Re: Too many files open after upgrading to 10.8
Date Wed, 01 Feb 2012 21:06:55 GMT
On 2/1/2012 3:13 AM, Kristian Waagan wrote:
> Hi Kathey,
> I once tried to add tracing to Derby (using dynamic byte code 
> instrumentation) for this, but found it somewhat hard to get it 
> working well enough. At this stage, I'd go for operating system tools, 
> for instance 'lsof' on Linux and the resource manager available on 
> Windows (depends on Windows version).
Thanks Kristian, we'll stick with the os tools for starters to try to 
figure out what is going on.

> Would also be helpful to know the limit they're hitting (i.e. ulimit -n).

I am waiting to hear back on experiments to see what files are open, but 
my understanding is that their tests are using the default so 1024 per 
process on Linux.  We usually recommend upping that, but it makes sense 
that they would like to understand what has changed with the 10.8 
upgrade.  One thing I have noticed that every classapath entry, internal 
to the jre and user specified has its own open file. In my environment, 
which just has a few other things besides Derby, it really adds up with 
the IBM 1.6 JVM.
166 total,  112 for the java classes, 22 for the derby jars including 
Locales, 13 os  libraries and locale  stuff and the rest my other 
classpath entries.   The user is seeing 512 open just  with their 
launcher that sets the classpath before doing anything.

One thing Mike mentioned is that it is possible that the istat daemon is 
opening files and pushing them over the edge.  Not a bug but just an 
increase if there are a lot of tables to be updated.


> Regards,

View raw message