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.
Kathey
Regards,
