28.09.2012 19:27, Andy Seaborne wrote:
Can you use a bit more heap? The default is just a general default,
including small 32 bit machines.
I have it running at 2G and have executed 75 PUTs and it's still going.
Hi Andy!
Thanks for the quick reply and for testing this yourself. You're right,
I made hasty conclusion and giving more heap to the JVM does seem to
help. I tried using 2GB heap and could run 200 PUTs without problems on
a recent snapshot. So there is indeed no memory leak.
This seems to be a GC issue: if you run many PUTs with a small heap size
the GC doesn't get around to freeing enough memory before it's too late,
despite the sleeping between PUTs. When I watched the process memory
consumption using top in the latest test run, there was a steady rise to
around 2GB and then suddenly 600-700MB is released when the GC kicks in.
This process then repeats every dozen requests or so.
I will see whether tuning the GC parameters would help. It's a bit
frustrating - I'm trying to set up a public SPARQL endpoint on a
dedicated server machine and PUTs are the easiest way to update the data
from outside the server, SOA-style. The server is a 64bit RHEL6 running
Fuseki with 3GB heap and I can easily push it over the edge by accident
with a few relatively small (<1M triples) PUTs. Total physical memory is
4GB, so there's not that much room for increasing the heap size - okay,
I should just get more memory...
-Osma
--
Osma Suominen | [email protected] | +358 40 5255 882
Aalto University, Department of Media Technology, Semantic Computing
Research Group
Room 2541, Otaniementie 17, Espoo, Finland; P.O. Box 15500, FI-00076
Aalto, Finland
