hi group,
there's a problem I currently have with a webapp, that makes me go crazy.
the webapp has been live for about two months now, and I think the problem
didn't exist in the beginning.
the problem itself seems to be some leak.
config:
- linux box (dual processor)
- tomcat 4.1.18
- cocoon 2.0.4
symptoms:
- webapp runs fine for hours (12-24 hours) with a max. cpu usage of about
4%
- memory usage is continuously rising
- at some point cpu usage continuously around 100%, distributed to the
processors
strange points:
- though having specified java option -Xmx128 the memory usage rises above
that value (when viewed in top)
- discrepancy between memory usage shown by ps/top and memory usage logged
by the store-janitor
- in the store-janitors's logs the 'JVM total memory' is never above the
maximum specified via -Xmx
- according to the store-janitor's logs the webapp (cocoon) always has
enough memory (> 15mb)
can anyone explain
- the discrepancy between the memory usage reported by the store-janitor
and ps/top?
- where the leak may be? (from the janitor's values I assume it's not
within the JVM but within the java process?)
- how to determine the kind of leak/where the leak may be
finally, a snip from the janitor's log. please note that top reports a
memory usage of about 223MB. -Xmx is -Xmx196. cpu usage is currently normal.
but this maybe because the JVM's heap size hasn't reached its maximum yet
(according to the janitor).
...
DEBUG (2003-03-20) 19:01.15:335 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM total Memory: 157827072
DEBUG (2003-03-20) 19:01.15:336 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM free Memory: 16551888
DEBUG (2003-03-20) 19:01.15:336 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: Memory is low = false
DEBUG (2003-03-20) 19:01.25:349 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM total Memory: 157827072
DEBUG (2003-03-20) 19:01.25:349 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM free Memory: 15666808
DEBUG (2003-03-20) 19:01.25:350 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: Memory is low = false
DEBUG (2003-03-20) 19:01.35:369 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM total Memory: 157827072
DEBUG (2003-03-20) 19:01.35:370 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM free Memory: 18108320
DEBUG (2003-03-20) 19:01.35:370 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: Memory is low = false
DEBUG (2003-03-20) 19:01.45:389 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM total Memory: 157827072
DEBUG (2003-03-20) 19:01.45:390 [core.store.janitor] (Unknown-URI)
Unknown-t
hread/StoreJanitorImpl: JVM free Memory: 17840184
...
