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From Mark Washeim <>
Subject Re: load related problem
Date Mon, 10 Jul 2000 16:52:23 GMT
on 10/7/00 5:31 am, Donald Ball at wrote:

>> Mark Washeim wrote:
>>> I've been load testing an xsp application (one of the eurofootball apps) and
>>> am having difficulty determining the origin of this exception:
>>> java.lang.NullPointerException
>>> at org.apache.cocoon.processor.xsp.XSPUtil.cloneNode(Compiled Code)
>>> at org.apache.cocoon.processor.xsp.XSPUtil.cloneNode(Compiled Code)
>>> at org.apache.cocoon.processor.xsp.XSPUtil.cloneNode(Compiled Code)
>>> at org.apache.cocoon.processor.xsp.XSPPage.xspExpr(Compiled Code)
>>> at
>>> _opt._IBMHTTPD._htdocs._en_US._editorial._gb_home.populateDocument(Compiled
>>> Code)
>>> it only occurs when I bring the load up to about 40 to 50 concurrent
>>> requests (per second).
>> Interesting thorughput :o)
>>> I'm wondering if it's because the method within the xsp:expr isn't returning
>>> (which shouldn't happen and doesn't under less load) or whether it's
>>> something else?
>>> Any ideas ?
>> One might wonder if some OutOfMemoryError has been caught and ignored...
> one might also check and see if the library method being invoked by
> xsp:expr is the cause of the null pointer by simply forking 40-50 threads
> and repeatedly call it from them. my gut says that xsp is the problem, but
> it'd be good to eliminate the external possibilities first. other likely
> candidate is the jvm.
> - donald

Ok. It's not xsp per se. It's the number of objects created during
XSPUtil.cloneNode() operations, performed recursively over 4 to 5 times.

I'm just toying with the jvm
options to see if allocating more stack RAM (in the 10s of mb) will make a

Otherwise, I'll have to remove one dom-wise operation and add some
application structure to deal with the issue (sigh) . . .

Can't believe this is an issue. Bloody jvm. :(

Mark (Poetaster) Washeim

'On the linen wrappings of certain mummified remains
found near the Etrurian coast are invaluable writings
that await translation.

Quem colorem habet sapientia?'

Evan S. Connell


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