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Posted to dev@cocoon.apache.org by Mark Washeim <es...@canuck.com> on 2000/07/09 17:42:50 UTC
load related problem
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).
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 ?
--
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
Re: load related problem
Posted by Stefano Mazzocchi <st...@apache.org>.
Mark Washeim wrote:
>
> on 10/7/00 6:52 pm, Mark Washeim at esalon@canuck.com wrote:
>
> > on 10/7/00 5:31 am, Donald Ball at balld@webslingerZ.com 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
> >>
> >
>
> For those of you who are macintosh fans, you'll be pleased with this:
>
> I can't reproduce the outOfMemory error related problems I get when testing
> on Solaris (an Enterprise 250 machine with 2 processors and 1 GB of RAM) . .
> . It's amazing.
>
> The mac I tested on is a G4 with 256 mb of ram. Tomcat 3.1 used as the
> servlet engine (and webserver).
>
> Even running 30 or 40 concurrent threads, XSPUtil.cloneNode kept on
> churning.
>
> It's so wierd that a deficient virtual memory scheme like the mac's could
> deal with this.
I told you, it's a GC problem: try IBM 1.3 on Linux.
--
Stefano Mazzocchi One must still have chaos in oneself to be
able to give birth to a dancing star.
<st...@apache.org> Friedrich Nietzsche
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Re: load related problem
Posted by Mark Washeim <es...@canuck.com>.
on 10/7/00 6:52 pm, Mark Washeim at esalon@canuck.com wrote:
> on 10/7/00 5:31 am, Donald Ball at balld@webslingerZ.com 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
>>
>
For those of you who are macintosh fans, you'll be pleased with this:
I can't reproduce the outOfMemory error related problems I get when testing
on Solaris (an Enterprise 250 machine with 2 processors and 1 GB of RAM) . .
. It's amazing.
The mac I tested on is a G4 with 256 mb of ram. Tomcat 3.1 used as the
servlet engine (and webserver).
Even running 30 or 40 concurrent threads, XSPUtil.cloneNode kept on
churning.
It's so wierd that a deficient virtual memory scheme like the mac's could
deal with this.
--
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
Re: load related problem
Posted by Mark Washeim <es...@canuck.com>.
on 10/7/00 5:31 am, Donald Ball at balld@webslingerZ.com 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
-oss
and
-ss
options to see if allocating more stack RAM (in the 10s of mb) will make a
difference...
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
Re: load related problem
Posted by Donald Ball <ba...@webslingerZ.com>.
> 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
Re: load related problem
Posted by Mark Washeim <es...@canuck.com>.
on 10/7/00 5:02 am, Niclas Hedhman at niclas@localbar.com 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...
>
> Niclas
>
Turns out that this is the case. I was unable to see it while running under
Websphere. When running with the same jvm and settings ( -ms 512m -mx768m )
under solaris (7x) with tomcat, I can see the out of memory error being
generated, whereupon, xsp stops producing that page...
Ok, any ideas for a fix (this has been stalling me for more than a week now,
sigh) . . .
--
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
Re: load related problem
Posted by Niclas Hedhman <ni...@localbar.com>.
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...
Niclas