[Geoserver-users] Null pointer exception

GeoServer GeoServer User
1

All,

I took a look at my logs yesterday and noticed that the catalina.out file
was up to 50 Gigs! And it's all just repeats of this warning every few
milliseconds:

534949094 [WARNING] WeakCollection - NullPointerException
java.lang.NullPointerException
        at
org.geotools.util.WeakCollectionCleaner.run(WeakCollectionCleaner.java:76)

How do I make it stop??!!??!!

Thanks,
Steve

Stephen Crawford
Center for Environmental Informatics
GeoVISTA Center
The Pennsylvania State University
814.865.9905
src176@anonymised.com

2

Stephen Crawford ha scritto:

All,

I took a look at my logs yesterday and noticed that the catalina.out file
was up to 50 Gigs! And it's all just repeats of this warning every few
milliseconds:

534949094 [WARNING] WeakCollection - NullPointerException
java.lang.NullPointerException
        at
org.geotools.util.WeakCollectionCleaner.run(WeakCollectionCleaner.java:76)

How do I make it stop??!!??!!

Ouch, 50GB... what version of Geoserver are you using?
Cheers
Andrea

3

Stephen Crawford ha scritto:

All,

I took a look at my logs yesterday and noticed that the catalina.out file
was up to 50 Gigs! And it's all just repeats of this warning every few
milliseconds:

534949094 [WARNING] WeakCollection - NullPointerException
java.lang.NullPointerException
        at
org.geotools.util.WeakCollectionCleaner.run(WeakCollectionCleaner.java:76)

How do I make it stop??!!??!!

I checked the code, if the java runtime is behaving properly that
npe should be impossible... The line of code is:

referenceQueue.remove().clear();

where referenceQueue is never set to null, and it's created in the
WeakCollectionCleaner costruction, and ReferenceQueue.remove()
javadoc says:

"Removes the next reference object in this queue, blocking until one
becomes available."

and in fact the code inside ReferenceQueue seems to guarantee that
null is never returned...

Cheers
Andrea

4

I'm using 1.4.0....I upgraded from 1.4 RC 5 about 2 weeks ago, and come to
think of it that's roughly the time the catalina logs started getting large.

-----Original Message-----
From: Andrea Aime [mailto:aaime@anonymised.com]
Sent: Wednesday, January 17, 2007 9:35 AM
To: Stephen Crawford
Cc: geoserver-users@lists.sourceforge.net
Subject: Re: [Geoserver-users] Null pointer exception

Stephen Crawford ha scritto:

All,

I took a look at my logs yesterday and noticed that the catalina.out
file was up to 50 Gigs! And it's all just repeats of this warning
every few
milliseconds:

534949094 [WARNING] WeakCollection - NullPointerException
java.lang.NullPointerException
        at
org.geotools.util.WeakCollectionCleaner.run(WeakCollectionCleaner.java
:76)

How do I make it stop??!!??!!

Ouch, 50GB... what version of Geoserver are you using?
Cheers
Andrea

5

Stephen Crawford ha scritto:

I'm using 1.4.0....I upgraded from 1.4 RC 5 about 2 weeks ago, and come to
think of it that's roughly the time the catalina logs started getting large.

Have you changed the jdk as well?
As I noted in my other post, I don't see any way that code may throw an NPE besides a runtime misbehaviour...
I checked the ReferenceQueue suource code in jdk 1.4.2, 1.5.0 and 1.6.0,
all seem to guarantee against a null pointer exception...

Cheers
Andrea

6

Hi Andrea,

JDK 1.5.0 and Tomcat 5.5.15, which I did not change when I changed
Geoserver. However, this morning, after letting Tomcat "rest" overnight and
then restarting this morning, the problem does not seem to happening....so I
guess I'll just keep my eye on it.

Thanks,
Steve

-----Original Message-----
From: geoserver-users-bounces@lists.sourceforge.net
[mailto:geoserver-users-bounces@lists.sourceforge.net] On Behalf Of Andrea
Aime
Sent: Wednesday, January 17, 2007 9:51 AM
To: Stephen Crawford
Cc: geoserver-users@lists.sourceforge.net
Subject: Re: [Geoserver-users] Null pointer exception

Stephen Crawford ha scritto:

I'm using 1.4.0....I upgraded from 1.4 RC 5 about 2 weeks ago, and
come to think of it that's roughly the time the catalina logs started

getting large.

Have you changed the jdk as well?
As I noted in my other post, I don't see any way that code may throw an NPE
besides a runtime misbehaviour...
I checked the ReferenceQueue suource code in jdk 1.4.2, 1.5.0 and 1.6.0, all
seem to guarantee against a null pointer exception...

Cheers
Andrea

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7

Stephen Crawford ha scritto:

Hi Andrea,

JDK 1.5.0 and Tomcat 5.5.15, which I did not change when I changed
Geoserver. However, this morning, after letting Tomcat "rest" overnight and
then restarting this morning, the problem does not seem to happening....so I
guess I'll just keep my eye on it.

Ok. Let me know if this happens again. In the meantime, I've forwarded the question to the developer that made the WeakCollectionCleaner class,
he may have some insight on how it could happen...

Cheers
Andrea Aime