Thanks so much Kevin, that did the trick. Some of the issues you
mentioned where introduced by me not copying right from the
jUDDI project, but the main issue is that the openjpa-plugin simply does
not run for some reason. Anyway it is no longer leaking now! I learned a
lot from this exercise. And yes my class jumped from 2 to 10 k. BTW I'm
pretty sure this used to work..
Thanks again! Going to fix it the jUDDI build now :)!
--Kurt
Kevin Sutter wrote:
Hi Kurt,
I have not run a profiler to verify the memory leak, but I think I found the
problem...
Although you thought you were running the PCEnhancer during build time, it
was not being performed. When I looked at the Tomcat log with the original
jar file, the following message was logged which indicates you were falling
back to the "not ready for production" subclassing support:
1844 juddiDatabase INFO [http-8080-1] openjpa.Enhance - Creating
subclass for "[class org.apache.juddi.AuthToken]". This means that your
application will be less efficient and will consume more memory than it
would if you ran the OpenJPA enhancer. Additionally, lazy loading will not
be available for one-to-one and many-to-one persistent attributes in types
using field access; they will be loaded eagerly instead.
I made a few changes to your pom.xml and the "core" module to get the
enhancement to work and I believe the memory leak has went away. Like I
said, I did not run a profiler, but I added a "finalize" method to your
AuthToken class and I now see that these entities are getting GC'd.
One thing I would do is add the following property to your persistence.xml.
<property name="openjpa.RuntimeUnenhancedClasses" value="warn"/>
This property will produce the following warning if you accidentally fall
into this subclassing support. We turn this off by default when running
within WebSphere since we really don't want customers to accidentally use
this subclassing. And, we have turned this off for 1.3.x and trunk due to
the various problems associated with it. Unfortunately, the 1.2.x branch is
kind of stuck with it...
1688 juddiDatabase WARN [http-8080-1] openjpa.Enhance - This
configuration disallows runtime optimization, but the following listed types
were not enhanced at build time or at class load time with a javaagent:
"[class org.apache.juddi.AuthToken]".
And, of course, your webservice no longer works either. You will get an
HTTP Status 500 error with an error message and call stack that further
explains the error.
To get the maven plugin to work properly... I made several changes, so
hopefully I remember everything...
o The number one thing is that the openjpa:enhance goal doesn't seem to get
automatically invoked when you compile. I have no idea why, but that
doesn't seem to work.
o You have to make your persistence.xml file available to the "core"
module. For my testing, I just created a new directory in the "core" module
called "\openjpa-leak\core\src\main\resources\META-INF\persistence.xml".
This will automatically get copied over to "target" and then the
openjpa:enhance goal will find it.
o How you want to make your persistence.xml file available to both your
"core" module and the "leak-war" module is up to you... :-)
o I added a dependency in your core\pom.xml file for the 1.2.1 openjpa.
The documentation [1] says it will default to 1.2.0, if none is specified.
<dependencies>
<dependency>
<groupId>org.apache.openjpa</groupId>
<artifactId>openjpa</artifactId>
<version>1.2.1</version>
</dependency>
</dependencies>
o Your plugin properties don't seem to be specified correctly, at least
according to the documentation, but I didn't touch them and things still
seemed to work (once I got around the other problems).
o I also changed where to find the entities to enhance since this pom.xml
still specified the "model" directory. There also seems to be confusion as
to whether to specify <classes> or <includes>. I went with <includes> since
that's what the example showed.
o It's very easy to see if the enhancement process worked or not since the
size of your entity classes increases by a few thousand bytes. And, with
the extra property above, this will prevent you from accidentally using the
unenhanced version.
Hope this helps! Let me know if this gets you around the memory leak.
Kevin
[1] http://mojo.codehaus.org/openjpa-maven-plugin/usage.html
On Thu, Jan 14, 2010 at 2:12 PM, Kurt T Stam <kurt.s...@gmail.com> wrote:
1. Cool that you got it running :)
2. I just ran with openjpa 1.2.2.SNAPSHOT and still see an accumulation of
AuthToken objects.
--K
Kevin Sutter wrote:
Hey, this wasn't so difficult... :-) Maybe I can still learn new
things... I have Tomcat up and running and I can get your app running.
On Thu, Jan 14, 2010 at 1:46 PM, Kevin Sutter <kwsut...@gmail.com> wrote:
Hi Kurt,
These instructions, of course, assume that I know something about Tomcat.
This would not be a good assumption... :-) If you really want me to see
this in action, I will need more information on how to start Tomcat and
how
to load applications. In the mean time, a trace log of OpenJPA would be
an
excellent start.
Thanks!
Kevin
On Thu, Jan 14, 2010 at 11:30 AM, Kurt T Stam <kurt.s...@gmail.com>
wrote:
Hi Kevin,
I tried adding the javaagent stuff, and it still ends up leaking. I
extracted the code into a tiny
war with just one servlet which persist the authToken. The build creates
a
Tomcat distro backed by a
derby database. You can download it from:
http://people.apache.org/~kstam/leak.tgz<http://people.apache.org/%7Ekstam/leak.tgz>
<http://people.apache.org/%7Ekstam/leak.tgz>
You can build it with: mvn install, you can find the final tomcat in
tomcat/target/tomcat-1.0.SNAPSHOT.zip
or if you don't want to build it:
http://people.apache.org/~kstam/tomcat-1.0.SNAPSHOT.zip<http://people.apache.org/%7Ekstam/tomcat-1.0.SNAPSHOT.zip>
<http://people.apache.org/%7Ekstam/tomcat-1.0.SNAPSHOT.zip>
After you bring up tomcat it persistent an authToken when you hit
http://localhost:8080/leak/test
In the profiler I see an org.apache.juddi.AuthToken left behind for each
request.
Hopefully this little example will pinpoint what's going on.
Thx Kev for sticking with me :)
--Kurt
Kevin Sutter wrote:
Hi Kurt,
Since you have the environment to reproduce this, could you run with
the
OpenJPA trace enabled? I'm not even sure what I'm looking for at this
point. :-) But, maybe there's some tracing that would point us in the
right direction.
<property name="openjpa.Log" value="DefaultLevel=TRACE"/>
We have been always been on the watch for memory leaks, so this one is
puzzling. You did mention blocked threads as well. At this point, you
are
probably hitting blocked threads due to the GC and Memory problems.
But,
we
did recently resolve some locking situations [1] in our
MetaDataRepository
that could affect scaling (under extreme load). This was resolved in
the
1.2.x SNAPSHOT drivers (Mike is currently pushing for a 1.2.2 release,
so
that should be coming soon).
Does your WebService version of the problem use EntityManager
transactions,
or is the transaction service coming from Tomcat? And, does your
WebService
version also do the em.clear() and em.close()? Basically, are you
using
application-managed or container-managed persistence while running as a
WebService?
I'm very interested in helping to resolve this issue. Like I
mentioned,
we
do a lot of memory leakage and scalability testing of the OpenJPA
solution
and we're not aware of anything. Although there is always the
possibility
that something was resolved in the 1.2.x branch after the 1.2.1 release
that
I'm not remembering...
Thanks for your help,
Kevin
[1] https://issues.apache.org/jira/browse/OPENJPA-250
On Wed, Jan 13, 2010 at 9:27 PM, Kurt T Stam <kurt.s...@gmail.com>
wrote:
Thanks Kevin,
We're enhancing at build time:
http://svn.apache.org/repos/asf/webservices/juddi/trunk/juddi-core/pom.xml
Yeah we've been running load tests and things are nice and stable with
Hibernate but with Openjpa we see increasing memory use, blocking
threads
and then an OOM. http://issues.apache.org/jira/browse/JUDDI-267. Our
preference would be to ship with openjpa by default; but our build
supports
both hibernate and openjpa.
And yes we use openjpa 1.2.1 (latest stable version).
--Kurt
Kevin Sutter wrote:
Interesting detective work, Kurt. Thanks.
Why the WebService version of the app would behave differently as far
as
GC
is concerned is a mystery. And, you said that plugging in Hibernate
into
this scenario, everything works okay? Very confusing.
How are you performing the Entity enhancement processing? Are you
pre-enhancing via your build process? Or, are you using the
-javaagent
mechanism? Or, are you falling back to the subclassing support
within
OpenJPA? (See [1] for more information on these questions in case
they
don't make sense.)
This would be one area that is different between Hibernate and
OpenJPA
--
enhancement processing.
In the Tomcat environment, you may be falling back to the subclassing
support (which we do not recommend) and hitting a memory leak with
that.
You said OpenJPA 1.2.x, right?
Just a couple of thoughts on the subject...
Kevin
[1]
http://webspherepersistence.blogspot.com/2009/02/openjpa-enhancement.html
On Wed, Jan 13, 2010 at 4:25 PM, Kurt T Stam <kurt.s...@gmail.com>
wrote:
The same code executed straight from a java client (inVM) shows no
memory
leak.
So is the fact that it is WebService significant then? What else can
be
different? I think one thread remains up, and somehow this causes
openjpa
not being able to clean up after itself. What can I do to debug this
more? I
can actually see in the profiler that the objects are allocated by
the
WebService, but why aren't they cleaned up?
Thx,
--Kurt
Kurt T Stam wrote:
Thanks Kevin, thanks for your response.
I just replaced the static call by:
apiAuthToken = new org.uddi.api_v3.AuthToken();
apiAuthToken.setAuthInfo(modelAuthToken.getAuthToken());
//MappingModelToApi.mapAuthToken(modelAuthToken,
apiAuthToken);
which did not make a difference.
I'm wondering if the fact that my class is a webservice makes a
difference. I'll try extracting it into
a regular class with a main method and profile that. At least I
know
that
I didn't forget something
completely obvious..
--Kurt
Kevin Sutter wrote:
Kurt,
I agree that this is very common usage of the JPA programming
model.
And,
we are not aware of any memory leaks. About the only thing that
jumps
out
at me is the following two lines:
apiAuthToken = new org.uddi.api_v3.AuthToken();
MappingModelToApi.mapAuthToken(modelAuthToken,
apiAuthToken);
What do these do? Can you comment these out and see if the memory
leak
still exists? Since you are passing the modelAuthToken into this
method,
I
don't know what it's doing with the reference and could it be
holding
onto
something to prevent the GC from cleaning up?
The rest of your example seems very straight forward with creating
and
persisting objects.
Kevin
On Wed, Jan 13, 2010 at 2:09 PM, Rick Curtis <curti...@gmail.com>
wrote:
If you change the 1000 to something like 1000000... does your
application
go
OOM? Are you running in a JSE environment? What is
PersistenceManager?
On Wed, Jan 13, 2010 at 2:05 PM, Kurt T Stam <
kurt.s...@gmail.com>
wrote:
BTW I'm running with the cache off
<property name="openjpa.DataCache" value="false"/>
(that turns it off right?)
--Kurt
Kurt T Stam wrote:
Hi guys,
[DESCRIPTION] The code below inserts a 1000 records in the
database.
for (int i=1; i<1000; i++) {
EntityManager em = PersistenceManager.getEntityManager();
EntityTransaction tx = em.getTransaction();
try {
tx.begin();
// Generate auth token and store it!
String authInfo = AUTH_TOKEN_PREFIX +
UUID.randomUUID();
org.apache.juddi.model.AuthToken modelAuthToken = new
org.apache.juddi.model.AuthToken();
if (authInfo != null) {
modelAuthToken.setAuthToken(authInfo);
modelAuthToken.setCreated(new Date());
modelAuthToken.setLastUsed(new Date());
modelAuthToken.setAuthorizedName(publisherId);
modelAuthToken.setNumberOfUses(0);
modelAuthToken.setTokenState(AUTHTOKEN_ACTIVE);
em.persist(modelAuthToken);
}
apiAuthToken = new org.uddi.api_v3.AuthToken();
MappingModelToApi.mapAuthToken(modelAuthToken,
apiAuthToken);
tx.commit();
} finally {
if (tx.isActive()) {
tx.rollback();
}
em.clear();
em.close();
}
}
[ISSUE]
After it leaving this code I end up with a 1000
org.apache.juddi.model.AuthToken objects in memory. I've been
using
the
profiler, and these objects cannot be garbage collected.
This seems to be pretty the most common use case of using an
OR-mapping
tool, so I find it hard to believe openjpa has a memory leak
here.
Does
anyone see what I'm doing wrong? Or can someone point me to an
example
that
does not exhibit this behavior? BTW same code using hibernate
does
not
accumulate these objects.
We're using openjpa 1.2.1.
Thx,
Kurt
Apache jUDDI.
--
Thanks,
Rick
