Hi,
i think i found a possible bug / memory leak within the
DispatchQueue and EventManager.
First a little bit about my setup:
I have 3 servers. Each server runs an axis service. The service
uses cayenne 1.2.1 to connect to a database. It reads
customer and
account information from the DB etc..
The servers are using cayenne's shared caching with
javagroups as
the messaging service so that changes made from one server are
dispatched to the other servers.
The avarage connections per second is somewhere around 4-5.
However I have a very strange problem with this setup so I
startet
to search for the reason. The problem is that with nearly
constant
and unchanging usage the load of each server increases over
time.
To further test this I created a test server with a similar
setup.
There I created a test program that creates totally constant
usage.
But even with the unchanging usage the load of the server is
increasing until the cpu load is so high that the requests
can not
be processed anymore.
I installed a java profiler to trying to pinpoint the
location of
this error and this is what I found out.
I let the server run for 24 hours and then stopped the program
which creates the test usage.
But even while the server was idle there where still a lot of
instances in the java heap after the GC run.
http://img206.imageshack.us/img206/9769/memorysy5.jpg
Please note the HashMap, WeakReference and Invocation counts. I
pressume that the $ObjectProvider_*** is cayenne aswell but I am
not sure.
Now the following image shows the cpu profile with incoming
connections.
http://img339.imageshack.us/img339/2441/cpuci0.jpg
As you can see 58% of the cpu time is used within HashSet.add().
So when I consider the two facts i think that there might be a
possible problem with the EventManager. The first table tells us
that there are over 1 million instances of HashSet's and cayenne
Invocations. So it seems like the set's within the DispatchQueue
are not recycled properly so that the object count rises over
time
which result in extremly high processtime when trying to add new
HashSet's.
Thanks
Ayhan
Ayhan Kondoz
Software-Entwicklung
----------------------------------------------------------------
--
--
--
------------
Telefon: +49 (0) 40 513 06 616
Telefax: +49 (0) 40 513 06 998 616
E-Mail: [EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]
ag.de>
Website: http://www.freenet.de <http://www.freenet.de/> ;
http://
www.freenet-ag.de <http://www.freenet-ag.de/>
----------------------------------------------------------------
--
--
--
------------
freenet.de AG
Deelbögenkamp 4c
22297 Hamburg
----------------------------------------------------------------
--
--
--
------------
Vorsitzender des Aufsichtsrates: Prof. Dr. Helmut Thoma
Vorstand: Eckhard Spoerr (Vors.),
Axel Krieger, Stephan Esch, Eric Berger
Amtsgericht Hamburg HRB 74048
Diese Information ist ausschließlich für die adressierte Person
oder Organisation bestimmt und könnte vertrauliches und/oder
privilegiertes Material enthalten. Personen oder Organisationen,
für die diese Information nicht bestimmt ist, ist es nicht
gestattet, diese zu lesen, erneut zu übertragen, zu verbreiten,
anderweitig zu verwenden oder sich durch sie veranlasst zu
sehen,
Maßnahmen irgendeiner Art zu ergreifen. Sollten Sie diese
Nachricht
irrtümlich erhalten haben, bitten wir Sie, sich mit dem
Absender in
Verbindung zu setzen und das Material von Ihrem Computer zu
löschen.
The information transmitted is intended only for the person or
entity to which it is addressed and may contain confidential
and/or
privileged material. Any review, retransmission,
dissemination or
other use of, or taking of any action in reliance upon, this
information by persons or entities other than the intended
recipient is prohibited. If you received this in error, please
contact the sender and delete the material from any computer.
