Interestingly enough, I already read this part of the documentation and
I was releasing the CAS in my first implementation, but it didn't help.....
- If I release the CAS just after calling the sendCAS, it was not
actually processing the CAS (or at least the callback listener was never
called). The blocking situation is occuring... I have the following
logs :
"ERROR:org.apache.uima.adapter.jms.client.BaseUIMAAsynchronousEngine_impl.:onMessage:NullPointerException"
- I tried to release the CAS in the callback listener, the blocking
situation was the same and I have the following warning log on release
"WARNING :org.apache.uima.util.CasPool : releaseCas: The system tried to
return a common analysis structure to the pool from which it was not
checked out. "
- I looked at the process method of
BaseUIMAAsynchronousEngineCommon_impl and saw the CAS are not released
there (see below) nor in the implementation of the test callback
implementation.....
do
{
if(!initialized || !running)
break;
try
{
if(!(hasNext = collectionReader.hasNext()))
break;
cas = getCAS();
collectionReader.getNext(cas);
sendCAS(cas);
}
catch(Exception e)
{
e.printStackTrace();
}
} while(true);
I am really confused.... Where should I release the CAS ?
Thanks
Pierre
Le 31/03/2010 15:52, Jaroslaw Cwiklik a écrit :
You are not calling cas.release() when you are done with the CAS.
Per UIMA AS documentation ("4.2 The UimaAsynchronousEngine Interface - CAS
getCAS()"
"...CAS getCAS(): Requests a new CAS instance from the CAS pool. This method
blocks until a free instance of CAS is available in the CAS pool.
Applications that
use getCAS() need to call CAS.reset() before reusing the CAS, or
CAS.release()
to return it to the Cas pool."
The release() places a CAS back into the pool so the subsequent call to
getCAS()
succeeds. An alternate strategy is to have a single CAS instance in the CAS
pool
call getCAS() to get that instance and enter a while loop. When done
processing
reply, call cas.reset() and do *not* call getCAS() again.
JC
On Tue, Mar 30, 2010 at 5:41 AM, pierre yahoo<[email protected]> wrote:
I'm trying to use UIMA-AS to scale a part of the process of our
application.
I have successfully deployed our process as asynchronous services but I
have tremendous issues with the client.
I'm basically looping synchronously(one at a time) on the following code.
CAS cas = uimaEEEngine.getCAS();
JCas jcas;
try {
jcas = cas.getJCas();
} catch (CASException e) {
throw new ResourceProcessException(e);
}
fillCas(jcas);
uimaEEEngine.sendCAS(cas);
When I run the application, the client works fine for a while and suddenly
gets stuck waiting on cas.getJCas()..
I have checked that the asynchronous service have processed all the
previous CAS. The service is still up and running as I can send requests
from an another client.
When I tracked down who locks the process, I can see that the semaphore on
CasQueueEntry is not released.
When I looked further, I noticed that the all process is basically lock
when the CasManager_Impl is calling CasPool.getCas(0) . The CasPool is then
waiting with no timeout for someone to notify it.
I try to change the size of the client CasPool but it didn't really fix the
issue. Just pushing further the lock...
Does anyone have ever experienced this? Am I doing something wrong ?
Pierre
