Re: OutOfMemoryError with Proxy

Hi,

could you post the OJB.properties and jdbc-connection-descriptor too? 
This would help to find problematic settings.
Which version of OJB do you use?

mananthakris wrote:
> Hi,
> We are using OJB with Jboss,Mysql on linux.
> We have implemented all we could as suggested by OJB performance tutorial.
> We are using Proxies,default cache,PB-api,odmg transaction,but we can't use
> getIteratorByQuery because the results are processed after the transaction
> is closed. We are facing outofmemory error in two places always. One while
> materializing subject from proxy and two using getObjectByQuery for finding
> an object by primarykey. 

Isn't it possible to lookup the object by Identity instead of using a query?
http://db.apache.org/ojb/docu/tutorials/pb-tutorial.html#Find+object+by+primary+key


> It happens only if a lot of users around 200 are
> using the system. 

How many objects are materialized?

regards,
Armin

> We have two tier systems with jboss running on a linux
> machine with 4GB ram and we have also finetuned jvm options that has reduced
> frequency of OutOfMemoryError (we use -Xms768M -Xmx768M -XX:NewSize=256M)
> Any suggestions are appreciated? Should we be looking at mysql
> performance,any good tools for profiling ojb?
> Here is the stack trace of two errors
> 1)java.lang.OutOfMemoryError
> rethrown as
> org.apache.ojb.broker.PersistenceBrokerException
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollectionByQuery(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveCollection(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveCollections(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getExtentDBObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getReferencedObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReference(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReferences(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.DelegatingPersistenceBroker.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.DelegatingPersistenceBroker.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.accesslayer.IndirectionHandler.materializeSubject(Unknown
> Source)
>         at
> org.apache.ojb.broker.accesslayer.IndirectionHandler.getRealSubject(Unknown
> Source)
>         at org.apache.ojb.broker.VirtualProxy.getRealSubject(Unknown Source)
>         at
> com.tk20.bo.BaseServerObjectProxy.realSubject(BaseServerObjectProxy.java:46)
>         at
> com.tk20.bo.BaseServerObjectProxy.getRelatedObjects(BaseServerObjectProxy.java:334)
>         at com.tk20.ejb.api.query.QueryMgrEJB.getList(QueryMgrEJB.java:83)
> 
> 2)java.lang.OutOfMemoryError
> rethrown as
> org.apache.ojb.broker.PersistenceBrokerException
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getCollectionByQuery(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveCollection(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveCollections(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getExtentDBObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getReferencedObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReference(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReferences(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getExtentDBObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getReferencedObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReference(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReferences(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getExtentDBObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getReferencedObject(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReference(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.retrieveReferences(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getDBObject(Unknown Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByQuery(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.DelegatingPersistenceBroker.getObjectByQuery(Unknown
> Source)
>         at
> org.apache.ojb.broker.core.DelegatingPersistenceBroker.getObjectByQuery(Unknown
> Source)
>         at
> com.tk20.ejb.api.BaseServiceEJB.findByPrimaryKey(BaseServiceEJB.java:189)
>