getSalesRank opens the JDBC connection, creates a PreparedStatement,
executes it, then takes the ResultSet and copies the data out into an
ArrayList of HashMaps... it then closes the ResultSet, followed by the
Statement, followed by the Connection ... It only returns the ArrayList to
the caller after the connection to the DB has been closed ... does that
narrow things down at all?
-Dave
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of David
> Jencks
> Sent: Monday, July 23, 2001 11:29 PM
> To: [EMAIL PROTECTED]
> Subject: Re: [JBoss-dev] client application gets stuck, hangs, freezes,
> whatever you want to call it
>
>
> Well these are just several wild guesses, but I am curious.
>
> If you generate the SalesRank arraylist without reference to the db, like
> from random numbers, do you _ever_ get the hang?
>
> I assume getSalesRankData closes whatever resultsets and statements it
> uses? How about the connection?
>
> I don't know much about postgres but have heard rumors it has snapshot
> isolation/versioning similar to firebird/interbase. If so, have you
> committed after your (presumably read only) query in getSalesRankData?
>
>
> Thanks
> david jencks
>
> On 2001.07.23 17:37:50 -0400 David Esposito wrote:
> > Hello all,
> >
> > Let's start with the summary of my problem: My client application hangs
> > after a while when working with CMP Entity beans
> >
> > Environment:
> >
> > JBOSS is running on AppServer.mycompany.com (2.4.0.6 Beta) on Sun JDK
> > 1.3.0_03
> >
> > PostGreSQL 7.1.2 is running on DBServer.mycompany.com
> >
> > My client application is ALSO running on DBServer.mycompany.com on Sun
> > JDK
> > 1.3.0_03
> >
> > so it makes a nifty little out-and-back loop ... my client opens up a
> > connection to JBOSS over the network, then JBOSS contacts the
> DB via JDBC
> > over the network ...
> >
> > Here's the pseudocode of what happens:
> >
> > void run()
> > {
> > //Perform some aggregate operation on the rows in my table
> > //This is a straight SQL query executed over a direct JDBC
> > connection
> > ArrayList salesRank = getSalesRankData();
> >
> > //Get all of the records from my table (~1500 records)
> > Enumeration beans = myHome.findAll();
> >
> > while(beans.hasMoreElements())
> > {
> > //Get the new value for this row
> > Float curSalesRank = (Float)salesRank.get(i++);
> >
> > //Get the remote interface
> > MyBean curBean = beans.nextElement();
> >
> > //Set the sales rank
> > curBean.setSalesRank(curSalesRank);
> >
> > }
> >
> > }
> >
> > The problem is that, without warning, the while() loop gets stuck at the
> > setSalesRank() call ... I installed OptimizeIt which was able to reveal
> > the
> > following stack trace:
> >
> > 100.0% - 653169 ms - java.net.SocketInputStream.socketRead()
> > 100.0% - 653169 ms - java.net.SocketInputStream.read()
> > 100.0% - 653169 ms - java.io.BufferedInputStream.fill()
> > 100.0% - 653169 ms - java.io.BufferedInputStream.read()
> > 100.0% - 653169 ms - java.io.DataInputStream.readByte()
> > 100.0% - 653169 ms -
> > sun.rmi.transport.StreamRemoteCall.executeCall()
> > 100.0% - 653169 ms - sun.rmi.server.UnicastRef.invoke()
> > 100.0% - 653169 ms -
> > org.jboss.ejb.plugins.jrmp.server.JRMPContainerInvoker_Stub.invoke()
> > 100.0% - 653169 ms -
> > org.jboss.ejb.plugins.jrmp.interfaces.GenericProxy.invokeContainer()
> > 100.0% - 653169 ms -
> > org.jboss.ejb.plugins.jrmp.interfaces.EntityProxy.invoke()
> > 100.0% - 653169 ms - $Proxy5.setSalesRank()
> > 100.0% - 653169 ms -
> > com.mycompany.CatalogItemSalesRankHandler.handleEvent()
> > 100.0% - 653169 ms -
> > com.mycompany.EventServer.doJob()
> > 100.0% - 653169 ms -
> > com.mycompany.EventServer.run()
> > 100.0% - 653169 ms -
> > java.lang.Thread.run()
> >
> >
> >
> > Back on the JBOSS box, after at least a minute or so, the following
> > exception shows up:
> >
> > [Catalog_Item] XAException: tx=XidImpl [FormatId=257,
> > GlobalId=timqa1.amsnet.com//193493, BranchQual=] errorCode=XA_UNKNOWN(0)
> > [Catalog_Item] javax.transaction.xa.XAException: Rollback failed: An I/O
> > error has occured while flushing the output - Exception:
> > java.io.IOException: Broken pipe
> > [Catalog_Item] Stack Trace:
> > [Catalog_Item]
> > [Catalog_Item] java.io.IOException: Broken pipe
> > [Catalog_Item] at
> java.net.SocketOutputStream.socketWrite(Native Method)
> > [Catalog_Item] at
> > java.net.SocketOutputStream.write(SocketOutputStream.java:83)
> > [Catalog_Item] at
> > java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:72)
> > [Catalog_Item] at
> > java.io.BufferedOutputStream.flush(BufferedOutputStream.java:130)
> > [Catalog_Item] at org.postgresql.PG_Stream.flush(PG_Stream.java:414)
> > [Catalog_Item] at
> org.postgresql.Connection.ExecSQL(Connection.java:464)
> > [Catalog_Item] at
> org.postgresql.Connection.ExecSQL(Connection.java:400)
> > [Catalog_Item] at
> > org.postgresql.jdbc2.Connection.rollback(Connection.java:242)
> > [Catalog_Item] at
> >
> org.jboss.pool.jdbc.xa.wrapper.XAResourceImpl.rollback(XAResourceI
> mpl.java:2
> > 17)
> > [Catalog_Item] at
> > org.jboss.tm.TxCapsule.rollbackResources(TxCapsule.java:1539)
> > [Catalog_Item] at org.jboss.tm.TxCapsule.rollback(TxCapsule.java:394)
> > [Catalog_Item] at
> > org.jboss.tm.TransactionImpl.rollback(TransactionImpl.java:88)
> > [Catalog_Item] at
> >
> org.jboss.ejb.plugins.TxInterceptorCMT.runWithTransactions(TxInter
> ceptorCMT.
> > java:343)
> > [Catalog_Item] at
> > org.jboss.ejb.plugins.TxInterceptorCMT.invoke(TxInterceptorCMT.java:99)
> > [Catalog_Item] at
> >
> org.jboss.ejb.plugins.SecurityInterceptor.invoke(SecurityIntercept
> or.java:12
> > 7)
> > [Catalog_Item] at
> > org.jboss.ejb.plugins.LogInterceptor.invoke(LogInterceptor.java:195)
> > [Catalog_Item] at
> > org.jboss.ejb.EntityContainer.invoke(EntityContainer.java:349)
> > [Catalog_Item] at
> >
> org.jboss.ejb.plugins.jrmp.server.JRMPContainerInvoker.invoke(JRMP
> ContainerI
> > nvoker.java:390)
> > [Catalog_Item] at java.lang.reflect.Method.invoke(Native Method)
> > [Catalog_Item] at
> > sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:241)
> > [Catalog_Item] at sun.rmi.transport.Transport$1.run(Transport.java:142)
> > [Catalog_Item] at java.security.AccessController.doPrivileged(Native
> > Method)
> > [Catalog_Item] at
> > sun.rmi.transport.Transport.serviceCall(Transport.java:139)
> > [Catalog_Item] at
> > sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:443)
> > [Catalog_Item] at
> >
> sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransp
> ort.java:6
> > 43)
> > [Catalog_Item] at java.lang.Thread.run(Thread.java:484)
> > [Catalog_Item] End of Stack Trace
> >
> > (I have more stack traces ... in fact, it generated about 8 of them ...
> > all
> > seem to be related to some connectivity issue between Postgres
> and JBOSS)
> > ... i'll forward them along if you'd like more ...
> >
> > I've played with the standardjboss.xml to adjust the bean cache
> sizes and
> > this has had no effect on the hanging ...
> >
> > So there are a couple of questions:
> >
> > 1) What is causing JBOSS to hang with, in my opinion, pretty lightweight
> > stuff ... If it's related to the DB driver, why doesn't an exception get
> > propagated back to my client app?
> >
> > 2) What could be causing a broken pipe between PG and JBOSS ... My guess
> > is
> > that it has to do with #1 and the fact that there has been too much
> > inactivity between PG and JBOSS and PG has decided to drop the
> connection
> > ... I'm going under the assumption that #2 is a result of #1 ...
> >
> > Luckily, I can replicate this problem fairly quickly ... (usually it
> > won't
> > go for more than an hour or two without getting stuck) ... so
> if there is
> > anything that you can think of that I should be trying, please let me
> > know
> > and I'll try to run some more tests ASAP ..
> >
> > -Dave
> >
> >
> >
> > _______________________________________________
> > Jboss-development mailing list
> > [EMAIL PROTECTED]
> > http://lists.sourceforge.net/lists/listinfo/jboss-development
> >
> >
>
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