Starvation in MDBs ?

Our application receives 10 different types of messages on one queue each. Thus we have 10 queues (MQ as a Foreign JMS provider with MDBs in a WLS). We have MDBs processing each of these queues. The producer (mainframe) that sends messages to these queues operates in batch mode.
Option (1) Configure all MDBs in the same custom thread pool. If a blast of 500 messages arrives on one of the queues and all the threads start consuming messages, what happens to new messages that arrive on other queues ? Do they have to wait until these 500 messages are processed ? I would like someone from the BEA JMS implementation team to comment on this.
Option (2) Configure smaller custom thread pools - one for each queue. Solves the problem above. Let us say we allocate 2 threads per MDB in custom thread pools. This ensures that none of the queues starve, however, if there is a practical limit on the maximum number of threads that can be configured, then this option introduces an inefficiency. What if there are 200 messages in one queue and zero messages in all others ? We are allowing only two threads to process those 200 messages while the other threads just sit and watch.

This item was moved from the JMS newsgroup to the EJB newsgroup by BEA moderators. I have added EJB to the subject to ensure that the EJB experts don't overlook it.

Similar Messages

Starvation in EJB/MDB thread pool ?

I am re-posting this article including the acronym EJB in the subject so that the EJB experts don't overlook this question. This question was moved from the JMS newsgroup to this newsgroup by a BEA moderator.
Our application receives 10 different types of messages on one queue each. Thus we have 10 queues (MQ as a Foreign JMS provider with MDBs in a WLS). We have MDBs processing each of these queues. The producer (mainframe) that sends messages to these queues operates in batch mode.
Option (1) Configure all MDBs in the same custom thread pool. If a blast of 500 messages arrives on one of the queues and all the threads start consuming messages, what happens to new messages that arrive on other queues ? Do they have to wait until these 500 messages are processed ? I would like someone from the BEA JMS implementation team to comment on this.
Option (2) Configure smaller custom thread pools - one for each queue. Solves the problem above. Let us say we allocate 2 threads per MDB in custom thread pools. This ensures that none of the queues starve, however, if there is a practical limit on the maximum number of threads that can be configured, then this option introduces an inefficiency. What if there are 200 messages in one queue and zero messages in all others ? We are allowing only two threads to process those 200 messages while the other threads just sit and watch.

I am re-posting this article including the acronym EJB in the subject so that the EJB experts don't overlook this question. This question was moved from the JMS newsgroup to this newsgroup by a BEA moderator.
Our application receives 10 different types of messages on one queue each. Thus we have 10 queues (MQ as a Foreign JMS provider with MDBs in a WLS). We have MDBs processing each of these queues. The producer (mainframe) that sends messages to these queues operates in batch mode.
Option (1) Configure all MDBs in the same custom thread pool. If a blast of 500 messages arrives on one of the queues and all the threads start consuming messages, what happens to new messages that arrive on other queues ? Do they have to wait until these 500 messages are processed ? I would like someone from the BEA JMS implementation team to comment on this.
Option (2) Configure smaller custom thread pools - one for each queue. Solves the problem above. Let us say we allocate 2 threads per MDB in custom thread pools. This ensures that none of the queues starve, however, if there is a practical limit on the maximum number of threads that can be configured, then this option introduces an inefficiency. What if there are 200 messages in one queue and zero messages in all others ? We are allowing only two threads to process those 200 messages while the other threads just sit and watch.

Queues - 1 MDB or many?

I need an opinion - how well would a system with a single MDB that handles multiple message types (e.g. xml messages, with tags to indicate the type of message) vs having multiple MDB's per topic. I guess I'm looking at a "best practice" pattern. I've been thinking of this and realized that if you have a single MDB with multiple message types, then this could mean that if there were a message type that sees a high volume vs another that sees a lower volume, the lower volume message processing of the messages would be delayed.
From what I've read, the container is supposed to compensate for a high volume of messages through creating more instances, but this still doesn't stop the fact that the messages are processed FIFO, so having multiple topics would be a far more better way to go.
The hope here however was to have a model where we would only have two types of messages initially processed asynchronously, while the others were processed synchronously through regular session beans, but additional message types may be turned on later to run asynchronously without having to create new MDB's for each additional topic. But I think this could just mean creating unnecessary delays for other types of messages.
(reposted from AQ forum...figured this may be a better forum for this)
Any thoughts?
Thanks

Jason -- One important point is that the EJB specification (specifically MDBs) does not guarantee FIFO processing. Here is the quote from section 15.4.6 of the spec:
A container allows many instances of a message-driven bean class to be executing concurrently, thus allowing for the concurrent processing of a stream of messages. No guarantees are made as to the exact order in which messages are delivered to the instances of the message-driven bean class, although the container should attempt to deliver messages in order when it does not impair the concurrency of message processing. Message-driven beans should therefore be prepared to handle messages that are out of sequence: for example, the message to cancel a reservation may be delivered before the message to make the reservation.
That said, I have seen queuing systems that have used both types of arrangements you describe (although none were using JMS.) For the generic case, there were problems if the queue was backed up so you might consider multiple queues with different priorities, each of which has a generic payload. This helps starvation of time critical messages.
If you do establish different topics, then you will have more work to do in terms of deployment and management of the topics, but the messages will be cleanly separated and you may be able to make some optimizaitons of message processing since they can be created in a form that best mathces their use.
Overall, my experiences with generic queues, once we established multiple queues with different priorities, was good. Just be ready for the additional overhead of processing XML messages.
Thanks -- Jeff

Topic vs MDB's

          Hi,
          We are designing an application which will serve as message broker between different
          publisher and subscriber applications. We are planning to use Weblogic 6.1 JMS
          for that purpose. Could you please let me know what are the pros and cons of having
          multiple topics for different types of messages VS having a single topic serving
          all types of messages and multiple MDB's with message selectors to process those
          messages?
          Also, could you please let me know the resources I can refer for looking at different
          design patterns and design considerations for this type of JMS message broker?
          Thanks,
          Goutam.


Jason -- One important point is that the EJB specification (specifically MDBs) does not guarantee FIFO processing. Here is the quote from section 15.4.6 of the spec:
A container allows many instances of a message-driven bean class to be executing concurrently, thus allowing for the concurrent processing of a stream of messages. No guarantees are made as to the exact order in which messages are delivered to the instances of the message-driven bean class, although the container should attempt to deliver messages in order when it does not impair the concurrency of message processing. Message-driven beans should therefore be prepared to handle messages that are out of sequence: for example, the message to cancel a reservation may be delivered before the message to make the reservation.
That said, I have seen queuing systems that have used both types of arrangements you describe (although none were using JMS.) For the generic case, there were problems if the queue was backed up so you might consider multiple queues with different priorities, each of which has a generic payload. This helps starvation of time critical messages.
If you do establish different topics, then you will have more work to do in terms of deployment and management of the topics, but the messages will be cleanly separated and you may be able to make some optimizaitons of message processing since they can be created in a form that best mathces their use.
Overall, my experiences with generic queues, once we established multiple queues with different priorities, was good. Just be ready for the additional overhead of processing XML messages.
Thanks -- Jeff

MDB Timeouts and transaction behavior

Hi, thanks in advance for any help with this.
We have a MDB where we have set the timeout to five minutes. In a particular case this timeout is being reached but even though the MDB times out the transaction and sends the message for redelivery the original transaction that was processing the message continues until something happens from an application standpoint to cause that original transaction to complete. This means that we have the same message processed twice under these circumstances.
I would have expected that if a transaction timed out that the transaction would have been terminated and therefore our processing would have stopped. Is there a way to force this behavior or do we have to put an alarm in our code and kill ourselves such that we never encounter the transaction time out?
Thanks,
Sue Shanabrook

I should have mentioned that we are using container managed transactions.

How to read .mdb file from shared folder

Hi All,
In one of my local computer I have a shared folder and within the folder I have a .mdb file. Now I am trying to read that file from MII. I have tried with Get_File_List action block. I am providing the following information to Get_File_List
Folder :
<Computer Name>\<Shared Folder Name>
Mask: .mdb
But in return of Get_File_List, I am not getting any file related information. It is only providing like below
<Rowsets>
<Rowset>
<Columns>
<Column Description="Name" MaxRange="0" MinRange="0" Name="Name" SQLDataType="1" SourceColumn="Name"/>
<Column Description="Date" MaxRange="0" MinRange="0" Name="Date" SQLDataType="93" SourceColumn="Date"/>
<Column Description="Size" MaxRange="100" MinRange="0" Name="Size" SQLDataType="4" SourceColumn="Size"/>
<Column Description="LastWriteDate" MaxRange="0" MinRange="0" Name="LastWriteDate" SQLDataType="93" SourceColumn="LastWriteDate"/>
<Column Description="ReadOnly" MaxRange="1" MinRange="0" Name="ReadOnly" SQLDataType="4" SourceColumn="ReadOnly"/>
<Column Description="FullPath" MaxRange="0" MinRange="0" Name="FullPath" SQLDataType="1" SourceColumn="FullPath"/>
</Columns>
</Rowset>
</Rowsets>
Can anybody suggest me how to achieve it.
Thanks in advance
Chandan

Hi Chandan,
Specify the mask as *.mdb and try.
Thanks,
Dipankar

I have a web service that I am trying to use an MDB with.

I have a web service where I request using soapUI, and the the response from the soapUI that I get is correct. However, in addition to this "regular" program flow, I am sending data to a queue where 2 things should happen:
1. my message should get put in that queue....(not a problem I think, it's says it can connect and send to this one)
2. a MDB should get triggered, but isn't, and the MDB should start it's own program flow after this.
this is the basics as to what is happening in my program, and I get this error below on the end of the output. so would anyone have any theories as to what might be wrong?
ApplicationDispatcher[] Servlet.service() for servlet HandlePrecompiledJsp threw exception
com.sun.enterprise.tools.guiframework.exception.FrameworkException: Unabled to handle pre-compiled JSP '/jsp/LogDetail.jsp'. Expected pre-compiled classname: 'org.apache.jsp.jsp.LogDetail_jsp'.
at com.sun.enterprise.tools.admingui.servlet.HandlePrecompiledJsp.doPost(HandlePrecompiledJsp.java:59)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:767)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:860)
at sun.reflect.GeneratedMethodAccessor56.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:249)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:282)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:165)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:257)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:55)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:161)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:723)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:482)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:417)
at org.apache.catalina.core.ApplicationDispatcher.access$000(ApplicationDispatcher.java:80)
at org.apache.catalina.core.ApplicationDispatcher$PrivilegedForward.run(ApplicationDispatcher.java:95)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:313)
at com.iplanet.jato.view.ViewBeanBase.forward(ViewBeanBase.java:340)
at com.iplanet.jato.view.ViewBeanBase.forwardTo(ViewBeanBase.java:261)
at com.sun.enterprise.tools.guiframework.view.DescriptorViewHelper.execute(DescriptorViewHelper.java:316)
at com.sun.enterprise.tools.guiframework.view.DescriptorViewBeanBase.execute(DescriptorViewBeanBase.java:192)
at com.iplanet.jato.view.RequestHandlingViewBase.handleRequest(RequestHandlingViewBase.java:308)
at com.iplanet.jato.view.ViewBeanBase.dispatchInvocation(ViewBeanBase.java:802)
at com.iplanet.jato.view.ViewBeanBase.invokeRequestHandlerInternal(ViewBeanBase.java:740)
Caused by: javax.servlet.ServletException: com.sun.enterprise.tools.guiframework.exception.FrameworkException: java.lang.reflect.InvocationTargetException while attempting to process a 'beginDisplay' event for 'LogDetail'.
at org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:830)
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:763)
at org.apache.jsp.jsp.LogDetail_jsp._jspService(LogDetail_jsp.java:126)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:105)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:860)
at com.sun.enterprise.tools.admingui.servlet.HandlePrecompiledJsp.doPost(HandlePrecompiledJsp.java:57)
... 67 more
Lavanya

You cannot gift to another country at all.

MDB(Message Driven Bean) is not working in MDM2.0.1

Hi,
I am trying to use MDB for importing files.I followed the Weblogic_jms_Integration(1308181.1) document and i created all the xml files CM_config.xmCM_ejb-jar.xml.wls.jms_1.includel.win.exit_4.include,CM_config.xml.win.jms.include,CM_ejb-jar.xml.wls.mdb.include,CM_weblogic-ejb-jar.xml.jms.include and put these files in respective directory as mentioned in the document.I have created one XAI inbound service ,XAI JNDI Servers,JMS Connection,Jms Queue and i am putting my msgs in queue in web logic server.But it is nt picking files from queues.It is showing some errors like:
Error:
Table CI_XAI_JNDI_SVR has a maintenance program entry CIPXJSVR that is not found in the program components table
I think here MDB is nt enabling thats why it is not picking the files from queue.
But we are able to pick that files from queue by MPL.
Please help me in this regards.
Thanks.
SUNIL

Hi,
I am trying to use MDB for importing files.I followed the Weblogic_jms_Integration(1308181.1) document and i created all the xml files CM_config.xmCM_ejb-jar.xml.wls.jms_1.includel.win.exit_4.include,CM_config.xml.win.jms.include,CM_ejb-jar.xml.wls.mdb.include,CM_weblogic-ejb-jar.xml.jms.include and put these files in respective directory as mentioned in the document.I have created one XAI inbound service ,XAI JNDI Servers,JMS Connection,Jms Queue and i am putting my msgs in queue in web logic server.But it is nt picking files from queues.It is showing some errors like:
Error:
Table CI_XAI_JNDI_SVR has a maintenance program entry CIPXJSVR that is not found in the program components table
I think here MDB is nt enabling thats why it is not picking the files from queue.
But we are able to pick that files from queue by MPL.
Please help me in this regards.
Thanks.
SUNIL

How to read accdb and mdb files using JDBC or File Adapter

Hi,
How to read and extract the .accdb and .mdb files from FTP server and parsing into xml by using FTP or JDBC Adapter in SAP PI7.11 With linx Os.
Regards
Upendra

Hi,
As per SAP note:1681420 i have to install the below driver from Microsoft
Our SAP PI installed under Unxi OS ,how to install the driver (.exe file) .
Driver name :AccessDatabaseEngine_x64.exe
Url:Download Microsoft Access Database Engine 2010 Redistributable from Official Microsoft Download Center
1681420 - PI : Where to locate the JDBC Driver for Microsoft Access
Regards
Upendra

Access Database (.mdb) on Windows Server 2012 R2 Essentials

Hi guys, thanks for your time!
SCENARIO:
- Windows Server 2012 R2 Essentials
- Windows 7 Ultimate Clients (3 clients)
- VB6 application on clients using a MS Database (.mdb) hosted on the server.
- Clients access the database (.mdb) via a mapped network drive (K:).
PROBLEM:
- Microsoft Database (.mdb) on server gets corrupted frequently.
- Clients don't "flush their changes" back to the database: database was not updated.
WORKAROUND:
- Database was moved from the server to one of the Windows 7 clients.
- Application is running OK.
CONFIGURATION:
- Permissions are correct: network and NTFS.
- No faulty network hardware: switch, cabling, NICs.
- Computers and Server hardware is new.
- UPS are used everywhere.
SOME LINKS:
SMB 3.0
- Opportunistic Locking and Read Caching on Microsoft Windows Networks.
- Windows 7 cannot
open the shared MS Access database if it's opened by another user
- Initializing the
Microsoft Jet 4.0 Database Engine Driver
- Moved to
Server 2012 getting Access Database Corruption
Oplocks
- Configuring
opportunistic locking in Windows
- Understanding
offline files
- How to
enable and disable SMBv1, SMBv2, and SMBv3
- Is it possible to
monitor and log actual queries against an Access MDB?
Now, server is useless if it is not hosting our database. Any ideas, please? Do I need to diagnose using Wireshark? Or using Sysinternals Process Monitor? I think that is a waste of time.
Thank you!

Thanks for your reply.
Software is from a 3rd party provider. It currently supports concurrency. It was deployed on Windows XP. SQL Server would be a nice upgrade, however that is
not an option.
Something has changed with newer versions of Windows. That is what I am going to study in a lab I prepared with a real server and some clients.
File-sharing databases (Microsoft JET databases) are very old technology even before I was a college student. However, I have been very busy researching this technology.
It was made for multi-user environments. It is highly tied to file sharing services from Windows: SMB protocol.
Windows XP, Vista, 7 and 8 use different versions of this protocol. I think that is the root of the problem. With old technology, application was running fine.
With new technology, application is troublesome. I will check several things: JET drivers vs. ACE drivers, SMB tweaks, etc.
UPDATE:
Basically, there are 4 general answers to this issue:
1) Migrate your Access Database to SQL Server Express (or another RDBMS engine).
2) @Server: disable SMB 2.0/3.0 protocol stack by powershell command. Network speed decreases.
3) @Clients: disable client redirector caches by using regedit.
4) @Server: disable the leasing on the file server.
5) @Server: tuning Broadcom NIC parameters.
References:
- https://technet.microsoft.com/en-us/library/ff686200(WS.10).aspx
- https://msdn.microsoft.com/en-us/library/windows/desktop/aa365433(v=vs.85).aspx
- http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Windows/Q_28482197.html
- http://tipsntricks.sherr.co.uk/stop-smb-corrupting-files/
- http://www.dataaccess.com/whitepapers/opportunlockingreadcaching.html
- https://social.technet.microsoft.com/forums/windowsserver/en-US/67baa9fd-5eaf-438e-9cc4-dc1a531b9e19/disabling-oplocksmb2-vs-fileinfocachelifetime
- https://social.technet.microsoft.com/Forums/windowsserver/en-US/7336d31b-6c24-468a-9c47-750244ae3a8c/moved-to-server-2012-getting-access-database-corruption
- https://social.technet.microsoft.com/Forums/en-US/e9567167-22db-4b8c-9f96-a08b97d507f9/server-2012-r2-file-server-stops-responding-to-smb-connections
- http://support2.microsoft.com/kb/2957623
- http://support2.microsoft.com/kb/2899011
- http://support2.microsoft.com/kb/2955164
- https://social.technet.microsoft.com/Forums/en-US/7bd0aa5b-eb95-40a8-a56d-c6013273665c/extremely-slow-smb-network-speed-server-2012-r2?forum=winserver8gen

MS SQL Server problem with MDB's: javax.transaction.xa.XAException

          I am programming agents in j2ee and using MDB to implement the asynchronicity of
          the agents.
          Those MDB's get messages (MapMessage) from a controller (an SFSB) that contain
          the agent's ID and the action that the agent has to perform. The MDB creates a
          SFSB, and calls the appropriate action from this session bean. Those actions require
          to read and write from my MS SQL Server 2000 XA database. But when running my
          program, I often get this error, which doesn't seem to affect the action, because
          when I check my database data, everything is updated correctly. So the program
          still completes, but the errors slow down the execution (the program hangs for
          about 3 seconds, each time the error occurs).
          Does anybody has an explanation or solution for this?
          Thank you...
          This is the error output:
          onMessage()
          Reading MapMessage: 1
          <26-apr-2004 14.34 u. CEST> <Error> <EJB> <BEA-010026> <Exception occurred during
          commit of transaction Xid=BEA1-005F88135FFBA636FFF7(15619088),Status=Rolled back.
          [Reason=javax.transaction.xa.XAException: [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare
          (0) returns -4],numRepliesOwedMe=0,numRepliesOwedOthers=0,seconds since begin=4,seconds
          left=30,XAServerResourceInfo[JMS_JMS Server2_NotDurable]=(ServerResourceInfo[JMS_JMS
          Server2_NotDurable]=(state=rolledback,assigned=lucille3_ms),xar=JMS_JMS Server2_NotDurable),XAServerResourceInfo[MSSQL
          Connection Pool]=(ServerResourceInfo[MSSQL Connection Pool]=(state=rolledback,assigned=lucille3_ms),xar=MSSQL
          Connection Pool),SCInfo[cluster+lucille3_ms]=(state=rolledback),local properties=({}),OwnerTransactionManager=ServerTM[ServerCoordinatorDescriptor=(CoordinatorURL=lucille3_ms+127.0.0.1:8001+cluster+t3+,
          XAResources={},NonXAResources={})],CoordinatorURL=lucille3_ms+127.0.0.1:8001+cluster+t3+):
          javax.transaction.xa.XAException: [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare
          (0)returns -4
          at weblogic.jdbcx.sqlserver.SQLServerImplXAResource.executeXaRpc(Unknown
          Source)
          at weblogic.jdbcx.sqlserver.SQLServerImplXAResource.prepare(Unknown Source)
          at weblogic.jdbcx.base.BaseXAResource.prepare(Unknown Source)
          at weblogic.jdbc.jta.DataSource.prepare(DataSource.java:821)
          at weblogic.transaction.internal.XAServerResourceInfo.prepare(XAServerResourceInfo.java:1161)
          at weblogic.transaction.internal.XAServerResourceInfo.prepare(XAServerResourceInfo.java:395)
          at weblogic.transaction.internal.ServerSCInfo$1.execute(ServerSCInfo.java:253)
          at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
          --------------- nested within: ------------------
          weblogic.transaction.RollbackException: Could not prepare resource 'MSSQL Connection
          Pool
          [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare (0) returns -4 - with nested
          exception:
          [javax.transaction.xa.XAException: [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare
          (0) returns -4]
          at weblogic.transaction.internal.TransactionImpl.throwRollbackException(TransactionImpl.java:1644)
          at weblogic.transaction.internal.ServerTransactionImpl.internalCommit(ServerTransactionImpl.java:300)
          at weblogic.transaction.internal.ServerTransactionImpl.commit(ServerTransactionImpl.java:221)
          at weblogic.ejb20.internal.MDListener.execute(MDListener.java:412)
          at weblogic.ejb20.internal.MDListener.transactionalOnMessage(MDListener.java:316)
          at weblogic.ejb20.internal.MDListener.onMessage(MDListener.java:281)
          at weblogic.jms.client.JMSSession.onMessage(JMSSession.java:2596)
          at weblogic.jms.client.JMSSession.execute(JMSSession.java:2516)
          at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170).>


          I am programming agents in j2ee and using MDB to implement the asynchronicity of
          the agents.
          Those MDB's get messages (MapMessage) from a controller (an SFSB) that contain
          the agent's ID and the action that the agent has to perform. The MDB creates a
          SFSB, and calls the appropriate action from this session bean. Those actions require
          to read and write from my MS SQL Server 2000 XA database. But when running my
          program, I often get this error, which doesn't seem to affect the action, because
          when I check my database data, everything is updated correctly. So the program
          still completes, but the errors slow down the execution (the program hangs for
          about 3 seconds, each time the error occurs).
          Does anybody has an explanation or solution for this?
          Thank you...
          This is the error output:
          onMessage()
          Reading MapMessage: 1
          <26-apr-2004 14.34 u. CEST> <Error> <EJB> <BEA-010026> <Exception occurred during
          commit of transaction Xid=BEA1-005F88135FFBA636FFF7(15619088),Status=Rolled back.
          [Reason=javax.transaction.xa.XAException: [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare
          (0) returns -4],numRepliesOwedMe=0,numRepliesOwedOthers=0,seconds since begin=4,seconds
          left=30,XAServerResourceInfo[JMS_JMS Server2_NotDurable]=(ServerResourceInfo[JMS_JMS
          Server2_NotDurable]=(state=rolledback,assigned=lucille3_ms),xar=JMS_JMS Server2_NotDurable),XAServerResourceInfo[MSSQL
          Connection Pool]=(ServerResourceInfo[MSSQL Connection Pool]=(state=rolledback,assigned=lucille3_ms),xar=MSSQL
          Connection Pool),SCInfo[cluster+lucille3_ms]=(state=rolledback),local properties=({}),OwnerTransactionManager=ServerTM[ServerCoordinatorDescriptor=(CoordinatorURL=lucille3_ms+127.0.0.1:8001+cluster+t3+,
          XAResources={},NonXAResources={})],CoordinatorURL=lucille3_ms+127.0.0.1:8001+cluster+t3+):
          javax.transaction.xa.XAException: [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare
          (0)returns -4
          at weblogic.jdbcx.sqlserver.SQLServerImplXAResource.executeXaRpc(Unknown
          Source)
          at weblogic.jdbcx.sqlserver.SQLServerImplXAResource.prepare(Unknown Source)
          at weblogic.jdbcx.base.BaseXAResource.prepare(Unknown Source)
          at weblogic.jdbc.jta.DataSource.prepare(DataSource.java:821)
          at weblogic.transaction.internal.XAServerResourceInfo.prepare(XAServerResourceInfo.java:1161)
          at weblogic.transaction.internal.XAServerResourceInfo.prepare(XAServerResourceInfo.java:395)
          at weblogic.transaction.internal.ServerSCInfo$1.execute(ServerSCInfo.java:253)
          at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
          --------------- nested within: ------------------
          weblogic.transaction.RollbackException: Could not prepare resource 'MSSQL Connection
          Pool
          [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare (0) returns -4 - with nested
          exception:
          [javax.transaction.xa.XAException: [BEA][SQLServer JDBC Driver][SQLServer]xa_prepare
          (0) returns -4]
          at weblogic.transaction.internal.TransactionImpl.throwRollbackException(TransactionImpl.java:1644)
          at weblogic.transaction.internal.ServerTransactionImpl.internalCommit(ServerTransactionImpl.java:300)
          at weblogic.transaction.internal.ServerTransactionImpl.commit(ServerTransactionImpl.java:221)
          at weblogic.ejb20.internal.MDListener.execute(MDListener.java:412)
          at weblogic.ejb20.internal.MDListener.transactionalOnMessage(MDListener.java:316)
          at weblogic.ejb20.internal.MDListener.onMessage(MDListener.java:281)
          at weblogic.jms.client.JMSSession.onMessage(JMSSession.java:2596)
          at weblogic.jms.client.JMSSession.execute(JMSSession.java:2516)
          at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170).>

MDB (2-phase commit) behavior during abnormal JMS termination

Hello to everyone!
I plan to test the following scenario tomorrow (sort of a bug replication in our system).
Anyway, wanted to know in advance the expected behavior (just in case one of you already know
or have an experience related to this test). Thank you in advance.
Scenario:
I want to test/know the behavior of a 2-phase commit (2PC) MDB when JMS server abnormally exits
(say the process was killed).
Test flow:
start app server --> deploy 2pc-mdb --> send dummy data --> kill jms process --> restart jms process
1. will the connection be closed properly?
2. when jms server restarts, will the value of active consumer(count) doubled?
note: i think after mdb deployment, corresponding destination consumer count is 1.
the problem that occurred in our system was that the consumer count doubled after server restarted.
it seem like the previous connection was not closed when the jms server abnormally terminated.
any inputs will be greatly appreciated.
thanks and best regards.

You have to use TxDataSource for container managed tx or if you are using JTA (in
addition to ofcourse doing 2PC).
S
"Dale Olzer" <[email protected]> wrote:
>
Using weblogic 6.1 SP 4
I have a simple container managed Message Driven Bean. Using a destination
type
javax.jms.Queue.
When the onMessage method finishes the Message is still Pending on the
queue.
see the ejb-jar.xml below
<ejb-jar>
<enterprise-beans>
<message-driven>
<display-name>IvrMessageBean</display-name>
<ejb-name>IvrMsgBean</ejb-name>
<ejb-class>com.edocs.ps.ivr.IvrMsgBean</ejb-class>
<transaction-type>Container</transaction-type>
<acknowledge-mode>Auto-acknowledge</acknowledge-mode>
<message-driven-destination>
<destination-type>javax.jms.Queue</destination-type>
</message-driven-destination>
</message-driven>
</enterprise-beans>
</ejb-jar>
I noticed when I set a JDBC TX DataSource to 2 Phase Commit, the JMS
transaction
started commitig and nothing was left pending in the Queue.
Does 2PC have to be set in a DataSource for Container Managed MDB's to
work?

MDB container managed transaction demarcation not working in wls 6.1 beta

I have an MDB which sends the messages it receives onto another JMS
          destination within the onMessage method. These messages are not sent to
          the JMS destination unless I explicitly use a transacted session for the
          destination and subsequently commit the session. If I set the transacted
          parameter to Session as false the messages are sent. If I set the
          transacted parameter to true the messages will only be output if the
          session is committed. This is the standard behaviour for a JMS session
          but this is not the correct behaviour for an MDB running with
          container-managed transaction demarcation.
          For a start the transacted parameter to session should be ignored when
          run in the context of a container transaction and the commit method
          should thrown an exception as it is not allowed within the context of a
          container transaction.
          This is the MDB code and the deployment descriptor: -
          public class MessageBean implements MessageDrivenBean, MessageListener
          private String topicName = null;
          private TopicConnectionFactory topicConnectionFactory = null;
          private TopicConnection topicConnection = null;
          private TopicSession topicSession = null;
          private Topic topic = null;
          private TopicPublisher topicPublisher = null;
          private TextMessage textMessage=null;
          private transient MessageDrivenContext messageDrivenContext = null;
          private Context jndiContext;
          public final static String
          JMS_FACTORY="weblogic.examples.jms.TopicConnectionFactory";
          public final static String
          TOPIC="weblogic.examples.jms.exampleTopic";
          public MessageBean()
          public void setMessageDrivenContext(MessageDrivenContext
          messageDrivenContext)
          this.messageDrivenContext = messageDrivenContext;
          public void ejbCreate()
          public void onMessage(Message inMessage)
          try
          jndiContext = new InitialContext();
          topicConnectionFactory =
          (TopicConnectionFactory)jndiContext.lookup(JMS_FACTORY);
          topic = (Topic) jndiContext.lookup(TOPIC);
          topicConnection =
          topicConnectionFactory.createTopicConnection();
          topicConnection.start();
          // The transacted parameter should be ignored in the context of a
          container tx
          topicSession = topicConnection.createTopicSession(true,
          Session.AUTO_ACKNOWLEDGE);
          topicPublisher = topicSession.createPublisher(topic);
          textMessage = (TextMessage)inMessage;
          topicPublisher.publish(inMessage);
          // this is illegal in a container transaction
          topicSession.commit();
          topicConnection.close();
          catch (JMSException je)
          throw new EJBException(je);
          catch (NamingException ne)
          throw new EJBException(ne);
          public void ejbRemove()
          <?xml version="1.0" encoding="UTF-8"?>
          <!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise
          JavaBeans 2.0//EN' 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>
          <ejb-jar>
          <enterprise-beans>
          <message-driven>
          <display-name>MessageBean</display-name>
          <ejb-name>MessageBean</ejb-name>
          <ejb-class>MessageBean</ejb-class>
          <transaction-type>Container</transaction-type>
          <message-driven-destination>
          <destination-type>javax.jms.Queue</destination-type>
          </message-driven-destination>
          <security-identity>
          <description></description>
          <run-as>
          <description></description>
          <role-name></role-name>
          </run-as>
          </security-identity>
          </message-driven>
          </enterprise-beans>
          <assembly-descriptor>
          <container-transaction>
          <method>
          <ejb-name>MessageBean</ejb-name>
          <method-name>*</method-name>
          </method>
          <trans-attribute>Required</trans-attribute>
          </container-transaction>
          </assembly-descriptor>
          </ejb-jar>


Please see the response in the EJB newsgroup.
          Also, could you kindly only post to a single newsgroup?
          Thanks.
          "Jimmy Johns" <[email protected]> wrote in message
          news:[email protected]...
          > I have an MDB which sends the messages it receives onto another JMS
          > destination within the onMessage method. These messages are not sent to
          > the JMS destination unless I explicitly use a transacted session for the
          >
          > destination and subsequently commit the session. If I set the transacted
          >
          > parameter to Session as false the messages are sent. If I set the
          > transacted parameter to true the messages will only be output if the
          > session is committed. This is the standard behaviour for a JMS session
          > but this is not the correct behaviour for an MDB running with
          > container-managed transaction demarcation.
          >
          > For a start the transacted parameter to session should be ignored when
          > run in the context of a container transaction and the commit method
          > should thrown an exception as it is not allowed within the context of a
          > container transaction.
          >
          > This is the MDB code and the deployment descriptor: -
          >
          > public class MessageBean implements MessageDrivenBean, MessageListener
          > {
          > private String topicName = null;
          > private TopicConnectionFactory topicConnectionFactory = null;
          > private TopicConnection topicConnection = null;
          > private TopicSession topicSession = null;
          > private Topic topic = null;
          > private TopicPublisher topicPublisher = null;
          > private TextMessage textMessage=null;
          > private transient MessageDrivenContext messageDrivenContext = null;
          >
          > private Context jndiContext;
          >
          > public final static String
          > JMS_FACTORY="weblogic.examples.jms.TopicConnectionFactory";
          > public final static String
          > TOPIC="weblogic.examples.jms.exampleTopic";
          >
          > public MessageBean()
          > {
          > }
          >
          > public void setMessageDrivenContext(MessageDrivenContext
          > messageDrivenContext)
          > {
          > this.messageDrivenContext = messageDrivenContext;
          > }
          >
          > public void ejbCreate()
          > {
          > }
          >
          > public void onMessage(Message inMessage)
          > {
          > try
          > {
          > jndiContext = new InitialContext();
          > topicConnectionFactory =
          > (TopicConnectionFactory)jndiContext.lookup(JMS_FACTORY);
          > topic = (Topic) jndiContext.lookup(TOPIC);
          > topicConnection =
          > topicConnectionFactory.createTopicConnection();
          > topicConnection.start();
          > // The transacted parameter should be ignored in the context of a
          > container tx
          > topicSession = topicConnection.createTopicSession(true,
          > Session.AUTO_ACKNOWLEDGE);
          > topicPublisher = topicSession.createPublisher(topic);
          > textMessage = (TextMessage)inMessage;
          > topicPublisher.publish(inMessage);
          > // this is illegal in a container transaction
          > topicSession.commit();
          > topicConnection.close();
          > }
          > catch (JMSException je)
          > {
          > throw new EJBException(je);
          > }
          > catch (NamingException ne)
          > {
          > throw new EJBException(ne);
          > }
          > }
          >
          > public void ejbRemove()
          > {
          > }
          > }
          >
          >
          >
          >
          > <?xml version="1.0" encoding="UTF-8"?>
          >
          > <!DOCTYPE ejb-jar PUBLIC '-//Sun Microsystems, Inc.//DTD Enterprise
          > JavaBeans 2.0//EN' 'http://java.sun.com/dtd/ejb-jar_2_0.dtd'>
          >
          > <ejb-jar>
          > <enterprise-beans>
          > <message-driven>
          > <display-name>MessageBean</display-name>
          > <ejb-name>MessageBean</ejb-name>
          > <ejb-class>MessageBean</ejb-class>
          > <transaction-type>Container</transaction-type>
          > <message-driven-destination>
          > <destination-type>javax.jms.Queue</destination-type>
          > </message-driven-destination>
          > <security-identity>
          > <description></description>
          > <run-as>
          > <description></description>
          > <role-name></role-name>
          > </run-as>
          > </security-identity>
          > </message-driven>
          > </enterprise-beans>
          > <assembly-descriptor>
          > <container-transaction>
          > <method>
          > <ejb-name>MessageBean</ejb-name>
          > <method-name>*</method-name>
          > </method>
          > <trans-attribute>Required</trans-attribute>
          > </container-transaction>
          > </assembly-descriptor>
          > </ejb-jar>
          >
          >
          >
          >
          >
          >
          >
          >

MDB rollbacks and stops the listener port with error code 2072

Hi
We have a MDB listening on QUEUE1. This MDB processes the message and puts another message in QUEUE2. Transaction is "required" for this MDB.
The processing could somtime take more than 2 min. We used to get EJB timeout error in this scenario. We changed EJB timeout to 5 min (default was 2 min). This resolved the timeout error. But it started throwing following exception. Note that if the processing takes less than 2 min, MDB never rollbacks.
After this rollack, listener port can not pick up the next message and it throws error (MQJMS2002: failed to get message from MQ queue. MQ Error Code 2072) . It stops as a result and restarts after 60 sec. Even after restart it can not process the messages till we restart the JVM.
Regarding error handling, Backout threshold is 3. If the message is redelivered, we discard this message.
We are using 2 Phase commit for 2 resources MQ (5.3) and MS SQL.
Websphere version is 5.1.
Two issues here
1. Why is MDB rolling back if processing takes more than 2 min.
2. After the rollback, why is listener port not picking up the messages. Why do we need to recycle the JVM.
Any pointers to resolve this issue?
EXCEPTION
[11/29/05 15:03:37:752 EST] 1b9bccc XATransaction E J2CA0027E: An exception occurred while invoking end on an XA Resource Adapter from dataSource JMS$postprocessor$JMSManagedConnection@25078403, within transaction ID {XID: formatId(57415344), gtrid_length(51), bqual_length(2, data(00000000000000950000000113238145f813eccfef12249c6aab206666f96901636c5f6170703130355f73656e7431715f716113238145f813eccfef12249c6aab206666f969010000000100000000)}: javax.transaction.xa.XAException: XA operation failed, see errorCode
at com.ibm.mq.MQXAResource.end(MQXAResource.java:520)
at com.ibm.ejs.jms.JMSManagedSession$JMSXAResource.end(JMSManagedSession.java:1557)
at com.ibm.ejs.j2c.XATransactionWrapper.end(XATransactionWrapper.java:525)
at com.ibm.ws.Transaction.JTA.JTAResourceBase.end(JTAResourceBase.java:253)
at com.ibm.ws.Transaction.JTA.RegisteredResources.distributeEnd(RegisteredResources.java:629)
at com.ibm.ws.Transaction.JTA.TransactionImpl.internalPrepare(TransactionImpl.java:1241)
at com.ibm.ws.Transaction.JTA.TransactionImpl.commit(TransactionImpl.java:981)
at com.ibm.ws.Transaction.JTA.TranManagerImpl.commit(TranManagerImpl.java:150)
at com.ibm.ws.Transaction.JTA.TranManagerSet.commit(TranManagerSet.java:177)
at com.ibm.ejs.csi.TranStrategy.commit(TranStrategy.java:712)
at com.ibm.ejs.csi.TranStrategy.postInvoke(TranStrategy.java:167)
at com.ibm.ejs.csi.TransactionControlImpl.postInvoke(TransactionControlImpl.java:570)
at com.ibm.ejs.container.EJSContainer.postInvoke(EJSContainer.java:3068)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:102)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:127)
at com.ibm.ejs.jms.listener.ServerSession.run(ServerSession.java:375)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:912)
[11/29/05 15:03:38:089 EST] 1b9bccc ServerSession W WMSG0031E: Exception processing JMS Message for MDB BatchProcessorMDB, JMSDestination jms/PostprocessorQ : javax.ejb.TransactionRolledbackLocalException: ; nested exception is: com.ibm.ws.exception.WsEJBException
com.ibm.ws.exception.WsEJBException
at com.ibm.ejs.container.LocalExceptionMappingStrategy.mapException(LocalExceptionMappingStrategy.java:159)
at com.ibm.ejs.container.LocalExceptionMappingStrategy.mapCSITransactionRolledBackException(LocalExceptionMappingStrategy.java:293)
at com.ibm.ejs.container.EJSContainer.postInvoke(EJSContainer.java:3159)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:102)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:127)
at com.ibm.ejs.jms.listener.ServerSession.run(ServerSession.java:375)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:912)
javax.ejb.TransactionRolledbackLocalException: ; nested exception is: com.ibm.ws.exception.WsEJBException
at com.ibm.ejs.container.LocalExceptionMappingStrategy.mapCSIException(LocalExceptionMappingStrategy.java:96)
at com.ibm.ejs.container.LocalExceptionMappingStrategy.mapException(LocalExceptionMappingStrategy.java:165)
at com.ibm.ejs.container.LocalExceptionMappingStrategy.mapCSITransactionRolledBackException(LocalExceptionMappingStrategy.java:293)
at com.ibm.ejs.container.EJSContainer.postInvoke(EJSContainer.java:3159)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:102)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:127)
at com.ibm.ejs.jms.listener.ServerSession.run(ServerSession.java:375)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:912)
[11/29/05 15:03:38:124 EST] 1e9aa18 JMSExceptionL E WMSG0018E: Error on JMSConnection for MDB BatchProcessorMDB , JMSDestination jms/PostprocessorQ : javax.jms.JMSException: MQJMS2002: failed to get message from MQ queue
at com.ibm.mq.jms.services.ConfigEnvironment.newException(ConfigEnvironment.java:553)
at com.ibm.mq.jms.MQSession.consume(MQSession.java:3144)
at com.ibm.mq.jms.MQSession.run(MQSession.java:1585)
at com.ibm.ejs.jms.JMSSessionHandle.run(JMSSessionHandle.java:924)
at com.ibm.ejs.jms.listener.ServerSession.connectionConsumerOnMessage(ServerSession.java:752)
at com.ibm.ejs.jms.listener.ServerSession.onMessage(ServerSession.java:527)
at com.ibm.ejs.jms.listener.ServerSession.dispatch(ServerSession.java:494)
at sun.reflect.GeneratedMethodAccessor40.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.ibm.ejs.jms.listener.ServerSessionDispatcher.dispatch(ServerSessionDispatcher.java:37)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:91)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:127)
at com.ibm.ejs.jms.listener.ServerSession.run(ServerSession.java:375)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:912)
---- Begin backtrace for Nested Throwables
com.ibm.mq.MQException: MQJE001: Completion Code 2, Reason 2072
at com.ibm.mq.jms.MQSession.consume(MQSession.java:3118)
at com.ibm.mq.jms.MQSession.run(MQSession.java:1585)
at com.ibm.ejs.jms.JMSSessionHandle.run(JMSSessionHandle.java:924)
at com.ibm.ejs.jms.listener.ServerSession.connectionConsumerOnMessage(ServerSession.java:752)
at com.ibm.ejs.jms.listener.ServerSession.onMessage(ServerSession.java:527)
at com.ibm.ejs.jms.listener.ServerSession.dispatch(ServerSession.java:494)
at sun.reflect.GeneratedMethodAccessor40.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.ibm.ejs.jms.listener.ServerSessionDispatcher.dispatch(ServerSessionDispatcher.java:37)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:91)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:127)
at com.ibm.ejs.jms.listener.ServerSession.run(ServerSession.java:375)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:912)
[11/29/05 15:03:38:149 EST] 1e9aa18 JMSExceptionL E WMSG0057E: Error on JMSConnection for MDB BatchProcessorMDB , JMSDestination jms/PostprocessorQ , JMS Linked Exception : com.ibm.mq.MQException: MQJE001: Completion Code 2, Reason 2072
at com.ibm.mq.jms.MQSession.consume(MQSession.java:3118)
at com.ibm.mq.jms.MQSession.run(MQSession.java:1585)
at com.ibm.ejs.jms.JMSSessionHandle.run(JMSSessionHandle.java:924)
at com.ibm.ejs.jms.listener.ServerSession.connectionConsumerOnMessage(ServerSession.java:752)
at com.ibm.ejs.jms.listener.ServerSession.onMessage(ServerSession.java:527)
at com.ibm.ejs.jms.listener.ServerSession.dispatch(ServerSession.java:494)
at sun.reflect.GeneratedMethodAccessor40.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.ibm.ejs.jms.listener.ServerSessionDispatcher.dispatch(ServerSessionDispatcher.java:37)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:91)
at com.ibm.ejs.container.MDBWrapper.onMessage(MDBWrapper.java:127)
at com.ibm.ejs.jms.listener.ServerSession.run(ServerSession.java:375)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:912)
[11/29/05 15:03:38:190 EST] 1e9aa18 MDBListenerIm I WMSG0043I: MDB Listener ProcessorLP stopped for JMSDestination jms/PostprocessorQ
[11/29/05 15:03:38:192 EST] 1e9aa18 MDBListenerIm I WMSG0058I: Listener Port ProcessorLP will attempt to restart in 60 seconds
[11/29/05 15:03:38:194 EST] 1e9aa18 ConnectionEve A J2CA0056I: The Connection Manager received a fatal connection error from the Resource Adaptor for resource jms/PostprocessorQF. The exception which was received is javax.jms.JMSException: MQJMS2002: failed to get message from MQ queue
[11/29/05 15:04:38:230 EST] 1436f66 MDBListenerIm I WMSG0042I: MDB Listener ProcessorLP started successfully for JMSDestination jms/PostprocessorQ

Have been able to solve this problem? The same occurs in our environment. I have a nagging feelin git has something to do with a known bug that is solved in some fixpack or something. We're on Websphere 5.1.1.4.
Any feedback would be appreciated.
Thanks,
Jaap

MDB Container Managed Transaction and Log4J

Hi,
I'm programming and MDB that reads and updates a database then sends out an HTTP Post and logs using log4j. I've read that when an MDB is configured as CMT or container managed transaction and the OnMessage method executes without errors, the transaction is implicitly commited. You can rollback the transaction by explicitly calling setRollbackOnly() or when a RuntimeException has been thrown. My worry is that after I have sent out an HTTP POST (a transaction has been completed) I would have to log a transaction completion using log4j. My problems is if log4j throws a RuntimeException thereby rolling back my transaction which shouldn't be the case. What I have done is to catch all Exceptions (and swallow them) whenever I log using log4j after I have sent out an HTTP POST succesfully (since my transaction should be complete by then). Is this a correct workaround?
Thanks :)

Your approach is correct. If you think, Log4J might throw errors, swallow the exceptions and try not to roll back.

Starvation in MDBs ?

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