Fix (APAR): JR24986 Status: Fix Release: 6.0.1.2 Operating System: AIX,HP-UX,Linux,Solaris,Windows,z/OS Supersedes Fixes: CMVC Defect: 378010 Byte size of APAR: 14627 Date: 2007-03-19 Abstract: Potential inactive transactions caused by race condition between Messaging Engine and JCA Adapter Applications. Description/symptom of problem: JR24986 resolves the following problem: ERROR DESCRIPTION: Due to the design of the messaging engine in WAS there is a possibility that an application, which may need the messaging engine up and running, will be started and available before the ME is available. The messaging engine and application are on separate threads, and there is a possible race condition between the application that needs the ME and the ME itself. Because there is no messaging engine available, the application might throw an exception stating "No suitable messaging found". This problem poses a bigger risk when using adapter applications. By nature the adapter will start polling immediately after the application is started. If there is no suitable messaging engine available when the adapter starts polling (in other words the ME isn't yet started when the adapter application starts), then a "no suitable messaging" engine error will be thrown and after 120 seconds the adapter will stop polling entirely, even after the ME becomes available. Restarting the server may not be viable, since there is no guarantee upon restart that the ME will be available when the server starts. LOCAL FIX: Restart the app manually after the ME is up and running. PROBLEM SUMMARY USERS AFFECTED: WebSphere Process Server v6.0.1.2+ PROBLEM DESCRIPTION: Potential inactive transactions caused by race condition between Messaging Engine and JCA Adapter Applications. RECOMMENDATION: None If Messaging Engien is inactive when a JCA Adapter Application starts, the adapter will stop polling and stop retrying even after Messaging Egnine become active. Transactions will not start until the application is restarted. PROBLEM CONCLUSION: Introduce a configurable wait time when acquiring a connection to the Messaging Engine. The Maxium wait time is defaulted to 120 seconds. The frequency of the wait is based on the exponential backoff algorithm as used in TCP 3-way handshakes, that is, 1,2,4,8,16 until timeout is reached. Timeout can be configured in Admin Console, and restart of applications is required once timeout is reached. A Tech Note is published at http://www-1.ibm.com/support/docview.wss?rs =2307&context=SSQH9M&q1=JR24986&uid=swg21256866&loc=en_US &cs=utf-8&lang=en for detail steps on configuring timeout value. Directions to apply fix: Before applying the iFix ensure that WebSphere Process Server 6.0.1 is installed on the system. Also download and follow Update Installer installation instructions. The Update Installer can be downloaded from the following link: http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991 1) Copy the pak file to the directory maintenance in the UpdateInstaller directory 2) Shutdown WebSphere Process Server. It is important that you perform a controlled and complete shutdown of the server to ensure that all transactions have completed, before installing the fix. 3) Run the UpdateInstaller and follow the prompts. 4) Restart WebSphere Directions to remove fix: NOTE: FIXES MUST BE REMOVED IN THE REVERSE ORDER IN WHICH THEY WERE APPLIED. DO NOT REMOVE A FIX UNLESS ALL FIXES APPLIED AFTER IT HAVE FIRST BEEN REMOVED. YOU MAY REAPPLY ANY REMOVED FIX. Example: If your system has fix1, fix2, and fix3 applied in that order and fix2 is to be removed, fix3 must be removed first, then fix2 may be removed 1) Shutdown WebSphere. It is important that you perform a controlled and complete shutdown of the server to ensure that all transactions have completed, before installing the fix. 2) Follow the Fix instructions that are packaged with the Fix Installer on how to uninstall and reinstall the Fix. 3) Restart WebSphere Directions to re-apply fix: 1) Shutdown WebSphere. It is important that you perform a controlled and complete shutdown of the server to ensure that all transactions have completed, before installing the fix. 2) Run the UpdateInstaller and follow the instructions. The Update Installer can be downloaded from the following link: http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991 3) Restart WebSphere Process Server Additional Information: