PK20083: DEADLOCKS OCCURRING IN THE SESSION MANAGER | |||||||||||||||||||||||||||||||||||||||||||
![]() |
|||||||||||||||||||||||||||||||||||||||||||
![]() APAR status Closed as program error. Error description The customer has a total of two nodes, and each node has two AppServers fora total of four AppServers. All four AppServers belong to the same cluster. When the customer shut down two AppServers in Node A, one AppServer in Node B was hung (the other AppServer in Node B did not hang and performed as expected). . When analyzing the customer's dumps, the following deadlock was detected: "Deadlock(s) detected !!! Thread 0x0x9b8690 "DRSThreadPool : 2" is waiting to be notified for: (0x2a6fbd68) "com/ibm/ws/webcontainer/httpsession/DRSSessionData" which is owned by: Thread 0x0x9bf828 "WebSphere t=009bf828" which is waiting to be notified for: (0x1d8be2b8) "java/util/HashMap" which is owned by: Thread 0x0x9b8690 "DRSThreadPool : 2" . The following code stack was shown for the thread: 9b8690 CEEOPCW pthread_cond_wait condWait sysMonitorWait lkMonitorEnter com/ibm/ws/webcontainer/httpsession/DRSSessionData.clone()java/ lang/Object; com/ibm/ws/webcontainer/httpsession/DRSHttpSessCache.convertSess ion(com/ibm/ws/webcontainer/httpsession/DRSSessionData;)com/ibm/ ws/webcontainer/httpsession/DRSSessionData; . This is a route of APAR PQ84217. . The 5.1 5655I3500 version of this fix was fixed via internal defect MD20543 which was included in z/OS rollup apar PQ99636 which ships in service level W510204.Local fix Problem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V5.0 for z/OS * **************************************************************** * PROBLEM DESCRIPTION: When the Application Server * * administrator restarts Application * * Servers one by one in a Network * * Deployment cluster, a deadlock occurs. * **************************************************************** * RECOMMENDATION: * **************************************************************** When an administrator restarts Application Server one by one in ND cluster, the thread that is about to shutdown the session manager conflicts with another thread that is sending local session data to another newly started app server in the ND cluster. This causes a deadlock to occur.Problem conclusion The code was modified to prevent the deadlock. APAR PK20083 is associated with SERVICE LEVEL W502039 of WebSphere Application Server V5.0 for z/OS.Temporary fix Comments
APAR is sysrouted FROM one or more of the following: PQ84217 APAR is sysrouted TO one or more of the following: Modules/Macros
Publications Referenced
|
Document Information |
Current web document: swg1PK20083.html
Product categories: Software > Application Servers >
Distributed Application & Web Servers > WebSphere Application
Server for z/OS
Operating system(s):
Software version: 500
Software edition:
Reference #: PK20083
IBM Group: Software Group
Modified date: Oct 17, 2006
(C) Copyright IBM Corporation 2000, 2009. All Rights Reserved.