PQ73853: Stateful session beans become zombies when client ends | |||||||||||||||||||||||||||||||||||||||||
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![]() APAR status Closed as program error. Error description There are many "zombie" stateful session beans in the J2EE server region. They appear to be caused by terminating communication with the clients. The deployment descriptor does have the session timeout property specified, but it does not seem to have any effect.Local fix ensure the ejbs are defined with an activation policy of at-transaction, that the timeout value is reasonable (the default is 8 hours) and that the BEAN_DELETE_SLEEP_TIME environment variable for the server is set appropriately. Passivated beans will be cleaned from the table according to the interval (in minutes) specified by BEAN_DELETE_SLEEP_TIME.Problem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V4.0.1 for z/OS and OS/390 * **************************************************************** * PROBLEM DESCRIPTION: Customers servers experience JAVA * * "Out Of Memory" errors after server has * * been active for a short period of time. * **************************************************************** * RECOMMENDATION: * **************************************************************** JAVA "Out Of Memory" errors experienced when using activate once Stateful Session Beans. Activate Once Stateful Session Beans timeout value is not check unless the bean is referenced. If the client of these beans goes away the reference is lost and the bean will not be timed-out.Problem conclusion Code was added to periodically check for timedout Stateful Session Beans. If the bean timeout value has ben reached the bean is removed from the EJB container. The amount of time between the check is controlled by the environment variable BEAN_DELETE_SLEEP_TIME in current.env. The default is 70 minutes. The value is expressed in seconds eg: 60 minutes equals 3600 seconds. APAR PQ73853 requires a change a change to V4.0.1 WebSphere for z/OS: Installation and Customization, GA22-7834-04 will be available in the next refresh of the documentation. To access the latest online documentation, go to the product library page at: www.ibm.com/software/webservers/appserv/zos_os390/ The change is to the table on page 397, which now reads: |--------------------------------------------------------------| | Env variable=<default> | Dmn | SM | Nam | IR | App | zOS | |--------------------------------------------------------------| | ... | | | | | | | |--------------------------------------------------------------| | BEAN_DELETE_SLEEP_TIME= | | R^5 | | | O^20| | | 4200 | | | | | | | |--------------------------------------------------------------| | ... | | | | | | | |--------------------------------------------------------------| and text on page 402, which now reads: ... 20. If you have an application that uses large numbers of "activate once" stateful session beans, taking the default for BEAN_DELETE_SLEEP_TIME could cause Java out of memory errors. and text on page 413, which now reads: BEAN_DELETE_SLEEP_TIME=n The time in seconds allowed before an expired stateful session bean's state is deleted from its backing datastore (DB2). The default time is 4200 seconds (70 minutes). You can increase the time to 2147483 seconds (24.85 days). Recommendation: Do not set this variable less than 300 seconds (5 minutes). Note: If you change the value of this variable for your application server, you may also need to adjust the bean timeout value for your stateful beans. The default stateful bean timeout is 8 hours, which, when coupled with the BEAN_DELETE_SLEEP_TIME default value, means it could take up to 9 hours and 10 minutes to delete a bean. See WebSphere Application Server V4.0.1 for z/OS and OS/390: Assembling J2EE Applications, SA22-7836, for more information about stateful session bean timeout. Example: BEAN_DELETE_SLEEP_TIME=1000000 APAR PQ73853 is associated with SERVICE LEVEL W401507 of WebSphere Application Server V4.0.1 for z/OS and OS/390.Temporary fix Comments
APAR is sysrouted FROM one or more of the following: APAR is sysrouted TO one or more of the following: Modules/Macros
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Document Information |
Product categories: Software > Application Servers >
Distributed Application & Web Servers > WebSphere Application
Server for z/OS
Operating system(s):
Software version: 401
Software edition:
Reference #: PQ73853
IBM Group: Software Group
Modified date: Jul 3, 2003
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