PQ62464: NEED TO HAVE AN ABILITY TO SET KEEPALIVE TIMEOUT OPTION FOR EACHIIOP CONNECTION IN WEBSPHERE FOR Z/OS SERVER | |||||||||||||||||||||||||||||||||||||||||
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![]() APAR status Closed as program error. Error description Currently WebSphere for z/OS Server doesn't have a timeout function for IIOP connection. When establishing a connection from a remote client to a server, this prevents to re-use the same server port which was previously used by a gone_away client. A similar function was already provided for HTTP connection by BBOC_HTTP_PERSISTENT_SESSION_TIMEOUT.Local fix Problem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V4.0.1 for z/OS and OS/390 * **************************************************************** * PROBLEM DESCRIPTION: If the client has gone away * * (e.g. rebooted) in such a way that the * * server never got notified, the server * * side TCP/IP session will remain active * * forever. It may be desireable to make * * these sessions go away. * **************************************************************** * RECOMMENDATION: * **************************************************************** If a client, for example a workstation, is using IIOP over TCP/IP to communicate with the server and the client goes away by rebooting, unplugging a cable, etc., the server TCP/IP stack may never be notified. This causes the Control Region to retain the session forever. This ties up resources on the server. It also makes the client-side port unusable to reach this server because the server thinks it already has a session from this client/port and won't accept another one. The client can select another client-side port, but over time this problem could invalidate numerous client-side ports causing delays in finding a usable port.Problem conclusion TCP/IP provides options via SO_KEEPALIVE and SOCK_TCP_KEEPALIVE that will cause TCP/IP to monitor for idle sessions and attempt to contact the client TCP/IP stack to ensure the client is still present. If it is not, then the server-side session will be closed. The SOCK_TCP_KEEPALIVE option was introduced by TCP/IP APAR PQ18618. Please see that APAR for documentation on how the time values specified on SOCK_TCP_KEEPALIVE affect TCP/IP behaviour. WebSphere does not set these socket options by default, but will do so if the new environment variables IIOP_SERVER_SESSION_KEEPALIVE or SSLIIOP_SERVER_SESSION_KEEPALIVE (for SSL IIOP sessions) are set. If you do not have PQ18618 installed and specify the environment variables listed above, the setsockopt for SOCK_TCP_KEEPALIVE will fail and you will receive message BBOU0639E indicating setsockopt() failed with a RC of ENOPROTOOPT (1109). When a session is closed because the time expired and the server TCP/IP stack was unable to contact the client TCP/IP stack, message BBOU0244E will be logged indicating a failure with RC of ETIMEDOUT (1127). The following publication was revised as a result of APAR PQ62464: ________________________________________________________________ WebSphere Application Server V4.0.1 for z/OS and OS/390 Installation and Customization GA22-7834-05 ________________________________________________________________ This APAR requires changes to documentation. NOTE: Periodically, we refresh the documentation on our Web site, so the changes might have been made before you read this text. To access the latest on-line documentation, go to the product library page at: http://www.ibm.com/software/webservers/appserv/zos_os390/ ________________________________________________________________ Appendix A, pg. 387 (new section) IIOP_SERVER_SESSION_KEEPALIVE=n This variable, if set, defines the value in seconds provided to TCP/IP on the SOCK_TCP_KEEPALIVE option for the IIOP listener. The function of this option is to verify if idle sessions are still valid by polling the client TCP/IP stack. If the client does not respond, the session is closed. If the client goes away without notifying the server, it would unnecessarily leave the session active on the server side. Use this option to clean up these unnecessary sessions. See TCP/IP APAR PQ18618 for more information about the TCP/IP SOCK_TCP_KEEPALIVE option. Notes: If the environment variable is not set, the TCP/IP option is not set. Setting the SOCK_TCP_KEEPALIVE option generates network traffic on idle sessions, which can be undesirable. Example: IIOP_SERVER_SESSION_KEEPALIVE=3600 ... ________________________________________________________________ Appendix A, pg. 398 (new section) SSLIIOP_SERVER_SESSION_KEEPALIVE=n This variable, if set, defines the value in seconds provided to TCP/IP on the SOCK_TCP_KEEPALIVE option for the SSL IIOP listener. The function of this option is to verify if idle sessions are still valid by polling the client TCP/IP stack. If the client does not respond, the session is closed. If the client goes away without notifying the server, it would unnecessarily leave the session active on the server side. Use this option to clean up these unnecessary sessions. See TCP/IP APAR PQ18618 for more information about the TCP/IP SOCK_TCP_KEEPALIVE option. Notes: If the environment variable is not set, the TCP/IP option is not set. Setting the SOCK_TCP_KEEPALIVE option generates network traffic on idle sessions, which can be undesirable. Example: SSLIIOP_SERVER_SESSION_KEEPALIVE=3600 ... ________________________________________________________________ APAR PQ62464 is associated with SERVICE LEVEL W401088 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: UQ68406 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: 400
Software edition:
Reference #: PQ62464
IBM Group: Software Group
Modified date: Sep 4, 2002
(C) Copyright IBM Corporation 2000, 2006. All Rights Reserved.