PQ74029: BACKLOG PARAMETER FOR LISTEN() WILL BE USER-CONFIGURABLE. | |||||||||||||||||||||||||||||||||||||||||
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![]() APAR status Closed as program error. Error description The symptom is that you can get ECONNREFUSED errors at the client when trying to connect to WebSphere. Issue IPCS command: "IP TCPIPCS TCB" scroll down a couple pages to find the list of current connections in the system. i.e.: J2EE servers socket: 7F5D3508 000244EF BBOASR2A Listening WLOIDLE 0.0.0.0..8084 Now using the first field, termed the "TCB" in command: "IP TCPIPCS TCB(7F5D3508 DETAIL)" Here, the TCB_MAX_BACKLOG looks like: +0220 TCB_MAX_BACKLOG......... 0000000A +0224 TCB_CURR_BACKLOG........ 00000000 +0228 TCB_EXCEED_BACKLOG...... 00000098 So, the BACKLOG is set to 10 and it exceeded the backlog at an one instance in time by '98'x or 152. ECONNREFUSED is seen in the plugin, the server is marked not available for period of time. A reattempt to connect to the J2E J2EE server can occur, and if successful, the server is marked "up". During the period of time the server is marked down, all requests will get the 500 error, unless there are other servers that are "up".Local fix Problem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V4.0.1 for z/OS and OS/390 * **************************************************************** * PROBLEM DESCRIPTION: ECONNREFUSED errors at the client when * * trying to connect to WebSphere. * **************************************************************** * RECOMMENDATION: * **************************************************************** If a large number of concurrent connection requests are received by the server, they can be rejected with ECONNREFUSED whatever if the backlog of unprocessed connection requests exceeds the defined limit which is fixed at 10.Problem conclusion Four environment variables have been added added to define number of backlog connections which can occur before a connection refused condition reults. Documentation for these new envirionment varibles follows: APAR PQ74029 requires 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 396, which now reads: |--------------------------------------------------------------| | Env variable=<default> | Dmn | SM | Nam | IR | App | zOS | |--------------------------------------------------------------| | ... | | | | | | | |--------------------------------------------------------------| | BBOC_HTTP_BACKLOG=10 | O | O | O | O | O | | |--------------------------------------------------------------| | BBOC_HTTPS_BACKLOG=10 | O | O | O | O | O | | |--------------------------------------------------------------| | ... | | | | | | | |--------------------------------------------------------------| | BBOC_IIOP_BACKLOG=10 | O | O | O | O | O | | |--------------------------------------------------------------| | BBOC_IIOPSSL_BACKLOG=10 | O | O | O | O | O | | |--------------------------------------------------------------| | ... | | | | | | | |--------------------------------------------------------------| and text starting on page 404, which now reads: BBOC_HTTP_BACKLOG=n An integer value that indicates the maximum queue length for pending connections that use HTTP. You may set the maximum value up to 2147483647, but the specification of the SOMAXCONN statement in the TCP/IP profile may result in limitations to this. The default is 10. Example: BBOC_HTTP_BACKLOG=25 BBOC_HTTPS_BACKLOG=n An integer value that indicates the maximum queue length for pending connections that use HTTPS. You may set the maximum value up to 2147483647, but the specification of the SOMAXCONN statement in the TCP/IP profile may result in limitations to this. The default is 10. Example: BBOC_HTTPS_BACKLOG=25 BBOC_IIOP_BACKLOG=n An integer value that indicates the maximum queue length for pending connections that use IIOP. You may set the maximum value up to 2147483647, but the specification of the SOMAXCONN statement in the TCP/IP profile may result in limitations to this. The default is 10. Example: BBOC_IIOP_BACKLOG=25 BBOC_IIOPSSL_BACKLOG=n An integer value that indicates the maximum queue length for pending connections that use IIOP SSL. You may set the maximum value up to 2147483647, but the specification of the SOMAXCONN statement in the TCP/IP profile may result in limitations to this. The default is 10. Example: BBOC_IIOPSSL_BACKLOG=25 APAR PQ74029 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 #: PQ74029
IBM Group: Software Group
Modified date: Jul 3, 2003
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