PQ75521: Webserver plugins to restrict the number of connections | |||||||||||||||||||||||||||||||||||||||||||||||||
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![]() APAR status Closed as program error. Error description Webserver plugins to restrict the number of connectionsLocal fix Problem summary **************************************************************** * USERS AFFECTED: All WebSphere Application Server users of * * HTTP plugin for webservers. * **************************************************************** * PROBLEM DESCRIPTION: Application Servers could get over * * loaded with many connections. * * * * There is a need to throttle the * * number of connections to the * * Application Servers. * **************************************************************** * RECOMMENDATION: * **************************************************************** Plugin is now enhanced to limit the number of connections going to the Application Server.Problem conclusion HTTP plugin is enhanced so that users can set a limit of the number of pending connections to an App Server using the new attribute "MaxConnections". If the number of current pending connections reaches "MaxConnections", then that server will not be selected. If no other servers are selectable, the request will end with HTTP return code 503. This feature will work well if the webservers follow **threading model (not a process model)** and only **one** process is started by the web server. The following changes are to be made to have the feature fully enabled. The plugin config file should be updated to include the attribute "MaxConnections" for the server definition. The following is a sample configuration. <ServerGroup Name="PLUGINCLUSTER"> <Server CloneID="ujsv71f3" Name="myhost1_server1" MaxConnections="50"> <Transport Hostname="myhost1" Port="9080" Protocol="http"/> </Server> <Server CloneID="ujsvembh" Name="myhost2_server1" MaxConnections="100"> <Transport Hostname="myhost2" Port="9081" Protocol="http"/> </Server> </ServerGroup> Changes to IHS 2.0 config file (httpd.conf) : Replace the existing block for worker.c with the following. <IfModule worker.c> ServerLimit 1 ThreadLimit 4000 StartServers 1 MaxClients 1024 MinSpareThreads 1 MaxSpareThreads 1024 ThreadsPerChild 1024 MaxRequestsPerChild 0 </IfModule> Eventhough, IHS 2.0 follows threading model, it allows more than one process to be started. Above changes to the httpd.conf will ensure that only one process is started by IHS 2.0.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
Publications Referenced
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Product categories: Software > Application Servers >
Distributed Application & Web Servers > WebSphere Application
Server > General
Operating system(s):
Software version: 00W
Software edition:
Reference #: PQ75521
IBM Group: Software Group
Modified date: Jul 18, 2003
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