PQ53132: THE ADMIN CONSOLE HANGS. | |||||||||||||||||||||||||||||||
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APAR status Closed as program error. Error description Problem: ***The Admin Console hangs. Recap: ***AIX/WAS 3.5.4 ***Client/Admin server/JVM local. ***Restarting the adminconsole fully recovers the problem. ***The heap(s) of the other JVM's (nanny, appserver) did not grow. ***The JVM (of the consle) grew slightly (by +3mB over a 20 hour test period). ***The system wide allocate virtual memory didn't increase. ***There were no more messages seen in the message window. ***The (servlet) engine continued to perform the auto reload. ***Attempting to change an object through the console rulted in an entirely grey foreground/background (at this point I got the java.lang.OutOfMemoryError exceptions thrown). ***No errors in the system log. ***The adminclient debug trace file gives no clues. It shows the log messages to the client up until the console hangs, then only Act waiting for notification and BackgroundLru going to sleep and waking up. ***Thread dumps of the client before and after the hang are exactly the same (the same running threads) except the SeriousEventMessagePanelUpdater thread is present before the hang. Description: Run the following script in AIX - while true do touch SnoopServlet.class echo touch to SnoopServlet.class ls -al SnoopServlet.class sleep 60 done This will modify the time stamp on the snoop class. From the console set the auto reload for the default_app to TRUE, interval 60 sec., and for the snoop servlet set load at startup to true. Start the app server (Default Server), the auto reload will generate messages that are written to the 'Console Messages' window in the console. After time, in the test about 5 hours, the messages will stop appearing in the window and the console will hang. This problem was reproduced by an IBM Japan team and by the WebSphere team in Raleigh.Local fix Restart the Admin ConsoleProblem summary **************************************************************** * USERS AFFECTED: All WebSphere Application Server 4.0 * * Advanced Edition users of the Administrative * * Console * **************************************************************** * PROBLEM DESCRIPTION: Administrative Console can be * * overwhelmed by a large volume of * * Serious Event messages, becoming * * unusable * **************************************************************** * RECOMMENDATION: * **************************************************************** After the RAS component logs warnings and errors in the activity log, it makes them available to the server (either Administrative server or Application server) to be logged in the Serious Event table of the admin database -- this is done by the SeriousEventListener in each server. The Administrative Console reads from this table to display messages in the bottom portion of the the display. Errant applications may result in a large number of errors or warnings being created in a short time -- these are all written to the database and the Administrative Console attempts to display them all. If the arrival rate is too fast, the console can't keep up, and it may become unusable.Problem conclusion The code has been changed to create a governor in the SeriousEventListener. As the listener is notified of serious events, it checks to see if the arrival rate exceeds certain parameters -- it shuts off writing the events to the data base if this is the case and resumes again when the arrival rate drops off. The events continue to be logged to the activity log, so the information contained within is not lost. There are several new properties that can be used to regulate the operation of the serious event logging governor: com.ibm.ejs.sm.server.maxnorm: (double) this is the arrival rate threshhold above which SeriousEvent logging is turned off. If it is set to 4 and we get messages at a rate of 5 per second, we will stop logging SeriousEvents to the database. They continue to be recorded in the activity log. Default value is 10. com.ibm.ejs.sm.server.minclog: (double) this is the arrival rate threshhold below which SeriousEvent logging is resumed if it had previously been turned off. If it is set to 4 and the message arrival rate drops to 3.5 per second, we will resume logging. Default value is 5. com.ibm.ejs.sm.server.restarttrigger (double) this is the time interval in milliseconds that can result in resuming logging if it has been turned off. If it is set to 1000 and 2000 milliseconds elapse between message arrivals, we will resume logging. Default value is 2000. com.ibm.ejs.sm.server.clumpsize (integer) this is the number of messages grouped together in a "clump" for purposes determining arrival rates. Default value is 20.Temporary fix Comments
APAR is sysrouted FROM one or more of the following: PQ51338 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 > General
Operating system(s):
Software version: 400
Software edition:
Reference #: PQ53132
IBM Group: Software Group
Modified date: Dec 21, 2001
(C) Copyright IBM Corporation 2000, 2006. All Rights Reserved.