Hi First, 5.5.9 is definitly outdated. Update. [This might help.]
Second, if tomcat is not reaction to kill -9, then it's you VM or even the OS that has a problem. Javacode can never to anything against kill -9, which is only handled by the OS. [This is only about symptoms.] Regards, Steffen > -----Original Message----- > From: Matthew Lee [mailto:[EMAIL PROTECTED] > Sent: Wednesday, November 29, 2006 8:24 AM > To: users@tomcat.apache.org > Subject: Running Tomcat 5.5.9 in AIX 5.2 with Java 5 64-bit - > Tomcat freezes at a high level of workload > > Hello All, > > Setup > --------- > We are researching into a site running a Webapplication using > the following setup: > > IBM AIX 5.2 > Tomcat 5.5.9 > Java 5 64-bits (IBM Patch level is set to pap64dev-20061003a > and downloaded from the IBM URL of : > http://www-128.ibm.com/developerworks/java/jdk/aix/service.html) > There is 16Gb of memory on the server with > 6 CPU on the > server which is running both Tomcat and the Oracle/Progress > DBMS components. > Tomcat startup script has allocated 2 Gb of memory as min and max. > > Symptoms > -------------- > When Tomcat is under heavy load running a webappliccation (at > around 180 users although it varies), Tomcat 8080 will > "freeze", whereby no more new uses can access the > Webapplication, nor can they access the Tomcat Manager page. > > During this "freezes/hanging", we can perform a "telnet" to > <servername>:8080 from a Unix prompt on the server, so it > seems that the Tomcat 8080 port is able to listen, although > not able to process any request. > > The worst thing about this is when the hanging occurs, the > normal "shutdown.sh" script cannot shut down the hanging > Tomcat process. > We also find that the "kill" command is ineffective using any > signal, including "-9". Therefore, when the hanging occurs, > the only to restart Tomcat and the associated webapp is to > reboot the whole server. > > While the Tomcat server hangs, all other process seems to run > correctly - for example, we have an Oracle database and > Progress DBMS components such as Webspeed and Appserver and > they all continue to run with no problem. > The CPU time is NOT fully utilized when the Tomcat freezes up. > We have not been able to find any error message associated > with the catalina.out log when the freeze occurs. > > Research Done So Far > ------------------------------- > We did a search thru the email archive > (http://marc.theaimsgroup.com/) using the keywords of "tomcat > aix hangs", the most relevant entry I found was the following: > http://marc.theaimsgroup.com/?t=116097948400003&r=1&w=2 > But the above uses much older component as follow, and did > not seem like a good match: > to our setup: > > Tomcat 3.3.1a > > AIX 5.3 > > IBM JDK 1.3.1 > > Apache/1.3.28 > The last reply on the above posting was also not conclusive > in what the root cause was. > Other things found in Bugzilla which we initially thought > were relevant > were: > http://issues.apache.org/bugzilla/show_bug.cgi?id=40000 > http://issues.apache.org/bugzilla/show_bug.cgi?id=34693 > http://issues.apache.org/bugzilla/show_bug.cgi?id=32040 > Again, upon closer inspection we were unable to find ways to > apply the info in the above entries in our situation. > > The one entry where we have extracted some application was > the following: > http://issues.apache.org/bugzilla/show_bug.cgi?id=31142 > > I tried a telnet task with ANT 1.6.2: > > - AIX 5.1 it's OK > > - AIX 5.2 it's not OK the task freeze. I must make a CTRL-C > to stop it > > > > > > You may want to try adding -Djava.net.preferIPv4Stack=true > to the Ant > command > > line to see if that helps. I have seen some very long delays on AIX > > 5.2 > with the > > IBM 1.4 VM when it needs to resolve remote addresses. > So we have now implemented the above in our Tomcat startup > script and see whether the Tomcat server will hold up. > Other things we are trying is to switch to using Java 5 > 32-bit to run our Tomcat 5.5.9 instead of Tomcat 64-bit and > see how things goes - the system has been stable for 24 hours > so far using this setting. > > Questions > ---------------- > Has anyone encountered similarly issues in the past, > especially with Tomcat 5 on AIX 5.2 + Java 5? > > Any suggestion from you good folks on what other setting to > configure in order to increase our chance to get some error > messages logged during a system freezes/hanging? > > Conclusion > ---------------- > Thanks for reviewing the above and any suggestion you might > have on this. > > Best Regards, > Matthew
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