Running Tomcat 5.5.9 in AIX 5.2 with Java 5 64-bit - Tomcat freezes at a hig 2006-11-29 - By Steffen Heil
Back
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First, 5.5.9 is definitly outdated.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:mkl@(protected)]
> Sent: Wednesday, November 29, 2006 8:24 AM
> To: users@(protected)
> 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-20061003 (See http://dev-20061003.ora-code.com)a
> and downloaded from the IBM URL of :
> http://www-128 (See http://www-128.ora-code.com).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
|
|
