But sometimes under heavy load jvm 1.4 crashes... see the links:
Ok this is the bug:
http://developer.java.sun.com/developer/bugParade/bugs/4779653.html
unfortunately it is closed, affects 1.4.1 and will not apparently be fixed. It oiccurs in large apps under load.on Linux and Solaris ( and most likely Windows )
It is related to / a copy of the following bug which
http://developer.java.sun.com/developer/bugParade/bugs/4724356.html
what is the best suggestion?
just trying to determine if tomcat is running..
if not i will restart it ..
(jvm just crashed last saturday night....I did not know anything until the sunday evening)..
At 09:29 AM 2/25/03 -0500, you wrote:
Yes, Tomcat is generally very stable. But: Trust, but verify. ;)
John
> -----Original Message----- > From: Hannes Schmidt [mailto:[EMAIL PROTECTED] > Sent: Tuesday, February 25, 2003 9:23 AM > To: Tomcat Users List > Subject: Re: crontab problems > > > Yes, using wget is probably the second best solution. The > best one is to > find the reason why Tomcat crashes at all, since it generally > is a stable > and reliable product. > > Cron doesn't execute more than once a minute (at least mine > doesn't) which > still is quite often. 5 or 10 minutes would be ok too. But > that's a matter > of taste, really. > > ----- Original Message ----- > From: "Turner, John" <[EMAIL PROTECTED]> > To: "'Tomcat Users List'" <[EMAIL PROTECTED]> > Sent: Tuesday, February 25, 2003 3:00 PM > Subject: RE: crontab problems > > > > > > Agreed...using a Java program to watch Tomcat seems a > little circular. > > Plus, I don't see any sort of delay or "sleep" in the poster's JAva > > code...it looks like it just keeps hammering at Tomcat, as > the cron job is > > "* * * * *". Creating all those Runtime objects over and > over can't be > > helping performance any. > > > > A simple shell script using wget would be fine...sure, you > can watch the > > output of "ps -ef", but that doesn't tell you if Tomcat is accepting > > requests or not. There could be an entry for Tomcat in the > process table, > > but Tomcat could be refusing requests. > > > > I just write a simple JSP page that outputs the contents of > a variable, > like > > "***SUCCESS***" or something like that, then use wget to > grab that page > > every so often and check for the string in the output...if > it's there, > > things should be OK (there are no guarantees). If it's > not, you have a > > problem. This way, the JSP page is compiled and cached by > Tomcat, it uses > > very little memory, and doesn't bog down the server. > > > > There are plenty of other alternatives much more robust > than a simple > shell > > script...you could use Netsaint/Nagios, Big Brother, and a > whole bunch of > > others. > > > > John > > > > > -----Original Message----- > > > From: Hannes Schmidt [mailto:[EMAIL PROTECTED] > > > Sent: Tuesday, February 25, 2003 6:29 AM > > > To: Tomcat Users List > > > Subject: Re: crontab problems > > > > > > > > > Right, you might also just put > > > > > > JAVA_HOME=... > > > > > > at the beginning of your crontab. > > > > > > I assume you have good reasons to use a Java program to > watch Tomcat. > > > Personally, I would have written a shell script. If you > > > really want to use > > > Java, you might want to use a different, more reliable > > > approach to detect > > > (un)availability of Tomcat, something like > > > > > > import java.net.*; > > > URL url = new URL( "http://localhost:8080/examples"; ); > > > URLConnection con = url.openConnection(); > > > con.setUseCaches( false ); > > > con.connect(); > > > if( con.getContentLength() > 0 ) { > > > // restart tomcat > > > } > > > > > > But I just wrote this out of my head ... > > > > > > ----- Original Message ----- > > > From: "Ralph Einfeldt" <[EMAIL PROTECTED]> > > > To: "Tomcat Users List" <[EMAIL PROTECTED]> > > > Sent: Tuesday, February 25, 2003 10:43 AM > > > Subject: RE: crontab problems > > > > > > > > > You have to make shure that your script retstart_tomcat > > > sets and exports all needed environment variables before > > > calling ./startup.sh: > > > > > > JAVA_HOME=/usr/local/java/jdk1.3.1 > > > CATALINA_HOME=<path to tomcat installation> > > > CATALINA_BASE=<path to tomcat instance> or $CATALINA_HOME > > > # JAVA_OPTS='-client -v' > > > > > > export JAVA_HOME CATALINA_HOME CATALINA_BASE JAVA_OPTS > > > ./startup.sh > > > > > > > -----Original Message----- > > > > From: Ayhan Peker [mailto:[EMAIL PROTECTED] > > > > Sent: Tuesday, February 25, 2003 10:30 AM > > > > To: [EMAIL PROTECTED] > > > > Subject: crontab problems > > > > > > > > but the last two lines returns > > > > ///////////////////////// > > > > The JAVA_HOME environment variable is not defined > > > > message.. > > > > ///////////////////////// > > > > my retstart_tomcat scrip is > > > > #!/bin/sh > > > > cd /usr/local/tomcat/bin > > > > ./startup.sh > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > For additional commands, e-mail: > [EMAIL PROTECTED] > > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > For additional commands, e-mail: > [EMAIL PROTECTED] > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] >
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