Update
Ugh. I'm not so sure I like this daemontools. It doesn't seem to be the
most reliable thing. Granted, it could just be that it can't quite
understand Java processes, for this evening it magically decided that our
Tomcat wasn't running, so it started another one… and then another one…
Hmm… maybe I will just create a script that doesn't run Tomcat as a
background process (like the catalina.sh script does) and then place that
script in the /etc/inittab file.
A bit unorthodox, but … I'm not really a system administrator. I just
play one on TV.
Comment
Hi,
the daemontools depend on the runscript not to exit if everything is ok and
catalina.sh does.. so there you go.
Have you already found a way to not run tomcat in the background?
—Peter
Comment
Oops sorry, its very simple:
just call catalina.sh with run instead of start…
—Peter
Tomcat Always On
by Howard the Author
Just went through a mildly painful experience trying to get Tomcat (or any
daemon for that matter) to run forever, and if it dies (Tomcat sometimes
does), it should be restarted. Wanted to make some notes as I tend to
forget things.
First, grab a copy of Dan Bernstein's daemontools and extract it…
say in /usr/local/daemontools
Like most Unix programs, it won't compile right out of the box due to a bug
in Dan's code (see this note for details).
However, it isn't too difficult to get it to compile. Hop down into the
directory: admin/daemontools-0.76/src and edit the errno.h file…
Change the line that reads:
extern int errno;
To the following:
#include <errno.h>
Now, you can compile the suckah by typing in package/install and it
should rock. Basically, it adds an entry to your inittab to start a
program called svscan. This program will look for stuff in the (now new)
directory: /service
To get tomcat working, grab these goods and extract the archive
directly into the /service directory. However, it probably won't work
without the run file having a few modifications.
Basically, all you really need is to create a /service/tomcat directory
and create a run script that looks something like:
#!/bin/sh
export JAVA_HOME=/usr/java/j2sdk1.4.2_04
export JAVA_OPTS="-Xmx1024M -Xms256M -server"
export TOMCAT_HOME=/usr/local/tomcat
exec 2>&1
exec setuidgid tomcat ${TOMCAT_HOME}/bin/catalina.sh run
Now you probably know enough to get any other service running.
BTW: Just by executing the package/install command, it will not only
install the programs, but will also automatically start them as well.
Update
These daemontools are not very well documented, but if you need to stop or
restart Tomcat (or any other service that you have running under these
tools), the command to call is:
svc -d /service/tomcat
This svc program, I guess, does most of the controlling, and it has the
following options:
- -u: Up. If the service is not running, start it. If the service stops,
restart it.
- -d: Down. If the service is running, send it a TERM signal and then a
CONT signal. After it stops, do not restart it.
- -o: Once. If the service is not running, start it. Do not restart it if
it stops.
- -p: Pause. Send the service a STOP signal.
- -c: Continue. Send the service a CONT signal.
- -h: Hangup. Send the service a HUP signal.
- -a: Alarm. Send the service an ALRM signal.
- -i: Interrupt. Send the service an INT signal.
- -t: Terminate. Send the service a TERM signal.
- -k: Kill. Send the service a KILL signal.
- -x: Exit. supervise will exit as soon as the service is down. If you use
this option on a stable system, you're doing something wrong; supervise is
designed to run forever.
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