Earlier this week, we noticed that the JVM job (QP0ZPWT) assocated with
the CATALINA job of a Tomcat server runs at Priority 6. This priority
level puts it ahead of everything but the operating system itself.
This morning, a response to a query on the Java forum at Midrange.com
pointed me to this excerpt from catalina.sh:
if $os400; then
# Set job priority to standard for interactive (interactive - 6) by using
# the interactive priority - 6, the helper threads that respond to requests
# will be running at the same priority as interactive jobs.
COMMAND='chgjob job('$JOBNAME') runpty(6)'
system $COMMAND
# Enable multi threading
export QIBM_MULTI_THREADED=Y
fi
This seems to be based on a misconception: run priority is a value from
0 to 99, with lower numbers denoting greater importantce. 0 is reserved
for the operating system itself, 1-15 typically also used for the
operating system itself, 20 used for most interactive jobs, 50 and up
used for most batch jobs (including server jobs).
Note: interactive jobs -- people signed on to physical terminals, or to
terminal emulators -- typically run at priority 20. NOT priority 6.
By setting Tomcat's JVM job at priority 6, we are not only putting it
ahead of interactive jobs, but also ahead of all but the most important
system jobs.
Is there a reason for this? Or was it a simple misunderstanding of how
priority works on AS/400s?
--
JHHL
---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org
For additional commands, e-mail: users-h...@tomcat.apache.org
