#! /bin/sh
#
# Monitor zmailer activity and try to buzz people when something goes wrong.
# Written by cks@utcs.utoronto.ca
#
PATH=/local/bin:/local/etc:$PATH; export PATH

# people to send frantic plaintive whines to about the brokenness.
PEOPLE="cks@hawkwind.utcs cks rayan pkern molnar glenn"
# limits for how high the queues can reasonably be
RQUEUE=2000
SQUEUE=500;     # the scheduler is fast; the bottleneck is the router
DQUEUE=1000;    # pretty high.
TQUEUE=1000;    # also pretty high

# save the report; we'll be checking for a lot of things.
mailq -ss >/tmp/rep.$$ 2>&1

# everything is aokay ... we think.
host=`hostname`
OK=1; MESSAGE="Zmailer is dead on $host"

# Start checking:
if fgrep -s "no daemon" /tmp/rep.$$; then OK=0; fi
if fgrep -s "core dumped" /tmp/rep.$$; then OK=0; fi
if fgrep -s "Connection refused" /tmp/rep.$$; then OK=0; fi

# The above are all confirmed things. Now we'll get into the
# intangibles.
case "$OK" in
        0) : no point in further checking;;
        *)
rmsgs=0`fgrep "in router queue" /tmp/rep.$$ | awk '{print $1}'`
smsgs=0`fgrep "in scheduler queue" /tmp/rep.$$ | awk '{print $1}'`
tmsgs=0`fgrep "in transport queue" /tmp/rep.$$ | awk '{print $1}'`
dmsgs=0`fgrep "messages deferred" /tmp/rep.$$ | awk '{print $1}'`
if [ "$rmsgs" -gt $RQUEUE ] ; then OK=0; fi
if [ "$smsgs" -gt $SQUEUE ] ; then OK=0; fi
if [ "$tmsgs" -gt $TQUEUE ] ; then OK=0; fi
if [ "$dmsgs" -gt $DQUEUE ] ; then OK=0; fi
case $OK in
        0) MESSAGE="Zmailer queue(s) on $host are high -- check.";;
esac
esac

# Now we actually buzz people.
case $OK in
        1) ;;
        0) msg -m "$MESSAGE" $PEOPLE 2>/dev/null;;
esac
rm -f /tmp/rep.$$