Stopping the Application

The STOP method provides a two-tiered approach to stopping the data service: an orderly or smooth approach using a SIGTERM signal through pmfadm and an abrupt or hard approach using a SIGKILL signal. The STOP method obtains the Stop_timeout value (the amount of time in which the STOP method must return). STOP then allocates 80% of this time to stopping smoothly and 15% to stopping abruptly (5% is reserved), as shown in the following sample.

STOP_TIMEOUT=`scha_resource_get -O STOP_TIMEOUT -R $RESOURCE_NAME
\

-G $RESOURCEGROUP_NAME`
((SMOOTH_TIMEOUT=$STOP_TIMEOUT * 80/100))

((HARD_TIMEOUT=$STOP_TIMEOUT * 15/100))

The STOP method uses pmfadm -q to verify that the DNS daemon is running. If it is, STOP first uses pmfadm -s to send a TERM signal to terminate the DNS process. If this signal fails to terminate the process after 80% of the timeout value has expired STOP sends a SIGKILL signal. If this signal also fails to terminate the process within 15% of the timeout value, the method logs an error message and exits with error status.

If pmfadm terminates the process, the method logs a message that the process has stopped and exits with success.

If the DNS process is not running, the method logs a message that it is not running and exits with success anyway. The following code sample shows how STOP uses pmfadm to stop the DNS process.

# See if in.named is running, and if so, kill it. 
if pmfadm -q $PMF_TAG; then 
	# Send a SIGTERM signal to the data service and wait for 80% of
the
	# total timeout value.
	pmfadm -s $RESOURCE_NAME.named -w $SMOOTH_TIMEOUT TERM
	if [ $? -ne 0 ]; then 
		logger -p ${SYSLOG_FACILITY}.err \
		    -t [$RESOURCETYPE_NAME,$RESOURCEGROUP_NAME,$RESOURCE_NAME]
\
		    "${ARGV0} Failed to stop HA-DNS with SIGTERM; Retry
with \
		     SIGKILL"
		
		# Since the data service did not stop with a SIGTERM signal, use 
		# SIGKILL now and wait for another 15% of the total timeout value.
		pmfadm -s $PMF_TAG -w $HARD_TIMEOUT KILL
		if [ $? -ne 0 ]; then
		    logger -p ${SYSLOG_FACILITY}.err \
		    -t [$SYSLOG_TAG]
		    "${ARGV0} Failed to stop HA-DNS; Exiting UNSUCCESFUL"
		    
		    exit 1
		fi	
fi
else 
	# The data service is not running as of now. Log a message and 
	# exit success.
	logger -p ${SYSLOG_FACILITY}.err \
    	    -t [$SYSLOG_TAG] \
    	    "HA-DNS is not started"

	# Even if HA-DNS is not running, exit success to avoid putting
	# the data service resource in STOP_FAILED State.

	exit 0

fi

# Could successfully stop DNS. Log a message and exit success.
logger -p ${SYSLOG_FACILITY}.err \
    -t [$RESOURCETYPE_NAME,$RESOURCEGROUP_NAME,$RESOURCE_NAME]
\
    "HA-DNS successfully stopped"
exit 0