Creating an Action Shell Script for Loss of Heartbeat

You can create an action shell script that is executed when the local cluster detects a loss of heartbeat with the partner cluster. The script is executed with root permissions, so the file must have root ownership and execution permissions.

If you have configured the Notification_actioncmd property, the action command is executed with arguments that provide information about the event in the following command line:

# custom-action-command-path -c local-cluster-name -r remote-cluster-name -e 1 \
-n node-name -t time

custom-action-command-path

Specifies a path to the action command you have created

-c local-cluster-name

Specifies the name of the local cluster

-p remote-cluster-name

Specifies the name of the remote partner cluster

-e1

Specifies that HBLOST=1, meaning that a heartbeat-loss event has occurred

-nnode-name

Specifies name of the cluster node that sent the heartbeat-loss event notification

-t timestamp

Specifies the time of the heartbeat-loss event as the number of milliseconds since January 1, 1970, 00:00:00 GMT

You can use this script to perform an automatic takeover on the secondary cluster. However, such an automated action is risky. If the heartbeat loss notification is caused by a total loss of all heartbeat connectivity on both the primary and secondary clusters, such an automated action could lead to a situation where two primary clusters exist.

Example 12–11 How a Notification Action Script Parses the Command-Line Information Provided by the Sun Cluster Geographic Edition Software

This example shows the event information that is provided in the command-line being parsed in a notification action shell script.

#!/bin/sh

set -- `getopt abo: $*`
if [ $? != 0]
then
      echo $USAGE
      exit 2

fi
for i in $*
do

      case $i in
      -p)      PARTNER_CLUSTER=$1; shift;;
      -e)      HB_EVENT=$2; shift;;
      -c)      LOCAL_CLUSTER=$3; shift;;
      -n)      EVENT_NODE=$4; shift;;
      esac
done