3.6.0 MxDB for SQL Server Installation and Administration Guide (5697-7088, December 2007)

Chapter 5: Configuration and Operation 66

Script Pathnames: The SQL monitor can optionally be configured with

the following types of scripts:

Recovery script. Runs after a monitor probe failure is detected, in an

attempt to restore the service.

Post Start script. Runs after the service has become active on a server. For

example, you might want a Post Start script to start a Web server.

Pre Stop script. Runs after the service has become inactive on a server.

When a monitor is instantiated, the ClusterPulse process chooses the best

server to make the service active. The Post Start script is run on this

server. On all other servers configured for the monitor, the Pre Stop script

is run to ensure that the service is not active.

Post Start scripts must be robust enough to run when the service is

already started, without considering this to be an error. Similarly, Pre

Stop scripts must be robust enough to run when the service is already

stopped, without considering this to be an error. In both of these cases,

the script should exit with a zero exit status.

This behavior is necessary because the Post Start and Pre Stop scripts are

run to establish the desired start/stop activity, even though the service

may actually have been started by something other than MxDB for SQL

Server. The Post Start and Pre Stop scripts must also handle recovery

from events that may cause them to run unsuccessfully.

For example, if the system encounters a problem, the script will fail and

exit non-zero. The service could then become active on another node,

causing the Pre Stop script to run on the original node even though the

Post Start script did not complete successfully.

Use Custom Scripts to Modify Start/Stop Activities

The SQL monitor performs certain starting or stopping activities. If you

need to take an action before or after the starting or stopping activity, you

can create a custom Start or Stop script for the action and specify it on the

Scripts tab for the monitor.

The default order for starting is:

• Run the monitor’s starting activities (if any)