Highly Available HP-UX Internet Services (May 2008)

This section addresses the following topics:
• “The Sendmail HP ServiceGuard Monitor Script” (page 11)
• “The Sendmail HP ServiceGuard Startup/Stop Script” (page 11)
• “Integrating HP ServiceGuard with Sendmail” (page 12)
The Sendmail HP ServiceGuard Monitor Script
A Sendmail HP ServiceGuard monitor script performs the following tasks:
• Verifies the validity of the Process ID
The monitor script obtains the Sendmail process PID from the O PidFile
configuration option or from the /etc/mail/sendmail.pid file, and verifies
if the previously retrieved PID is a process ID of the currently running Sendmail
instance.
• Verifies the process hang
The monitor script performs the following tasks to verify if a process is hanging:
— Connects to the standard SMTP port number 25.
— Issues the EHLO and QUIT commands
— Searches for the pleased to meet you phrase.
The monitor script also ensures that these tasks do not take more than 20 seconds
to complete.
If the monitor script fails to perform either of the tasks discussed previously, the script
reports the failover notification to the HP ServiceGuard.
NOTE: If delay_checks is configured in the Sendmail configuration file, the time
defined in delay_checks must be added to the default_timeout variable (which
is a part of the monitor script) as mentioned in the following example:
default_timeout = (value of delay_checks) + (intended
default_timeout)
For a sample monitor script, see “HP ServiceGuard Monitor Script for Sendmail”
(page 22). In this sample monitor script, the default_timeout value is defined as
10.
The Sendmail HP ServiceGuard Startup/Stop Script
The HP ServiceGuard startup/stop script for Sendmail is similar to the Sendmail 8.13.3
startup (rc) script but the HP ServiceGuard startup script functions based on the values
of the following variables in the /etc/rc.config.d/mailservs file:
SG_SENDMAIL_SERVER
Starts or stops a default Sendmail server.
SG_SENDMAIL_RECVONLY
Starts or stops the Sendmail server in a receive-only
mode.
Configuring Sendmail with HP ServiceGuard 11