This chapter provides information about the INFORMIX database agent that is added to the base IRIS FailSafe product by the IRIS FailSafe INFORMIX option. It assumes that you are familiar with the basic components of IRIS FailSafe described in Chapter 1 of the IRIS FailSafe Administrator's Guide . This chapter also lists some important points about setting up INFORMIX databases and lists the steps you must take to add INFORMIX databases to the highly available services that are failed over on an IRIS FailSafe cluster.
This chapter provides information about configuring the IRIS FailSafe INFORMIX database option for use on an IRIS FailSafe system. The major sections in this chapter are as follows:
The IRIS FailSafe INFORMIX option adds a database agent, shown in Figure 1-1, to the IRIS FailSafe base software. The database agent, /usr/etc/ha_ifmx, monitors INFORMIX databases regularly. If ha_ifmx detects a failure, it dies. When the INFORMIX local monitoring script, /var/ha/actions/ha_ifmx_lmon, detects that ha_ifmx has died, it sends a message to the application monitor and the failover process begins.
The IRIS FailSafe INFORMIX database agent can perform two types of monitoring:
Performing an SQL query to detect the state of On-Line.
The query checks the sh_mode from the [email protected] table and reports success if INFORMIX is in one of these modes: initialization, quiescent, fast recovery, archive backup, or on-line. It reports failure if the server is in shutdown mode or the system is aborting.
Checking the output of the onstat command.
To check the output of the onstat command, the IRIS FailSafe INFORMIX database agent parses the output to look for strings that are specified in the configuration file /var/ha/ha.conf. If it finds any of these strings, it assumes that the INFORMIX database is running.
When setting up INFORMIX database servers, follow these guidelines:
IRIS FailSafe requires that all INFORMIX database servers be set up using the root account.
Because IRIS FailSafe INFORMIX software runs as root, each INFORMIX database server must be set up so that root can access it to monitor it.
The interactive logging sequence for INFORMIX users is not recommended.
The configuration files involved in setting up INFORMIX such as $ONCONFIG, $INFORMIXDIR/etc/sqlhosts, /etc/services, and /etc/hosts do not require any additional modification for IRIS FailSafe beyond the changes described in Chapter 3 of the IRIS FailSafe Administrator's Guide .
To configure an IRIS FailSafe cluster for failover of INFORMIX databases, follow these steps:
Install, configure, and test the base IRIS FailSafe software as described in the IRIS FailSafe Administrator's Guide .
Install additional software if required. See the section “Required Software” in Chapter 2.
Choose how to configure INFORMIX software and databases on the disks. See the section “Planning INFORMIX Configuration” in Chapter 2.
Add INFORMIX information to the configuration file, /var/ha/ha.conf. See the section “Adding INFORMIX Information to the Configuration File” in Chapter 2.
Install the new configuration file. See the section “Installing the Configuration File” in Chapter 2.
Test INFORMIX failover. See the section “Testing INFORMIX Failover” in Chapter 2.