High-availability hub monitoring server

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An operational hub monitoring server is essential to a monitoring environment. If the hub monitoring server address space fails, or if the system on which the hub is installed has a planned or unplanned outage, the flow of monitoring data comes to a halt. Therefore, it is important to restart the hub or move it to another system as quickly as possible. You can ensure continuous availability by using a high-availability (HA) hub monitoring server.

You can configure an HA hub monitoring server in any sysplex environment with dynamic virtual IP addressing (DVIPA) and shared DASD. An HA hub is configured in its own runtime environment, without any monitoring agents, and can be configured on the same LPAR with a remote monitoring server. System variables are not enabled on an HA hub. This configuration allows the hub monitoring server to be relocated to any suitable LPAR in the sysplex with no changes, and with minimal disruption to the components connecting to the hub.

Best practices: If you are configuring a hub monitoring server on z/OS and the requirements for configuring an HA are met, it is best practice to create one.

Figure 1 shows a typical configuration with a high-availability hub runtime environment deployed.

Figure 1. High-availability runtime environment

Typical configuration with high-availability hub
In this monitoring environment, you have two LPARs: LPAR 1 and LPAR 2. In LPAR 1, a runtime environment (RTE A) has been created containing just the hub monitoring server, which has been defined as a high-availability hub monitoring server with DVIPA. Because you also want to monitor LPAR 1 in addition to the subsystems running on it (in this example, CICS), a second runtime environment (RTE B) is created with a remote monitoring server and any monitoring agents that are needed.
Note: The OMEGAMON® for z/OS® monitoring agent shares an address space with the remote monitoring server while the OMEGAMON AI for CICS monitoring agent runs within its own address space.

On the second LPAR, a runtime environment (RTE C) is created in the same fashion as RTE B to monitor the systems and subsystems on that LPAR. It connects to the high-availability hub monitoring server through the DVIPA address. The advantage of the high-availability configuration is that if anything happens to LPAR 1, either planned or unplanned, the hub can be restarted on LPAR 2 without the need for reconfiguring the existing runtime environments.

For information about configuring a high-availability hub on z/OS systems, see the following topics:

For detailed information about the high-availability hub on distributed systems, see IBM Tivoli Monitoring: High-Availability Guide for Distributed Systems.