Pacemaker (Linux)

Pacemaker is an open source high-availability cluster resource manager software that runs on a set of nodes. Together with Corosync, an open source group communication system that provides ordered communication delivery, cluster membership, quorum enforcement, and other features among the nodes, it helps detect component failures and orchestrate necessary failover procedures to minimize interruptions to applications.

Important: Starting from version 11.5.6, the Pacemaker cluster manager for automated fail-over to HADR standby databases is packaged and installed with Db2®. In version 11.5.5, Pacemaker is included and available for production environments. In version 11.5.4, Pacemaker is included as a technical preview, and should be restricted to development, test, and proof-of-concept environments.
Pacemaker provides a framework to manage the availability of resources. Resources are services on a host that needs to be kept highly available. In Db2, the following are considered resources:
  • Db2 member process (also known as a Db2 instance)
  • HADR Database
  • Ethernet network adapter
  • Virtual IP address

Prerequisites

For more information on prerequisites, refer to Prerequisites for an integrated solution using Pacemaker.

Disk storage

There is no specific requirement. The Db2 database can use these resources for local data storage:
  • Raw disk (for example, /dev/sda1)
  • Logical volume that is managed by a Logical Volume Manager (LVM)
  • File system (for example, ext4, jfs2, gpfs, etc.)

Db2 data can be stored either entirely on one or more raw disks, entirely on logical volumes, entirely on file systems, or on a mixture of all three. Db2 binaries such as executables and shared libraries need to be on a file system.

Db2 database requirements for the virtual IP address

The Db2 database has no special requirements for the virtual IP address. It is not necessary to define a virtual IP address in order for the instance to be considered highly available. However, it is important to remember that the virtual IP address is the user's access point to the data, and as such, this address must be known by all database clients. In practice, it is recommended that this IP address be the one that is used by the users in their CATALOG TCPIP NODE commands.
Note: While Db2 has no specific requirement for the virtual IP address, the system typically requires that the local physical IP address used as the map for virtual IP address, on both hosts, in a HADR cluster be on the same IP subnet. Failing to adhere to this requirement may cause issues during failover. Please consult your network administrator during virtual IP setup.

Setting up Pacemaker with a Db2 environment

For detailed configuration information to help set up Pacemaker to work with a Db2 environment, refer to Configuring a clustered environment using the Db2 cluster manager (db2cm) utility.
Note: The db2haicu utility is not supported for configuring and managing a highly available cluster using Pacemaker.