Networks in a Pacemaker cluster

To configure elements of your Pacemaker cluster domain that are related to networks, you can use Db2® cluster manager (db2cm) utility to add a physical network to your cluster domain. A physical network is composed of: network interface cards, IP addresses, and subnet masks.

Important: In Db2 11.5.8 and later, Mutual Failover high availability is supported when using Pacemaker as the integrated cluster manager. In Db2 11.5.6 and later, the Pacemaker cluster manager for automated fail-over to HADR standby databases is packaged and installed with Db2. In Db2 11.5.5, Pacemaker is included and available for production environments. In Db2 11.5.4, Pacemaker is included as a technology preview only, for development, test, and proof-of-concept environments.

Network interface cards

A network interface card (NIC) is hardware that connects a computer (also called a cluster node) to a network. A NIC is sometimes referred to as an interface, a network adaptor, or an adaptor. When you use db2cm to add a physical network to your cluster domain, you specify the name of the NIC as well as the host name of the computer to which the NIC belongs to.

IP addresses

An Internet Protocol address (IP address) is a unique address on a network. In IP version 4, an IP address is 32 bits large, and is normally expressed in dot-decimal notation, for example: 129.30.180.16. An IP address is composed of a network portion and a host computer portion.

Subnet masks

A network can be partitioned into multiple logical subnets using subnet masks. A subnet mask is a mechanism for moving some bits of the host portion of an IP address to the network portion of the IP address. When you use db2cm to add an IP address to your cluster domain, you have an option to specify the subnet mask for the IP address, else it would be automatically detected.

Virtual IP address (VIP)

For non-public cloud deployments:

Configuring a VIP resource via the db2cm utility is supported for both primary and standby. The latter is for read-on standby usage. Network adapters that are in different subnets (or equivalently, in different virtual local area networks) cannot be added to the same network. A VIP address cannot failover between different subnets or virtual local area networks.

For public cloud deployments:

The setup instructions are available in the appropriate cloud vendor section in Public cloud vendors supported with Db2 Pacemaker.