TruCluster Server Handbook (HP Technologies)

17.1 What is the Connection Manager?

The simple answer is that the Connection Manager dynamically collects data reflecting the connectivity and communications between cluster members and uses this data to make cluster membership decisions. In order for a cluster to form (or for a node to join an established cluster), all members must be able to fully communicate with one another.

The more complex answer is that the Connection Manager is a distributed, multi-threaded kernel component that performs the following tasks:

• Forms a cluster.

• Maintains the cluster membership list and insures that each active member has the same list.

• Adds members to the cluster.

• Removes members from the cluster.

• Detects and handles member failures.

• Notifies registered kernel subsystems when CNX events occur.

• Reconfigures the cluster when members join or leave the cluster (also known as a cluster state transition).

• Detects a potential cluster partition and ensures that at most one side of that partition remains active as the cluster.