Heartbeat connection and state synchronization for clusters

The nodes in a cluster use a heartbeat connection to monitor the other nodes’ operation and to synchronize their state tables.

The nodes in a cluster exchange status information through a heartbeat network using multicast transmissions. If a node becomes unavailable, the other nodes of the cluster immediately notice the change, and connections are reallocated to the available nodes. A dedicated network is recommended for at least the primary heartbeat communications.

The heartbeat connection is essential for the operation of the cluster. Make sure that these conditions are true:
  • The heartbeat network works correctly and reliably.
  • You are using the correct type of network cables (after testing that they work).
  • The network interface cards’ duplex and speed settings match.
  • Any network devices between the nodes are correctly configured.

It is possible to authenticate and encrypt the heartbeat traffic.

Problems in the heartbeat network might seriously degrade the performance and operation of the cluster.

In the Engine/VPN role, the nodes of a Engine Cluster periodically exchange synchronization messages to synchronize state data.