The Heartbeat project is an integral part of the Linux-HA project, which implements a highly available cluster system. Heartbeat service and cluster communication are two key components of a high-availability cluster. In the Heartbeat project, the heartbeat module implements these two functions.
The working principle of heartbeat (Linux-HA): The core of heartbeat includes two parts, the heartbeat monitoring part and the resource takeover part. The heartbeat monitoring can be carried out through the network link and serial port, and supports redundant links, which send each other. message to tell the other party its current status. If the message sent by the other party is not received within the specified time, then the other party is considered to be invalid. At this time, the resource takeover module needs to be activated to take over the resources or services running on the other party's host.