LifeKeeper for Windows monitors resource operations and provides failover using shared communication paths (comm paths) between servers. It is critical to LifeKeeper for Windows fault detection and resource recovery that communication between the servers remains active. As a result, you need to define multiple comm paths using different protocols to guard against a system failover simply because a communication line fails.
Before you can define resources or resource hierarchies in LifeKeeper for Windows, you must define your comm paths on each of the servers. LifeKeeper for Windows uses the comm paths to coordinate resource definitions and states between the nodes and for fault detection and recovery.
The Communication Path Types section describes these comm path topics:
- Comm path types. LifeKeeper for Windows supports two types of comm paths for two-server configurations: TCP/IP and Shared Disk. Configurations with greater than two servers support only TCP/IP comm paths.
- LifeKeeper for Windows heartbeat. A key function of the comm path between the servers is the LifeKeeper for Windows heartbeat. This periodic signal between the servers assures each server that the other is still alive and processing.
- Safety check. If all comm paths die, LifeKeeper for Windows performs a safety check to verify system failure before switching over resources.