Oracle CRS的心跳主要分为Disk和Network Heartbeat，不同种类的心跳超时会对RAC造成不同的影响。
Heartbeat Mechanisms Disk Heartbeat ( Voting device ) – IOT Network Heartbeat ( across the interconnect ) – misscount Misscount – max time a heartbeat can be missed before entering into a cluster reconfig to evict a node IOT – internal I/O timeout, in seconds where an I/O to the disk must complete IOT = misscount [ during initial cluster formation time] IOT = disktimeout [ all other times ] Hardware Storage timeout Software Storage timeout OCFS Heartbeat timeouts disktimeout > max(O2CB_HEARTBEAT_THRESHOLD * 2, HW_STORAGE_TIMEOUT, SW_STORAGE_TIMEOUT)
