RAC 腦裂 處理機制 Oracle RAC Brain Split

Cluster nodes maintain their heartbeat via private network and voting disk. When there is a private network disruption, cluster nodes can not communicate to each other via private network for the time period of misscount setting, split brain will happen. In such case, voting disk will be used to determine which node(s) survive and which node(s) will be evicted. The common voting result will be:

a. The group with more cluster nodes survive
b. The group with lower node member in case of same number of node(s) available in each group
c. Some improvement has been made to ensure node(s) with lower load survive in case the eviction is caused by high system load.