What is Oracle RAC Node Eviction
One of the most common and complex issue is node eviction issue. A node is evicted from the cluster after it kills itself because it is not able to
service the applications.
This generally happens during the communication failure between the instances, when the instance is not able to send heartbeat information to the
control file and various other reasons.
Oracle Clusterware is designed to perform a node eviction by removing one or more nodes from the cluster if some critical problem is detected. A
critical problem could be a node not responding via a network heartbeat, a node not responding via a disk heartbeat, a hung or severely degraded machine, or
a hung ocssd.bin process. The purpose of this node eviction is to maintain the overall health of the cluster by removing bad members.
During failures, to avoid data corruption, the failing instance evicts itself from the cluster group. The node eviction process is reported as
Oracle error ORA-29740 in the alert log and LMON trace files.
