What causes Node eviction in Oracle RAC?

What is node eviction?

Node eviction in RAC is done when a heartbeat indicates that a node is not responding, 

and the evicted node is re-started to make it a part of cluster.

Causes for RAC node eviction:

Node eviction on Oracle RAC environment can be due to any of the below reasons. 

- A failure of any of the major hardware components (CPU, RAM, network interconnect).

- A server that is experiencing RAM swapping.

- When communications to the voting disk is interrupted, causing the disconnected node to be evicted and re-boot.

- Database or ASM hang condition.

Below is the list of important log files to review in case of a node eviction

- Clusterware alert log

- Database alert log

- CSSD agent logs

- CSSD monitor logs

- System Message logs (/var/log/messages)