What is Oracle RAC Node eviction and what are the common causes of evictions?

Issue

• Red Hat Enterprise Linux Server which is a part of Oracle Clusterware is getting rebooted.
• System rebooted by cssdmonitor process.
• VMware guest part of Oracle cluster is suddenly rebooted.
• Host rebooted, RCA required.

Example 1

server1 logger: Oracle CSSD failure 134.
server1 logger: Oracle CRS failure.  Rebooting for cluster integrity.
server1 su(pam_unix)[29052]: session closed for user oracle
server1 logger: Oracle clsomon failed with fatal status 12.
server1 logger: Oracle CRS failure.  Rebooting for cluster integrity.

Example 2:

server2 logger: Oracle clsomon failed with fatal status 13.
server2 logger: Oracle CRS failure.  Rebooting for cluster integrity.
server2 syslogd 1.4.1: restart.

Example 3:
From a vmcore analysis:

PANIC: "SysRq : Trigger a crashdump"
PID: 17340
COMMAND: "cssdagent"