What are the events that EVMd process in Oracle RAC distributes across cluster

oracleoracle-11g-r2oracle-12crac

I am new to Oracle RAC. I was studying about Oracle RAC background processes, in which I came across EVMd process which distributes the event message across other nodes in the cluster.

Could you please make me understand, what are these event message? I worked on it but didn't get proper answer.

Thanks
Prabhakar

Best Answer

The Cluster Ready Services (CRS) process is the primary program for managing high availability operations(start, stop, monitor, and fail over) in a cluster.

The crsd process generates events when the status of a resource changes and EVMd publishes these events.

For example, if one of the cluster node goes down then the VIP running should fail over to another node. In this case crsd does the work of fail over and that changes the status of the resource-which is VIP in our example.

EVMd process distributes such events to all of the cluster members so that they are aware of the cluster changes.