Voting algorithms in Oracle RAC

There are three machines in the RAC cluster, a,b,c

A,b,c will have 3 votes, assuming this is a heart jumper problem, the entire RAC cluster is divided into two paritition,

One is only a partition, one is a b,c composed of partition,

Two partition all want to think that the other side of the problem, they need to take over the business, if there is no voting algorithm will cause two partition simultaneous operation of the database (shared storage), note that the database here is not what we usually say the database, because in the RAC cluster, data files, configuration files , the log files are placed on the back-end shared storage, which is shared by multiple nodes in the RAC cluster.

In other words, after the first two partition, because a is located in the partition only own, no other heartbeat line connection, so it only own 1 votes,

and b,c partition because there are each other's heart jumpers exist, can vote to each other, so they have 2 votes, this time the number of votes to get control of the RAC Cluster, a where the partition was kicked out of the cluster. A node is forced to restart, avoiding a and BC nodes operating the database at the same time.

Voting algorithms in Oracle RAC