What is the voting process in WSFC?

Question

Node and File Share Majority. Similar to Node Majority quorum mode, except that a remote file share is also configured as a voting witness, and connectivity from any node to that share is also counted as an affirmative vote. More than one-half of the possible votes must be affirmative for the cluster to be healthy.

Link: https://learn.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/wsfc-quorum-modes-and-voting-configuration-sql-server?view=sql-server-ver15

A 2 node + 1 file share cluster is healthy upon receiving greater than 50% votes (2/3 votes).

Assuming vote means connectivity check, does the active node send signal to the other node and the file share? Or does node2 and file share send its vote to the active node?

Answer 1

A vote does not mean a connectivity check. WSFC uses some form of the Paxos protocol for voting. I could not find the specific implementation details published anywhere, but I suppose it might work more or less like this: whenever a cluster member loss is detected, by means of the heartbeat, the node that detected it sends out a quorum proposal to all known members. If enough nodes respond that they are willing to accept the proposal, the quorum is maintained and the state is committed to all listening nodes.

There are additional details in this old KnowledgeBase article.