Active Server
There is a single Active server in the group. This server was the first to obtain the exclusive lock for storage. For the FileStore
implementation, it means trying to get an advisory lock for a file located in the shared datastore. For the SQLStore
implementation, a special table is used in which the owner of the lock updates a column. Other instances will steal the lock if the column is not updated for a certain amount of time.
If the elected server fails to grab this lock because it is already locked, it will go back to standby.
Only the active server accesses the store and service all clients.