Ceph » CephFS

QuiesceDb is an ephemeral versioned replicated database holding a collection of QuiesceSet s. Each quiesce set carries a QuiesceState which can be observed by clients. QuiesceSet manages a collection of members - QuiesceRoot s and their corresponding QuiesceState s. When all members of a set reach quiesced state then the set is considered quiesced.

QuiesceDb is replicated across ranks of a file system. A single rank is selected to be the leader. The leader is authorized to maintain the database by processing external requests, peer acks, and timeout events. Updates to the database are sent out by the leader to all registered peers.

QuiesceDbManager is the class that maintains the quiesce db. Managers should be instantiated by the ranks and configured to form a cluster. The QuiesceDbManager only cares about the consistency of the quiesce db, and relies on the QuiesceAgent to perform the quiescing operations.