Ceph

Keep a log of sent/received MMonSync messages, obtainable through the admin socket, for offline matching.

Completing this with a script that would describe the messages effects on the receiving end, would enable us to pinpoint incorrect behaviors.

For instance, stating that a MMonSync::OP_START would cause a MMonSync::OP_START_REPLY with or without the MMonSync::FLAG_RETRY set, would allow us to infer if something in the code path is wrong if we ended up receiving any other kind of MMonSync::OP_*.