.

go/NOTES

@@ -350,6 +350,52 @@ PACKET    x          #0x0003 GetObject                      > S1 (127.0.0.1:4452
 ...
 
 
+Replication communication
+-------------------------
+
+replication types:
+
+- asynchronous	(e.g. to backup cluster or to replicate already committed data to newly added storage node)
+- synchronous	(on transaction commit - C stores data to all S assigned for
+		 oid in PT and waits for all stores to complete)
+
+XXX synchronous replication interracts with commit.
+XXX "OUT_OF_DATE -> UP_TO_DATE is done in several steps"	-> XXX which?
+
+XXX
+	""" A replicating node can not depend on other nodes to fetch the data
+	recently/being committed because that can not be done atomically: it could miss
+	writes between the processing of its request by a source node and the reception
+	of the answer. """
+
+XXX -> should not be the case with proper dump-stream based replication protocol.
+XXX -> jm: document example
+
+	Therefore, outdated cells are writable: a storage node asks the master for
+	transactions being committed and then it is expected to fully receive from the
+	client any transaction that is started after this answer.
+
+XXX -> recheck this is good idea.
+
+
+
+
+R = requester
+S = seeder
+
+item = Transaction(meta)  | Object(meta+data)
+
+R -> S	[]items	(which R already has)		XXX exact message
+R <- S  missing-item
+R <- S  missing-item
+...
+R <- S  missing-item
+R <- S  []items-to-delete
+
+
+
+
+
 Py: out-of-order answers
 ------------------------