Review comments

docs/tcp_replication.md

@@ -175,7 +175,8 @@ client (C):
 #### POSITION (S)
 
    On receipt of a POSITION command clients should check if they have missed any
-   updates, and if so then fetch them out of band.
+   updates, and if so then fetch them out of band. Sent in response to a
+   REPLICATE command (but can happen at any time).
 
 #### ERROR (S, C)
 

synapse/replication/tcp/protocol.py

@@ -648,7 +648,6 @@ class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
         # We've now caught up to position sent to us, notify handler.
         await self.handler.on_position(cmd.stream_name, cmd.token)
 
-        # We're now up to date wit the stream
         self.streams_connecting.discard(cmd.stream_name)
         if not self.streams_connecting:
             self.handler.finished_connecting()

synapse/replication/tcp/streams/_base.py

@@ -105,9 +105,6 @@ class Stream(object):
             to fetch.
         """
 
-        if from_token in ("NOW", "now"):
-            return [], upto_token, False
-
         from_token = int(from_token)
 
         if from_token == upto_token: