Wake up transaction queue when remote server comes back online (#6706)

This will be used to retry outbound transactions to a remote server if
we think it might have come back up.

1 files changed, 3 insertions, 0 deletions

diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py

index 52a0aefe68..fc06a7b053 100644
--- a/synapse/replication/tcp/client.py
+++ b/synapse/replication/tcp/client.py
@@ -143,6 +143,9 @@ class ReplicationClientHandler(AbstractReplicationClientHandler):
         if d:
             d.callback(data)
 
+    def on_remote_server_up(self, server: str):
+        """Called when get a new REMOTE_SERVER_UP command."""
+
     def get_streams_to_replicate(self) -> Dict[str, int]:
         """Called when a new connection has been established and we need to
         subscribe to streams.