From 9bac5d62b33f34c25bed27824a12d697b8b6b163 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 27 May 2020 11:44:19 +0100
Subject: [PATCH] Ensure ReplicationStreamer is always started when replication
 enabled. (#7579)

Fixes #7566.
---
 changelog.d/7579.bugfix            | 1 +
 synapse/replication/tcp/handler.py | 3 +++
 2 files changed, 4 insertions(+)
 create mode 100644 changelog.d/7579.bugfix

diff --git a/changelog.d/7579.bugfix b/changelog.d/7579.bugfix
new file mode 100644
index 000000000..54542b602
--- /dev/null
+++ b/changelog.d/7579.bugfix
@@ -0,0 +1 @@
+Fix bug where `ReplicationStreamer` was not always started when replication was enabled. Bug introduced in v1.14.0rc1.
diff --git a/synapse/replication/tcp/handler.py b/synapse/replication/tcp/handler.py
index 03300e533..cbcf46f3a 100644
--- a/synapse/replication/tcp/handler.py
+++ b/synapse/replication/tcp/handler.py
@@ -159,6 +159,9 @@ class ReplicationCommandHandler:
                 hs.config.redis_port,
             )
 
+            # First let's ensure that we have a ReplicationStreamer started.
+            hs.get_replication_streamer()
+
             # We need two connections to redis, one for the subscription stream and
             # one to send commands to (as you can't send further redis commands to a
             # connection after SUBSCRIBE is called).