Run replication streamers on workers (#7146)

Currently we never write to streams from workers, but that will change soon

1 files changed, 9 insertions, 4 deletions

diff --git a/synapse/app/generic_worker.py b/synapse/app/generic_worker.py

index 2a56fe0bd5..d125327f08 100644
--- a/synapse/app/generic_worker.py
+++ b/synapse/app/generic_worker.py
@@ -960,17 +960,22 @@ def start(config_options):
 
     synapse.events.USE_FROZEN_DICTS = config.use_frozen_dicts
 
-    ss = GenericWorkerServer(
+    hs = GenericWorkerServer(
         config.server_name,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
     )
 
-    setup_logging(ss, config, use_worker_options=True)
+    setup_logging(hs, config, use_worker_options=True)
+
+    hs.setup()
+
+    # Ensure the replication streamer is always started in case we write to any
+    # streams. Will no-op if no streams can be written to by this worker.
+    hs.get_replication_streamer()
 
-    ss.setup()
     reactor.addSystemEventTrigger(
-        "before", "startup", _base.start, ss, config.worker_listeners
+        "before", "startup", _base.start, hs, config.worker_listeners
     )
 
     _base.start_worker_reactor("synapse-generic-worker", config)