Always notify replication when a stream advances (#14877)

This ensures that all other workers are told about stream updates in a timely manner, without having to remember to manually poke replication.

1 files changed, 7 insertions, 16 deletions

diff --git a/tests/replication/tcp/test_handler.py b/tests/replication/tcp/test_handler.py
index 555922409d..6e4055cc21 100644
--- a/tests/replication/tcp/test_handler.py
+++ b/tests/replication/tcp/test_handler.py
@@ -14,7 +14,7 @@
 
 from twisted.internet import defer
 
-from synapse.replication.tcp.commands import PositionCommand, RdataCommand
+from synapse.replication.tcp.commands import PositionCommand
 
 from tests.replication._base import BaseMultiWorkerStreamTestCase
 
@@ -111,20 +111,14 @@ class ChannelsTestCase(BaseMultiWorkerStreamTestCase):
         next_token = self.get_success(ctx.__aenter__())
         self.get_success(ctx.__aexit__(None, None, None))
 
-        cmd_handler.send_command(
-            RdataCommand("caches", "worker1", next_token, ("func_name", [], 0))
-        )
-        self.replicate()
-
         self.get_success(
             data_handler.wait_for_stream_position("worker1", "caches", next_token)
         )
 
-        # `wait_for_stream_position` should only return once master receives an
-        # RDATA from the worker
-        ctx = cache_id_gen.get_next()
-        next_token = self.get_success(ctx.__aenter__())
-        self.get_success(ctx.__aexit__(None, None, None))
+        # `wait_for_stream_position` should only return once master receives a
+        # notification that `next_token` has persisted.
+        ctx_worker1 = cache_id_gen.get_next()
+        next_token = self.get_success(ctx_worker1.__aenter__())
 
         d = defer.ensureDeferred(
             data_handler.wait_for_stream_position("worker1", "caches", next_token)
@@ -142,10 +136,7 @@ class ChannelsTestCase(BaseMultiWorkerStreamTestCase):
         )
         self.assertFalse(d.called)
 
-        # ... but receiving the RDATA should
-        cmd_handler.send_command(
-            RdataCommand("caches", "worker1", next_token, ("func_name", [], 0))
-        )
-        self.replicate()
+        # ... but worker1 finishing (and so sending an update) should.
+        self.get_success(ctx_worker1.__aexit__(None, None, None))
 
         self.assertTrue(d.called)