Reintroduce "Reduce device lists replication traffic."" (#17361)

Reintroduces https://github.com/element-hq/synapse/pull/17333


Turns out the reason for revert was down two master instances running

1 files changed, 8 insertions, 4 deletions

diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py
index 661206c841..d021904de7 100644
--- a/synapse/replication/tcp/streams/_base.py
+++ b/synapse/replication/tcp/streams/_base.py
@@ -549,10 +549,14 @@ class DeviceListsStream(_StreamFromIdGen):
 
     @attr.s(slots=True, frozen=True, auto_attribs=True)
     class DeviceListsStreamRow:
-        entity: str
+        user_id: str
         # Indicates that a user has signed their own device with their user-signing key
         is_signature: bool
 
+        # Indicates if this is a notification that we've calculated the hosts we
+        # need to send the update to.
+        hosts_calculated: bool
+
     NAME = "device_lists"
     ROW_TYPE = DeviceListsStreamRow
 
@@ -594,13 +598,13 @@ class DeviceListsStream(_StreamFromIdGen):
             upper_limit_token = min(upper_limit_token, signatures_to_token)
 
         device_updates = [
-            (stream_id, (entity, False))
-            for stream_id, (entity,) in device_updates
+            (stream_id, (entity, False, hosts))
+            for stream_id, (entity, hosts) in device_updates
             if stream_id <= upper_limit_token
         ]
 
         signatures_updates = [
-            (stream_id, (entity, True))
+            (stream_id, (entity, True, False))
             for stream_id, (entity,) in signatures_updates
             if stream_id <= upper_limit_token
         ]