diff --git a/changelog.d/9042.feature b/changelog.d/9042.feature
new file mode 100644
index 0000000000..4ec319f1f2
--- /dev/null
+++ b/changelog.d/9042.feature
@@ -0,0 +1 @@
+Add experimental support for handling and persistence of to-device messages to happen on worker processes.
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 35e345ce70..e5339aca23 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -15,6 +15,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
+import random
from typing import (
TYPE_CHECKING,
Any,
@@ -860,8 +861,10 @@ class FederationHandlerRegistry:
) # type: Dict[str, Callable[[str, dict], Awaitable[None]]]
self.query_handlers = {} # type: Dict[str, Callable[[dict], Awaitable[None]]]
- # Map from type to instance name that we should route EDU handling to.
- self._edu_type_to_instance = {} # type: Dict[str, str]
+ # Map from type to instance names that we should route EDU handling to.
+ # We randomly choose one instance from the list to route to for each new
+ # EDU received.
+ self._edu_type_to_instance = {} # type: Dict[str, List[str]]
def register_edu_handler(
self, edu_type: str, handler: Callable[[str, JsonDict], Awaitable[None]]
@@ -905,7 +908,12 @@ class FederationHandlerRegistry:
def register_instance_for_edu(self, edu_type: str, instance_name: str):
"""Register that the EDU handler is on a different instance than master.
"""
- self._edu_type_to_instance[edu_type] = instance_name
+ self._edu_type_to_instance[edu_type] = [instance_name]
+
+ def register_instances_for_edu(self, edu_type: str, instance_names: List[str]):
+ """Register that the EDU handler is on multiple instances.
+ """
+ self._edu_type_to_instance[edu_type] = instance_names
async def on_edu(self, edu_type: str, origin: str, content: dict):
if not self.config.use_presence and edu_type == "m.presence":
@@ -924,8 +932,11 @@ class FederationHandlerRegistry:
return
# Check if we can route it somewhere else that isn't us
- route_to = self._edu_type_to_instance.get(edu_type, "master")
- if route_to != self._instance_name:
+ instances = self._edu_type_to_instance.get(edu_type, ["master"])
+ if self._instance_name not in instances:
+ # Pick an instance randomly so that we don't overload one.
+ route_to = random.choice(instances)
+
try:
await self._send_edu(
instance_name=route_to,
|
