push_notifications: Shard mobile push notifications.

zerver/worker/missedmessage_mobile_notifications.py

@@ -1,7 +1,8 @@
 # Documented in https://zulip.readthedocs.io/en/latest/subsystems/queuing.html
 import logging
-from typing import Any, Dict
+from typing import Any, Dict, Optional
 
+from django.conf import settings
 from typing_extensions import override
 
 from zerver.lib.push_notifications import (
@@ -23,6 +24,17 @@ class PushNotificationsWorker(QueueProcessingWorker):
     # play well with asyncio.
     MAX_CONSUME_SECONDS = None
 
+    @override
+    def __init__(
+        self,
+        threaded: bool = False,
+        disable_timeout: bool = False,
+        worker_num: Optional[int] = None,
+    ) -> None:
+        if settings.MOBILE_NOTIFICATIONS_SHARDS > 1 and worker_num is not None:  # nocoverage
+            self.queue_name = self.queue_name + f"_shard{worker_num}"
+        super().__init__(threaded, disable_timeout, worker_num)
+
     @override
     def start(self) -> None:
         # initialize_push_notifications doesn't strictly do anything