From 21b977ccfe11832aa1c7b448c6e657cf0df36ad4 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Tue, 30 Aug 2016 15:39:50 +0100
Subject: [PATCH 1/2] Occaisonally persist unpersisted presence updates

---
 synapse/handlers/presence.py | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index 73752b2f8904..a3c7952a4c7a 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -191,6 +191,13 @@ def __init__(self, hs):
             5000,
         )
 
+        self.clock.call_later(
+            60,
+            self.clock.looping_call,
+            self._persist_unpersisted_changes,
+            60 * 1000,
+        )
+
         metrics.register_callback("wheel_timer_size", lambda: len(self.wheel_timer))
 
     @defer.inlineCallbacks
@@ -216,6 +223,27 @@ def _on_shutdown(self):
             ])
         logger.info("Finished _on_shutdown")
 
+    @defer.inlineCallbacks
+    def _persist_unpersisted_changes(self):
+        """We periodically persist the unpersisted changes, as otherwise they
+        may stack up and slow down shutdown times.
+        """
+        logger.info(
+            "Performing _persist_unpersisted_changes. Persiting %d unpersisted changes",
+            len(self.user_to_current_state)
+        )
+
+        unpersisted = self.unpersisted_users_changes
+        self.unpersisted_users_changes = set()
+
+        if self.unpersisted_users_changes:
+            yield self.store.update_presence([
+                self.user_to_current_state[user_id]
+                for user_id in unpersisted
+            ])
+
+        logger.info("Finished _persist_unpersisted_changes")
+
     @defer.inlineCallbacks
     def _update_states(self, new_states):
         """Updates presence of users. Sets the appropriate timeouts. Pokes

From 097330bae8cd948ea34a882290efd2182431b51c Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Tue, 30 Aug 2016 15:50:20 +0100
Subject: [PATCH 2/2] Check correct variable

---
 synapse/handlers/presence.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index a3c7952a4c7a..ab33952cd2c8 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -236,7 +236,7 @@ def _persist_unpersisted_changes(self):
         unpersisted = self.unpersisted_users_changes
         self.unpersisted_users_changes = set()
 
-        if self.unpersisted_users_changes:
+        if unpersisted:
             yield self.store.update_presence([
                 self.user_to_current_state[user_id]
                 for user_id in unpersisted