diff --git a/synapse/federation/transaction_queue.py b/synapse/federation/transaction_queue.py
index 003eaba893..0d6687ee5f 100644
--- a/synapse/federation/transaction_queue.py
+++ b/synapse/federation/transaction_queue.py
@@ -176,17 +176,22 @@ class TransactionQueue(object):
                     if not is_mine and send_on_behalf_of is None:
                         continue
 
-                    # Get the state from before the event.
-                    # We need to make sure that this is the state from before
-                    # the event and not from after it.
-                    # Otherwise if the last member on a server in a room is
-                    # banned then it won't receive the event because it won't
-                    # be in the room after the ban.
-                    destinations = yield self.state.get_current_hosts_in_room(
-                        event.room_id, latest_event_ids=[
-                            prev_id for prev_id, _ in event.prev_events
-                        ],
-                    )
+                    try:
+                        # Get the state from before the event.
+                        # We need to make sure that this is the state from before
+                        # the event and not from after it.
+                        # Otherwise if the last member on a server in a room is
+                        # banned then it won't receive the event because it won't
+                        # be in the room after the ban.
+                        destinations = yield self.state.get_current_hosts_in_room(
+                            event.room_id, latest_event_ids=[
+                                prev_id for prev_id, _ in event.prev_events
+                            ],
+                        )
+                    except:
+                        logger.exception("Failed to calculate hosts in room")
+                        continue
+
                     destinations = set(destinations)
 
                     if send_on_behalf_of is not None:
@@ -246,6 +251,7 @@ class TransactionQueue(object):
         Args:
             states (list(UserPresenceState))
         """
+	return
 
         # First we queue up the new presence by user ID, so multiple presence
         # updates in quick successtion are correctly handled
diff --git a/synapse/handlers/user_directory.py b/synapse/handlers/user_directory.py
index 43eb1c78e9..d0fb27d5c1 100644
--- a/synapse/handlers/user_directory.py
+++ b/synapse/handlers/user_directory.py
@@ -99,6 +99,7 @@ class UserDirectoyHandler(object):
 
     @defer.inlineCallbacks
     def _unsafe_process(self):
+        return
         # If self.pos is None then means we haven't fetched it from DB
         if self.pos is None:
             self.pos = yield self.store.get_user_directory_stream_pos()
diff --git a/synapse/replication/tcp/streams.py b/synapse/replication/tcp/streams.py
index 369d5f2428..ceb5a91e7f 100644
--- a/synapse/replication/tcp/streams.py
+++ b/synapse/replication/tcp/streams.py
@@ -33,7 +33,7 @@ import logging
 logger = logging.getLogger(__name__)
 
 
-MAX_EVENTS_BEHIND = 10000
+MAX_EVENTS_BEHIND = 500000
 
 
 EventStreamRow = namedtuple("EventStreamRow", (
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 51730a88bf..4e728bf77d 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -184,7 +184,7 @@ class SQLBaseStore(object):
                                       max_entries=hs.config.event_cache_size)
 
         self._state_group_cache = DictionaryCache(
-            "*stateGroupCache*", 100000 * CACHE_SIZE_FACTOR
+            "*stateGroupCache*", 500000 * CACHE_SIZE_FACTOR
         )
 
         self._event_fetch_lock = threading.Condition()
diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index 8656455f6e..5a9771043d 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -638,7 +638,7 @@ class RoomMemberStore(SQLBaseStore):
 
         defer.returnValue(result)
 
-    @cached(max_entries=10000, iterable=True)
+    @cached(max_entries=10000)
     def _get_joined_hosts_cache(self, room_id):
         return _JoinedHostsCache(self, room_id)
 
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index c3eecbe824..c1a2ee31e7 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -697,8 +697,7 @@ class StateStore(SQLBaseStore):
                 state_dict = results[group]
 
                 state_dict.update(
-                    ((intern_string(k[0]), intern_string(k[1])), to_ascii(v))
-                    for k, v in group_state_dict.iteritems()
+                    group_state_dict.iteritems()
                 )
 
                 self._state_group_cache.update(