Merge tag 'v1.3.0'

Synapse 1.3.0 (2019-08-15)
==========================

Bugfixes
--------

- Fix 500 Internal Server Error on `publicRooms` when the public room list was
  cached. ([\#5851](https://github.com/matrix-org/synapse/issues/5851))

Synapse 1.3.0rc1 (2019-08-13)
==========================

Features
--------

- Use `M_USER_DEACTIVATED` instead of `M_UNKNOWN` for errcode when a deactivated user attempts to login. ([\#5686](https://github.com/matrix-org/synapse/issues/5686))
- Add sd_notify hooks to ease systemd integration and allows usage of Type=Notify. ([\#5732](https://github.com/matrix-org/synapse/issues/5732))
- Synapse will no longer serve any media repo admin endpoints when `enable_media_repo` is set to False in the configuration. If a media repo worker is used, the admin APIs relating to the media repo will be served from it instead. ([\#5754](https://github.com/matrix-org/synapse/issues/5754), [\#5848](https://github.com/matrix-org/synapse/issues/5848))
- Synapse can now be configured to not join remote rooms of a given "complexity" (currently, state events) over federation. This option can be used to prevent adverse performance on resource-constrained homeservers. ([\#5783](https://github.com/matrix-org/synapse/issues/5783))
- Allow defining HTML templates to serve the user on account renewal attempt when using the account validity feature. ([\#5807](https://github.com/matrix-org/synapse/issues/5807))

Bugfixes
--------

- Fix UISIs during homeserver outage. ([\#5693](https://github.com/matrix-org/synapse/issues/5693), [\#5789](https://github.com/matrix-org/synapse/issues/5789))
- Fix stack overflow in server key lookup code. ([\#5724](https://github.com/matrix-org/synapse/issues/5724))
- start.sh no longer uses deprecated cli option. ([\#5725](https://github.com/matrix-org/synapse/issues/5725))
- Log when we receive an event receipt from an unexpected origin. ([\#5743](https://github.com/matrix-org/synapse/issues/5743))
- Fix debian packaging scripts to correctly build sid packages. ([\#5775](https://github.com/matrix-org/synapse/issues/5775))
- Correctly handle redactions of redactions. ([\#5788](https://github.com/matrix-org/synapse/issues/5788))
- Return 404 instead of 403 when accessing /rooms/{roomId}/event/{eventId} for an event without the appropriate permissions. ([\#5798](https://github.com/matrix-org/synapse/issues/5798))
- Fix check that tombstone is a state event in push rules. ([\#5804](https://github.com/matrix-org/synapse/issues/5804))
- Fix error when trying to login as a deactivated user when using a worker to handle login. ([\#5806](https://github.com/matrix-org/synapse/issues/5806))
- Fix bug where user `/sync` stream could get wedged in rare circumstances. ([\#5825](https://github.com/matrix-org/synapse/issues/5825))
- The purge_remote_media.sh script was fixed. ([\#5839](https://github.com/matrix-org/synapse/issues/5839))

Deprecations and Removals
-------------------------

- Synapse now no longer accepts the `-v`/`--verbose`, `-f`/`--log-file`, or `--log-config` command line flags, and removes the deprecated `verbose` and `log_file` configuration file options. Users of these options should migrate their options into the dedicated log configuration. ([\#5678](https://github.com/matrix-org/synapse/issues/5678), [\#5729](https://github.com/matrix-org/synapse/issues/5729))
- Remove non-functional 'expire_access_token' setting. ([\#5782](https://github.com/matrix-org/synapse/issues/5782))

Internal Changes
----------------

- Make Jaeger fully configurable. ([\#5694](https://github.com/matrix-org/synapse/issues/5694))
- Add precautionary measures to prevent future abuse of `window.opener` in default welcome page. ([\#5695](https://github.com/matrix-org/synapse/issues/5695))
- Reduce database IO usage by optimising queries for current membership. ([\#5706](https://github.com/matrix-org/synapse/issues/5706), [\#5738](https://github.com/matrix-org/synapse/issues/5738), [\#5746](https://github.com/matrix-org/synapse/issues/5746), [\#5752](https://github.com/matrix-org/synapse/issues/5752), [\#5770](https://github.com/matrix-org/synapse/issues/5770), [\#5774](https://github.com/matrix-org/synapse/issues/5774), [\#5792](https://github.com/matrix-org/synapse/issues/5792), [\#5793](https://github.com/matrix-org/synapse/issues/5793))
- Improve caching when fetching `get_filtered_current_state_ids`. ([\#5713](https://github.com/matrix-org/synapse/issues/5713))
- Don't accept opentracing data from clients. ([\#5715](https://github.com/matrix-org/synapse/issues/5715))
- Speed up PostgreSQL unit tests in CI. ([\#5717](https://github.com/matrix-org/synapse/issues/5717))
- Update the coding style document. ([\#5719](https://github.com/matrix-org/synapse/issues/5719))
- Improve database query performance when recording retry intervals for remote hosts. ([\#5720](https://github.com/matrix-org/synapse/issues/5720))
- Add a set of opentracing utils. ([\#5722](https://github.com/matrix-org/synapse/issues/5722))
- Cache result of get_version_string to reduce overhead of `/version` federation requests. ([\#5730](https://github.com/matrix-org/synapse/issues/5730))
- Return 'user_type' in admin API user endpoints results. ([\#5731](https://github.com/matrix-org/synapse/issues/5731))
- Don't package the sytest test blacklist file. ([\#5733](https://github.com/matrix-org/synapse/issues/5733))
- Replace uses of returnValue with plain return, as returnValue is not needed on Python 3. ([\#5736](https://github.com/matrix-org/synapse/issues/5736))
- Blacklist some flakey tests in worker mode. ([\#5740](https://github.com/matrix-org/synapse/issues/5740))
- Fix some error cases in the caching layer. ([\#5749](https://github.com/matrix-org/synapse/issues/5749))
- Add a prometheus metric for pending cache lookups. ([\#5750](https://github.com/matrix-org/synapse/issues/5750))
- Stop trying to fetch events with event_id=None. ([\#5753](https://github.com/matrix-org/synapse/issues/5753))
- Convert RedactionTestCase to modern test style. ([\#5768](https://github.com/matrix-org/synapse/issues/5768))
- Allow looping calls to be given arguments. ([\#5780](https://github.com/matrix-org/synapse/issues/5780))
- Set the logs emitted when checking typing and presence timeouts to DEBUG level, not INFO. ([\#5785](https://github.com/matrix-org/synapse/issues/5785))
- Remove DelayedCall debugging from the test suite, as it is no longer required in the vast majority of Synapse's tests. ([\#5787](https://github.com/matrix-org/synapse/issues/5787))
- Remove some spurious exceptions from the logs where we failed to talk to a remote server. ([\#5790](https://github.com/matrix-org/synapse/issues/5790))
- Improve performance when making `.well-known` requests by sharing the SSL options between requests. ([\#5794](https://github.com/matrix-org/synapse/issues/5794))
- Disable codecov GitHub comments on PRs. ([\#5796](https://github.com/matrix-org/synapse/issues/5796))
- Don't allow clients to send tombstone events that reference the room it's sent in. ([\#5801](https://github.com/matrix-org/synapse/issues/5801))
- Deny redactions of events sent in a different room. ([\#5802](https://github.com/matrix-org/synapse/issues/5802))
- Deny sending well known state types as non-state events. ([\#5805](https://github.com/matrix-org/synapse/issues/5805))
- Handle incorrectly encoded query params correctly by returning a 400. ([\#5808](https://github.com/matrix-org/synapse/issues/5808))
- Handle pusher being deleted during processing rather than logging an exception. ([\#5809](https://github.com/matrix-org/synapse/issues/5809))
- Return 502 not 500 when failing to reach any remote server. ([\#5810](https://github.com/matrix-org/synapse/issues/5810))
- Reduce global pauses in the events stream caused by expensive state resolution during persistence. ([\#5826](https://github.com/matrix-org/synapse/issues/5826))
- Add a lower bound to well-known lookup cache time to avoid repeated lookups. ([\#5836](https://github.com/matrix-org/synapse/issues/5836))
- Whitelist history visbility sytests in worker mode tests. ([\#5843](https://github.com/matrix-org/synapse/issues/5843))

1 files changed, 275 insertions, 75 deletions

diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index 32cfd010a5..eecb276465 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -24,6 +24,8 @@ from canonicaljson import json
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.storage._base import LoggingTransaction
 from synapse.storage.events_worker import EventsWorkerStore
 from synapse.types import get_domain_from_id
 from synapse.util.async_helpers import Linearizer
@@ -53,9 +55,51 @@ ProfileInfo = namedtuple("ProfileInfo", ("avatar_url", "display_name"))
 MemberSummary = namedtuple("MemberSummary", ("members", "count"))
 
 _MEMBERSHIP_PROFILE_UPDATE_NAME = "room_membership_profile_update"
+_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME = "current_state_events_membership"
 
 
 class RoomMemberWorkerStore(EventsWorkerStore):
+    def __init__(self, db_conn, hs):
+        super(RoomMemberWorkerStore, self).__init__(db_conn, hs)
+
+        # Is the current_state_events.membership up to date? Or is the
+        # background update still running?
+        self._current_state_events_membership_up_to_date = False
+
+        txn = LoggingTransaction(
+            db_conn.cursor(),
+            name="_check_safe_current_state_events_membership_updated",
+            database_engine=self.database_engine,
+        )
+        self._check_safe_current_state_events_membership_updated_txn(txn)
+        txn.close()
+
+    def _check_safe_current_state_events_membership_updated_txn(self, txn):
+        """Checks if it is safe to assume the new current_state_events
+        membership column is up to date
+        """
+
+        pending_update = self._simple_select_one_txn(
+            txn,
+            table="background_updates",
+            keyvalues={"update_name": _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME},
+            retcols=["update_name"],
+            allow_none=True,
+        )
+
+        self._current_state_events_membership_up_to_date = not pending_update
+
+        # If the update is still running, reschedule to run.
+        if pending_update:
+            self._clock.call_later(
+                15.0,
+                run_as_background_process,
+                "_check_safe_current_state_events_membership_updated",
+                self.runInteraction,
+                "_check_safe_current_state_events_membership_updated",
+                self._check_safe_current_state_events_membership_updated_txn,
+            )
+
     @cachedInlineCallbacks(max_entries=100000, iterable=True, cache_context=True)
     def get_hosts_in_room(self, room_id, cache_context):
         """Returns the set of all hosts currently in the room
@@ -64,19 +108,28 @@ class RoomMemberWorkerStore(EventsWorkerStore):
             room_id, on_invalidate=cache_context.invalidate
         )
         hosts = frozenset(get_domain_from_id(user_id) for user_id in user_ids)
-        defer.returnValue(hosts)
+        return hosts
 
     @cached(max_entries=100000, iterable=True)
     def get_users_in_room(self, room_id):
         def f(txn):
-            sql = (
-                "SELECT m.user_id FROM room_memberships as m"
-                " INNER JOIN current_state_events as c"
-                " ON m.event_id = c.event_id "
-                " AND m.room_id = c.room_id "
-                " AND m.user_id = c.state_key"
-                " WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?"
-            )
+            # If we can assume current_state_events.membership is up to date
+            # then we can avoid a join, which is a Very Good Thing given how
+            # frequently this function gets called.
+            if self._current_state_events_membership_up_to_date:
+                sql = """
+                    SELECT state_key FROM current_state_events
+                    WHERE type = 'm.room.member' AND room_id = ? AND membership = ?
+                """
+            else:
+                sql = """
+                    SELECT state_key FROM room_memberships as m
+                    INNER JOIN current_state_events as c
+                    ON m.event_id = c.event_id
+                    AND m.room_id = c.room_id
+                    AND m.user_id = c.state_key
+                    WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?
+                """
 
             txn.execute(sql, (room_id, Membership.JOIN))
             return [to_ascii(r[0]) for r in txn]
@@ -98,15 +151,29 @@ class RoomMemberWorkerStore(EventsWorkerStore):
             # first get counts.
             # We do this all in one transaction to keep the cache small.
             # FIXME: get rid of this when we have room_stats
-            sql = """
-                SELECT count(*), m.membership FROM room_memberships as m
-                 INNER JOIN current_state_events as c
-                 ON m.event_id = c.event_id
-                 AND m.room_id = c.room_id
-                 AND m.user_id = c.state_key
-                 WHERE c.type = 'm.room.member' AND c.room_id = ?
-                 GROUP BY m.membership
-            """
+
+            # If we can assume current_state_events.membership is up to date
+            # then we can avoid a join, which is a Very Good Thing given how
+            # frequently this function gets called.
+            if self._current_state_events_membership_up_to_date:
+                # Note, rejected events will have a null membership field, so
+                # we we manually filter them out.
+                sql = """
+                    SELECT count(*), membership FROM current_state_events
+                    WHERE type = 'm.room.member' AND room_id = ?
+                        AND membership IS NOT NULL
+                    GROUP BY membership
+                """
+            else:
+                sql = """
+                    SELECT count(*), m.membership FROM room_memberships as m
+                    INNER JOIN current_state_events as c
+                    ON m.event_id = c.event_id
+                    AND m.room_id = c.room_id
+                    AND m.user_id = c.state_key
+                    WHERE c.type = 'm.room.member' AND c.room_id = ?
+                    GROUP BY m.membership
+                """
 
             txn.execute(sql, (room_id,))
             res = {}
@@ -115,19 +182,30 @@ class RoomMemberWorkerStore(EventsWorkerStore):
 
             # we order by membership and then fairly arbitrarily by event_id so
             # heroes are consistent
-            sql = """
-                SELECT m.user_id, m.membership, m.event_id
-                FROM room_memberships as m
-                 INNER JOIN current_state_events as c
-                 ON m.event_id = c.event_id
-                 AND m.room_id = c.room_id
-                 AND m.user_id = c.state_key
-                 WHERE c.type = 'm.room.member' AND c.room_id = ?
-                 ORDER BY
-                    CASE m.membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
-                    m.event_id ASC
-                 LIMIT ?
-            """
+            if self._current_state_events_membership_up_to_date:
+                # Note, rejected events will have a null membership field, so
+                # we we manually filter them out.
+                sql = """
+                    SELECT state_key, membership, event_id
+                    FROM current_state_events
+                    WHERE type = 'm.room.member' AND room_id = ?
+                        AND membership IS NOT NULL
+                    ORDER BY
+                        CASE membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
+                        event_id ASC
+                    LIMIT ?
+                """
+            else:
+                sql = """
+                    SELECT c.state_key, m.membership, c.event_id
+                    FROM room_memberships as m
+                    INNER JOIN current_state_events as c USING (room_id, event_id)
+                    WHERE c.type = 'm.room.member' AND c.room_id = ?
+                    ORDER BY
+                        CASE m.membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
+                        c.event_id ASC
+                    LIMIT ?
+                """
 
             # 6 is 5 (number of heroes) plus 1, in case one of them is the calling user.
             txn.execute(sql, (room_id, Membership.JOIN, Membership.INVITE, 6))
@@ -189,31 +267,38 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         invites = yield self.get_invited_rooms_for_user(user_id)
         for invite in invites:
             if invite.room_id == room_id:
-                defer.returnValue(invite)
-        defer.returnValue(None)
+                return invite
+        return None
 
+    @defer.inlineCallbacks
     def get_rooms_for_user_where_membership_is(self, user_id, membership_list):
         """ Get all the rooms for this user where the membership for this user
         matches one in the membership list.
 
+        Filters out forgotten rooms.
+
         Args:
             user_id (str): The user ID.
             membership_list (list): A list of synapse.api.constants.Membership
             values which the user must be in.
+
         Returns:
-            A list of dictionary objects, with room_id, membership and sender
-            defined.
+            Deferred[list[RoomsForUser]]
         """
         if not membership_list:
             return defer.succeed(None)
 
-        return self.runInteraction(
+        rooms = yield self.runInteraction(
             "get_rooms_for_user_where_membership_is",
             self._get_rooms_for_user_where_membership_is_txn,
             user_id,
             membership_list,
         )
 
+        # Now we filter out forgotten rooms
+        forgotten_rooms = yield self.get_forgotten_rooms_for_user(user_id)
+        return [room for room in rooms if room.room_id not in forgotten_rooms]
+
     def _get_rooms_for_user_where_membership_is_txn(
         self, txn, user_id, membership_list
     ):
@@ -223,26 +308,33 @@ class RoomMemberWorkerStore(EventsWorkerStore):
 
         results = []
         if membership_list:
-            where_clause = "user_id = ? AND (%s) AND forgotten = 0" % (
-                " OR ".join(["membership = ?" for _ in membership_list]),
-            )
-
-            args = [user_id]
-            args.extend(membership_list)
+            if self._current_state_events_membership_up_to_date:
+                sql = """
+                    SELECT room_id, e.sender, c.membership, event_id, e.stream_ordering
+                    FROM current_state_events AS c
+                    INNER JOIN events AS e USING (room_id, event_id)
+                    WHERE
+                        c.type = 'm.room.member'
+                        AND state_key = ?
+                        AND c.membership IN (%s)
+                """ % (
+                    ",".join("?" * len(membership_list))
+                )
+            else:
+                sql = """
+                    SELECT room_id, e.sender, m.membership, event_id, e.stream_ordering
+                    FROM current_state_events AS c
+                    INNER JOIN room_memberships AS m USING (room_id, event_id)
+                    INNER JOIN events AS e USING (room_id, event_id)
+                    WHERE
+                        c.type = 'm.room.member'
+                        AND state_key = ?
+                        AND m.membership IN (%s)
+                """ % (
+                    ",".join("?" * len(membership_list))
+                )
 
-            sql = (
-                "SELECT m.room_id, m.sender, m.membership, m.event_id, e.stream_ordering"
-                " FROM current_state_events as c"
-                " INNER JOIN room_memberships as m"
-                " ON m.event_id = c.event_id"
-                " INNER JOIN events as e"
-                " ON e.event_id = c.event_id"
-                " AND m.room_id = c.room_id"
-                " AND m.user_id = c.state_key"
-                " WHERE c.type = 'm.room.member' AND %s"
-            ) % (where_clause,)
-
-            txn.execute(sql, args)
+            txn.execute(sql, (user_id, *membership_list))
             results = [RoomsForUser(**r) for r in self.cursor_to_dict(txn)]
 
         if do_invite:
@@ -283,11 +375,9 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         rooms = yield self.get_rooms_for_user_where_membership_is(
             user_id, membership_list=[Membership.JOIN]
         )
-        defer.returnValue(
-            frozenset(
-                GetRoomsForUserWithStreamOrdering(r.room_id, r.stream_ordering)
-                for r in rooms
-            )
+        return frozenset(
+            GetRoomsForUserWithStreamOrdering(r.room_id, r.stream_ordering)
+            for r in rooms
         )
 
     @defer.inlineCallbacks
@@ -297,7 +387,7 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         rooms = yield self.get_rooms_for_user_with_stream_ordering(
             user_id, on_invalidate=on_invalidate
         )
-        defer.returnValue(frozenset(r.room_id for r in rooms))
+        return frozenset(r.room_id for r in rooms)
 
     @cachedInlineCallbacks(max_entries=500000, cache_context=True, iterable=True)
     def get_users_who_share_room_with_user(self, user_id, cache_context):
@@ -314,7 +404,7 @@ class RoomMemberWorkerStore(EventsWorkerStore):
             )
             user_who_share_room.update(user_ids)
 
-        defer.returnValue(user_who_share_room)
+        return user_who_share_room
 
     @defer.inlineCallbacks
     def get_joined_users_from_context(self, event, context):
@@ -330,7 +420,7 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         result = yield self._get_joined_users_from_context(
             event.room_id, state_group, current_state_ids, event=event, context=context
         )
-        defer.returnValue(result)
+        return result
 
     def get_joined_users_from_state(self, room_id, state_entry):
         state_group = state_entry.state_group
@@ -444,7 +534,7 @@ class RoomMemberWorkerStore(EventsWorkerStore):
                         avatar_url=to_ascii(event.content.get("avatar_url", None)),
                     )
 
-        defer.returnValue(users_in_room)
+        return users_in_room
 
     @cachedInlineCallbacks(max_entries=10000)
     def is_host_joined(self, room_id, host):
@@ -453,8 +543,8 @@ class RoomMemberWorkerStore(EventsWorkerStore):
 
         sql = """
             SELECT state_key FROM current_state_events AS c
-            INNER JOIN room_memberships USING (event_id)
-            WHERE membership = 'join'
+            INNER JOIN room_memberships AS m USING (event_id)
+            WHERE m.membership = 'join'
                 AND type = 'm.room.member'
                 AND c.room_id = ?
                 AND state_key LIKE ?
@@ -469,14 +559,14 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         rows = yield self._execute("is_host_joined", None, sql, room_id, like_clause)
 
         if not rows:
-            defer.returnValue(False)
+            return False
 
         user_id = rows[0][0]
         if get_domain_from_id(user_id) != host:
             # This can only happen if the host name has something funky in it
             raise Exception("Invalid host name")
 
-        defer.returnValue(True)
+        return True
 
     @cachedInlineCallbacks()
     def was_host_joined(self, room_id, host):
@@ -509,14 +599,14 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         rows = yield self._execute("was_host_joined", None, sql, room_id, like_clause)
 
         if not rows:
-            defer.returnValue(False)
+            return False
 
         user_id = rows[0][0]
         if get_domain_from_id(user_id) != host:
             # This can only happen if the host name has something funky in it
             raise Exception("Invalid host name")
 
-        defer.returnValue(True)
+        return True
 
     def get_joined_hosts(self, room_id, state_entry):
         state_group = state_entry.state_group
@@ -543,7 +633,7 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         cache = self._get_joined_hosts_cache(room_id)
         joined_hosts = yield cache.get_destinations(state_entry)
 
-        defer.returnValue(joined_hosts)
+        return joined_hosts
 
     @cached(max_entries=10000)
     def _get_joined_hosts_cache(self, room_id):
@@ -573,7 +663,45 @@ class RoomMemberWorkerStore(EventsWorkerStore):
             return rows[0][0]
 
         count = yield self.runInteraction("did_forget_membership", f)
-        defer.returnValue(count == 0)
+        return count == 0
+
+    @cached()
+    def get_forgotten_rooms_for_user(self, user_id):
+        """Gets all rooms the user has forgotten.
+
+        Args:
+            user_id (str)
+
+        Returns:
+            Deferred[set[str]]
+        """
+
+        def _get_forgotten_rooms_for_user_txn(txn):
+            # This is a slightly convoluted query that first looks up all rooms
+            # that the user has forgotten in the past, then rechecks that list
+            # to see if any have subsequently been updated. This is done so that
+            # we can use a partial index on `forgotten = 1` on the assumption
+            # that few users will actually forget many rooms.
+            #
+            # Note that a room is considered "forgotten" if *all* membership
+            # events for that user and room have the forgotten field set (as
+            # when a user forgets a room we update all rows for that user and
+            # room, not just the current one).
+            sql = """
+                SELECT room_id, (
+                    SELECT count(*) FROM room_memberships
+                    WHERE room_id = m.room_id AND user_id = m.user_id AND forgotten = 0
+                ) AS count
+                FROM room_memberships AS m
+                WHERE user_id = ? AND forgotten = 1
+                GROUP BY room_id, user_id;
+            """
+            txn.execute(sql, (user_id,))
+            return set(row[0] for row in txn if row[1] == 0)
+
+        return self.runInteraction(
+            "get_forgotten_rooms_for_user", _get_forgotten_rooms_for_user_txn
+        )
 
     @defer.inlineCallbacks
     def get_rooms_user_has_been_in(self, user_id):
@@ -602,6 +730,17 @@ class RoomMemberStore(RoomMemberWorkerStore):
         self.register_background_update_handler(
             _MEMBERSHIP_PROFILE_UPDATE_NAME, self._background_add_membership_profile
         )
+        self.register_background_update_handler(
+            _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
+            self._background_current_state_membership,
+        )
+        self.register_background_index_update(
+            "room_membership_forgotten_idx",
+            index_name="room_memberships_user_room_forgotten",
+            table="room_memberships",
+            columns=["user_id", "room_id"],
+            where_clause="forgotten = 1",
+        )
 
     def _store_room_members_txn(self, txn, events, backfilled):
         """Store a room member in the database.
@@ -703,6 +842,9 @@ class RoomMemberStore(RoomMemberWorkerStore):
             txn.execute(sql, (user_id, room_id))
 
             self._invalidate_cache_and_stream(txn, self.did_forget, (user_id, room_id))
+            self._invalidate_cache_and_stream(
+                txn, self.get_forgotten_rooms_for_user, (user_id,)
+            )
 
         return self.runInteraction("forget_membership", f)
 
@@ -779,7 +921,65 @@ class RoomMemberStore(RoomMemberWorkerStore):
         if not result:
             yield self._end_background_update(_MEMBERSHIP_PROFILE_UPDATE_NAME)
 
-        defer.returnValue(result)
+        return result
+
+    @defer.inlineCallbacks
+    def _background_current_state_membership(self, progress, batch_size):
+        """Update the new membership column on current_state_events.
+
+        This works by iterating over all rooms in alphebetical order.
+        """
+
+        def _background_current_state_membership_txn(txn, last_processed_room):
+            processed = 0
+            while processed < batch_size:
+                txn.execute(
+                    """
+                        SELECT MIN(room_id) FROM current_state_events WHERE room_id > ?
+                    """,
+                    (last_processed_room,),
+                )
+                row = txn.fetchone()
+                if not row or not row[0]:
+                    return processed, True
+
+                next_room, = row
+
+                sql = """
+                    UPDATE current_state_events
+                    SET membership = (
+                        SELECT membership FROM room_memberships
+                        WHERE event_id = current_state_events.event_id
+                    )
+                    WHERE room_id = ?
+                """
+                txn.execute(sql, (next_room,))
+                processed += txn.rowcount
+
+                last_processed_room = next_room
+
+            self._background_update_progress_txn(
+                txn,
+                _CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
+                {"last_processed_room": last_processed_room},
+            )
+
+            return processed, False
+
+        # If we haven't got a last processed room then just use the empty
+        # string, which will compare before all room IDs correctly.
+        last_processed_room = progress.get("last_processed_room", "")
+
+        row_count, finished = yield self.runInteraction(
+            "_background_current_state_membership_update",
+            _background_current_state_membership_txn,
+            last_processed_room,
+        )
+
+        if finished:
+            yield self._end_background_update(_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME)
+
+        return row_count
 
 
 class _JoinedHostsCache(object):
@@ -807,7 +1007,7 @@ class _JoinedHostsCache(object):
             state_entry(synapse.state._StateCacheEntry)
         """
         if state_entry.state_group == self.state_group:
-            defer.returnValue(frozenset(self.hosts_to_joined_users))
+            return frozenset(self.hosts_to_joined_users)
 
         with (yield self.linearizer.queue(())):
             if state_entry.state_group == self.state_group:
@@ -844,7 +1044,7 @@ class _JoinedHostsCache(object):
             else:
                 self.state_group = object()
             self._len = sum(len(v) for v in itervalues(self.hosts_to_joined_users))
-        defer.returnValue(frozenset(self.hosts_to_joined_users))
+        return frozenset(self.hosts_to_joined_users)
 
     def __len__(self):
         return self._len