Commit Graph

826 Commits

Author SHA1 Message Date
dependabot[bot]
1e68b56a62
Bump black from 23.10.1 to 24.2.0 (#16936) 2024-03-13 16:46:44 +00:00
Erik Johnston
23740eaa3d
Correctly mention previous copyright (#16820)
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
2024-01-23 11:26:48 +00:00
Patrick Cloke
8e1e62c9e0 Update license headers 2023-11-21 15:29:58 -05:00
dependabot[bot]
0a67743d9e
Bump ruff from 0.0.290 to 0.0.292 (#16449)
* Bump ruff from 0.0.290 to 0.0.292

Bumps [ruff](https://github.com/astral-sh/ruff) from 0.0.290 to 0.0.292.
- [Release notes](https://github.com/astral-sh/ruff/releases)
- [Changelog](https://github.com/astral-sh/ruff/blob/main/BREAKING_CHANGES.md)
- [Commits](https://github.com/astral-sh/ruff/compare/v0.0.290...v0.0.292)

---
updated-dependencies:
- dependency-name: ruff
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

* Fix up lint

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Erik Johnston <erik@matrix.org>
2023-10-09 10:46:17 +01:00
Patrick Cloke
fc31b495b3
Stop sending incorrect knock_state_events. (#16403)
Synapse was incorrectly implemented with a knock_state_events
property on some APIs (instead of knock_room_state). This was
correct in Synapse 1.70.0, but *both* fields were sent to also be
compatible with Synapse versions expecting the wrong field.

Enough time has passed that only the correct field needs to be
included/handled.
2023-10-06 07:27:35 -04:00
Erik Johnston
dffe095642
Only lock when we're backfilling (#16159) 2023-08-23 09:23:41 +01:00
Erik Johnston
ad52db3b5c
Reduce the amount of state we pull out (#15968) 2023-07-20 10:46:37 +01:00
Patrick Cloke
6d81aec09f
Support room version 11 (#15912)
And fix a bug in the implementation of the updated redaction
format (MSC2174) where the top-level redacts field was not
properly added for backwards-compatibility.
2023-07-18 08:44:59 -04:00
Eric Eastwood
0f02f0b4da
Remove experimental MSC2716 implementation to incrementally import history into existing rooms (#15748)
Context for why we're removing the implementation:

 - https://github.com/matrix-org/matrix-spec-proposals/pull/2716#issuecomment-1487441010
 - https://github.com/matrix-org/matrix-spec-proposals/pull/2716#issuecomment-1504262734

Anyone wanting to continue MSC2716, should also address these leftover tasks: https://github.com/matrix-org/synapse/issues/10737

Closes https://github.com/matrix-org/synapse/issues/10737 in the fact that it is not longer necessary to track those things.
2023-06-16 14:12:24 -05:00
Eric Eastwood
fcc3ca37e1
Backfill in the background if we're doing it "just because" (#15710)
Fix https://github.com/matrix-org/synapse/issues/15702
2023-06-09 15:39:49 -05:00
Eric Eastwood
f9561b9e37
Some house keeping on maybe_backfill() functions (#15709) 2023-06-05 23:38:52 -05:00
Patrick Cloke
1e89976b26
Rename blacklist/whitelist internally. (#15620)
Avoid renaming configuration settings for now and rename internal code
to use blocklist and allowlist instead.
2023-05-19 12:25:25 +00:00
Sean Quah
e46d5f3586
Factor out an is_mine_server_name method (#15542)
Add an `is_mine_server_name` method, similar to `is_mine_id`.

Ideally we would use this consistently, instead of sometimes comparing
against `hs.hostname` and other times reaching into
`hs.config.server.server_name`.

Also fix a bug in the tests where `hs.hostname` would sometimes differ
from `hs.config.server.server_name`.

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-05-05 15:06:22 +01:00
Andrew Morgan
2e59e97ebd
Move ThirdPartyEventRules into module_api/callbacks (#15535) 2023-05-04 14:18:22 +00:00
Andrew Morgan
aec639e3e3
Move Spam Checker callbacks to a dedicated file (#15453) 2023-04-18 00:57:40 +00:00
Sean Quah
d9f694932c
Fix spinloop during partial state sync when a prev event is in backoff (#15351)
Previously, we would spin in a tight loop until
`update_state_for_partial_state_event` stopped raising
`FederationPullAttemptBackoffError`s. Replace the spinloop with a wait
until the backoff period has expired.

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-03-30 13:36:41 +01:00
David Robertson
4bb26c95a9
Refactor filter_events_for_server (#15240)
* Tweak docstring and type hint

* Flip logic and provide better name

* Separate decision from action

* Track a set of strings, not EventBases

* Require explicit boolean options from callers

* Add explicit option for partial state rooms

* Changelog

* Rename param
2023-03-10 15:31:25 +00:00
Sean Quah
4f4f27e57f
Mitigate a race where /make_join could 403 for restricted rooms (#15080)
Previously, when creating a join event in /make_join, we would decide
whether to include additional fields to satisfy restricted room checks
based on the current state of the room. Then, when building the event,
we would capture the forward extremities of the room to use as prev
events.

This is subject to race conditions. For example, when leaving and
rejoining a room, the following sequence of events leads to a misleading
403 response:
1. /make_join reads the current state of the room and sees that the user
   is still in the room. It decides to omit the field required for
   restricted room joins.
2. The leave event is persisted and the room's forward extremities are
   updated.
3. /make_join builds the event, using the post-leave forward extremities.
   The event then fails the restricted room checks.

To mitigate the race, we move the read of the forward extremities closer
to the read of the current state. Ideally, we would compute the state
based off the chosen prev events, but that can involve state resolution,
which is expensive.

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-02-17 09:40:32 +00:00
David Robertson
06ba71083e
Fix order of partial state tables when purging (#15068)
* Fix order of partial state tables when purging

`partial_state_rooms` has an FK on `events` pointing to the join event we
get from `/send_join`, so we must delete from that table before deleting
from `events`.

**NB:** It would be nice to cancel any resync processes for the room
being purged. We do not do this at present. To do so reliably we'd need
an internal HTTP "replication" endpoint, because the worker doing the
resync process may be different to that handling the purge request.

The first time the resync process tries to write data after the deletion
it will fail because we have deleted necessary data e.g. auth
events. AFAICS it will not retry the resync, so the only downside to
not cancelling the resync is a scary-looking traceback.

(This is presumably extremely race-sensitive.)

* Changelog

* admist(?) -> between

* Warn about a race

* Fix typo, thanks Sean

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

---------

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>
2023-02-14 23:42:29 +00:00
Mathieu Velten
6cddf24e36
Faster joins: don't stall when a user joins during a fast join (#14606)
Fixes #12801.
Complement tests are at
https://github.com/matrix-org/complement/pull/567.

Avoid blocking on full state when handling a subsequent join into a
partial state room.

Also always perform a remote join into partial state rooms, since we do
not know whether the joining user has been banned and want to avoid
leaking history to banned users.

Signed-off-by: Mathieu Velten <mathieuv@matrix.org>
Co-authored-by: Sean Quah <seanq@matrix.org>
Co-authored-by: David Robertson <davidr@element.io>
2023-02-10 23:31:05 +00:00
Shay
03bccd542b
Add a class UnpersistedEventContext to allow for the batching up of storing state groups (#14675)
* add class UnpersistedEventContext

* modify create new client event to create unpersistedeventcontexts

* persist event contexts after creation

* fix tests to persist unpersisted event contexts

* cleanup

* misc lints + cleanup

* changelog + fix comments

* lints

* fix batch insertion?

* reduce redundant calculation

* add unpersisted event classes

* rework compute_event_context, split into function that returns unpersisted event context and then persists it

* use calculate_context_info to create unpersisted event contexts

* update typing

* $%#^&*

* black

* fix comments and consolidate classes, use attr.s for class

* requested changes

* lint

* requested changes

* requested changes

* refactor to be stupidly explicit

* clearer renaming and flow

* make partial state non-optional

* update docstrings

---------

Co-authored-by: Erik Johnston <erik@matrix.org>
2023-02-09 13:05:02 -08:00
Sean Quah
0a686d1d13
Faster joins: Refactor handling of servers in room (#14954)
Ensure that the list of servers in a partial state room always contains
the server we joined off.

Also refactor `get_partial_state_servers_at_join` to return `None` when
the given room is no longer partial stated, to explicitly indicate when
the room has partial state. Otherwise it's not clear whether an empty
list means that the room has full state, or the room is partial stated,
but the server we joined off told us that there are no servers in the
room.

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-02-03 15:39:59 +00:00
Patrick Cloke
ba79fb4a61
Use StrCollection in place of Collection[str] in (most) handlers code. (#14922)
Due to the increased safety of StrCollection over Collection[str]
and Sequence[str].
2023-01-26 12:31:58 -05:00
David Robertson
80d44060c9
Faster joins: omit partial rooms from eager syncs until the resync completes (#14870)
* Allow `AbstractSet` in `StrCollection`

Or else frozensets are excluded. This will be useful in an upcoming
commit where I plan to change a function that accepts `List[str]` to
accept `StrCollection` instead.

* `rooms_to_exclude` -> `rooms_to_exclude_globally`

I am about to make use of this exclusion mechanism to exclude rooms for
a specific user and a specific sync. This rename helps to clarify the
distinction between the global config and the rooms to exclude for a
specific sync.

* Better function names for internal sync methods

* Track a list of excluded rooms on SyncResultBuilder

I plan to feed a list of partially stated rooms for this sync to ignore

* Exclude partial state rooms during eager sync

using the mechanism established in the previous commit

* Track un-partial-state stream in sync tokens

So that we can work out which rooms have become fully-stated during a
given sync period.

* Fix mutation of `@cached` return value

This was fouling up a complement test added alongside this PR.
Excluding a room would mean the set of forgotten rooms in the cache
would be extended. This means that room could be erroneously considered
forgotten in the future.

Introduced in #12310, Synapse 1.57.0. I don't think this had any
user-visible side effects (until now).

* SyncResultBuilder: track rooms to force as newly joined

Similar plan as before. We've omitted rooms from certain sync responses;
now we establish the mechanism to reintroduce them into future syncs.

* Read new field, to present rooms as newly joined

* Force un-partial-stated rooms to be newly-joined

for eager incremental syncs only, provided they're still fully stated

* Notify user stream listeners to wake up long polling syncs

* Changelog

* Typo fix

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Unnecessary list cast

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Rephrase comment

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Another comment

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Fixup merge(?)

* Poke notifier when receiving un-partial-stated msg over replication

* Fixup merge whoops

Thanks MV :)

Co-authored-by: Mathieu Velen <mathieuv@matrix.org>

Co-authored-by: Mathieu Velten <mathieuv@matrix.org>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>
2023-01-23 15:44:39 +00:00
Sean Quah
2ec9c58496
Faster joins: Update room stats and the user directory on workers when finishing join (#14874)
* Faster joins: Update room stats and user directory on workers when done

When finishing a partial state join to a room, we update the current
state of the room without persisting additional events. Workers receive
notice of the current state update over replication, but neglect to wake
the room stats and user directory updaters, which then get incidentally
triggered the next time an event is persisted or an unrelated event
persister sends out a stream position update.

We wake the room stats and user directory updaters at the appropriate
time in this commit.

Part of #12814 and #12815.

Signed-off-by: Sean Quah <seanq@matrix.org>

* fixup comment

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-01-23 10:31:36 +00:00
reivilibre
22cc93afe3
Enable Faster Remote Room Joins against worker-mode Synapse. (#14752)
* Enable Complement tests for Faster Remote Room Joins on worker-mode

* (dangerous) Add an override to allow Complement to use FRRJ under workers

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

* Fix race where we didn't send out replication notification

* MORE HACKS

* Fix get_un_partial_stated_rooms_token to take instance_name

* Fix bad merge

* Remove warning

* Correctly advance un_partial_stated_room_stream

* Fix merge

* Add another notify_replication

* Fixups

* Create a separate ReplicationNotifier

* Fix test

* Fix portdb

* Create a separate ReplicationNotifier

* Fix test

* Fix portdb

* Fix presence test

* Newsfile

* Apply suggestions from code review

* Update changelog.d/14752.misc

Co-authored-by: Erik Johnston <erik@matrix.org>

* lint

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
Co-authored-by: Erik Johnston <erik@matrix.org>
2023-01-22 21:10:11 +00:00
Sean Quah
d329a566df
Faster joins: Fix incompatibility with restricted joins (#14882)
* Avoid clearing out forward extremities when doing a second remote join

When joining a restricted room where the local homeserver does not have
a user able to issue invites, we perform a second remote join. We want
to avoid clearing out forward extremities in this case because the
forward extremities we have are up to date and clearing out forward
extremities creates a window in which the room can get bricked if
Synapse crashes.

Signed-off-by: Sean Quah <seanq@matrix.org>

* Do a full join when doing a second remote join into a full state room

We cannot persist a partial state join event into a joined full state
room, so we perform a full state join for such rooms instead. As a
future optimization, we could always perform a partial state join and
compute or retrieve the full state ourselves if necessary.

Signed-off-by: Sean Quah <seanq@matrix.org>

* Add lock around partial state flag for rooms

Signed-off-by: Sean Quah <seanq@matrix.org>

* Preserve partial state info when doing a second partial state join

Signed-off-by: Sean Quah <seanq@matrix.org>

* Add newsfile

* Add a TODO(faster_joins) marker

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-01-22 19:19:31 +00:00
Sean Quah
cdea7c11d0
Faster joins: Avoid starting duplicate partial state syncs (#14844)
Currently, we will try to start a new partial state sync every time we
perform a remote join, which is undesirable if there is already one
running for a given room.

We intend to perform remote joins whenever additional local users wish
to join a partial state room, so let's ensure that we do not start more
than one concurrent partial state sync for any given room.

------------------------------------------------------------------------

There is a race condition where the homeserver leaves a room and later
rejoins while the partial state sync from the previous membership is
still running. There is no guarantee that the previous partial state
sync will process the latest join, so we restart it if needed.

Signed-off-by: Sean Quah <seanq@matrix.org>
2023-01-20 12:06:19 +00:00
Mathieu Velten
54c012c5a8
Make handle_new_client_event throws PartialStateConflictError (#14665)
Then adapts calling code to retry when needed so it doesn't 500
to clients.

Signed-off-by: Mathieu Velten <mathieuv@matrix.org>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>
2022-12-15 16:04:23 +00:00
David Robertson
b5b5f66084
Move StateFilter to synapse.types (#14668)
* Move `StateFilter` to `synapse.types`

* Changelog
2022-12-12 16:19:30 +00:00
reivilibre
501f62d1a6
Faster remote room joins: stream the un-partial-stating of rooms over replication. [rei:frrj/streams/unpsr] (#14473) 2022-12-05 13:07:55 +00:00
Mathieu Velten
1526ff389f
Faster joins: filter out non local events when a room doesn't have its full state (#14404)
Signed-off-by: Mathieu Velten <mathieuv@matrix.org>
2022-11-21 16:46:14 +01:00
Patrick Cloke
d8cc86eff4
Remove redundant types from comments. (#14412)
Remove type hints from comments which have been added
as Python type hints. This helps avoid drift between comments
and reality, as well as removing redundant information.

Also adds some missing type hints which were simple to fill in.
2022-11-16 15:25:24 +00:00
Eric Eastwood
40fa8294e3
Refactor MSC3030 /timestamp_to_event to move away from our snowflake pull from destination pattern (#14096)
1. `federation_client.timestamp_to_event(...)` now handles all `destination` looping and uses our generic `_try_destination_list(...)` helper.
 2. Consistently handling `NotRetryingDestination` and `FederationDeniedError` across `get_pdu` , backfill, and the generic `_try_destination_list` which is used for many places we use this pattern.
 3. `get_pdu(...)` now returns `PulledPduInfo` so we know which `destination` we ended up pulling the PDU from
2022-10-26 16:10:55 -05:00
Shay
b7a7ff6ee3
Add initial power level event to batch of bulk persisted events when creating a new room. (#14228) 2022-10-21 10:46:22 -07:00
Shay
847e2393f3
Prepatory work for adding power level event to batched events (#14214) 2022-10-18 09:58:47 -07:00
David Robertson
c3a4780080
When restarting a partial join resync, prioritise the server which actioned a partial join (#14126) 2022-10-18 12:33:18 +01:00
Eric Eastwood
40bb37eb27
Stop getting missing prev_events after we already know their signature is invalid (#13816)
While https://github.com/matrix-org/synapse/pull/13635 stops us from doing the slow thing after we've already done it once, this PR stops us from doing one of the slow things in the first place.

Related to
 - https://github.com/matrix-org/synapse/issues/13622
    - https://github.com/matrix-org/synapse/pull/13635
 - https://github.com/matrix-org/synapse/issues/13676

Part of https://github.com/matrix-org/synapse/issues/13356

Follow-up to https://github.com/matrix-org/synapse/pull/13815 which tracks event signature failures.

With this PR, we avoid the call to the costly `_get_state_ids_after_missing_prev_event` because the signature failure will count as an attempt before and we filter events based on the backoff before calling `_get_state_ids_after_missing_prev_event` now.

For example, this will save us 156s out of the 185s total that this `matrix.org` `/messages` request. If you want to see the full Jaeger trace of this, you can drag and drop this `trace.json` into your own Jaeger, https://gist.github.com/MadLittleMods/4b12d0d0afe88c2f65ffcc907306b761

To explain this exact scenario around `/messages` -> backfill, we call `/backfill` and first check the signatures of the 100 events. We see bad signature for `$luA4l7QHhf_jadH3mI-AyFqho0U2Q-IXXUbGSMq6h6M` and `$zuOn2Rd2vsC7SUia3Hp3r6JSkSFKcc5j3QTTqW_0jDw` (both member events). Then we process the 98 events remaining that have valid signatures but one of the events references `$luA4l7QHhf_jadH3mI-AyFqho0U2Q-IXXUbGSMq6h6M` as a `prev_event`. So we have to do the whole `_get_state_ids_after_missing_prev_event` rigmarole which pulls in those same events which fail again because the signatures are still invalid.

 - `backfill`
    - `outgoing-federation-request` `/backfill`
    - `_check_sigs_and_hash_and_fetch`
       - `_check_sigs_and_hash_and_fetch_one` for each event received over backfill
          -  `$luA4l7QHhf_jadH3mI-AyFqho0U2Q-IXXUbGSMq6h6M` fails with `Signature on retrieved event was invalid.`: `unable to verify signature for sender domain xxx: 401: Failed to find any key to satisfy: _FetchKeyRequest(...)`
          -  `$zuOn2Rd2vsC7SUia3Hp3r6JSkSFKcc5j3QTTqW_0jDw` fails with `Signature on retrieved event was invalid.`: `unable to verify signature for sender domain xxx: 401: Failed to find any key to satisfy: _FetchKeyRequest(...)`
   - `_process_pulled_events`
      - `_process_pulled_event` for each validated event
         -  Event `$Q0iMdqtz3IJYfZQU2Xk2WjB5NDF8Gg8cFSYYyKQgKJ0` references `$luA4l7QHhf_jadH3mI-AyFqho0U2Q-IXXUbGSMq6h6M` as a `prev_event` which is missing so we try to get it
            - `_get_state_ids_after_missing_prev_event`
               - `outgoing-federation-request` `/state_ids`
               -  `get_pdu` for `$luA4l7QHhf_jadH3mI-AyFqho0U2Q-IXXUbGSMq6h6M` which fails the signature check again
               -  `get_pdu` for `$zuOn2Rd2vsC7SUia3Hp3r6JSkSFKcc5j3QTTqW_0jDw` which fails the signature check
2022-10-15 00:36:49 -05:00
Andrew Morgan
9c23442ac9
Correct field name for stripped state events when knocking. knock_state_events -> knock_room_state (#14102) 2022-10-12 14:37:20 +01:00
Erik Johnston
3dfc4a08dc
Fix performance regression in get_users_in_room (#13972)
Fixes #13942. Introduced in #13575.

Basically, let's only get the ordered set of hosts out of the DB if we need an ordered set of hosts. Since we split the function up the caching won't be as good, but I think it will still be fine as e.g. multiple backfill requests for the same room will hit the cache.
2022-09-30 13:15:32 +01:00
reivilibre
73ecff7e9e
Improve backfill robustness by trying more servers. (#13890)
Co-authored-by: Eric Eastwood <erice@element.io>
2022-09-29 10:00:02 +00:00
Eric Eastwood
df8b91ed2b
Limit and filter the number of backfill points to get from the database (#13879)
There is no need to grab thousands of backfill points when we only need 5 to make the `/backfill` request with. We need to grab a few extra in case the first few aren't visible in the history.

Previously, we grabbed thousands of backfill points from the database, then sorted and filtered them in the app. Fetching the 4.6k backfill points for `#matrix:matrix.org` from the database takes ~50ms - ~570ms so it's not like this saves a lot of time 🤷. But it might save us more time now that `get_backfill_points_in_room`/`get_insertion_event_backward_extremities_in_room` are more complicated after https://github.com/matrix-org/synapse/pull/13635 

This PR moves the filtering and limiting to the SQL query so we just have less data to work with in the first place.

Part of https://github.com/matrix-org/synapse/issues/13356
2022-09-28 15:26:16 -05:00
Erik Johnston
4b17a5ace8
Handle remote device list updates during partial join (#13913)
c.f. #12993 (comment), point 3

This stores all device list updates that we receive while partial joins are ongoing, and processes them once we have the full state.

Note: We don't actually process the device lists in the same ways as if we weren't partially joined. Instead of updating the device list remote cache, we simply notify local users that a change in the remote user's devices has happened. I think this is safe as if the local user requests the keys for the remote user and we don't have them we'll simply fetch them as normal.
2022-09-28 13:42:43 +00:00
Kateřina Churanová
6caa303083
fix: Push notifications for invite over federation (#13719) 2022-09-28 12:31:53 +00:00
David Robertson
f5aaa55e27
Add new columns tracking when we partial-joined (#13892) 2022-09-27 17:26:35 +01:00
Eric Eastwood
ac1a31740b
Only try to backfill event if we haven't tried before recently (#13635)
Only try to backfill event if we haven't tried before recently (exponential backoff). No need to keep trying the same backfill point that fails over and over.

Fix https://github.com/matrix-org/synapse/issues/13622
Fix https://github.com/matrix-org/synapse/issues/8451

Follow-up to https://github.com/matrix-org/synapse/pull/13589

Part of https://github.com/matrix-org/synapse/issues/13356
2022-09-23 14:01:29 -05:00
reivilibre
c06b2b7142
Faster Remote Room Joins: tell remote homeservers that we are unable to authorise them if they query a room which has partial state on our server. (#13823) 2022-09-23 11:47:16 +01:00
Eric Eastwood
51d732db3b
Optimize how we calculate likely_domains during backfill (#13575)
Optimize how we calculate `likely_domains` during backfill because I've seen this take 17s in production just to `get_current_state` which is used to `get_domains_from_state` (see case [*2. Loading tons of events* in the `/messages` investigation issue](https://github.com/matrix-org/synapse/issues/13356)).

There are 3 ways we currently calculate hosts that are in the room:

 1. `get_current_state` -> `get_domains_from_state`
    - Used in `backfill` to calculate `likely_domains` and `/timestamp_to_event` because it was cargo-culted from `backfill`
    - This one is being eliminated in favor of `get_current_hosts_in_room` in this PR 🕳
 1. `get_current_hosts_in_room`
    - Used for other federation things like sending read receipts and typing indicators
 1. `get_hosts_in_room_at_events`
    - Used when pushing out events over federation to other servers in the `_process_event_queue_loop`

Fix https://github.com/matrix-org/synapse/issues/13626

Part of https://github.com/matrix-org/synapse/issues/13356

Mentioned in [internal doc](https://docs.google.com/document/d/1lvUoVfYUiy6UaHB6Rb4HicjaJAU40-APue9Q4vzuW3c/edit#bookmark=id.2tvwz3yhcafh)


### Query performance

#### Before

The query from `get_current_state` sucks just because we have to get all 80k events. And we see almost the exact same performance locally trying to get all of these events (16s vs 17s):
```
synapse=# SELECT type, state_key, event_id FROM current_state_events WHERE room_id = '!OGEhHVWSdvArJzumhm:matrix.org';
Time: 16035.612 ms (00:16.036)

synapse=# SELECT type, state_key, event_id FROM current_state_events WHERE room_id = '!OGEhHVWSdvArJzumhm:matrix.org';
Time: 4243.237 ms (00:04.243)
```

But what about `get_current_hosts_in_room`: When there is 8M rows in the `current_state_events` table, the previous query in `get_current_hosts_in_room` took 13s from complete freshness (when the events were first added). But takes 930ms after a Postgres restart or 390ms if running back to back to back.

```sh
$ psql synapse
synapse=# \timing on
synapse=# SELECT COUNT(DISTINCT substring(state_key FROM '@[^:]*:(.*)$'))
FROM current_state_events
WHERE
    type = 'm.room.member'
    AND membership = 'join'
    AND room_id = '!OGEhHVWSdvArJzumhm:matrix.org';
 count
-------
  4130
(1 row)

Time: 13181.598 ms (00:13.182)

synapse=# SELECT COUNT(*) from current_state_events where room_id = '!OGEhHVWSdvArJzumhm:matrix.org';
 count
-------
 80814

synapse=# SELECT COUNT(*) from current_state_events;
  count
---------
 8162847

synapse=# SELECT pg_size_pretty( pg_total_relation_size('current_state_events') );
 pg_size_pretty
----------------
 4702 MB
```

#### After

I'm not sure how long it takes from complete freshness as I only really get that opportunity once (maybe restarting computer but that's cumbersome) and it's not really relevant to normal operating times. Maybe you get closer to the fresh times the more access variability there is so that Postgres caches aren't as exact. Update: The longest I've seen this run for is 6.4s and 4.5s after a computer restart.

After a Postgres restart, it takes 330ms and running back to back takes 260ms.

```sh
$ psql synapse
synapse=# \timing on
Timing is on.
synapse=# SELECT
    substring(c.state_key FROM '@[^:]*:(.*)$') as host
FROM current_state_events c
/* Get the depth of the event from the events table */
INNER JOIN events AS e USING (event_id)
WHERE
    c.type = 'm.room.member'
    AND c.membership = 'join'
    AND c.room_id = '!OGEhHVWSdvArJzumhm:matrix.org'
GROUP BY host
ORDER BY min(e.depth) ASC;
Time: 333.800 ms
```

#### Going further

To improve things further we could add a `limit` parameter to `get_current_hosts_in_room`. Realistically, we don't need 4k domains to choose from because there is no way we're going to query that many before we a) probably get an answer or b) we give up. 

Another thing we can do is optimize the query to use a index skip scan:

 - https://wiki.postgresql.org/wiki/Loose_indexscan
 - Index Skip Scan, https://commitfest.postgresql.org/37/1741/
 - https://www.timescale.com/blog/how-we-made-distinct-queries-up-to-8000x-faster-on-postgresql/
2022-08-30 01:38:14 -05:00
Eric Eastwood
9385c41ba4
Fix Prometheus metrics being negative (mixed up start/end) (#13584)
Fix:

 - https://github.com/matrix-org/synapse/pull/13535#discussion_r949582508
 - https://github.com/matrix-org/synapse/pull/13533#discussion_r949577244
2022-08-23 08:47:30 +01:00
Eric Eastwood
088bcb7ecb
Time how long it takes us to do backfill processing (#13535) 2022-08-17 10:33:19 +01:00