Bounce recalculation of current state to the correct event persister and
move recalculation of current state into the event persistence queue, to
avoid concurrent updates to a room's current state.
Also give recalculation of a room's current state a real stream
ordering.
Signed-off-by: Sean Quah <seanq@matrix.org>
Whenever we want to persist an event, we first compute an event context,
which includes the state at the event and a flag indicating whether the
state is partial. After a lot of processing, we finally try to store the
event in the database, which can fail for partial state events when the
containing room has been un-partial stated in the meantime.
We detect the race as a foreign key constraint failure in the data store
layer and turn it into a special `PartialStateConflictError` exception,
which makes its way up to the method in which we computed the event
context.
To make things difficult, the exception needs to cross a replication
request: `/fed_send_events` for events coming over federation and
`/send_event` for events from clients. We transport the
`PartialStateConflictError` as a `409 Conflict` over replication and
turn `409`s back into `PartialStateConflictError`s on the worker making
the request.
All client events go through
`EventCreationHandler.handle_new_client_event`, which is called in
*a lot* of places. Instead of trying to update all the code which
creates client events, we turn the `PartialStateConflictError` into a
`429 Too Many Requests` in
`EventCreationHandler.handle_new_client_event` and hope that clients
take it as a hint to retry their request.
On the federation event side, there are 7 places which compute event
contexts. 4 of them use outlier event contexts:
`FederationEventHandler._auth_and_persist_outliers_inner`,
`FederationHandler.do_knock`, `FederationHandler.on_invite_request` and
`FederationHandler.do_remotely_reject_invite`. These events won't have
the partial state flag, so we do not need to do anything for then.
The remaining 3 paths which create events are
`FederationEventHandler.process_remote_join`,
`FederationEventHandler.on_send_membership_event` and
`FederationEventHandler._process_received_pdu`.
We can't experience the race in `process_remote_join`, unless we're
handling an additional join into a partial state room, which currently
blocks, so we make no attempt to handle it correctly.
`on_send_membership_event` is only called by
`FederationServer._on_send_membership_event`, so we catch the
`PartialStateConflictError` there and retry just once.
`_process_received_pdu` is called by `on_receive_pdu` for incoming
events and `_process_pulled_event` for backfill. The latter should never
try to persist partial state events, so we ignore it. We catch the
`PartialStateConflictError` in `on_receive_pdu` and retry just once.
Refering to the graph of code paths in
https://github.com/matrix-org/synapse/issues/12988#issuecomment-1156857648
may make the above make more sense.
Signed-off-by: Sean Quah <seanq@matrix.org>
* Remove redundant references to `event_edges.room_id`
We don't need to care about the room_id here, because we are already checking
the event id.
* Clean up the event_edges table
We make a number of changes to `event_edges`:
* We give the `room_id` and `is_state` columns defaults (null and false
respectively) so that we can stop populating them.
* We drop any rows that have `is_state` set true - they should no longer
exist.
* We drop any rows that do not exist in `events` - these should not exist
either.
* We drop the old unique constraint on all the colums, which wasn't much use.
* We create a new unique index on `(event_id, prev_event_id)`.
* We add a foreign key constraint to `events`.
These happen rather differently depending on whether we are on Postgres or
SQLite. For SQLite, we just rebuild the whole table, copying only the rows we
want to keep. For Postgres, we try to do things in the background as much as
possible.
* Stop populating `event_edges.room_id` and `is_state`
We can just rely on the defaults.
Implements the following behind an experimental configuration flag:
* A new push rule kind for mutually related events.
* A new default push rule (`.m.rule.thread_reply`) under an unstable prefix.
This is missing part of MSC3772:
* The `.m.rule.thread_reply_to_me` push rule, this depends on MSC3664 / #11804.
Parse the `m.relates_to` event content field (which describes relations)
in a single place, this is used during:
* Event persistence.
* Validation of the Client-Server API.
* Fetching bundled aggregations.
* Processing of push rules.
Each of these separately implement the logic and each made slightly
different assumptions about what was valid. Some had minor / potential
bugs.
Refactor how the `EventContext` class works, with the intention of reducing the amount of state we fetch from the DB during event processing.
The idea here is to get rid of the cached `current_state_ids` and `prev_state_ids` that live in the `EventContext`, and instead defer straight to the database (and its caching).
One change that may have a noticeable effect is that we now no longer prefill the `get_current_state_ids` cache on a state change. However, that query is relatively light, since its just a case of reading a table from the DB (unlike fetching state at an event which is more heavyweight). For deployments with workers this cache isn't even used.
Part of #12684
This works by taking a row level lock on the `rooms` table at the start of both transactions, ensuring that they don't run at the same time. In the event persistence transaction we also check that there is an entry still in the `rooms` table.
I can't figure out how to do this in SQLite. I was just going to lock the table, but it seems that we don't support that in SQLite either, so I'm *really* confused as to how we maintain integrity in SQLite when using `lock_table`....
We work through all the events with partial state, updating the state at each
of them. Once it's done, we recalculate the state for the whole room, and then
mark the room as having complete state.
Principally, `prometheus_client.REGISTRY.register` now requires its argument to
extend `prometheus_client.Collector`.
Additionally, `Gauge.set` is now annotated so that passing `Optional[int]`
causes an error.
This should speed up push rule calculations for rooms with large numbers of local users when the main push rule cache fails.
Co-authored-by: reivilibre <oliverw@matrix.org>
The unstable identifiers are still supported if the experimental configuration
flag is enabled. The unstable identifiers will be removed in a future release.
This is allowed per MSC2675, although the original implementation did
not allow for it and would return an empty chunk / not bundle aggregations.
The main thing to improve is that the various caches get cleared properly
when an event is redacted, and that edits must not leak if the original
event is redacted (as that would presumably leak something similar to
the original event content).
When we get a partial_state response from send_join, store information in the
database about it:
* store a record about the room as a whole having partial state, and stash the
list of member servers too.
* flag the join event itself as having partial state
* also, for any new events whose prev-events are partial-stated, note that
they will *also* be partial-stated.
We don't yet make any attempt to interpret this data, so API calls (and a bunch
of other things) are just going to get incorrect data.
Don't attempt to add non-string `value`s to `event_search` and add a
background update to clear out bad rows from `event_search` when
using sqlite.
Signed-off-by: Sean Quah <seanq@element.io>
When the server leaves a room the `get_rooms_for_user` cache is not
correctly invalidated for the remote users in the room. This means that
subsequent calls to `get_rooms_for_user` for the remote users would
incorrectly include the room (it shouldn't be included because the
server no longer knows anything about the room).
This should reduce database usage when fetching bundled aggregations
as the number of individual queries (and round trips to the database) are
reduced.
This should reduce database usage when fetching bundled aggregations
as the number of individual queries (and round trips to the database) are
reduced.
I've never found this terribly useful. I think it was added in the early days
of Synapse, without much thought as to what would actually be useful to log,
and has just been cargo-culted ever since.
Rather, it tends to clutter up debug logs with useless information.
Create a new dict helper method `simple_insert_many_values_txn`, which takes
raw row values, rather than {key=>value} dicts. This saves us a bunch of dict
munging, and makes it easier to use generators rather than creating
intermediate lists and dicts.
Part of https://github.com/matrix-org/synapse/issues/11300
Call stack:
- `_persist_events_and_state_updates` (added `use_negative_stream_ordering`)
- `_persist_events_txn`
- `_update_room_depths_txn` (added `update_room_forward_stream_ordering`)
- `_update_metadata_tables_txn`
- `_store_room_members_txn` (added `inhibit_local_membership_updates`)
Using keyword-only arguments (`*`) to reduce the mistakes from `backfilled` being left as a positional argument somewhere and being interpreted wrong by our new arguments.
Instead of only known relation types. This also reworks the background
update for thread relations to crawl events and search for any relation
type, not just threaded relations.
* change display names/avatar URLS to None if they contain null bytes
* add changelog
* add POC test, requested changes
* add a saner test and remove old one
* update test to verify that display name has been changed to None
* make test less fragile
Resolve and share `state_groups` for all historical events in batch. This also helps for showing the appropriate avatar/displayname in Element and will work whenever `/messages` has one of the historical messages as the first message in the batch.
This does have the flaw where if you just insert a single historical event somewhere, it probably won't resolve the state correctly from `/messages` or `/context` since it will grab a non historical event above or below with resolved state which never included the historical state back then. For the same reasions, this also does not work in Element between the transition from actual messages to historical messages. In the Gitter case, this isn't really a problem since all of the historical messages are in one big lump at the beginning of the room.
For a future iteration, might be good to look at `/messages` and `/context` to additionally add the `state` for any historical messages in that batch.
---
How are the `state_groups` shared? To illustrate the `state_group` sharing, see this example:
**Before** (new `state_group` for every event 😬, very inefficient):
```
# Tests from https://github.com/matrix-org/complement/pull/206
$ COMPLEMENT_ALWAYS_PRINT_SERVER_LOGS=1 COMPLEMENT_DIR=../complement ./scripts-dev/complement.sh TestBackfillingHistory/parallel/should_resolve_member_state_events_for_historical_events
create_new_client_event m.room.member event=$_JXfwUDIWS6xKGG4SmZXjSFrizhARM7QblhATVWWUcA state_group=None
create_new_client_event org.matrix.msc2716.insertion event=$1ZBfmBKEjg94d-vGYymKrVYeghwBOuGJ3wubU1-I9y0 state_group=9
create_new_client_event org.matrix.msc2716.insertion event=$Mq2JvRetTyclPuozRI682SAjYp3GqRuPc8_cH5-ezPY state_group=10
create_new_client_event m.room.message event=$MfmY4rBQkxrIp8jVwVMTJ4PKnxSigpG9E2cn7S0AtTo state_group=11
create_new_client_event m.room.message event=$uYOv6V8wiF7xHwOMt-60d1AoOIbqLgrDLz6ZIQDdWUI state_group=12
create_new_client_event m.room.message event=$PAbkJRMxb0bX4A6av463faiAhxkE3FEObM1xB4D0UG4 state_group=13
create_new_client_event org.matrix.msc2716.batch event=$Oy_S7AWN7rJQe_MYwGPEy6RtbYklrI-tAhmfiLrCaKI state_group=14
```
**After** (all events in batch sharing `state_group=10`) (the base insertion event has `state_group=8` which matches the `prev_event` we're inserting next to):
```
# Tests from https://github.com/matrix-org/complement/pull/206
$ COMPLEMENT_ALWAYS_PRINT_SERVER_LOGS=1 COMPLEMENT_DIR=../complement ./scripts-dev/complement.sh TestBackfillingHistory/parallel/should_resolve_member_state_events_for_historical_events
create_new_client_event m.room.member event=$PWomJ8PwENYEYuVNoG30gqtybuQQSZ55eldBUSs0i0U state_group=None
create_new_client_event org.matrix.msc2716.insertion event=$e_mCU7Eah9ABF6nQU7lu4E1RxIWccNF05AKaTT5m3lw state_group=9
create_new_client_event org.matrix.msc2716.insertion event=$ui7A3_GdXIcJq0C8GpyrF8X7B3DTjMd_WGCjogax7xU state_group=10
create_new_client_event m.room.message event=$EnTIM5rEGVezQJiYl62uFBl6kJ7B-sMxWqe2D_4FX1I state_group=10
create_new_client_event m.room.message event=$LGx5jGONnBPuNhAuZqHeEoXChd9ryVkuTZatGisOPjk state_group=10
create_new_client_event m.room.message event=$wW0zwoN50lbLu1KoKbybVMxLbKUj7GV_olozIc5i3M0 state_group=10
create_new_client_event org.matrix.msc2716.batch event=$5ZB6dtzqFBCEuMRgpkU201Qhx3WtXZGTz_YgldL6JrQ state_group=10
```
We correctly allowed using the MSC2716 batch endpoint for
the room creator in existing room versions but accidentally didn't track
the events because of a logic flaw.
This prevented you from connecting subsequent chunks together because it would
throw the unknown batch ID error.
We only want to process MSC2716 events when:
- The room version supports MSC2716
- Any room where the homeserver has the `msc2716_enabled` experimental feature enabled and the event is from the room creator
Before Synapse 1.31 (#9411), we relied on `outlier` being stored in the
`internal_metadata` column. We can now assume nobody will roll back their
deployment that far and drop the legacy support.
