Sliding sync: Add classes for per-connection state #17574

erikjohnston · 2024-08-15T10:12:58Z

This is some prep work ahead of correctly tracking receipts, where we will also want to track the room status in terms of last receipt we had sent down.

Essentially, we add two classes PerConnectionState and a mutable version, and then operate on those.

synapse/handlers/sliding_sync.py

MadLittleMods · 2024-08-15T21:43:49Z

synapse/handlers/sliding_sync.py

+
+
+@attr.s(auto_attribs=True)
+class PerConnectionState:


I'm having a lot of trouble keeping all of these structures straight:

SlidingSyncConnectionStore -> PerConnectionState -> RoomStatusesForStream -> HaveSentRoom -> HaveSentRoomFlag

Maybe it's just a naming thing or because this is my first exposure.

Yeah, it's a lot. I don't know if maybe it'd help moving to a different file so its a bit more clearly laid out? Suggestions on naming is also more than welcome.

synapse/handlers/sliding_sync.py

MadLittleMods · 2024-08-15T21:56:23Z

synapse/handlers/sliding_sync.py

+class RoomStatusesForStream:
+    """For a given stream, e.g. events, records what we have or have not sent
+    down for that stream in a given room."""


The name RoomStatusesForStream is confusing because it implies that it maps from room status to stream or vice versa. But it actually keeps track of room_id to whether we have sent this room down the connection before.

And elsewhere, we have one for each type of stream that we want to track things in (rooms and receipts).

Perhaps just RoomStatusMap or HaveSentRoomMap

(docstring could also be updated)

I've renamed to RoomStatusMap. I think in future we might want to rename HaveSentRoom to something else (as e.g. tracking timeline_limitdoesn't fit into the name really).

synapse/handlers/sliding_sync.py

MadLittleMods · 2024-08-15T23:14:20Z

synapse/handlers/sliding_sync.py

+class MutableRoomStatusesForStream(RoomStatusesForStream):
+    """A mutable version of `RoomStatusesForStream`"""
+
+    _statuses: typing.ChainMap[str, HaveSentRoom]


Are we worried about the memory footprint over time? For a long-running connection, this seems like it will grow and grow until we restart the server. Every sync request with updates will add another layer to this ChainMap.

There's never a chance to garbage collect anything even once a map layer is completely superseded by the layers below with all of the keys. Seems like we should do a clean-up /consolidation pass after a certain number of layers.

Yeah so actually when we store the mutable connection state we actually end up doing a RoomStatusesForStream.copy(), which then flattens the chainmap into a dict again. I think that stops us from every ending up with nested chain maps like that.

I'm also wanting to rip all this out and replace it with DB tables once the receipts and subscription PRs land, so I'm not overly concerned about resources for this stuff.

Ahh, we should add some comments in various places. Something about how the copy() flattens the ChainMap back out.

Or maybe a better word about, we only ever use the MutablePerConnectionState during the lifetime of the request and always end up making a flat PerConnectionState copy before we store it in the ConnectionStore.

Because we record_new_state(...) (which flattens out the ChainMap) after each request, the ChainMap doesn't grow indefinitely.

Thanks, will try and add some comments.

Have tried to add a couple of comments in 7f5bccc

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

MadLittleMods

Looks good after understanding the PerConnectionState life-times better. I think it would be good to point it out in some comments

… sent down. (#17575) Add connection tracking to the receipts extension. Based on #17574 --------- Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

@kfiven

# Synapse 1.114.0 (2024-09-02) This release enables support for [MSC4186](matrix-org/matrix-spec-proposals#4186) — Simplified Sliding Sync. This allows using the upcoming releases of the Element X mobile apps without having to run a Sliding Sync Proxy. ### Features - Enable native sliding sync support ([MSC3575](matrix-org/matrix-spec-proposals#3575) and [MSC4186](matrix-org/matrix-spec-proposals#4186)) by default. ([\#17648](element-hq/synapse#17648)) # Synapse 1.114.0rc3 (2024-08-30) ### Bugfixes - Fix regression in v1.114.0rc2 that caused workers to fail to start. ([\#17626](element-hq/synapse#17626)) # Synapse 1.114.0rc2 (2024-08-30) ### Features - Improve cross-signing upload when using [MSC3861](matrix-org/matrix-spec-proposals#3861) to use a custom UIA flow stage, with web fallback support. ([\#17509](element-hq/synapse#17509)) - Make `hash_password` script accept password input from stdin. ([\#17608](element-hq/synapse#17608)) ### Bugfixes - Fix hierarchy returning 403 when room is accessible through federation. Contributed by Krishan (@kfiven). ([\#17194](element-hq/synapse#17194)) - Fix content-length on federation `/thumbnail` responses. ([\#17532](element-hq/synapse#17532)) - Fix authenticated media responses using a wrong limit when following redirects over federation. ([\#17543](element-hq/synapse#17543)) ### Internal Changes - MSC3861: load the issuer and account management URLs from OIDC discovery. ([\#17407](element-hq/synapse#17407)) - Refactor sliding sync class into multiple files. ([\#17595](element-hq/synapse#17595)) - Store sliding sync per-connection state in the database. ([\#17599](element-hq/synapse#17599)) - Make the sliding sync `PerConnectionState` class immutable. ([\#17600](element-hq/synapse#17600)) - Add support to `@tag_args` for standalone functions. ([\#17604](element-hq/synapse#17604)) - Speed up incremental syncs in sliding sync by adding some more caching. ([\#17606](element-hq/synapse#17606)) - Always return the user's own read receipts in sliding sync. ([\#17617](element-hq/synapse#17617)) - Replace `isort` and `black` with `ruff`. ([\#17620](element-hq/synapse#17620)) - Refactor sliding sync code to move room list logic out into a separate class. ([\#17622](element-hq/synapse#17622)) ### Updates to locked dependencies * Bump attrs from 23.2.0 to 24.2.0. ([\#17609](element-hq/synapse#17609)) * Bump cryptography from 42.0.8 to 43.0.0. ([\#17584](element-hq/synapse#17584)) * Bump phonenumbers from 8.13.43 to 8.13.44. ([\#17610](element-hq/synapse#17610)) * Bump pygithub from 2.3.0 to 2.4.0. ([\#17612](element-hq/synapse#17612)) * Bump pyyaml from 6.0.1 to 6.0.2. ([\#17611](element-hq/synapse#17611)) * Bump sentry-sdk from 2.12.0 to 2.13.0. ([\#17585](element-hq/synapse#17585)) * Bump serde from 1.0.206 to 1.0.208. ([\#17581](element-hq/synapse#17581)) * Bump serde from 1.0.208 to 1.0.209. ([\#17613](element-hq/synapse#17613)) * Bump serde_json from 1.0.124 to 1.0.125. ([\#17582](element-hq/synapse#17582)) * Bump serde_json from 1.0.125 to 1.0.127. ([\#17614](element-hq/synapse#17614)) * Bump types-jsonschema from 4.23.0.20240712 to 4.23.0.20240813. ([\#17583](element-hq/synapse#17583)) * Bump types-setuptools from 71.1.0.20240726 to 71.1.0.20240818. ([\#17586](element-hq/synapse#17586)) # Synapse 1.114.0rc1 (2024-08-20) ### Features - Add a flag to `/versions`, `org.matrix.simplified_msc3575`, to indicate whether experimental sliding sync support has been enabled. ([\#17571](element-hq/synapse#17571)) - Handle changes in `timeline_limit` in experimental sliding sync. ([\#17579](element-hq/synapse#17579)) - Correctly track read receipts that should be sent down in experimental sliding sync. ([\#17575](element-hq/synapse#17575), [\#17589](element-hq/synapse#17589), [\#17592](element-hq/synapse#17592)) ### Bugfixes - Start handlers for new media endpoints when media resource configured. ([\#17483](element-hq/synapse#17483)) - Fix timeline ordering (using `stream_ordering` instead of topological ordering) in experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17510](element-hq/synapse#17510)) - Fix experimental sliding sync implementation to remember any updates in rooms that were not sent down immediately. ([\#17535](element-hq/synapse#17535)) - Better exclude partially stated rooms if we must await full state in experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17538](element-hq/synapse#17538)) - Handle lower-case http headers in `_Mulitpart_Parser_Protocol`. ([\#17545](element-hq/synapse#17545)) - Fix fetching federation signing keys from servers that omit `old_verify_keys`. Contributed by @tulir @ Beeper. ([\#17568](element-hq/synapse#17568)) - Fix bug where we would respond with an error when a remote server asked for media that had a length of 0, using the new multipart federation media endpoint. ([\#17570](element-hq/synapse#17570)) ### Improved Documentation - Clarify default behaviour of the [`auto_accept_invites.worker_to_run_on`](https://element-hq.github.io/synapse/develop/usage/configuration/config_documentation.html#auto-accept-invites) option. ([\#17515](element-hq/synapse#17515)) - Improve docstrings for profile methods. ([\#17559](element-hq/synapse#17559)) ### Internal Changes - Add more tracing to experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17514](element-hq/synapse#17514)) - Fixup comment in sliding sync implementation. ([\#17531](element-hq/synapse#17531)) - Replace override of deprecated method `HTTPAdapter.get_connection` with `get_connection_with_tls_context`. ([\#17536](element-hq/synapse#17536)) - Fix performance of device lists in `/key/changes` and sliding sync. ([\#17537](element-hq/synapse#17537), [\#17548](element-hq/synapse#17548)) - Bump setuptools from 67.6.0 to 72.1.0. ([\#17542](element-hq/synapse#17542)) - Add a utility function for generating random event IDs. ([\#17557](element-hq/synapse#17557)) - Speed up responding to media requests. ([\#17558](element-hq/synapse#17558), [\#17561](element-hq/synapse#17561), [\#17564](element-hq/synapse#17564), [\#17566](element-hq/synapse#17566), [\#17567](element-hq/synapse#17567), [\#17569](element-hq/synapse#17569)) - Test github token before running release script steps. ([\#17562](element-hq/synapse#17562)) - Reduce log spam of multipart files. ([\#17563](element-hq/synapse#17563)) - Refactor per-connection state in experimental sliding sync handler. ([\#17574](element-hq/synapse#17574)) - Add histogram metrics for sliding sync processing time. ([\#17593](element-hq/synapse#17593)) ### Updates to locked dependencies * Bump bytes from 1.6.1 to 1.7.1. ([\#17526](element-hq/synapse#17526)) * Bump lxml from 5.2.2 to 5.3.0. ([\#17550](element-hq/synapse#17550)) * Bump phonenumbers from 8.13.42 to 8.13.43. ([\#17551](element-hq/synapse#17551)) * Bump regex from 1.10.5 to 1.10.6. ([\#17527](element-hq/synapse#17527)) * Bump sentry-sdk from 2.10.0 to 2.12.0. ([\#17553](element-hq/synapse#17553)) * Bump serde from 1.0.204 to 1.0.206. ([\#17556](element-hq/synapse#17556)) * Bump serde_json from 1.0.122 to 1.0.124. ([\#17555](element-hq/synapse#17555)) * Bump sigstore/cosign-installer from 3.5.0 to 3.6.0. ([\#17549](element-hq/synapse#17549)) * Bump types-pyyaml from 6.0.12.20240311 to 6.0.12.20240808. ([\#17552](element-hq/synapse#17552)) * Bump types-requests from 2.31.0.20240406 to 2.32.0.20240712. ([\#17524](element-hq/synapse#17524)) # Synapse 1.113.0 (2024-08-13) No significant changes since 1.113.0rc1. # Synapse 1.113.0rc1 (2024-08-06) ### Features - Track which rooms have been sent to clients in the experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17447](element-hq/synapse#17447)) - Add Account Data extension support to experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17477](element-hq/synapse#17477)) - Add receipts extension support to experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17489](element-hq/synapse#17489)) - Add typing notification extension support to experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint. ([\#17505](element-hq/synapse#17505)) ### Bugfixes - Update experimental [MSC3575](matrix-org/matrix-spec-proposals#3575) Sliding Sync `/sync` endpoint to handle invite/knock rooms when filtering. ([\#17450](element-hq/synapse#17450)) - Fix a bug introduced in v1.110.0 which caused `/keys/query` to return incomplete results, leading to high network activity and CPU usage on Matrix clients. ([\#17499](element-hq/synapse#17499)) ### Improved Documentation - Update the [`allowed_local_3pids`](https://element-hq.github.io/synapse/v1.112/usage/configuration/config_documentation.html#allowed_local_3pids) config option's msisdn address to a working example. ([\#17476](element-hq/synapse#17476)) ### Internal Changes - Change sliding sync to use their own token format in preparation for storing per-connection state. ([\#17452](element-hq/synapse#17452)) - Ensure we don't send down negative `bump_stamp` in experimental sliding sync endpoint. ([\#17478](element-hq/synapse#17478)) - Do not send down empty room entries down experimental sliding sync endpoint. ([\#17479](element-hq/synapse#17479)) - Refactor Sliding Sync tests to better utilize the `SlidingSyncBase`. ([\#17481](element-hq/synapse#17481), [\#17482](element-hq/synapse#17482)) - Add some opentracing tags and logging to the experimental sliding sync implementation. ([\#17501](element-hq/synapse#17501)) - Split and move Sliding Sync tests so we have some more sane test file sizes. ([\#17504](element-hq/synapse#17504)) - Update the `limited` field description in the Sliding Sync response to accurately describe what it actually represents. ([\#17507](element-hq/synapse#17507)) - Easier to understand `timeline` assertions in Sliding Sync tests. ([\#17511](element-hq/synapse#17511)) - Reset the sliding sync connection if we don't recognize the per-connection state position. ([\#17529](element-hq/synapse#17529)) ### Updates to locked dependencies * Bump bcrypt from 4.1.3 to 4.2.0. ([\#17495](element-hq/synapse#17495)) * Bump black from 24.4.2 to 24.8.0. ([\#17522](element-hq/synapse#17522)) * Bump phonenumbers from 8.13.39 to 8.13.42. ([\#17521](element-hq/synapse#17521)) * Bump ruff from 0.5.4 to 0.5.5. ([\#17494](element-hq/synapse#17494)) * Bump serde_json from 1.0.120 to 1.0.121. ([\#17493](element-hq/synapse#17493)) * Bump serde_json from 1.0.121 to 1.0.122. ([\#17525](element-hq/synapse#17525)) * Bump towncrier from 23.11.0 to 24.7.1. ([\#17523](element-hq/synapse#17523)) * Bump types-pyopenssl from 24.1.0.20240425 to 24.1.0.20240722. ([\#17496](element-hq/synapse#17496)) * Bump types-setuptools from 70.1.0.20240627 to 71.1.0.20240726. ([\#17497](element-hq/synapse#17497))

erikjohnston added 4 commits August 14, 2024 18:44

Migrate to per-connection state class

da5339d

Record with new class

baac6c5

Revamp

0561c86

Newsfile

2e7672d

erikjohnston added the A-Sync label Aug 15, 2024

erikjohnston mentioned this pull request Aug 15, 2024

Sliding sync: Correctly track which read receipts we have or have not sent down. #17575

Merged

erikjohnston marked this pull request as ready for review August 15, 2024 11:53

erikjohnston requested a review from a team as a code owner August 15, 2024 11:53

erikjohnston requested a review from MadLittleMods August 15, 2024 14:31

MadLittleMods requested changes Aug 15, 2024

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erikjohnston and others added 8 commits August 16, 2024 10:07

Update synapse/handlers/sliding_sync.py

64310ec

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

Update synapse/handlers/sliding_sync.py

79e80eb

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

Update synapse/handlers/sliding_sync.py

d982efe

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

Apply suggestions from code review

b0a5c0e

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

Simplify get room status

577370a

Add docstring

27b7a4a

Fixups

dec5314

Rename

5b6755a

erikjohnston requested a review from MadLittleMods August 16, 2024 09:24

MadLittleMods approved these changes Aug 19, 2024

View reviewed changes

Add some comments that chain map won't infinitely grow

7f5bccc

erikjohnston merged commit 261e746 into develop Aug 19, 2024
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erikjohnston deleted the erikj/ss_per_state_class branch August 19, 2024 19:09

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Sliding sync: Add classes for per-connection state #17574

Sliding sync: Add classes for per-connection state #17574

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Sliding sync: Add classes for per-connection state #17574

Sliding sync: Add classes for per-connection state #17574

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