Commit graph

16 commits

Author SHA1 Message Date
Erik Johnston
81e0f57800
Fix perf when streams don't change often (#17767)
There is a bug with the `StreamChangeCache` where it would incorrectly
return that all entities had changed if asked for entities changed
*since* the earliest stream position.

Note that for streams we use the inequalities: `$min_stream_id <
stream_id <= $max_stream_id`, i.e. when we ask the stream change cache
for all things that have changed since `$stream_id` we don't care for
events that happened *at* `$stream_id`.

Specifically: `_earliest_known_stream_pos` is the position at which we
know that we'll have entries for all changes since that point, we can
use the cache for any stream IDs that equal
`_earliest_known_stream_pos`.

`_earliest_known_stream_pos` is set in three places:
- On startup we set it either to:
  - the current maximum stream ID, with not prefilled values; or
  - the minimum of the latest N values we pulled from the DB
- When we evict items from the bottom, we set it to the stream ID of the
evicted items.

This was changed in https://github.com/matrix-org/synapse/pull/14435,
but I think we were overly conservative there.

---------

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2024-09-30 13:52:33 +01:00
Erik Johnston
d225b6b3eb
Speed up SS room sorting (#17468)
We do this by bulk fetching the latest stream ordering.

---------

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2024-07-23 14:03:14 +01:00
Erik Johnston
3e6ee8ff88
Add optimisation to StreamChangeCache (#17130)
When there have been lots of changes compared with the number of
entities, we can do a fast(er) path.

Locally I ran some benchmarking, and the comparison seems to give the
best determination of which method we use.
2024-05-06 12:56:52 +01:00
Patrick Cloke
da77720752
Check the stream position before checking if the cache is empty. (#14639)
An empty cache does not mean the entity has no changed, if
it is earlier than the earliest known stream position return that
the entity *has* changed since the cache cannot accurately
answer that query.
2022-12-08 11:35:49 -05:00
Erik Johnston
cee9445884
Better return type for get_all_entities_changed (#14604)
Help callers from using the return value incorrectly by ensuring
that callers explicitly check if there was a cache hit or not.
2022-12-05 15:19:14 -05:00
Patrick Cloke
6a8310f3df
Compare to the earliest known stream pos in the stream change cache. (#14435)
The internal methods of the StreamChangeCache were inconsistently
treating the earliest known stream position as valid. It is now treated as
invalid, meaning the cache cannot determine if an entity at the earliest
known stream position has changed or not.
2022-12-05 09:00:59 -05:00
Patrick Cloke
acea4d7a2f
Add missing types to tests.util. (#14597)
Removes files under tests.util from the ignored by list, then
fully types all tests/util/*.py files.
2022-12-02 17:58:56 +00:00
Eric Eastwood
0a00b7ff14
Update black, and run auto formatting over the codebase (#9381)
- Update black version to the latest
 - Run black auto formatting over the codebase
    - Run autoformatting according to [`docs/code_style.md
`](80d6dc9783/docs/code_style.md)
 - Update `code_style.md` docs around installing black to use the correct version
2021-02-16 22:32:34 +00:00
Amber Brown
7cb8b4bc67
Allow configuration of Synapse's cache without using synctl or environment variables (#6391) 2020-05-11 18:45:23 +01:00
Richard van der Hoff
13683a3a22
Extend StreamChangeCache to support multiple entities per stream ID (#7303)
First some background: StreamChangeCache is used to keep track of what "entities" have 
changed since a given stream ID. So for example, we might use it to keep track of when the last
to-device message for a given user was received [1], and hence whether we need to pull any to-device messages from the database on a sync [2].

Now, it turns out that StreamChangeCache didn't support more than one thing being changed at
a given stream_id (this was part of the problem with #7206). However, it's entirely valid to send
to-device messages to more than one user at a time.

As it turns out, this did in fact work, because *some* methods of StreamChangeCache coped
ok with having multiple things changing on the same stream ID, and it seems we never actually
use the methods which don't work on the stream change caches where we allow multiple
changes at the same stream ID. But that feels horribly fragile, hence: let's update
StreamChangeCache to properly support this, and add some typing and some more tests while
we're at it.

[1]: https://github.com/matrix-org/synapse/blob/release-v1.12.3/synapse/storage/data_stores/main/deviceinbox.py#L301
[2]: https://github.com/matrix-org/synapse/blob/release-v1.12.3/synapse/storage/data_stores/main/deviceinbox.py#L47-L51
2020-04-22 13:45:40 +01:00
Patrick Cloke
509e381afa
Clarify list/set/dict/tuple comprehensions and enforce via flake8 (#6957)
Ensure good comprehension hygiene using flake8-comprehensions.
2020-02-21 07:15:07 -05:00
black
8b3d9b6b19 Run black. 2018-08-10 23:54:09 +10:00
Erik Johnston
850238b4ef Add unit test 2018-07-17 10:59:02 +01:00
Erik Johnston
bc832f822f Fixup unit test 2018-07-13 17:03:04 +01:00
Amber Brown
49af402019 run isort 2018-07-09 16:09:20 +10:00
Amber Brown
f7869f8f8b
Port to sortedcontainers (with tests!) (#3332) 2018-06-06 00:13:57 +10:00