Commit Graph

194 Commits

Author SHA1 Message Date
Erik Johnston
a6ea1a957e
Don't pull event from DB when handling replication traffic. (#8669)
I was trying to make it so that we didn't have to start a background task when handling RDATA, but that is a bigger job (due to all the code in `generic_worker`). However I still think not pulling the event from the DB may help reduce some DB usage due to replication, even if most workers will simply go and pull that event from the DB later anyway.

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
2020-10-28 12:11:45 +00:00
Erik Johnston
4215a3acd4
Don't unnecessarily start bg process in replication sending loop. (#8670) 2020-10-27 17:37:08 +00:00
Erik Johnston
2b7c180879
Start fewer opentracing spans (#8640)
#8567 started a span for every background process. This is good as it means all Synapse code that gets run should be in a span (unless in the sentinel logging context), but it means we generate about 15x the number of spans as we did previously.

This PR attempts to reduce that number by a) not starting one for send commands to Redis, and b) deferring starting background processes until after we're sure they're necessary.

I don't really know how much this will help.
2020-10-26 09:30:19 +00:00
Erik Johnston
8de3703d21
Make event persisters periodically announce position over replication. (#8499)
Currently background proccesses stream the events stream use the "minimum persisted position" (i.e. `get_current_token()`) rather than the vector clock style tokens. This is broadly fine as it doesn't matter if the background processes lag a small amount. However, in extreme cases (i.e. SyTests) where we only write to one event persister the background processes will never make progress.

This PR changes it so that the `MultiWriterIDGenerator` keeps the current position of a given instance as up to date as possible (i.e using the latest token it sees if its not in the process of persisting anything), and then periodically announces that over replication. This then allows the "minimum persisted position" to advance, albeit with a small lag.
2020-10-12 15:51:41 +01:00
Erik Johnston
5009ffcaa4
Only send RDATA for instance local events. (#8496)
When pulling events out of the DB to send over replication we were not
filtering by instance name, and so we were sending events for other
instances.
2020-10-09 13:10:33 +01:00
Erik Johnston
6c5d5e507e
Add unit test for event persister sharding (#8433) 2020-10-02 09:57:12 +01:00
Patrick Cloke
4ff0201e62
Enable mypy checking for unreachable code and fix instances. (#8432) 2020-10-01 08:09:18 -04:00
Erik Johnston
ea70f1c362
Various clean ups to room stream tokens. (#8423) 2020-09-29 21:48:33 +01:00
Erik Johnston
ac11fcbbb8
Add EventStreamPosition type (#8388)
The idea is to remove some of the places we pass around `int`, where it can represent one of two things:

1. the position of an event in the stream; or
2. a token that partitions the stream, used as part of the stream tokens.

The valid operations are then:

1. did a position happen before or after a token;
2. get all events that happened before or after a token; and
3. get all events between two tokens.

(Note that we don't want to allow other operations as we want to change the tokens to be vector clocks rather than simple ints)
2020-09-24 13:24:17 +01:00
Patrick Cloke
8a4a4186de
Simplify super() calls to Python 3 syntax. (#8344)
This converts calls like super(Foo, self) -> super().

Generated with:

    sed -i "" -Ee 's/super\([^\(]+\)/super()/g' **/*.py
2020-09-18 09:56:44 -04:00
Patrick Cloke
aec294ee0d
Use slots in attrs classes where possible (#8296)
slots use less memory (and attribute access is faster) while slightly
limiting the flexibility of the class attributes. This focuses on objects
which are instantiated "often" and for short periods of time.
2020-09-14 12:50:06 -04:00
Patrick Cloke
d2a3eb04a4 Fix typos in comments. 2020-09-14 11:46:58 -04:00
Erik Johnston
04cc249b43
Add experimental support for sharding event persister. Again. (#8294)
This is *not* ready for production yet. Caveats:

1. We should write some tests...
2. The stream token that we use for events can get stalled at the minimum position of all writers. This means that new events may not be processed and e.g. sent down sync streams if a writer isn't writing or is slow.
2020-09-14 10:16:41 +01:00
Erik Johnston
5d3e306d9f
Clean up Notifier.on_new_room_event code path (#8288)
The idea here is that we pass the `max_stream_id` to everything, and only use the stream ID of the particular event to figure out *when* the max stream position has caught up to the event and we can notify people about it.

This is to maintain the distinction between the position of an item in the stream (i.e. event A has stream ID 513) and a token that can be used to partition the stream (i.e. give me all events after stream ID 352). This distinction becomes important when the tokens are more complicated than a single number, which they will be once we start tracking the position of multiple writers in the tokens.

The valid operations here are:

1. Is a position before or after a token
2. Fetching all events between two tokens
3. Merging multiple tokens to get the "max", i.e. `C = max(A, B)` means that for all positions P where P is before A *or* before B, then P is before C.

Future PR will change the token type to a dedicated type.
2020-09-10 13:24:43 +01:00
Erik Johnston
c9dbee50ae
Fixup pusher pool notifications (#8287)
`pusher_pool.on_new_notifications` expected a min and max stream ID, however that was not what we were passing in. Instead, let's just pass it the current max stream ID and have it track the last stream ID it got passed.

I believe that it mostly worked as we called the function for every event. However, it would break for events that got persisted out of order, i.e, that were persisted but the max stream ID wasn't incremented as not all preceding events had finished persisting, and push for that event would be delayed until another event got pushed to the effected users.
2020-09-09 16:56:08 +01:00
Erik Johnston
dc9dcdbd59 Revert "Fixup pusher pool notifications"
This reverts commit e7fd336a53.
2020-09-09 16:19:22 +01:00
Erik Johnston
e7fd336a53 Fixup pusher pool notifications 2020-09-09 16:17:50 +01:00
Patrick Cloke
c619253db8
Stop sub-classing object (#8249) 2020-09-04 06:54:56 -04:00
Brendan Abolivier
9f8abdcc38
Revert "Add experimental support for sharding event persister. (#8170)" (#8242)
* Revert "Add experimental support for sharding event persister. (#8170)"

This reverts commit 82c1ee1c22.

* Changelog
2020-09-04 10:19:42 +01:00
Erik Johnston
82c1ee1c22
Add experimental support for sharding event persister. (#8170)
This is *not* ready for production yet. Caveats:

1. We should write some tests...
2. The stream token that we use for events can get stalled at the minimum position of all writers. This means that new events may not be processed and e.g. sent down sync streams if a writer isn't writing or is slow.
2020-09-02 15:48:37 +01:00
Erik Johnston
3b4556cf87
Fix wait_for_stream_position for multiple waiters. (#8196)
This fixes a bug where having multiple callers waiting on the same
stream and position will cause it to try and compare two deferreds,
which fails (due to the sorted list having an entry of `Tuple[int,
Deferred]`).
2020-08-28 17:12:45 +01:00
Erik Johnston
c9c544cda5
Remove ChainedIdGenerator. (#8123)
It's just a thin wrapper around two ID gens to make `get_current_token`
and `get_next` return tuples. This can easily be replaced by calling the
appropriate methods on the underlying ID gens directly.
2020-08-19 13:41:51 +01:00
Patrick Cloke
eebf52be06
Be stricter about JSON that is accepted by Synapse (#8106) 2020-08-19 07:26:03 -04:00
Erik Johnston
76d21d14a0
Separate get_current_token into two. (#8113)
The function is used for two purposes: 1) for subscribers of streams to
get a token they can use to get further updates with, and 2) for
replication to track position of the writers of the stream.

For streams with a single writer the two scenarios produce the same
result, however the situation becomes complicated for streams with
multiple writers. The current `MultiWriterIdGenerator` does not
correctly handle the first case (which is not an issue as its only used
for the `caches` stream which nothing subscribes to outside of
replication).
2020-08-19 10:39:31 +01:00
David Vo
4dd27e6d11
Reduce unnecessary whitespace in JSON. (#7372) 2020-08-07 08:02:55 -04:00
Richard van der Hoff
f57b99af22
Handle replication commands synchronously where possible (#7876)
Most of the stuff we do for replication commands can be done synchronously. There's no point spinning up background processes if we're not going to need them.
2020-07-27 18:54:43 +01:00
Erik Johnston
84d099ae11
Fix typing replication not being handled on master (#7959)
Handling of incoming typing stream updates from replication was not
hooked up on master, effecting set ups where typing was handled on a
different worker.

This is really only a problem if the master process is also handling
sync requests, which is unlikely for those that are at the stage of
moving typing off.

The other observable effect is that if a worker restarts or a
replication connect drops then the typing worker will issue a
`POSITION typing`, triggering master process to try and stream *all*
typing updates from position 0.

Fixes #7907
2020-07-27 14:10:53 +01:00
Richard van der Hoff
931b026844
Remove an unused prometheus metric (#7878) 2020-07-22 00:40:55 +01:00
Richard van der Hoff
05060e0223
Track command processing as a background process (#7879)
I'm going to be doing more stuff synchronously, and I don't want to lose the
CPU metrics down the sofa.
2020-07-22 00:40:42 +01:00
Karthikeyan Singaravelan
a7b06a81f0
Fix deprecation warning: import ABC from collections.abc (#7892) 2020-07-20 13:33:04 -04:00
Richard van der Hoff
e5300063ed
Optimise queueing of inbound replication commands (#7861)
When we get behind on replication, we tend to stack up background processes
behind a linearizer. Bg processes are heavy (particularly with respect to
prometheus metrics) and linearizers aren't terribly efficient once the queue
gets long either.

A better approach is to maintain a queue of requests to be processed, and
nominate a single process to work its way through the queue.

Fixes: #7444
2020-07-16 15:49:37 +01:00
Erik Johnston
f2e38ca867
Allow moving typing off master (#7869) 2020-07-16 15:12:54 +01:00
Erik Johnston
f299441cc6
Add ability to shard the federation sender (#7798) 2020-07-10 18:26:36 +01:00
Patrick Cloke
38e1fac886
Fix some spelling mistakes / typos. (#7811) 2020-07-09 09:52:58 -04:00
Patrick Cloke
e7efd8f827
Do not use simplejson in Synapse. (#7800) 2020-07-08 07:15:08 -04:00
Erik Johnston
67d7756fcf
Refactor getting replication updates from database v2. (#7740) 2020-07-07 12:11:35 +01:00
Will Hunt
62b1ce8539
isort 5 compatibility (#7786)
The CI appears to use the latest version of isort, which is a problem when isort gets a major version bump. Rather than try to pin the version, I've done the necessary to make isort5 happy with synapse.
2020-07-05 16:32:02 +01:00
Erik Johnston
f6f7511a4c
Refactor getting replication updates from database. (#7636)
The aim here is to make it easier to reason about when streams are limited and when they're not, by moving the logic into the database functions themselves. This should mean we can kill of `db_query_to_update_function` function.
2020-06-16 17:10:28 +01:00
Patrick Cloke
7d2532be36
Discard RDATA from already seen positions. (#7648) 2020-06-15 08:44:54 -04:00
Erik Johnston
664409b169
Fix bug in account data replication stream. (#7656)
* Ensure account data stream IDs are unique.

The account data stream is shared between three tables, and the maximum
allocated ID was tracked in a dedicated table. Updating the max ID
happened outside the transaction that allocated the ID, leading to a
race where if the server was restarted then the same ID could be
allocated but the max ID failed to be updated, leading it to be reused.

The ID generators have support for tracking across multiple tables, so
we may as well use that instead of a dedicated table.

* Fix bug in account data replication stream.

If the same stream ID was used in both global and room account data then
the getting updates for the replication stream would fail due to
`heapq.merge(..)` trying to compare a `str` with a `None`. (This is
because you'd have two rows like `(534, '!room')` and `(534, None)` from
the room and global account data tables).

Fix is just to order by stream ID, since we don't rely on the ordering
beyond that. The bug where stream IDs can be reused should be fixed now,
so this case shouldn't happen going forward.

Fixes #7617
2020-06-09 16:28:57 +01:00
Patrick Cloke
f1e61ef85c Typo fixes. 2020-06-05 08:43:21 -04:00
Erik Johnston
9bac5d62b3
Ensure ReplicationStreamer is always started when replication enabled. (#7579)
Fixes #7566.
2020-05-27 11:44:19 +01:00
Erik Johnston
e5c67d04db
Add option to move event persistence off master (#7517) 2020-05-22 16:11:35 +01:00
Erik Johnston
1531b214fc
Add ability to wait for replication streams (#7542)
The idea here is that if an instance persists an event via the replication HTTP API it can return before we receive that event over replication, which can lead to races where code assumes that persisting an event immediately updates various caches (e.g. current state of the room).

Most of Synapse doesn't hit such races, so we don't do the waiting automagically, instead we do so where necessary to avoid unnecessary delays. We may decide to change our minds here if it turns out there are a lot of subtle races going on.

People probably want to look at this commit by commit.
2020-05-22 14:21:54 +01:00
Richard van der Hoff
6c1f7c722f
Fix limit logic for AccountDataStream (#7384)
Make sure that the AccountDataStream presents complete updates, in the right
order.

This is much the same fix as #7337 and #7358, but applied to a different stream.
2020-05-15 19:03:25 +01:00
Erik Johnston
4734a7bbe4
Move EventStream handling into default ReplicationDataHandler (#7493)
This is so that the logic can happen on both master and workers when we move event persistence out.
2020-05-14 14:01:39 +01:00
Erik Johnston
7ee24c5674
Have all instances correctly respond to REPLICATE command. (#7475)
Before all streams were only written to from master, so only master needed to respond to `REPLICATE` commands.

Before all instances wrote to the cache invalidation stream, but didn't respond to `REPLICATE`. This was a bug, which could lead to missed rows from cache invalidation stream if an instance is restarted, however all the caches would be empty in that case so it wasn't a problem.
2020-05-13 10:27:02 +01:00
Erik Johnston
8ca79613e6
Fix Redis reconnection logic (#7482)
Proactively send out `POSITION` commands (as if we had just received a `REPLICATE`) when we connect to Redis. This is important as other instances won't notice we've connected to issue a `REPLICATE` command (unlike for direct TCP connections). This is only currently an issue if master process reconnects without restarting (if it restarts then it won't have written anything and so other instances probably won't have missed anything).
2020-05-13 09:57:15 +01:00
Andrew Morgan
5cf758cdd6 Merge branch 'release-v1.13.0' into develop
* release-v1.13.0:
  Don't UPGRADE database rows
  RST indenting
  Put rollback instructions in upgrade notes
  Fix changelog typo
  Oh yeah, RST
  Absolute URL it is then
  Fix upgrade notes link
  Provide summary of upgrade issues in changelog. Fix )
  Move next version notes from changelog to upgrade notes
  Changelog fixes
  1.13.0rc1
  Documentation on setting up redis (#7446)
  Rework UI Auth session validation for registration (#7455)
  Fix errors from malformed log line (#7454)
  Drop support for redis.dbid (#7450)
2020-05-11 16:46:33 +01:00
Richard van der Hoff
aa5aa6f96a
Fix errors from malformed log line (#7454) 2020-05-07 19:51:38 +01:00