Commit Graph

43 Commits

Author SHA1 Message Date
Patrick Cloke
33a02f0f52
Fix additional type hints from Twisted upgrade. () 2021-03-03 15:47:38 -05:00
Erik Johnston
a6ea1a957e
Don't pull event from DB when handling replication traffic. ()
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
8de3703d21
Make event persisters periodically announce position over replication. ()
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
ea70f1c362
Various clean ups to room stream tokens. () 2020-09-29 21:48:33 +01:00
Erik Johnston
ac11fcbbb8
Add EventStreamPosition type ()
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
Erik Johnston
5d3e306d9f
Clean up Notifier.on_new_room_event code path ()
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 ()
`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
Erik Johnston
3b4556cf87
Fix wait_for_stream_position for multiple waiters. ()
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
84d099ae11
Fix typing replication not being handled on master ()
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 
2020-07-27 14:10:53 +01:00
Will Hunt
62b1ce8539
isort 5 compatibility ()
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
Patrick Cloke
f1e61ef85c Typo fixes. 2020-06-05 08:43:21 -04:00
Erik Johnston
1531b214fc
Add ability to wait for replication streams ()
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
Erik Johnston
4734a7bbe4
Move EventStream handling into default ReplicationDataHandler ()
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
d7983b63a6
Support any process writing to cache invalidation stream. () 2020-05-07 13:51:08 +01:00
Erik Johnston
0e719f2398
Thread through instance name to replication client. ()
For in memory streams when fetching updates on workers we need to query the source of the stream, which currently is hard coded to be master. This PR threads through the source instance we received via `POSITION` through to the update function in each stream, which can then be passed to the replication client for in memory streams.
2020-05-01 17:19:56 +01:00
Erik Johnston
3085cde577
Use stream.current_token() and remove stream_positions() ()
We move the processing of typing and federation replication traffic into their handlers so that `Stream.current_token()` points to a valid token. This allows us to remove `get_streams_to_replicate()` and `stream_positions()`.
2020-05-01 15:21:35 +01:00
Erik Johnston
51f7eaf908
Add ability to run replication protocol over redis. ()
This is configured via the `redis` config options.
2020-04-22 13:07:41 +01:00
Erik Johnston
5016b162fc
Move client command handling out of TCP protocol ()
The aim here is to move the command handling out of the TCP protocol classes and to also merge the client and server command handling (so that we can reuse them for redis protocol). This PR simply moves the client paths to the new `ReplicationCommandHandler`, a future PR will move the server paths too.
2020-04-06 09:58:42 +01:00
Erik Johnston
4f21c33be3
Remove usage of "conn_id" for presence. ()
* Remove `conn_id` usage for UserSyncCommand.

Each tcp replication connection is assigned a "conn_id", which is used
to give an ID to a remotely connected worker. In a redis world, there
will no longer be a one to one mapping between connection and instance,
so instead we need to replace such usages with an ID generated by the
remote instances and included in the replicaiton commands.

This really only effects UserSyncCommand.

* Add CLEAR_USER_SYNCS command that is sent on shutdown.

This should help with the case where a synchrotron gets restarted
gracefully, rather than rely on 5 minute timeout.
2020-03-30 16:37:24 +01:00
Erik Johnston
4cff617df1
Move catchup of replication streams to worker. ()
This changes the replication protocol so that the server does not send down `RDATA` for rows that happened before the client connected. Instead, the server will send a `POSITION` and clients then query the database (or master out of band) to get up to date.
2020-03-25 14:54:01 +00:00
Erik Johnston
c3d4ad8afd
Fix sending server up commands from workers ()
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
2020-01-30 16:42:11 +00:00
Erik Johnston
a8a50f5b57
Wake up transaction queue when remote server comes back online ()
This will be used to retry outbound transactions to a remote server if
we think it might have come back up.
2020-01-17 10:27:19 +00:00
Erik Johnston
48c3a96886
Port synapse.replication.tcp to async/await ()
* Port synapse.replication.tcp to async/await

* Newsfile

* Correctly document type of on_<FOO> functions as async

* Don't be overenthusiastic with the asyncing....
2020-01-16 09:16:12 +00:00
Erik Johnston
e8b68a4e4b
Fixup synapse.replication to pass mypy checks () 2020-01-14 14:08:06 +00:00
Richard van der Hoff
6964ea095b
Reduce the reconnect time when replication fails. () 2020-01-03 14:19:09 +00:00
Richard van der Hoff
cc6243b4c0
document the REPLICATE command a bit better ()
since I found myself wonder how it works
2019-11-04 12:40:18 +00:00
Andrew Morgan
54fef094b3
Remove usage of deprecated logger.warn method from codebase ()
Replace every instance of `logger.warn` with `logger.warning` as the former is deprecated.
2019-10-31 10:23:24 +00:00
Amber Brown
32e7c9e7f2
Run Black. () 2019-06-20 19:32:02 +10:00
Richard van der Hoff
f570916a3e Add parse_row method to replication stream class
This will allow individual stream classes to override how a row is parsed.
2019-03-27 21:32:33 +00:00
Richard van der Hoff
acaa18f7dd
Fix/improve some docstrings in the replication code. () 2019-03-27 21:12:36 +00:00
Erik Johnston
6870fc496f Move connecting logic into ClientReplicationStreamProtocol 2019-02-27 10:23:51 +00:00
Erik Johnston
25814921f1 Increase the max delay between retry attempts
Otherwise if you have many workers they can easily take out master with
their connection attempts
2019-02-26 15:12:33 +00:00
Erik Johnston
313987187e Fix tightloop over connecting to replication server
If the client failed to process incoming commands during the initial set
up of the replication connection it would immediately disconnect and
reconnect, resulting in a tightloop.

This can happen, for example, when subscribing to a stream that has a
row that is too long in the backlog.

The fix here is to not consider the connection successfully set up until
the client has succesfully subscribed and caught up with the streams.
This ensures that the retry logic timers aren't reset until then,
meaning that if an error does happen during start up the client will
continue backing off before retrying again.
2019-02-26 15:05:41 +00:00
Amber Brown
c4b3698a80
Make the replication logger quieter () 2018-10-29 22:59:44 +11:00
Richard van der Hoff
0e8d78f6aa Logcontexts for replication command handlers
Run the handlers for replication commands as background processes. This should
improve the visibility in our metrics, and reduce the number of "running db
transaction from sentinel context" warnings.

Ideally it means converting the things that fire off deferreds into the night
into things that actually return a Deferred when they are done. I've made a bit
of a stab at this, but it will probably be leaky.
2018-08-17 00:43:43 +01:00
Richard van der Hoff
f59be4eb0e Fix unit tests
on_notifier_poke no longer runs synchonously, so we have to do a different hack
to make sure that the replication data has been sent. Let's actually listen for
its arrival.
2018-07-25 10:30:36 +01:00
Amber Brown
49af402019 run isort 2018-07-09 16:09:20 +10:00
Amber Brown
07cad26d65
Remove all global reactor imports & pass it around explicitly () 2018-06-25 14:08:28 +01:00
Erik Johnston
78cefd78d6 Make workers report to master for user ip updates 2017-06-27 14:58:10 +01:00
Erik Johnston
69b3fd485d Fix incorrect type when using InvalidateCacheCommand 2017-04-06 09:36:38 +01:00
Erik Johnston
52bfa604e1 Add basic replication client handler and factory 2017-04-03 15:34:13 +01:00