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.
This is primarily for allowing us to send those commands from workers, but for now simply allows us to ignore echoed RDATA/POSITION commands that we sent (we get echoes of sent commands when using redis). Currently we log a WARNING on the master process every time we receive an echoed RDATA.
* Factor out functions for injecting events into database
I want to add some more flexibility to the tools for injecting events into the
database, and I don't want to clutter up HomeserverTestCase with them, so let's
factor them out to a new file.
* Rework TestReplicationDataHandler
This wasn't very easy to work with: the mock wrapping was largely superfluous,
and it's useful to be able to inspect the received rows, and clear out the
received list.
* Fix AssertionErrors being thrown by EventsStream
Part of the problem was that there was an off-by-one error in the assertion,
but also the limit logic was too simple. Fix it all up and add some tests.
Long story short: if we're handling presence on the current worker, we shouldn't be sending USER_SYNC commands over replication.
In an attempt to figure out what is going on here, I ended up refactoring some bits of the presencehandler code, so the first 4 commits here are non-functional refactors to move this code slightly closer to sanity. (There's still plenty to do here :/). Suggest reviewing individual commits.
Fixes (I hope) #7257.
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.
* 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.
The `http_proxy` and `HTTPS_PROXY` env vars can be set to a `host[:port]` value which should point to a proxy.
The address of the proxy should be excluded from IP blacklists such as the `url_preview_ip_range_blacklist`.
The proxy will then be used for
* push
* url previews
* phone-home stats
* recaptcha validation
* CAS auth validation
It will *not* be used for:
* Application Services
* Identity servers
* Outbound federation
* In worker configurations, connections from workers to masters
Fixes#4198.
Server Notices use a special room which the user can't dismiss. They are
created on demand when some other bit of the code calls send_notice.
(This doesn't actually do much yet becuse we don't call send_notice anywhere)
We extract the storage-independent bits of the state group resolution out to a
separate functiom, and stick it in a new handler, in preparation for its use
from the storage layer.
Non-functional refactoring to move set_password. This means that we'll be able
to properly deactivate devices and access tokens without introducing a
dependency loop.
Non-functional refactoring to move deactivate_account. This means that we'll be
able to properly deactivate devices and access tokens without introducing a
dependency loop.
This avoids the scenario where we have four different PreviewUrlResources
configured on a single app, each of which have their own caches and cache
clearing jobs.
Erik Johnston