* Correctly retry and back off if we get a HTTPerror response
* Refactor request sending to have better excpetions
MatrixFederationHttpClient blindly reraised exceptions to the caller
without differentiating "expected" failures (e.g. connection timeouts
etc) versus more severe problems (e.g. programming errors).
This commit adds a RequestSendFailed exception that is raised when
"expected" failures happen, allowing the TransactionQueue to log them as
warnings while allowing us to log other exceptions as actual exceptions.
When we receive events over federation we will need to know the room
version to be able to correctly handle them, e.g. once we start changing
event formats. Currently, we attempt to handle events in unknown rooms.
Broadly three things here:
* disable W504 which seems a bit whacko
* remove a bunch of `as e` expressions from exception handlers that don't use
them
* use `r""` for strings which include backslashes
Also, we don't use pep8 any more, so we can get rid of the duplicate config
there.
It's quite important that get_missing_events returns the *latest* events in the
room; however we were pulling event ids out of the database until we got *at
least* 10, and then taking the *earliest* of the results.
We also shouldn't really be relying on depth, and should be checking the
room_id.
- Improve logging: log things in the right order, include destination and txids
in all log lines, don't log successful responses twice
- Fix the docstring on TransportLayerClient.send_transaction
- Don't use treq.request, which is overcomplicated for our purposes: just use a
twisted.web.client.Agent.
- simplify the logic for setting up the bodyProducer
- fix bytes/str confusions
when processing incoming transactions, it can be hard to see what's going on,
because we process a bunch of stuff in parallel, and because we may end up
recursively working our way through a chain of three or four events.
This commit creates a way to use logcontexts to add the relevant event ids to
the log lines.
There's really no point in checking for destinations called "localhost" because
there is nothing stopping people creating other DNS entries which point to
127.0.0.1. The right fix for this is
https://github.com/matrix-org/synapse/issues/3953.
Blocking localhost, on the other hand, means that you get a surprise when
trying to connect a test server on localhost to an existing server (with a
'normal' server_name).
ExpiringCache required that `start()` be called before it would actually
start expiring entries. A number of places didn't do that.
This PR removes `start` from ExpiringCache, and automatically starts
backround reaping process on creation instead.
Add some informative comments about what's going on here.
Also, `sent_to_us_directly` and `get_missing` were doing the same thing (apart
from in `_handle_queued_pdus`, which looks like a bug), so let's get rid of
`get_missing` and use `sent_to_us_directly` consistently.
If we receive an event that doesn't pass their content hash check (e.g.
due to already being redacted) then we hit a bug which causes an
exception to be raised, which then promplty stops the event (and
request) from being processed.
This effects all sorts of federation APIs, including joining rooms with
a redacted state event.
We should check that both the sender's server, and the server which created the
event_id (which may be different from whatever the remote server has told us
the origin is), have signed the event.
When we get a federation request which refers to an event id, make sure that
said event is in the room the caller claims it is in.
(patch supplied by @turt2live)
This commit replaces SynapseError.from_http_response_exception with
HttpResponseException.to_synapse_error.
The new method actually returns a ProxiedRequestError, which allows us to pass
through additional metadata from the API call.
We really shouldn't be sending all CodeMessageExceptions back over the C-S API;
it will include things like 401s which we shouldn't proxy.
That means that we need to explicitly turn a few HttpResponseExceptions into
SynapseErrors in the federation layer.
The effect of the latter is that the matrix errcode will get passed through
correctly to calling clients, which might help with some of the random
M_UNKNOWN errors when trying to join rooms.
This fixes#3518, and ensures that we get useful logs and metrics for lots of
things that happen in the background.
(There are certainly more things that happen in the background; these are just
the common ones I've found running a single-process synapse locally).
This introduces a mechanism for tracking resource usage by background
processes, along with an example of how it will be used.
This will help address #3518, but more importantly will give us better insights
into things which are happening but not being shown up by the request metrics.
We *could* do this with Measure blocks, but:
- I think having them pulled out as a completely separate metric class will
make it easier to distinguish top-level processes from those which are
nested.
- I want to be able to report on in-flight background processes, and I don't
think we want to do this for *all* Measure blocks.
We need to do a bit more validation when we get a server name, but don't want
to be re-doing it all over the shop, so factor out a separate
parse_and_validate_server_name, and do the extra validation.
Also, use it to verify the server name in the config file.
Make sure that server_names used in auth headers are sane, and reject them with
a sensible error code, before they disappear off into the depths of the system.
While I was going through uses of preserve_fn for other PRs, I converted places
which only use the wrapped function once to use run_in_background, to avoid
creating the function object.
There were a bunch of places where we fire off a process to happen in the
background, but don't have any exception handling on it - instead relying on
the unhandled error being logged when the relevent deferred gets
garbage-collected.
This is unsatisfactory for a number of reasons:
- logging on garbage collection is best-effort and may happen some time after
the error, if at all
- it can be hard to figure out where the error actually happened.
- it is logged as a scary CRITICAL error which (a) I always forget to grep for
and (b) it's not really CRITICAL if a background process we don't care about
fails.
So this is an attempt to add exception handling to everything we fire off into
the background.
It turns out that most of the time we were calling have_events, we were only
using half of the result. Replace have_events with have_seen_events and
get_rejection_reasons, so that we can see what's going on a bit more clearly.
This reverts commit 9fbe70a7dc.
It turns out that sortedcontainers.SortedDict is not an exact match for
blist.sorteddict; in particular, `popitem()` removes things from the opposite
end of the dict.
This is trivial to fix, but I want to add some unit tests, and potentially some
more thought about it, before we do so.
Adds a `.wrap` method to ResponseCache which wraps up the boilerplate of a
(get, set) pair, and then use it throughout the codebase.
This will be largely non-functional, but does include the following functional
changes:
* federation_server.on_context_state_request: drops use of _server_linearizer
which looked redundant and could cause incorrect cache misses by yielding
between the get and the set.
* RoomListHandler.get_remote_public_room_list(): fixes logcontext leaks
* the wrap function includes some logging. I'm hoping this won't be too noisy
on production.
The API is now under
/groups/$group_id/setting/m.join_policy
and expects a JSON blob of the shape
```json
{
"m.join_policy": {
"type": "invite"
}
}
```
where "invite" could alternatively be "open".
Add federation_domain_whitelist
gives a way to restrict which domains your HS is allowed to federate with.
useful mainly for gracefully preventing a private but internet-connected HS from trying to federate to the wider public Matrix network
These processes take a long time compared to the request, so there is lots of
"Entering|Restoring dead context" in the logs. Let's try to shut it up a bit.
FederationServer doesn't have a send_failure (and nor does its subclass,
ReplicationLayer), so this was failing.
I'm not really sure what the idea behind send_failure is, given (a) we don't do
anything at the other end with it except log it, and (b) we also send back the
failure via the transaction response. I suspect there's a whole lot of dead
code around it, but for now I'm just removing the broken bit.
The response-building code expects there to be an entry in the `results` list
for each entry in the pdu_list, so the early `continue` was messing this
up. That doesn't really matter, because all that the federation client does is
log any errors, but it's pretty poor form.
