mirror of
https://git.anonymousland.org/anonymousland/synapse.git
synced 2024-10-01 11:49:51 -04:00
Prevent logging context going missing on federation request timeout (#10810)
In `MatrixFederationHttpClient._send_request()`, we make a HTTP request using an `Agent`, wrap that request in a timeout and await the resulting `Deferred`. On its own, the `Agent` performing the HTTP request correctly stashes and restores the logging context while waiting. The addition of the timeout introduces a path where the logging context is not restored when execution resumes. To address this, we wrap the timeout `Deferred` in a `make_deferred_yieldable()` to stash the logging context and restore it on completion of the `await`. However this is not sufficient, since by the time we construct the timeout `Deferred`, the `Agent` has already stashed and cleared the logging context when using `make_deferred_yieldable()` to produce its `Deferred` for the request. Hence, we wrap the `Agent` request in a `run_in_background()` to "fork" and preserve the logging context so that we can stash and restore it when `await`ing the timeout `Deferred`. This approach is similar to the one used with `defer.gatherResults`. Note that the code is still not fully correct. When a timeout occurs, the request remains running in the background (existing behavior which is nothing to do with the new call to `run_in_background`) and may re-start the logging context after it has finished.
This commit is contained in:
parent
51e1b96d04
commit
14b8c0476f
1
changelog.d/10810.bugfix
Normal file
1
changelog.d/10810.bugfix
Normal file
@ -0,0 +1 @@
|
||||
Fix a case where logging contexts would go missing when federation requests time out.
|
@ -66,7 +66,7 @@ from synapse.http.client import (
|
||||
)
|
||||
from synapse.http.federation.matrix_federation_agent import MatrixFederationAgent
|
||||
from synapse.logging import opentracing
|
||||
from synapse.logging.context import make_deferred_yieldable
|
||||
from synapse.logging.context import make_deferred_yieldable, run_in_background
|
||||
from synapse.logging.opentracing import set_tag, start_active_span, tags
|
||||
from synapse.types import JsonDict
|
||||
from synapse.util import json_decoder
|
||||
@ -553,20 +553,29 @@ class MatrixFederationHttpClient:
|
||||
with Measure(self.clock, "outbound_request"):
|
||||
# we don't want all the fancy cookie and redirect handling
|
||||
# that treq.request gives: just use the raw Agent.
|
||||
request_deferred = self.agent.request(
|
||||
|
||||
# To preserve the logging context, the timeout is treated
|
||||
# in a similar way to `defer.gatherResults`:
|
||||
# * Each logging context-preserving fork is wrapped in
|
||||
# `run_in_background`. In this case there is only one,
|
||||
# since the timeout fork is not logging-context aware.
|
||||
# * The `Deferred` that joins the forks back together is
|
||||
# wrapped in `make_deferred_yieldable` to restore the
|
||||
# logging context regardless of the path taken.
|
||||
request_deferred = run_in_background(
|
||||
self.agent.request,
|
||||
method_bytes,
|
||||
url_bytes,
|
||||
headers=Headers(headers_dict),
|
||||
bodyProducer=producer,
|
||||
)
|
||||
|
||||
request_deferred = timeout_deferred(
|
||||
request_deferred,
|
||||
timeout=_sec_timeout,
|
||||
reactor=self.reactor,
|
||||
)
|
||||
|
||||
response = await request_deferred
|
||||
response = await make_deferred_yieldable(request_deferred)
|
||||
except DNSLookupError as e:
|
||||
raise RequestSendFailed(e, can_retry=retry_on_dns_fail) from e
|
||||
except Exception as e:
|
||||
|
Loading…
Reference in New Issue
Block a user