Attempt to figure out what's going on with timeouts (#3857)

pull/3858/head
Amber Brown 2018-09-14 00:15:51 +10:00 committed by GitHub
parent b7d2fb5eb9
commit bfa0b759e0
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4 changed files with 241 additions and 57 deletions

1
changelog.d/3857.misc Normal file
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@ -0,0 +1 @@
Refactor some HTTP timeout code.

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@ -26,7 +26,7 @@ from canonicaljson import encode_canonical_json
from prometheus_client import Counter
from signedjson.sign import sign_json
from twisted.internet import defer, protocol, reactor
from twisted.internet import defer, protocol
from twisted.internet.error import DNSLookupError
from twisted.web._newclient import ResponseDone
from twisted.web.client import Agent, HTTPConnectionPool
@ -40,10 +40,8 @@ from synapse.api.errors import (
HttpResponseException,
SynapseError,
)
from synapse.http import cancelled_to_request_timed_out_error
from synapse.http.endpoint import matrix_federation_endpoint
from synapse.util import logcontext
from synapse.util.async_helpers import add_timeout_to_deferred
from synapse.util.logcontext import make_deferred_yieldable
logger = logging.getLogger(__name__)
@ -66,13 +64,14 @@ else:
class MatrixFederationEndpointFactory(object):
def __init__(self, hs):
self.reactor = hs.get_reactor()
self.tls_client_options_factory = hs.tls_client_options_factory
def endpointForURI(self, uri):
destination = uri.netloc.decode('ascii')
return matrix_federation_endpoint(
reactor, destination, timeout=10,
self.reactor, destination, timeout=10,
tls_client_options_factory=self.tls_client_options_factory
)
@ -90,6 +89,7 @@ class MatrixFederationHttpClient(object):
self.hs = hs
self.signing_key = hs.config.signing_key[0]
self.server_name = hs.hostname
reactor = hs.get_reactor()
pool = HTTPConnectionPool(reactor)
pool.maxPersistentPerHost = 5
pool.cachedConnectionTimeout = 2 * 60
@ -100,6 +100,7 @@ class MatrixFederationHttpClient(object):
self._store = hs.get_datastore()
self.version_string = hs.version_string.encode('ascii')
self._next_id = 1
self.default_timeout = 60
def _create_url(self, destination, path_bytes, param_bytes, query_bytes):
return urllib.parse.urlunparse(
@ -143,6 +144,11 @@ class MatrixFederationHttpClient(object):
(May also fail with plenty of other Exceptions for things like DNS
failures, connection failures, SSL failures.)
"""
if timeout:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
if (
self.hs.config.federation_domain_whitelist is not None and
destination not in self.hs.config.federation_domain_whitelist
@ -215,13 +221,9 @@ class MatrixFederationHttpClient(object):
headers=Headers(headers_dict),
data=data,
agent=self.agent,
reactor=self.hs.get_reactor()
)
add_timeout_to_deferred(
request_deferred,
timeout / 1000. if timeout else 60,
self.hs.get_reactor(),
cancelled_to_request_timed_out_error,
)
request_deferred.addTimeout(_sec_timeout, self.hs.get_reactor())
response = yield make_deferred_yieldable(
request_deferred,
)
@ -261,6 +263,13 @@ class MatrixFederationHttpClient(object):
delay = min(delay, 2)
delay *= random.uniform(0.8, 1.4)
logger.debug(
"{%s} Waiting %s before sending to %s...",
txn_id,
delay,
destination
)
yield self.clock.sleep(delay)
retries_left -= 1
else:
@ -279,10 +288,9 @@ class MatrixFederationHttpClient(object):
# :'(
# Update transactions table?
with logcontext.PreserveLoggingContext():
body = yield self._timeout_deferred(
treq.content(response),
timeout,
)
d = treq.content(response)
d.addTimeout(_sec_timeout, self.hs.get_reactor())
body = yield make_deferred_yieldable(d)
raise HttpResponseException(
response.code, response.phrase, body
)
@ -396,10 +404,9 @@ class MatrixFederationHttpClient(object):
check_content_type_is_json(response.headers)
with logcontext.PreserveLoggingContext():
body = yield self._timeout_deferred(
treq.json_content(response),
timeout,
)
d = treq.json_content(response)
d.addTimeout(self.default_timeout, self.hs.get_reactor())
body = yield make_deferred_yieldable(d)
defer.returnValue(body)
@defer.inlineCallbacks
@ -449,10 +456,14 @@ class MatrixFederationHttpClient(object):
check_content_type_is_json(response.headers)
with logcontext.PreserveLoggingContext():
body = yield self._timeout_deferred(
treq.json_content(response),
timeout,
)
d = treq.json_content(response)
if timeout:
_sec_timeout = timeout / 1000
else:
_sec_timeout = self.default_timeout
d.addTimeout(_sec_timeout, self.hs.get_reactor())
body = yield make_deferred_yieldable(d)
defer.returnValue(body)
@ -504,10 +515,9 @@ class MatrixFederationHttpClient(object):
check_content_type_is_json(response.headers)
with logcontext.PreserveLoggingContext():
body = yield self._timeout_deferred(
treq.json_content(response),
timeout,
)
d = treq.json_content(response)
d.addTimeout(self.default_timeout, self.hs.get_reactor())
body = yield make_deferred_yieldable(d)
defer.returnValue(body)
@ -554,10 +564,9 @@ class MatrixFederationHttpClient(object):
check_content_type_is_json(response.headers)
with logcontext.PreserveLoggingContext():
body = yield self._timeout_deferred(
treq.json_content(response),
timeout,
)
d = treq.json_content(response)
d.addTimeout(self.default_timeout, self.hs.get_reactor())
body = yield make_deferred_yieldable(d)
defer.returnValue(body)
@ -599,38 +608,15 @@ class MatrixFederationHttpClient(object):
try:
with logcontext.PreserveLoggingContext():
length = yield self._timeout_deferred(
_readBodyToFile(
response, output_stream, max_size
),
)
d = _readBodyToFile(response, output_stream, max_size)
d.addTimeout(self.default_timeout, self.hs.get_reactor())
length = yield make_deferred_yieldable(d)
except Exception:
logger.exception("Failed to download body")
raise
defer.returnValue((length, headers))
def _timeout_deferred(self, deferred, timeout_ms=None):
"""Times the deferred out after `timeout_ms` ms
Args:
deferred (Deferred)
timeout_ms (int|None): Timeout in milliseconds. If None defaults
to 60 seconds.
Returns:
Deferred
"""
add_timeout_to_deferred(
deferred,
timeout_ms / 1000. if timeout_ms else 60,
self.hs.get_reactor(),
cancelled_to_request_timed_out_error,
)
return deferred
class _ReadBodyToFileProtocol(protocol.Protocol):
def __init__(self, stream, deferred, max_size):

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@ -0,0 +1,157 @@
# -*- coding: utf-8 -*-
# Copyright 2018 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from mock import Mock
from twisted.internet.defer import TimeoutError
from twisted.internet.error import ConnectingCancelledError, DNSLookupError
from twisted.web.client import ResponseNeverReceived
from synapse.http.matrixfederationclient import MatrixFederationHttpClient
from tests.unittest import HomeserverTestCase
class FederationClientTests(HomeserverTestCase):
def make_homeserver(self, reactor, clock):
hs = self.setup_test_homeserver(reactor=reactor, clock=clock)
hs.tls_client_options_factory = None
return hs
def prepare(self, reactor, clock, homeserver):
self.cl = MatrixFederationHttpClient(self.hs)
self.reactor.lookups["testserv"] = "1.2.3.4"
def test_dns_error(self):
"""
If the DNS raising returns an error, it will bubble up.
"""
d = self.cl._request("testserv2:8008", "GET", "foo/bar", timeout=10000)
self.pump()
f = self.failureResultOf(d)
self.assertIsInstance(f.value, DNSLookupError)
def test_client_never_connect(self):
"""
If the HTTP request is not connected and is timed out, it'll give a
ConnectingCancelledError.
"""
d = self.cl._request("testserv:8008", "GET", "foo/bar", timeout=10000)
self.pump()
# Nothing happened yet
self.assertFalse(d.called)
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
self.assertEqual(clients[0][0], '1.2.3.4')
self.assertEqual(clients[0][1], 8008)
# Deferred is still without a result
self.assertFalse(d.called)
# Push by enough to time it out
self.reactor.advance(10.5)
f = self.failureResultOf(d)
self.assertIsInstance(f.value, ConnectingCancelledError)
def test_client_connect_no_response(self):
"""
If the HTTP request is connected, but gets no response before being
timed out, it'll give a ResponseNeverReceived.
"""
d = self.cl._request("testserv:8008", "GET", "foo/bar", timeout=10000)
self.pump()
# Nothing happened yet
self.assertFalse(d.called)
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
self.assertEqual(clients[0][0], '1.2.3.4')
self.assertEqual(clients[0][1], 8008)
conn = Mock()
client = clients[0][2].buildProtocol(None)
client.makeConnection(conn)
# Deferred is still without a result
self.assertFalse(d.called)
# Push by enough to time it out
self.reactor.advance(10.5)
f = self.failureResultOf(d)
self.assertIsInstance(f.value, ResponseNeverReceived)
def test_client_gets_headers(self):
"""
Once the client gets the headers, _request returns successfully.
"""
d = self.cl._request("testserv:8008", "GET", "foo/bar", timeout=10000)
self.pump()
conn = Mock()
clients = self.reactor.tcpClients
client = clients[0][2].buildProtocol(None)
client.makeConnection(conn)
# Deferred does not have a result
self.assertFalse(d.called)
# Send it the HTTP response
client.dataReceived(b"HTTP/1.1 200 OK\r\nServer: Fake\r\n\r\n")
# We should get a successful response
r = self.successResultOf(d)
self.assertEqual(r.code, 200)
def test_client_headers_no_body(self):
"""
If the HTTP request is connected, but gets no response before being
timed out, it'll give a ResponseNeverReceived.
"""
d = self.cl.post_json("testserv:8008", "foo/bar", timeout=10000)
self.pump()
conn = Mock()
clients = self.reactor.tcpClients
client = clients[0][2].buildProtocol(None)
client.makeConnection(conn)
# Deferred does not have a result
self.assertFalse(d.called)
# Send it the HTTP response
client.dataReceived(
(b"HTTP/1.1 200 OK\r\nContent-Type: application/json\r\n"
b"Server: Fake\r\n\r\n")
)
# Push by enough to time it out
self.reactor.advance(10.5)
f = self.failureResultOf(d)
self.assertIsInstance(f.value, TimeoutError)

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@ -4,9 +4,14 @@ from io import BytesIO
from six import text_type
import attr
from zope.interface import implementer
from twisted.internet import address, threads
from twisted.internet import address, threads, udp
from twisted.internet._resolver import HostResolution
from twisted.internet.address import IPv4Address
from twisted.internet.defer import Deferred
from twisted.internet.error import DNSLookupError
from twisted.internet.interfaces import IReactorPluggableNameResolver
from twisted.python.failure import Failure
from twisted.test.proto_helpers import MemoryReactorClock
@ -154,11 +159,46 @@ def render(request, resource, clock):
wait_until_result(clock, request)
@implementer(IReactorPluggableNameResolver)
class ThreadedMemoryReactorClock(MemoryReactorClock):
"""
A MemoryReactorClock that supports callFromThread.
"""
def __init__(self):
self._udp = []
self.lookups = {}
class Resolver(object):
def resolveHostName(
_self,
resolutionReceiver,
hostName,
portNumber=0,
addressTypes=None,
transportSemantics='TCP',
):
resolution = HostResolution(hostName)
resolutionReceiver.resolutionBegan(resolution)
if hostName not in self.lookups:
raise DNSLookupError("OH NO")
resolutionReceiver.addressResolved(
IPv4Address('TCP', self.lookups[hostName], portNumber)
)
resolutionReceiver.resolutionComplete()
return resolution
self.nameResolver = Resolver()
super(ThreadedMemoryReactorClock, self).__init__()
def listenUDP(self, port, protocol, interface='', maxPacketSize=8196):
p = udp.Port(port, protocol, interface, maxPacketSize, self)
p.startListening()
self._udp.append(p)
return p
def callFromThread(self, callback, *args, **kwargs):
"""
Make the callback fire in the next reactor iteration.