Merge pull request #3203 from matrix-org/rav/refactor_request_handler

Refactor request handling wrappers

synapse/http/additional_resource.py

@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.http.server import wrap_request_handler
+from synapse.http.server import wrap_json_request_handler
 from twisted.web.resource import Resource
 from twisted.web.server import NOT_DONE_YET
 
@@ -50,6 +50,6 @@ class AdditionalResource(Resource):
         self._async_render(request)
         return NOT_DONE_YET
 
-    @wrap_request_handler
+    @wrap_json_request_handler
     def _async_render(self, request):
         return self._handler(request)

synapse/http/request_metrics.py

@@ -0,0 +1,149 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# 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.
+
+import logging
+
+import synapse.metrics
+from synapse.util.logcontext import LoggingContext
+
+logger = logging.getLogger(__name__)
+
+metrics = synapse.metrics.get_metrics_for("synapse.http.server")
+
+# total number of responses served, split by method/servlet/tag
+response_count = metrics.register_counter(
+    "response_count",
+    labels=["method", "servlet", "tag"],
+    alternative_names=(
+        # the following are all deprecated aliases for the same metric
+        metrics.name_prefix + x for x in (
+            "_requests",
+            "_response_time:count",
+            "_response_ru_utime:count",
+            "_response_ru_stime:count",
+            "_response_db_txn_count:count",
+            "_response_db_txn_duration:count",
+        )
+    )
+)
+
+requests_counter = metrics.register_counter(
+    "requests_received",
+    labels=["method", "servlet", ],
+)
+
+outgoing_responses_counter = metrics.register_counter(
+    "responses",
+    labels=["method", "code"],
+)
+
+response_timer = metrics.register_counter(
+    "response_time_seconds",
+    labels=["method", "servlet", "tag"],
+    alternative_names=(
+        metrics.name_prefix + "_response_time:total",
+    ),
+)
+
+response_ru_utime = metrics.register_counter(
+    "response_ru_utime_seconds", labels=["method", "servlet", "tag"],
+    alternative_names=(
+        metrics.name_prefix + "_response_ru_utime:total",
+    ),
+)
+
+response_ru_stime = metrics.register_counter(
+    "response_ru_stime_seconds", labels=["method", "servlet", "tag"],
+    alternative_names=(
+        metrics.name_prefix + "_response_ru_stime:total",
+    ),
+)
+
+response_db_txn_count = metrics.register_counter(
+    "response_db_txn_count", labels=["method", "servlet", "tag"],
+    alternative_names=(
+        metrics.name_prefix + "_response_db_txn_count:total",
+    ),
+)
+
+# seconds spent waiting for db txns, excluding scheduling time, when processing
+# this request
+response_db_txn_duration = metrics.register_counter(
+    "response_db_txn_duration_seconds", labels=["method", "servlet", "tag"],
+    alternative_names=(
+        metrics.name_prefix + "_response_db_txn_duration:total",
+    ),
+)
+
+# seconds spent waiting for a db connection, when processing this request
+response_db_sched_duration = metrics.register_counter(
+    "response_db_sched_duration_seconds", labels=["method", "servlet", "tag"]
+)
+
+# size in bytes of the response written
+response_size = metrics.register_counter(
+    "response_size", labels=["method", "servlet", "tag"]
+)
+
+
+class RequestMetrics(object):
+    def start(self, time_msec, name):
+        self.start = time_msec
+        self.start_context = LoggingContext.current_context()
+        self.name = name
+
+    def stop(self, time_msec, request):
+        context = LoggingContext.current_context()
+
+        tag = ""
+        if context:
+            tag = context.tag
+
+            if context != self.start_context:
+                logger.warn(
+                    "Context have unexpectedly changed %r, %r",
+                    context, self.start_context
+                )
+                return
+
+        outgoing_responses_counter.inc(request.method, str(request.code))
+
+        response_count.inc(request.method, self.name, tag)
+
+        response_timer.inc_by(
+            time_msec - self.start, request.method,
+            self.name, tag
+        )
+
+        ru_utime, ru_stime = context.get_resource_usage()
+
+        response_ru_utime.inc_by(
+            ru_utime, request.method, self.name, tag
+        )
+        response_ru_stime.inc_by(
+            ru_stime, request.method, self.name, tag
+        )
+        response_db_txn_count.inc_by(
+            context.db_txn_count, request.method, self.name, tag
+        )
+        response_db_txn_duration.inc_by(
+            context.db_txn_duration_ms / 1000., request.method, self.name, tag
+        )
+        response_db_sched_duration.inc_by(
+            context.db_sched_duration_ms / 1000., request.method, self.name, tag
+        )
+
+        response_size.inc_by(request.sentLength, request.method, self.name, tag)

synapse/http/server.py

@@ -18,6 +18,9 @@
 from synapse.api.errors import (
     cs_exception, SynapseError, CodeMessageException, UnrecognizedRequestError, Codes
 )
+from synapse.http.request_metrics import (
+    requests_counter,
+)
 from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
 from synapse.util.caches import intern_dict
 from synapse.util.metrics import Measure
@@ -41,133 +44,26 @@ import simplejson
 
 logger = logging.getLogger(__name__)
 
-metrics = synapse.metrics.get_metrics_for(__name__)
 
-# total number of responses served, split by method/servlet/tag
+def wrap_json_request_handler(h):
-response_count = metrics.register_counter(
+    """Wraps a request handler method with exception handling.
-    "response_count",
-    labels=["method", "servlet", "tag"],
-    alternative_names=(
-        # the following are all deprecated aliases for the same metric
-        metrics.name_prefix + x for x in (
-            "_requests",
-            "_response_time:count",
-            "_response_ru_utime:count",
-            "_response_ru_stime:count",
-            "_response_db_txn_count:count",
-            "_response_db_txn_duration:count",
-        )
-    )
-)
 
-requests_counter = metrics.register_counter(
+    Also adds logging as per wrap_request_handler_with_logging.
-    "requests_received",
-    labels=["method", "servlet", ],
-)
 
-outgoing_responses_counter = metrics.register_counter(
+    The handler method must have a signature of "handle_foo(self, request)",
-    "responses",
+    where "self" must have "version_string" and "clock" attributes (and
-    labels=["method", "code"],
+    "request" must be a SynapseRequest).
-)
 
-response_timer = metrics.register_counter(
+    The handler must return a deferred. If the deferred succeeds we assume that
-    "response_time_seconds",
-    labels=["method", "servlet", "tag"],
-    alternative_names=(
-        metrics.name_prefix + "_response_time:total",
-    ),
-)
-
-response_ru_utime = metrics.register_counter(
-    "response_ru_utime_seconds", labels=["method", "servlet", "tag"],
-    alternative_names=(
-        metrics.name_prefix + "_response_ru_utime:total",
-    ),
-)
-
-response_ru_stime = metrics.register_counter(
-    "response_ru_stime_seconds", labels=["method", "servlet", "tag"],
-    alternative_names=(
-        metrics.name_prefix + "_response_ru_stime:total",
-    ),
-)
-
-response_db_txn_count = metrics.register_counter(
-    "response_db_txn_count", labels=["method", "servlet", "tag"],
-    alternative_names=(
-        metrics.name_prefix + "_response_db_txn_count:total",
-    ),
-)
-
-# seconds spent waiting for db txns, excluding scheduling time, when processing
-# this request
-response_db_txn_duration = metrics.register_counter(
-    "response_db_txn_duration_seconds", labels=["method", "servlet", "tag"],
-    alternative_names=(
-        metrics.name_prefix + "_response_db_txn_duration:total",
-    ),
-)
-
-# seconds spent waiting for a db connection, when processing this request
-response_db_sched_duration = metrics.register_counter(
-    "response_db_sched_duration_seconds", labels=["method", "servlet", "tag"]
-)
-
-# size in bytes of the response written
-response_size = metrics.register_counter(
-    "response_size", labels=["method", "servlet", "tag"]
-)
-
-_next_request_id = 0
-
-
-def request_handler(include_metrics=False):
-    """Decorator for ``wrap_request_handler``"""
-    return lambda request_handler: wrap_request_handler(request_handler, include_metrics)
-
-
-def wrap_request_handler(request_handler, include_metrics=False):
-    """Wraps a method that acts as a request handler with the necessary logging
-    and exception handling.
-
-    The method must have a signature of "handle_foo(self, request)". The
-    argument "self" must have "version_string" and "clock" attributes. The
-    argument "request" must be a twisted HTTP request.
-
-    The method must return a deferred. If the deferred succeeds we assume that
     a response has been sent. If the deferred fails with a SynapseError we use
     it to send a JSON response with the appropriate HTTP reponse code. If the
     deferred fails with any other type of error we send a 500 reponse.
-
-    We insert a unique request-id into the logging context for this request and
-    log the response and duration for this request.
     """
 
     @defer.inlineCallbacks
     def wrapped_request_handler(self, request):
-        global _next_request_id
-        request_id = "%s-%s" % (request.method, _next_request_id)
-        _next_request_id += 1
-
-        with LoggingContext(request_id) as request_context:
-            with Measure(self.clock, "wrapped_request_handler"):
-                request_metrics = RequestMetrics()
-                # we start the request metrics timer here with an initial stab
-                # at the servlet name. For most requests that name will be
-                # JsonResource (or a subclass), and JsonResource._async_render
-                # will update it once it picks a servlet.
-                servlet_name = self.__class__.__name__
-                request_metrics.start(self.clock, name=servlet_name)
-
-                request_context.request = request_id
-                with request.processing():
         try:
-                        with PreserveLoggingContext(request_context):
+            yield h(self, request)
-                            if include_metrics:
-                                yield request_handler(self, request, request_metrics)
-                            else:
-                                requests_counter.inc(request.method, servlet_name)
-                                yield request_handler(self, request)
         except CodeMessageException as e:
             code = e.code
             if isinstance(e, SynapseError):
@@ -176,22 +72,20 @@ def wrap_request_handler(request_handler, include_metrics=False):
                 )
             else:
                 logger.exception(e)
-                        outgoing_responses_counter.inc(request.method, str(code))
             respond_with_json(
                 request, code, cs_exception(e), send_cors=True,
                 pretty_print=_request_user_agent_is_curl(request),
                 version_string=self.version_string,
             )
+
         except Exception:
             # failure.Failure() fishes the original Failure out
             # of our stack, and thus gives us a sensible stack
             # trace.
             f = failure.Failure()
             logger.error(
-                            "Failed handle request %s.%s on %r: %r: %s",
+                "Failed handle request via %r: %r: %s",
-                            request_handler.__module__,
+                h,
-                            request_handler.__name__,
-                            self,
                 request,
                 f.getTraceback().rstrip(),
             )
@@ -206,13 +100,49 @@ def wrap_request_handler(request_handler, include_metrics=False):
                 pretty_print=_request_user_agent_is_curl(request),
                 version_string=self.version_string,
             )
-                    finally:
+
-                        try:
+    return wrap_request_handler_with_logging(wrapped_request_handler)
-                            request_metrics.stop(
+
-                                self.clock, request
+
-                            )
+def wrap_request_handler_with_logging(h):
-                        except Exception as e:
+    """Wraps a request handler to provide logging and metrics
-                            logger.warn("Failed to stop metrics: %r", e)
+
+    The handler method must have a signature of "handle_foo(self, request)",
+    where "self" must have a "clock" attribute (and "request" must be a
+    SynapseRequest).
+
+    As well as calling `request.processing` (which will log the response and
+    duration for this request), the wrapped request handler will insert the
+    request id into the logging context.
+    """
+    @defer.inlineCallbacks
+    def wrapped_request_handler(self, request):
+        """
+        Args:
+            self:
+            request (synapse.http.site.SynapseRequest):
+        """
+
+        request_id = request.get_request_id()
+        with LoggingContext(request_id) as request_context:
+            request_context.request = request_id
+            with Measure(self.clock, "wrapped_request_handler"):
+                # we start the request metrics timer here with an initial stab
+                # at the servlet name. For most requests that name will be
+                # JsonResource (or a subclass), and JsonResource._async_render
+                # will update it once it picks a servlet.
+                servlet_name = self.__class__.__name__
+                with request.processing(servlet_name):
+                    with PreserveLoggingContext(request_context):
+                        d = h(self, request)
+
+                        # record the arrival of the request *after*
+                        # dispatching to the handler, so that the handler
+                        # can update the servlet name in the request
+                        # metrics
+                        requests_counter.inc(request.method,
+                                             request.request_metrics.name)
+                        yield d
     return wrapped_request_handler
 
 
@@ -278,13 +208,9 @@ class JsonResource(HttpServer, resource.Resource):
         self._async_render(request)
         return server.NOT_DONE_YET
 
-    # Disable metric reporting because _async_render does its own metrics.
+    @wrap_json_request_handler
-    # It does its own metric reporting because _async_render dispatches to
-    # a callback and it's the class name of that callback we want to report
-    # against rather than the JsonResource itself.
-    @request_handler(include_metrics=True)
     @defer.inlineCallbacks
-    def _async_render(self, request, request_metrics):
+    def _async_render(self, request):
         """ This gets called from render() every time someone sends us a request.
             This checks if anyone has registered a callback for that method and
             path.
@@ -296,9 +222,7 @@ class JsonResource(HttpServer, resource.Resource):
             servlet_classname = servlet_instance.__class__.__name__
         else:
             servlet_classname = "%r" % callback
-
+        request.request_metrics.name = servlet_classname
-        request_metrics.name = servlet_classname
-        requests_counter.inc(request.method, servlet_classname)
 
         # Now trigger the callback. If it returns a response, we send it
         # here. If it throws an exception, that is handled by the wrapper
@@ -345,8 +269,6 @@ class JsonResource(HttpServer, resource.Resource):
 
     def _send_response(self, request, code, response_json_object,
                        response_code_message=None):
-        outgoing_responses_counter.inc(request.method, str(code))
-
         # TODO: Only enable CORS for the requests that need it.
         respond_with_json(
             request, code, response_json_object,
@@ -386,54 +308,6 @@ def _unrecognised_request_handler(request):
     raise UnrecognizedRequestError()
 
 
-class RequestMetrics(object):
-    def start(self, clock, name):
-        self.start = clock.time_msec()
-        self.start_context = LoggingContext.current_context()
-        self.name = name
-
-    def stop(self, clock, request):
-        context = LoggingContext.current_context()
-
-        tag = ""
-        if context:
-            tag = context.tag
-
-            if context != self.start_context:
-                logger.warn(
-                    "Context have unexpectedly changed %r, %r",
-                    context, self.start_context
-                )
-                return
-
-        response_count.inc(request.method, self.name, tag)
-
-        response_timer.inc_by(
-            clock.time_msec() - self.start, request.method,
-            self.name, tag
-        )
-
-        ru_utime, ru_stime = context.get_resource_usage()
-
-        response_ru_utime.inc_by(
-            ru_utime, request.method, self.name, tag
-        )
-        response_ru_stime.inc_by(
-            ru_stime, request.method, self.name, tag
-        )
-        response_db_txn_count.inc_by(
-            context.db_txn_count, request.method, self.name, tag
-        )
-        response_db_txn_duration.inc_by(
-            context.db_txn_duration_ms / 1000., request.method, self.name, tag
-        )
-        response_db_sched_duration.inc_by(
-            context.db_sched_duration_ms / 1000., request.method, self.name, tag
-        )
-
-        response_size.inc_by(request.sentLength, request.method, self.name, tag)
-
-
 class RootRedirect(resource.Resource):
     """Redirects the root '/' path to another path."""
 

synapse/http/site.py

@@ -12,24 +12,48 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.util.logcontext import LoggingContext
-from twisted.web.server import Site, Request
-
 import contextlib
 import logging
 import re
 import time
 
+from twisted.web.server import Site, Request
+
+from synapse.http.request_metrics import RequestMetrics
+from synapse.util.logcontext import LoggingContext
+
+logger = logging.getLogger(__name__)
+
 ACCESS_TOKEN_RE = re.compile(br'(\?.*access(_|%5[Ff])token=)[^&]*(.*)$')
 
+_next_request_seq = 0
+
 
 class SynapseRequest(Request):
+    """Class which encapsulates an HTTP request to synapse.
+
+    All of the requests processed in synapse are of this type.
+
+    It extends twisted's twisted.web.server.Request, and adds:
+     * Unique request ID
+     * Redaction of access_token query-params in __repr__
+     * Logging at start and end
+     * Metrics to record CPU, wallclock and DB time by endpoint.
+
+    It provides a method `processing` which should be called by the Resource
+    which is handling the request, and returns a context manager.
+
+    """
     def __init__(self, site, *args, **kw):
         Request.__init__(self, *args, **kw)
         self.site = site
         self.authenticated_entity = None
         self.start_time = 0
 
+        global _next_request_seq
+        self.request_seq = _next_request_seq
+        _next_request_seq += 1
+
     def __repr__(self):
         # We overwrite this so that we don't log ``access_token``
         return '<%s at 0x%x method=%s uri=%s clientproto=%s site=%s>' % (
@@ -41,6 +65,9 @@ class SynapseRequest(Request):
             self.site.site_tag,
         )
 
+    def get_request_id(self):
+        return "%s-%i" % (self.method, self.request_seq)
+
     def get_redacted_uri(self):
         return ACCESS_TOKEN_RE.sub(
             br'\1<redacted>\3',
@@ -50,7 +77,11 @@ class SynapseRequest(Request):
     def get_user_agent(self):
         return self.requestHeaders.getRawHeaders(b"User-Agent", [None])[-1]
 
-    def started_processing(self):
+    def _started_processing(self, servlet_name):
+        self.start_time = int(time.time() * 1000)
+        self.request_metrics = RequestMetrics()
+        self.request_metrics.start(self.start_time, name=servlet_name)
+
         self.site.access_logger.info(
             "%s - %s - Received request: %s %s",
             self.getClientIP(),
@@ -58,10 +89,8 @@ class SynapseRequest(Request):
             self.method,
             self.get_redacted_uri()
         )
-        self.start_time = int(time.time() * 1000)
-
-    def finished_processing(self):
 
+    def _finished_processing(self):
         try:
             context = LoggingContext.current_context()
             ru_utime, ru_stime = context.get_resource_usage()
@@ -72,6 +101,8 @@ class SynapseRequest(Request):
             ru_utime, ru_stime = (0, 0)
             db_txn_count, db_txn_duration_ms = (0, 0)
 
+        end_time = int(time.time() * 1000)
+
         self.site.access_logger.info(
             "%s - %s - {%s}"
             " Processed request: %dms (%dms, %dms) (%dms/%dms/%d)"
@@ -79,7 +110,7 @@ class SynapseRequest(Request):
             self.getClientIP(),
             self.site.site_tag,
             self.authenticated_entity,
-            int(time.time() * 1000) - self.start_time,
+            end_time - self.start_time,
             int(ru_utime * 1000),
             int(ru_stime * 1000),
             db_sched_duration_ms,
@@ -93,11 +124,36 @@ class SynapseRequest(Request):
             self.get_user_agent(),
         )
 
+        try:
+            self.request_metrics.stop(end_time, self)
+        except Exception as e:
+            logger.warn("Failed to stop metrics: %r", e)
+
     @contextlib.contextmanager
-    def processing(self):
+    def processing(self, servlet_name):
-        self.started_processing()
+        """Record the fact that we are processing this request.
+
+        Returns a context manager; the correct way to use this is:
+
+        @defer.inlineCallbacks
+        def handle_request(request):
+            with request.processing("FooServlet"):
+                yield really_handle_the_request()
+
+        This will log the request's arrival. Once the context manager is
+        closed, the completion of the request will be logged, and the various
+        metrics will be updated.
+
+        Args:
+            servlet_name (str): the name of the servlet which will be
+                processing this request. This is used in the metrics.
+
+                It is possible to update this afterwards by updating
+                self.request_metrics.servlet_name.
+        """
+        self._started_processing(servlet_name)
         yield
-        self.finished_processing()
+        self._finished_processing()
 
 
 class XForwardedForRequest(SynapseRequest):

synapse/rest/key/v2/remote_key_resource.py

@@ -12,7 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.http.server import request_handler, respond_with_json_bytes
+from synapse.http.server import (
+    respond_with_json_bytes, wrap_json_request_handler,
+)
 from synapse.http.servlet import parse_integer, parse_json_object_from_request
 from synapse.api.errors import SynapseError, Codes
 from synapse.crypto.keyring import KeyLookupError
@@ -99,7 +101,7 @@ class RemoteKey(Resource):
         self.async_render_GET(request)
         return NOT_DONE_YET
 
-    @request_handler()
+    @wrap_json_request_handler
     @defer.inlineCallbacks
     def async_render_GET(self, request):
         if len(request.postpath) == 1:
@@ -124,7 +126,7 @@ class RemoteKey(Resource):
         self.async_render_POST(request)
         return NOT_DONE_YET
 
-    @request_handler()
+    @wrap_json_request_handler
     @defer.inlineCallbacks
     def async_render_POST(self, request):
         content = parse_json_object_from_request(request)

synapse/rest/media/v1/download_resource.py

@@ -12,17 +12,19 @@
 # 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.
-import synapse.http.servlet
-
-from ._base import parse_media_id, respond_404
-from twisted.web.resource import Resource
-from synapse.http.server import request_handler, set_cors_headers
-
-from twisted.web.server import NOT_DONE_YET
-from twisted.internet import defer
-
 import logging
 
+from twisted.internet import defer
+from twisted.web.resource import Resource
+from twisted.web.server import NOT_DONE_YET
+
+from synapse.http.server import (
+    set_cors_headers,
+    wrap_json_request_handler,
+)
+import synapse.http.servlet
+from ._base import parse_media_id, respond_404
+
 logger = logging.getLogger(__name__)
 
 
@@ -43,7 +45,7 @@ class DownloadResource(Resource):
         self._async_render_GET(request)
         return NOT_DONE_YET
 
-    @request_handler()
+    @wrap_json_request_handler
     @defer.inlineCallbacks
     def _async_render_GET(self, request):
         set_cors_headers(request)

synapse/rest/media/v1/preview_url_resource.py

@@ -40,8 +40,9 @@ from synapse.util.stringutils import random_string
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.http.client import SpiderHttpClient
 from synapse.http.server import (
-    request_handler, respond_with_json_bytes,
+    respond_with_json_bytes,
     respond_with_json,
+    wrap_json_request_handler,
 )
 from synapse.util.async import ObservableDeferred
 from synapse.util.stringutils import is_ascii
@@ -90,7 +91,7 @@ class PreviewUrlResource(Resource):
         self._async_render_GET(request)
         return NOT_DONE_YET
 
-    @request_handler()
+    @wrap_json_request_handler
     @defer.inlineCallbacks
     def _async_render_GET(self, request):
 

synapse/rest/media/v1/thumbnail_resource.py

@@ -14,18 +14,21 @@
 # limitations under the License.
 
 
+import logging
+
+from twisted.internet import defer
+from twisted.web.resource import Resource
+from twisted.web.server import NOT_DONE_YET
+
+from synapse.http.server import (
+    set_cors_headers,
+    wrap_json_request_handler,
+)
+from synapse.http.servlet import parse_integer, parse_string
 from ._base import (
-    parse_media_id, respond_404, respond_with_file, FileInfo,
+    FileInfo, parse_media_id, respond_404, respond_with_file,
     respond_with_responder,
 )
-from twisted.web.resource import Resource
-from synapse.http.servlet import parse_string, parse_integer
-from synapse.http.server import request_handler, set_cors_headers
-
-from twisted.web.server import NOT_DONE_YET
-from twisted.internet import defer
-
-import logging
 
 logger = logging.getLogger(__name__)
 
@@ -48,7 +51,7 @@ class ThumbnailResource(Resource):
         self._async_render_GET(request)
         return NOT_DONE_YET
 
-    @request_handler()
+    @wrap_json_request_handler
     @defer.inlineCallbacks
     def _async_render_GET(self, request):
         set_cors_headers(request)

synapse/rest/media/v1/upload_resource.py

@@ -13,16 +13,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.http.server import respond_with_json, request_handler
+import logging
+
+from twisted.internet import defer
+from twisted.web.resource import Resource
+from twisted.web.server import NOT_DONE_YET
 
 from synapse.api.errors import SynapseError
-
+from synapse.http.server import (
-from twisted.web.server import NOT_DONE_YET
+    respond_with_json,
-from twisted.internet import defer
+    wrap_json_request_handler,
-
+)
-from twisted.web.resource import Resource
-
-import logging
 
 logger = logging.getLogger(__name__)
 
@@ -51,7 +52,7 @@ class UploadResource(Resource):
         respond_with_json(request, 200, {}, send_cors=True)
         return NOT_DONE_YET
 
-    @request_handler()
+    @wrap_json_request_handler
     @defer.inlineCallbacks
     def _async_render_POST(self, request):
         requester = yield self.auth.get_user_by_req(request)