From dbe80a286b85f9427763344c260921745c2ca78d Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 9 Mar 2018 16:17:27 +0000 Subject: [PATCH 1/3] refactor JsonResource rephrase the OPTIONS and unrecognised request handling so that they look similar to the common flow. --- synapse/http/server.py | 84 ++++++++++++++++++++++++------------------ 1 file changed, 49 insertions(+), 35 deletions(-) diff --git a/synapse/http/server.py b/synapse/http/server.py index 165c684d0..d774476e5 100644 --- a/synapse/http/server.py +++ b/synapse/http/server.py @@ -1,5 +1,6 @@ # -*- 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. @@ -276,49 +277,54 @@ class JsonResource(HttpServer, resource.Resource): This checks if anyone has registered a callback for that method and path. """ + callback, group_dict = self._get_handler_for_request(request) + + servlet_instance = getattr(callback, "__self__", None) + if servlet_instance is not None: + servlet_classname = servlet_instance.__class__.__name__ + else: + servlet_classname = "%r" % callback + + request_metrics.name = 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 + # installed by @request_handler. + + kwargs = intern_dict({ + name: urllib.unquote(value).decode("UTF-8") if value else value + for name, value in group_dict.items() + }) + + callback_return = yield callback(request, **kwargs) + if callback_return is not None: + code, response = callback_return + self._send_response(request, code, response) + + def _get_handler_for_request(self, request): + """Finds a callback method to handle the given request + + Args: + request (twisted.web.http.Request): + + Returns: + Tuple[Callable, dict[str, str]]: callback method, and the dict + mapping keys to path components as specified in the handler's + path match regexp + """ if request.method == "OPTIONS": - self._send_response(request, 200, {}) - return + return _options_handler, {} # Loop through all the registered callbacks to check if the method # and path regex match for path_entry in self.path_regexs.get(request.method, []): m = path_entry.pattern.match(request.path) - if not m: - continue - - # We found a match! First update the metrics object to indicate - # which servlet is handling the request. - - callback = path_entry.callback - - servlet_instance = getattr(callback, "__self__", None) - if servlet_instance is not None: - servlet_classname = servlet_instance.__class__.__name__ - else: - servlet_classname = "%r" % callback - - request_metrics.name = 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 - # installed by @request_handler. - - kwargs = intern_dict({ - name: urllib.unquote(value).decode("UTF-8") if value else value - for name, value in m.groupdict().items() - }) - - callback_return = yield callback(request, **kwargs) - if callback_return is not None: - code, response = callback_return - self._send_response(request, code, response) - - return + if m: + # We found a match! + return path_entry.callback, m.groupdict() # Huh. No one wanted to handle that? Fiiiiiine. Send 400. - request_metrics.name = self.__class__.__name__ + ".UnrecognizedRequest" - raise UnrecognizedRequestError() + return _unrecognised_request_handler, {} def _send_response(self, request, code, response_json_object, response_code_message=None): @@ -335,6 +341,14 @@ class JsonResource(HttpServer, resource.Resource): ) +def _options_handler(request): + return {} + + +def _unrecognised_request_handler(request): + raise UnrecognizedRequestError() + + class RequestMetrics(object): def start(self, clock, name): self.start = clock.time_msec() From 88541f9009a7ca39c85cac7483d6a240ef497d33 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 9 Mar 2018 16:19:18 +0000 Subject: [PATCH 2/3] Add a metric which increments when a request is received It's useful to know when there are peaks in incoming requests - which isn't quite the same as there being peaks in outgoing responses, due to the time taken to handle requests. --- synapse/http/server.py | 12 ++++++++++-- synapse/metrics/__init__.py | 16 ++++++++++++++++ 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/synapse/http/server.py b/synapse/http/server.py index d774476e5..6c5d8bb55 100644 --- a/synapse/http/server.py +++ b/synapse/http/server.py @@ -60,6 +60,11 @@ response_count = metrics.register_counter( ) ) +requests_counter = metrics.register_counter( + "requests_received", + labels=["method", "servlet", ], +) + outgoing_responses_counter = metrics.register_counter( "responses", labels=["method", "code"], @@ -146,7 +151,8 @@ def wrap_request_handler(request_handler, include_metrics=False): # 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. - request_metrics.start(self.clock, name=self.__class__.__name__) + servlet_name = self.__class__.__name__ + request_metrics.start(self.clock, name=servlet_name) request_context.request = request_id with request.processing(): @@ -155,6 +161,7 @@ def wrap_request_handler(request_handler, include_metrics=False): 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 @@ -286,6 +293,7 @@ class JsonResource(HttpServer, resource.Resource): servlet_classname = "%r" % callback 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 @@ -342,7 +350,7 @@ class JsonResource(HttpServer, resource.Resource): def _options_handler(request): - return {} + return 200, {} def _unrecognised_request_handler(request): diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py index e0cfb7d08..50d99d7a5 100644 --- a/synapse/metrics/__init__.py +++ b/synapse/metrics/__init__.py @@ -57,15 +57,31 @@ class Metrics(object): return metric def register_counter(self, *args, **kwargs): + """ + Returns: + CounterMetric + """ return self._register(CounterMetric, *args, **kwargs) def register_callback(self, *args, **kwargs): + """ + Returns: + CallbackMetric + """ return self._register(CallbackMetric, *args, **kwargs) def register_distribution(self, *args, **kwargs): + """ + Returns: + DistributionMetric + """ return self._register(DistributionMetric, *args, **kwargs) def register_cache(self, *args, **kwargs): + """ + Returns: + CacheMetric + """ return self._register(CacheMetric, *args, **kwargs) From 58dd148c4f67e1cb6b150bf43a437b33089cfe5e Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Fri, 9 Mar 2018 18:05:41 +0000 Subject: [PATCH 3/3] Add some docstrings to help figure this out --- synapse/http/server.py | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/synapse/http/server.py b/synapse/http/server.py index 6c5d8bb55..4b567215c 100644 --- a/synapse/http/server.py +++ b/synapse/http/server.py @@ -237,7 +237,7 @@ class JsonResource(HttpServer, resource.Resource): """ This implements the HttpServer interface and provides JSON support for Resources. - Register callbacks via register_path() + Register callbacks via register_paths() Callbacks can return a tuple of status code and a dict in which case the the dict will automatically be sent to the client as a JSON object. @@ -318,7 +318,11 @@ class JsonResource(HttpServer, resource.Resource): Returns: Tuple[Callable, dict[str, str]]: callback method, and the dict mapping keys to path components as specified in the handler's - path match regexp + path match regexp. + + The callback will normally be a method registered via + register_paths, so will return (possibly via Deferred) either + None, or a tuple of (http code, response body). """ if request.method == "OPTIONS": return _options_handler, {} @@ -350,10 +354,30 @@ class JsonResource(HttpServer, resource.Resource): def _options_handler(request): + """Request handler for OPTIONS requests + + This is a request handler suitable for return from + _get_handler_for_request. It returns a 200 and an empty body. + + Args: + request (twisted.web.http.Request): + + Returns: + Tuple[int, dict]: http code, response body. + """ return 200, {} def _unrecognised_request_handler(request): + """Request handler for unrecognised requests + + This is a request handler suitable for return from + _get_handler_for_request. It actually just raises an + UnrecognizedRequestError. + + Args: + request (twisted.web.http.Request): + """ raise UnrecognizedRequestError()