Move RequestsMetrics to its own file

This is useful in its own right, because server.py is full of stuff; but more
importantly, I want to do some refactoring that will cause a circular reference
as it is.

1 files changed, 147 insertions, 0 deletions

diff --git a/synapse/http/request_metrics.py b/synapse/http/request_metrics.py
new file mode 100644
index 0000000000..4a843a36a7
--- /dev/null
+++ b/synapse/http/request_metrics.py
@@ -0,0 +1,147 @@
+# -*- 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, 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)