Merge branch 'develop' into rav/hacky_cache_factor_fix

6 files changed, 320 insertions, 315 deletions

diff --git a/changelog.d/3948.misc b/changelog.d/3948.misc
new file mode 100644
index 0000000000..a93edbd1c3
--- /dev/null
+++ b/changelog.d/3948.misc
@@ -0,0 +1 @@
+Fix incompatibility with python3 on alpine
\ No newline at end of file
diff --git a/changelog.d/3956.bugfix b/changelog.d/3956.bugfix
new file mode 100644
index 0000000000..b0828c9fc6
--- /dev/null
+++ b/changelog.d/3956.bugfix
@@ -0,0 +1 @@
+Fix exceptions from metrics handler
\ No newline at end of file
diff --git a/synapse/app/synctl.py b/synapse/app/synctl.py
deleted file mode 100755
index 356e5cb6a7..0000000000
--- a/synapse/app/synctl.py
+++ /dev/null
@@ -1,294 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-# Copyright 2014-2016 OpenMarket 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 argparse
-import collections
-import errno
-import glob
-import os
-import os.path
-import signal
-import subprocess
-import sys
-import time
-
-from six import iteritems
-
-import yaml
-
-SYNAPSE = [sys.executable, "-B", "-m", "synapse.app.homeserver"]
-
-GREEN = "\x1b[1;32m"
-YELLOW = "\x1b[1;33m"
-RED = "\x1b[1;31m"
-NORMAL = "\x1b[m"
-
-
-def pid_running(pid):
-    try:
-        os.kill(pid, 0)
-        return True
-    except OSError as err:
-        if err.errno == errno.EPERM:
-            return True
-        return False
-
-
-def write(message, colour=NORMAL, stream=sys.stdout):
-    if colour == NORMAL:
-        stream.write(message + "\n")
-    else:
-        stream.write(colour + message + NORMAL + "\n")
-
-
-def abort(message, colour=RED, stream=sys.stderr):
-    write(message, colour, stream)
-    sys.exit(1)
-
-
-def start(configfile):
-    write("Starting ...")
-    args = SYNAPSE
-    args.extend(["--daemonize", "-c", configfile])
-
-    try:
-        subprocess.check_call(args)
-        write("started synapse.app.homeserver(%r)" %
-              (configfile,), colour=GREEN)
-    except subprocess.CalledProcessError as e:
-        write(
-            "error starting (exit code: %d); see above for logs" % e.returncode,
-            colour=RED,
-        )
-
-
-def start_worker(app, configfile, worker_configfile):
-    args = [
-        "python", "-B",
-        "-m", app,
-        "-c", configfile,
-        "-c", worker_configfile
-    ]
-
-    try:
-        subprocess.check_call(args)
-        write("started %s(%r)" % (app, worker_configfile), colour=GREEN)
-    except subprocess.CalledProcessError as e:
-        write(
-            "error starting %s(%r) (exit code: %d); see above for logs" % (
-                app, worker_configfile, e.returncode,
-            ),
-            colour=RED,
-        )
-
-
-def stop(pidfile, app):
-    if os.path.exists(pidfile):
-        pid = int(open(pidfile).read())
-        try:
-            os.kill(pid, signal.SIGTERM)
-            write("stopped %s" % (app,), colour=GREEN)
-        except OSError as err:
-            if err.errno == errno.ESRCH:
-                write("%s not running" % (app,), colour=YELLOW)
-            elif err.errno == errno.EPERM:
-                abort("Cannot stop %s: Operation not permitted" % (app,))
-            else:
-                abort("Cannot stop %s: Unknown error" % (app,))
-
-
-Worker = collections.namedtuple("Worker", [
-    "app", "configfile", "pidfile", "cache_factor", "cache_factors",
-])
-
-
-def main():
-
-    parser = argparse.ArgumentParser()
-
-    parser.add_argument(
-        "action",
-        choices=["start", "stop", "restart"],
-        help="whether to start, stop or restart the synapse",
-    )
-    parser.add_argument(
-        "configfile",
-        nargs="?",
-        default="homeserver.yaml",
-        help="the homeserver config file, defaults to homeserver.yaml",
-    )
-    parser.add_argument(
-        "-w", "--worker",
-        metavar="WORKERCONFIG",
-        help="start or stop a single worker",
-    )
-    parser.add_argument(
-        "-a", "--all-processes",
-        metavar="WORKERCONFIGDIR",
-        help="start or stop all the workers in the given directory"
-             " and the main synapse process",
-    )
-
-    options = parser.parse_args()
-
-    if options.worker and options.all_processes:
-        write(
-            'Cannot use "--worker" with "--all-processes"',
-            stream=sys.stderr
-        )
-        sys.exit(1)
-
-    configfile = options.configfile
-
-    if not os.path.exists(configfile):
-        write(
-            "No config file found\n"
-            "To generate a config file, run '%s -c %s --generate-config"
-            " --server-name=<server name>'\n" % (
-                " ".join(SYNAPSE), options.configfile
-            ),
-            stream=sys.stderr,
-        )
-        sys.exit(1)
-
-    with open(configfile) as stream:
-        config = yaml.load(stream)
-
-    pidfile = config["pid_file"]
-    cache_factor = config.get("synctl_cache_factor")
-    start_stop_synapse = True
-
-    if cache_factor:
-        os.environ["SYNAPSE_CACHE_FACTOR"] = str(cache_factor)
-
-    cache_factors = config.get("synctl_cache_factors", {})
-    for cache_name, factor in iteritems(cache_factors):
-        os.environ["SYNAPSE_CACHE_FACTOR_" + cache_name.upper()] = str(factor)
-
-    worker_configfiles = []
-    if options.worker:
-        start_stop_synapse = False
-        worker_configfile = options.worker
-        if not os.path.exists(worker_configfile):
-            write(
-                "No worker config found at %r" % (worker_configfile,),
-                stream=sys.stderr,
-            )
-            sys.exit(1)
-        worker_configfiles.append(worker_configfile)
-
-    if options.all_processes:
-        # To start the main synapse with -a you need to add a worker file
-        # with worker_app == "synapse.app.homeserver"
-        start_stop_synapse = False
-        worker_configdir = options.all_processes
-        if not os.path.isdir(worker_configdir):
-            write(
-                "No worker config directory found at %r" % (worker_configdir,),
-                stream=sys.stderr,
-            )
-            sys.exit(1)
-        worker_configfiles.extend(sorted(glob.glob(
-            os.path.join(worker_configdir, "*.yaml")
-        )))
-
-    workers = []
-    for worker_configfile in worker_configfiles:
-        with open(worker_configfile) as stream:
-            worker_config = yaml.load(stream)
-        worker_app = worker_config["worker_app"]
-        if worker_app == "synapse.app.homeserver":
-            # We need to special case all of this to pick up options that may
-            # be set in the main config file or in this worker config file.
-            worker_pidfile = (
-                worker_config.get("pid_file")
-                or pidfile
-            )
-            worker_cache_factor = worker_config.get("synctl_cache_factor") or cache_factor
-            worker_cache_factors = (
-                worker_config.get("synctl_cache_factors")
-                or cache_factors
-            )
-            daemonize = worker_config.get("daemonize") or config.get("daemonize")
-            assert daemonize, "Main process must have daemonize set to true"
-
-            # The master process doesn't support using worker_* config.
-            for key in worker_config:
-                if key == "worker_app":  # But we allow worker_app
-                    continue
-                assert not key.startswith("worker_"), \
-                    "Main process cannot use worker_* config"
-        else:
-            worker_pidfile = worker_config["worker_pid_file"]
-            worker_daemonize = worker_config["worker_daemonize"]
-            assert worker_daemonize, "In config %r: expected '%s' to be True" % (
-                worker_configfile, "worker_daemonize")
-            worker_cache_factor = worker_config.get("synctl_cache_factor")
-            worker_cache_factors = worker_config.get("synctl_cache_factors", {})
-        workers.append(Worker(
-            worker_app, worker_configfile, worker_pidfile, worker_cache_factor,
-            worker_cache_factors,
-        ))
-
-    action = options.action
-
-    if action == "stop" or action == "restart":
-        for worker in workers:
-            stop(worker.pidfile, worker.app)
-
-        if start_stop_synapse:
-            stop(pidfile, "synapse.app.homeserver")
-
-    # Wait for synapse to actually shutdown before starting it again
-    if action == "restart":
-        running_pids = []
-        if start_stop_synapse and os.path.exists(pidfile):
-            running_pids.append(int(open(pidfile).read()))
-        for worker in workers:
-            if os.path.exists(worker.pidfile):
-                running_pids.append(int(open(worker.pidfile).read()))
-        if len(running_pids) > 0:
-            write("Waiting for process to exit before restarting...")
-            for running_pid in running_pids:
-                while pid_running(running_pid):
-                    time.sleep(0.2)
-            write("All processes exited; now restarting...")
-
-    if action == "start" or action == "restart":
-        if start_stop_synapse:
-            # Check if synapse is already running
-            if os.path.exists(pidfile) and pid_running(int(open(pidfile).read())):
-                abort("synapse.app.homeserver already running")
-            start(configfile)
-
-        for worker in workers:
-            env = os.environ.copy()
-
-            if worker.cache_factor:
-                os.environ["SYNAPSE_CACHE_FACTOR"] = str(worker.cache_factor)
-
-            for cache_name, factor in worker.cache_factors.iteritems():
-                os.environ["SYNAPSE_CACHE_FACTOR_" + cache_name.upper()] = str(factor)
-
-            start_worker(worker.app, configfile, worker.configfile)
-
-            # Reset env back to the original
-            os.environ.clear()
-            os.environ.update(env)
-
-
-if __name__ == "__main__":
-    main()
diff --git a/synapse/util/caches/__init__.py b/synapse/util/caches/__init__.py
index 7b065b195e..f37d5bec08 100644
--- a/synapse/util/caches/__init__.py
+++ b/synapse/util/caches/__init__.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import logging
 import os
 
 import six
@@ -20,6 +21,8 @@ from six.moves import intern
 
 from prometheus_client.core import REGISTRY, Gauge, GaugeMetricFamily
 
+logger = logging.getLogger(__name__)
+
 CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.5))
 
 
@@ -76,16 +79,20 @@ def register_cache(cache_type, cache_name, cache):
             return []
 
         def collect(self):
-            if cache_type == "response_cache":
-                response_cache_size.labels(cache_name).set(len(cache))
-                response_cache_hits.labels(cache_name).set(self.hits)
-                response_cache_evicted.labels(cache_name).set(self.evicted_size)
-                response_cache_total.labels(cache_name).set(self.hits + self.misses)
-            else:
-                cache_size.labels(cache_name).set(len(cache))
-                cache_hits.labels(cache_name).set(self.hits)
-                cache_evicted.labels(cache_name).set(self.evicted_size)
-                cache_total.labels(cache_name).set(self.hits + self.misses)
+            try:
+                if cache_type == "response_cache":
+                    response_cache_size.labels(cache_name).set(len(cache))
+                    response_cache_hits.labels(cache_name).set(self.hits)
+                    response_cache_evicted.labels(cache_name).set(self.evicted_size)
+                    response_cache_total.labels(cache_name).set(self.hits + self.misses)
+                else:
+                    cache_size.labels(cache_name).set(len(cache))
+                    cache_hits.labels(cache_name).set(self.hits)
+                    cache_evicted.labels(cache_name).set(self.evicted_size)
+                    cache_total.labels(cache_name).set(self.hits + self.misses)
+            except Exception as e:
+                logger.warn("Error calculating metrics for %s: %s", cache_name, e)
+                raise
 
             yield GaugeMetricFamily("__unused", "")
 
diff --git a/synapse/util/caches/expiringcache.py b/synapse/util/caches/expiringcache.py
index 921a9c5b29..9af4ec4aa8 100644
--- a/synapse/util/caches/expiringcache.py
+++ b/synapse/util/caches/expiringcache.py
@@ -16,6 +16,8 @@
 import logging
 from collections import OrderedDict
 
+from six import itervalues
+
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.util.caches import register_cache
 
@@ -54,8 +56,6 @@ class ExpiringCache(object):
 
         self.iterable = iterable
 
-        self._size_estimate = 0
-
         self.metrics = register_cache("expiring", cache_name, self)
 
         if not self._expiry_ms:
@@ -74,16 +74,11 @@ class ExpiringCache(object):
         now = self._clock.time_msec()
         self._cache[key] = _CacheEntry(now, value)
 
-        if self.iterable:
-            self._size_estimate += len(value)
-
         # Evict if there are now too many items
         while self._max_len and len(self) > self._max_len:
             _key, value = self._cache.popitem(last=False)
             if self.iterable:
-                removed_len = len(value.value)
-                self.metrics.inc_evictions(removed_len)
-                self._size_estimate -= removed_len
+                self.metrics.inc_evictions(len(value.value))
             else:
                 self.metrics.inc_evictions()
 
@@ -134,7 +129,9 @@ class ExpiringCache(object):
         for k in keys_to_delete:
             value = self._cache.pop(k)
             if self.iterable:
-                self._size_estimate -= len(value.value)
+                self.metrics.inc_evictions(len(value.value))
+            else:
+                self.metrics.inc_evictions()
 
         logger.debug(
             "[%s] _prune_cache before: %d, after len: %d",
@@ -143,7 +140,7 @@ class ExpiringCache(object):
 
     def __len__(self):
         if self.iterable:
-            return self._size_estimate
+            return sum(len(entry.value) for entry in itervalues(self._cache))
         else:
             return len(self._cache)
 
diff --git a/synctl b/synctl
index 1bdceda20a..356e5cb6a7 120000..100755
--- a/synctl
+++ b/synctl
@@ -1 +1,294 @@
-./synapse/app/synctl.py
\ No newline at end of file
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket 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 argparse
+import collections
+import errno
+import glob
+import os
+import os.path
+import signal
+import subprocess
+import sys
+import time
+
+from six import iteritems
+
+import yaml
+
+SYNAPSE = [sys.executable, "-B", "-m", "synapse.app.homeserver"]
+
+GREEN = "\x1b[1;32m"
+YELLOW = "\x1b[1;33m"
+RED = "\x1b[1;31m"
+NORMAL = "\x1b[m"
+
+
+def pid_running(pid):
+    try:
+        os.kill(pid, 0)
+        return True
+    except OSError as err:
+        if err.errno == errno.EPERM:
+            return True
+        return False
+
+
+def write(message, colour=NORMAL, stream=sys.stdout):
+    if colour == NORMAL:
+        stream.write(message + "\n")
+    else:
+        stream.write(colour + message + NORMAL + "\n")
+
+
+def abort(message, colour=RED, stream=sys.stderr):
+    write(message, colour, stream)
+    sys.exit(1)
+
+
+def start(configfile):
+    write("Starting ...")
+    args = SYNAPSE
+    args.extend(["--daemonize", "-c", configfile])
+
+    try:
+        subprocess.check_call(args)
+        write("started synapse.app.homeserver(%r)" %
+              (configfile,), colour=GREEN)
+    except subprocess.CalledProcessError as e:
+        write(
+            "error starting (exit code: %d); see above for logs" % e.returncode,
+            colour=RED,
+        )
+
+
+def start_worker(app, configfile, worker_configfile):
+    args = [
+        "python", "-B",
+        "-m", app,
+        "-c", configfile,
+        "-c", worker_configfile
+    ]
+
+    try:
+        subprocess.check_call(args)
+        write("started %s(%r)" % (app, worker_configfile), colour=GREEN)
+    except subprocess.CalledProcessError as e:
+        write(
+            "error starting %s(%r) (exit code: %d); see above for logs" % (
+                app, worker_configfile, e.returncode,
+            ),
+            colour=RED,
+        )
+
+
+def stop(pidfile, app):
+    if os.path.exists(pidfile):
+        pid = int(open(pidfile).read())
+        try:
+            os.kill(pid, signal.SIGTERM)
+            write("stopped %s" % (app,), colour=GREEN)
+        except OSError as err:
+            if err.errno == errno.ESRCH:
+                write("%s not running" % (app,), colour=YELLOW)
+            elif err.errno == errno.EPERM:
+                abort("Cannot stop %s: Operation not permitted" % (app,))
+            else:
+                abort("Cannot stop %s: Unknown error" % (app,))
+
+
+Worker = collections.namedtuple("Worker", [
+    "app", "configfile", "pidfile", "cache_factor", "cache_factors",
+])
+
+
+def main():
+
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        "action",
+        choices=["start", "stop", "restart"],
+        help="whether to start, stop or restart the synapse",
+    )
+    parser.add_argument(
+        "configfile",
+        nargs="?",
+        default="homeserver.yaml",
+        help="the homeserver config file, defaults to homeserver.yaml",
+    )
+    parser.add_argument(
+        "-w", "--worker",
+        metavar="WORKERCONFIG",
+        help="start or stop a single worker",
+    )
+    parser.add_argument(
+        "-a", "--all-processes",
+        metavar="WORKERCONFIGDIR",
+        help="start or stop all the workers in the given directory"
+             " and the main synapse process",
+    )
+
+    options = parser.parse_args()
+
+    if options.worker and options.all_processes:
+        write(
+            'Cannot use "--worker" with "--all-processes"',
+            stream=sys.stderr
+        )
+        sys.exit(1)
+
+    configfile = options.configfile
+
+    if not os.path.exists(configfile):
+        write(
+            "No config file found\n"
+            "To generate a config file, run '%s -c %s --generate-config"
+            " --server-name=<server name>'\n" % (
+                " ".join(SYNAPSE), options.configfile
+            ),
+            stream=sys.stderr,
+        )
+        sys.exit(1)
+
+    with open(configfile) as stream:
+        config = yaml.load(stream)
+
+    pidfile = config["pid_file"]
+    cache_factor = config.get("synctl_cache_factor")
+    start_stop_synapse = True
+
+    if cache_factor:
+        os.environ["SYNAPSE_CACHE_FACTOR"] = str(cache_factor)
+
+    cache_factors = config.get("synctl_cache_factors", {})
+    for cache_name, factor in iteritems(cache_factors):
+        os.environ["SYNAPSE_CACHE_FACTOR_" + cache_name.upper()] = str(factor)
+
+    worker_configfiles = []
+    if options.worker:
+        start_stop_synapse = False
+        worker_configfile = options.worker
+        if not os.path.exists(worker_configfile):
+            write(
+                "No worker config found at %r" % (worker_configfile,),
+                stream=sys.stderr,
+            )
+            sys.exit(1)
+        worker_configfiles.append(worker_configfile)
+
+    if options.all_processes:
+        # To start the main synapse with -a you need to add a worker file
+        # with worker_app == "synapse.app.homeserver"
+        start_stop_synapse = False
+        worker_configdir = options.all_processes
+        if not os.path.isdir(worker_configdir):
+            write(
+                "No worker config directory found at %r" % (worker_configdir,),
+                stream=sys.stderr,
+            )
+            sys.exit(1)
+        worker_configfiles.extend(sorted(glob.glob(
+            os.path.join(worker_configdir, "*.yaml")
+        )))
+
+    workers = []
+    for worker_configfile in worker_configfiles:
+        with open(worker_configfile) as stream:
+            worker_config = yaml.load(stream)
+        worker_app = worker_config["worker_app"]
+        if worker_app == "synapse.app.homeserver":
+            # We need to special case all of this to pick up options that may
+            # be set in the main config file or in this worker config file.
+            worker_pidfile = (
+                worker_config.get("pid_file")
+                or pidfile
+            )
+            worker_cache_factor = worker_config.get("synctl_cache_factor") or cache_factor
+            worker_cache_factors = (
+                worker_config.get("synctl_cache_factors")
+                or cache_factors
+            )
+            daemonize = worker_config.get("daemonize") or config.get("daemonize")
+            assert daemonize, "Main process must have daemonize set to true"
+
+            # The master process doesn't support using worker_* config.
+            for key in worker_config:
+                if key == "worker_app":  # But we allow worker_app
+                    continue
+                assert not key.startswith("worker_"), \
+                    "Main process cannot use worker_* config"
+        else:
+            worker_pidfile = worker_config["worker_pid_file"]
+            worker_daemonize = worker_config["worker_daemonize"]
+            assert worker_daemonize, "In config %r: expected '%s' to be True" % (
+                worker_configfile, "worker_daemonize")
+            worker_cache_factor = worker_config.get("synctl_cache_factor")
+            worker_cache_factors = worker_config.get("synctl_cache_factors", {})
+        workers.append(Worker(
+            worker_app, worker_configfile, worker_pidfile, worker_cache_factor,
+            worker_cache_factors,
+        ))
+
+    action = options.action
+
+    if action == "stop" or action == "restart":
+        for worker in workers:
+            stop(worker.pidfile, worker.app)
+
+        if start_stop_synapse:
+            stop(pidfile, "synapse.app.homeserver")
+
+    # Wait for synapse to actually shutdown before starting it again
+    if action == "restart":
+        running_pids = []
+        if start_stop_synapse and os.path.exists(pidfile):
+            running_pids.append(int(open(pidfile).read()))
+        for worker in workers:
+            if os.path.exists(worker.pidfile):
+                running_pids.append(int(open(worker.pidfile).read()))
+        if len(running_pids) > 0:
+            write("Waiting for process to exit before restarting...")
+            for running_pid in running_pids:
+                while pid_running(running_pid):
+                    time.sleep(0.2)
+            write("All processes exited; now restarting...")
+
+    if action == "start" or action == "restart":
+        if start_stop_synapse:
+            # Check if synapse is already running
+            if os.path.exists(pidfile) and pid_running(int(open(pidfile).read())):
+                abort("synapse.app.homeserver already running")
+            start(configfile)
+
+        for worker in workers:
+            env = os.environ.copy()
+
+            if worker.cache_factor:
+                os.environ["SYNAPSE_CACHE_FACTOR"] = str(worker.cache_factor)
+
+            for cache_name, factor in worker.cache_factors.iteritems():
+                os.environ["SYNAPSE_CACHE_FACTOR_" + cache_name.upper()] = str(factor)
+
+            start_worker(worker.app, configfile, worker.configfile)
+
+            # Reset env back to the original
+            os.environ.clear()
+            os.environ.update(env)
+
+
+if __name__ == "__main__":
+    main()