Merge branch 'release-v1.12.4' of github.com:matrix-org/synapse into anoa/temp_working_cache_config

* 'release-v1.12.4' of github.com:matrix-org/synapse: (123 commits)
  1.12.4
  formatting for the changelog
  1.12.4rc1
  1.12.4rc1
  Do not treat display names as globs for push rules. (#7271)
  Query missing cross-signing keys on local sig upload (#7289)
  Fix changelog file
  Support GET account_data requests on a worker (#7311)
  Revert "Query missing cross-signing keys on local sig upload"
  Always send the user updates to their own device list (#7160)
  Query missing cross-signing keys on local sig upload
  Only register devices edu handler on the master process (#7255)
  tweak changelog
  1.12.3
  Fix the debian build in a better way. (#7212)
  Fix changelog wording
  1.12.2
  Pin Pillow>=4.3.0,<7.1.0 to fix dep issue
  1.12.1
  Note where bugs were introduced
  ...

changelog.d/6391.feature

@@ -0,0 +1 @@
+Synapse's cache factor can now be configured in `homeserver.yaml` by the `caches.global_factor` setting. Additionally, `caches.per_cache_factors` controls the cache factors for individual caches.

changelog.d/6446.misc

@@ -0,0 +1 @@
+Add benchmarks for LruCache.

synapse/api/auth.py

@@ -38,7 +38,7 @@ from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.config.server import is_threepid_reserved
 from synapse.events import EventBase
 from synapse.types import StateMap, UserID
-from synapse.util.caches import CACHE_SIZE_FACTOR, register_cache
+from synapse.util.caches import register_cache
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.metrics import Measure
 
@@ -74,7 +74,7 @@ class Auth(object):
         self.store = hs.get_datastore()
         self.state = hs.get_state_handler()
 
-        self.token_cache = LruCache(CACHE_SIZE_FACTOR * 10000)
+        self.token_cache = LruCache(10000)
         register_cache("cache", "token_cache", self.token_cache)
 
         self._account_validity = hs.config.account_validity

synapse/app/homeserver.py

@@ -69,7 +69,6 @@ from synapse.server import HomeServer
 from synapse.storage import DataStore
 from synapse.storage.engines import IncorrectDatabaseSetup
 from synapse.storage.prepare_database import UpgradeDatabaseException
-from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.manhole import manhole
 from synapse.util.module_loader import load_module
@@ -488,8 +487,8 @@ def phone_stats_home(hs, stats, stats_process=_stats_process):
 
     daily_sent_messages = yield hs.get_datastore().count_daily_sent_messages()
     stats["daily_sent_messages"] = daily_sent_messages
-    stats["cache_factor"] = CACHE_SIZE_FACTOR
-    stats["event_cache_size"] = hs.config.event_cache_size
+    stats["cache_factor"] = hs.config.caches.global_factor
+    stats["event_cache_size"] = hs.config.caches.event_cache_size
 
     #
     # Performance statistics

synapse/config/cache.py

@@ -0,0 +1,112 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 Matrix.org Foundation C.I.C.
+#
+# 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 os
+from typing import Dict
+
+from ._base import Config, ConfigError
+
+_CACHES = {}
+_CACHE_PREFIX = "SYNAPSE_CACHE_FACTOR"
+DEFAULT_CACHE_SIZE_FACTOR = float(os.environ.get(_CACHE_PREFIX, 0.5))
+
+_DEFAULT_CONFIG = """\
+# Cache configuration
+#
+# 'global_factor' controls the global cache factor. This overrides the
+# "SYNAPSE_CACHE_FACTOR" environment variable.
+#
+# 'per_cache_factors' is a dictionary of cache name to cache factor for that
+# individual cache.
+#
+#caches:
+#  global_factor: 0.5
+#  per_cache_factors:
+#    get_users_who_share_room_with_user: 2
+#
+"""
+
+# Callback to ensure that all caches are the correct size, registered when the
+# configuration has been loaded.
+_ENSURE_CORRECT_CACHE_SIZING = None
+
+
+def add_resizable_cache(cache_name, cache_resize_callback):
+    _CACHES[cache_name.lower()] = cache_resize_callback
+    if _ENSURE_CORRECT_CACHE_SIZING:
+        _ENSURE_CORRECT_CACHE_SIZING()
+
+
+class CacheConfig(Config):
+    section = "caches"
+    _environ = os.environ
+
+    @staticmethod
+    def _reset():
+        global DEFAULT_CACHE_SIZE_FACTOR
+        global _ENSURE_CORRECT_CACHE_SIZING
+
+        DEFAULT_CACHE_SIZE_FACTOR = float(os.environ.get(_CACHE_PREFIX, 0.5))
+        _ENSURE_CORRECT_CACHE_SIZING = None
+        _CACHES.clear()
+
+    def read_config(self, config, **kwargs):
+        self.event_cache_size = self.parse_size(config.get("event_cache_size", "10K"))
+
+        global DEFAULT_CACHE_SIZE_FACTOR
+        global _ENSURE_CORRECT_CACHE_SIZING
+
+        cache_config = config.get("caches", {})
+
+        self.global_factor = cache_config.get(
+            "global_factor", DEFAULT_CACHE_SIZE_FACTOR
+        )
+        if not isinstance(self.global_factor, (int, float)):
+            raise ConfigError("caches.global_factor must be a number.")
+
+        # Set the global one so that it's reflected in new caches
+        DEFAULT_CACHE_SIZE_FACTOR = self.global_factor
+
+        # Load cache factors from the environment, but override them with the
+        # ones in the config file if they exist
+        individual_factors = {
+            key[len(_CACHE_PREFIX) + 1 :].lower(): float(val)
+            for key, val in self._environ.items()
+            if key.startswith(_CACHE_PREFIX + "_")
+        }
+
+        individual_factors_config = cache_config.get("per_cache_factors", {}) or {}
+        if not isinstance(individual_factors_config, dict):
+            raise ConfigError("caches.per_cache_factors must be a dictionary")
+
+        individual_factors.update(individual_factors_config)
+
+        self.cache_factors = dict()  # type: Dict[str, float]
+
+        for cache, factor in individual_factors.items():
+            if not isinstance(factor, (int, float)):
+                raise ConfigError(
+                    "caches.per_cache_factors.%s must be a number" % (cache.lower(),)
+                )
+            self.cache_factors[cache.lower()] = factor
+
+        # Register the global callback so that the individual cache sizes get set.
+        def ensure_cache_sizes():
+            for cache_name, callback in _CACHES.items():
+                new_factor = self.cache_factors.get(cache_name, self.global_factor)
+                callback(new_factor)
+
+        _ENSURE_CORRECT_CACHE_SIZING = ensure_cache_sizes
+        _ENSURE_CORRECT_CACHE_SIZING()

synapse/config/database.py

@@ -57,8 +57,6 @@ class DatabaseConfig(Config):
     section = "database"
 
     def read_config(self, config, **kwargs):
-        self.event_cache_size = self.parse_size(config.get("event_cache_size", "10K"))
-
         # We *experimentally* support specifying multiple databases via the
         # `databases` key. This is a map from a label to database config in the
         # same format as the `database` config option, plus an extra

synapse/config/homeserver.py

@@ -17,6 +17,7 @@
 from ._base import RootConfig
 from .api import ApiConfig
 from .appservice import AppServiceConfig
+from .cache import CacheConfig
 from .captcha import CaptchaConfig
 from .cas import CasConfig
 from .consent_config import ConsentConfig
@@ -82,4 +83,5 @@ class HomeServerConfig(RootConfig):
         RoomDirectoryConfig,
         ThirdPartyRulesConfig,
         TracerConfig,
+        CacheConfig,
     ]

synapse/http/client.py

@@ -49,7 +49,6 @@ from synapse.http.proxyagent import ProxyAgent
 from synapse.logging.context import make_deferred_yieldable
 from synapse.logging.opentracing import set_tag, start_active_span, tags
 from synapse.util.async_helpers import timeout_deferred
-from synapse.util.caches import CACHE_SIZE_FACTOR
 
 logger = logging.getLogger(__name__)
 
@@ -241,7 +240,8 @@ class SimpleHttpClient(object):
         # tends to do so in batches, so we need to allow the pool to keep
         # lots of idle connections around.
         pool = HTTPConnectionPool(self.reactor)
-        pool.maxPersistentPerHost = max((100 * CACHE_SIZE_FACTOR, 5))
+        # XXX: Why does this use the cache factor????
+        pool.maxPersistentPerHost = max((100 * hs.config.caches.global_factor, 5))
         pool.cachedConnectionTimeout = 2 * 60
 
         self.agent = ProxyAgent(

synapse/metrics/_exposition.py

@@ -33,6 +33,8 @@ from prometheus_client import REGISTRY
 
 from twisted.web.resource import Resource
 
+from synapse.util import caches
+
 try:
     from prometheus_client.samples import Sample
 except ImportError:
@@ -103,13 +105,15 @@ def nameify_sample(sample):
 
 
 def generate_latest(registry, emit_help=False):
+
+    # Trigger the cache metrics to be rescraped, which updates the common
+    # metrics but do not produce metrics themselves
+    for collector in caches.collectors_by_name.values():
+        collector.collect()
+
     output = []
 
     for metric in registry.collect():
-
-        if metric.name.startswith("__unused"):
-            continue
-
         if not metric.samples:
             # No samples, don't bother.
             continue

synapse/push/bulk_push_rule_evaluator.py

@@ -51,6 +51,7 @@ push_rules_delta_state_cache_metric = register_cache(
     "cache",
     "push_rules_delta_state_cache_metric",
     cache=[],  # Meaningless size, as this isn't a cache that stores values
+    resizable=False,
 )
 
 
@@ -67,7 +68,8 @@ class BulkPushRuleEvaluator(object):
         self.room_push_rule_cache_metrics = register_cache(
             "cache",
             "room_push_rule_cache",
-            cache=[],  # Meaningless size, as this isn't a cache that stores values
+            cache=[],  # Meaningless size, as this isn't a cache that stores values,
+            resizable=False,
         )
 
     @defer.inlineCallbacks

synapse/push/push_rule_evaluator.py

@@ -22,7 +22,7 @@ from six import string_types
 
 from synapse.events import EventBase
 from synapse.types import UserID
-from synapse.util.caches import CACHE_SIZE_FACTOR, register_cache
+from synapse.util.caches import register_cache
 from synapse.util.caches.lrucache import LruCache
 
 logger = logging.getLogger(__name__)
@@ -165,7 +165,7 @@ class PushRuleEvaluatorForEvent(object):
 
 
 # Caches (string, is_glob, word_boundary) -> regex for push. See _glob_matches
-regex_cache = LruCache(50000 * CACHE_SIZE_FACTOR)
+regex_cache = LruCache(50000)
 register_cache("cache", "regex_push_cache", regex_cache)
 
 

synapse/replication/slave/storage/client_ips.py

@@ -15,7 +15,6 @@
 
 from synapse.storage.data_stores.main.client_ips import LAST_SEEN_GRANULARITY
 from synapse.storage.database import Database
-from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.caches.descriptors import Cache
 
 from ._base import BaseSlavedStore
@@ -26,7 +25,7 @@ class SlavedClientIpStore(BaseSlavedStore):
         super(SlavedClientIpStore, self).__init__(database, db_conn, hs)
 
         self.client_ip_last_seen = Cache(
-            name="client_ip_last_seen", keylen=4, max_entries=50000 * CACHE_SIZE_FACTOR
+            name="client_ip_last_seen", keylen=4, max_entries=50000
         )
 
     def insert_client_ip(self, user_id, access_token, ip, user_agent, device_id):

synapse/state/__init__.py

@@ -35,7 +35,6 @@ from synapse.state import v1, v2
 from synapse.storage.data_stores.main.events_worker import EventRedactBehaviour
 from synapse.types import StateMap
 from synapse.util.async_helpers import Linearizer
-from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.metrics import Measure, measure_func
 
@@ -53,7 +52,6 @@ state_groups_histogram = Histogram(
 KeyStateTuple = namedtuple("KeyStateTuple", ("context", "type", "state_key"))
 
 
-SIZE_OF_CACHE = 100000 * get_cache_factor_for("state_cache")
 EVICTION_TIMEOUT_SECONDS = 60 * 60
 
 
@@ -447,7 +445,7 @@ class StateResolutionHandler(object):
         self._state_cache = ExpiringCache(
             cache_name="state_cache",
             clock=self.clock,
-            max_len=SIZE_OF_CACHE,
+            max_len=100000,
             expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
             iterable=True,
             reset_expiry_on_get=True,

synapse/storage/data_stores/main/client_ips.py

@@ -22,7 +22,6 @@ from twisted.internet import defer
 from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import Database
-from synapse.util.caches import CACHE_SIZE_FACTOR
 from synapse.util.caches.descriptors import Cache
 
 logger = logging.getLogger(__name__)
@@ -367,7 +366,7 @@ class ClientIpStore(ClientIpBackgroundUpdateStore):
     def __init__(self, database: Database, db_conn, hs):
 
         self.client_ip_last_seen = Cache(
-            name="client_ip_last_seen", keylen=4, max_entries=50000 * CACHE_SIZE_FACTOR
+            name="client_ip_last_seen", keylen=4, max_entries=50000
         )
 
         super(ClientIpStore, self).__init__(database, db_conn, hs)

synapse/storage/data_stores/main/events_worker.py

@@ -75,7 +75,7 @@ class EventsWorkerStore(SQLBaseStore):
         super(EventsWorkerStore, self).__init__(database, db_conn, hs)
 
         self._get_event_cache = Cache(
-            "*getEvent*", keylen=3, max_entries=hs.config.event_cache_size
+            "*getEvent*", keylen=3, max_entries=hs.config.caches.event_cache_size
         )
 
         self._event_fetch_lock = threading.Condition()

synapse/storage/data_stores/state/store.py

@@ -28,7 +28,6 @@ from synapse.storage.data_stores.state.bg_updates import StateBackgroundUpdateSt
 from synapse.storage.database import Database
 from synapse.storage.state import StateFilter
 from synapse.types import StateMap
-from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.descriptors import cached
 from synapse.util.caches.dictionary_cache import DictionaryCache
 
@@ -90,11 +89,10 @@ class StateGroupDataStore(StateBackgroundUpdateStore, SQLBaseStore):
         self._state_group_cache = DictionaryCache(
             "*stateGroupCache*",
             # TODO: this hasn't been tuned yet
-            50000 * get_cache_factor_for("stateGroupCache"),
+            50000,
         )
         self._state_group_members_cache = DictionaryCache(
-            "*stateGroupMembersCache*",
-            500000 * get_cache_factor_for("stateGroupMembersCache"),
+            "*stateGroupMembersCache*", 500000,
         )
 
     @cached(max_entries=10000, iterable=True)

synapse/util/caches/__init__.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2015, 2016 OpenMarket Ltd
-# Copyright 2019 The Matrix.org Foundation C.I.C.
+# Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,28 +15,18 @@
 # limitations under the License.
 
 import logging
-import os
-from typing import Dict
+from typing import Callable, Dict, Optional
 
 import six
 from six.moves import intern
 
-from prometheus_client.core import REGISTRY, Gauge, GaugeMetricFamily
+import attr
+from prometheus_client.core import Gauge
+
+from synapse.config.cache import add_resizable_cache
 
 logger = logging.getLogger(__name__)
 
-CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.5))
-
-
-def get_cache_factor_for(cache_name):
-    env_var = "SYNAPSE_CACHE_FACTOR_" + cache_name.upper()
-    factor = os.environ.get(env_var)
-    if factor:
-        return float(factor)
-
-    return CACHE_SIZE_FACTOR
-
-
 caches_by_name = {}
 collectors_by_name = {}  # type: Dict
 
@@ -44,6 +34,7 @@ cache_size = Gauge("synapse_util_caches_cache:size", "", ["name"])
 cache_hits = Gauge("synapse_util_caches_cache:hits", "", ["name"])
 cache_evicted = Gauge("synapse_util_caches_cache:evicted_size", "", ["name"])
 cache_total = Gauge("synapse_util_caches_cache:total", "", ["name"])
+cache_max_size = Gauge("synapse_util_caches_cache_max_size", "", ["name"])
 
 response_cache_size = Gauge("synapse_util_caches_response_cache:size", "", ["name"])
 response_cache_hits = Gauge("synapse_util_caches_response_cache:hits", "", ["name"])
@@ -53,67 +44,82 @@ response_cache_evicted = Gauge(
 response_cache_total = Gauge("synapse_util_caches_response_cache:total", "", ["name"])
 
 
-def register_cache(cache_type, cache_name, cache, collect_callback=None):
-    """Register a cache object for metric collection.
+@attr.s
+class CacheMetric(object):
+
+    _cache = attr.ib()
+    _cache_type = attr.ib(type=str)
+    _cache_name = attr.ib(type=str)
+    _collect_callback = attr.ib(type=Optional[Callable])
+
+    hits = attr.ib(default=0)
+    misses = attr.ib(default=0)
+    evicted_size = attr.ib(default=0)
+
+    def inc_hits(self):
+        self.hits += 1
+
+    def inc_misses(self):
+        self.misses += 1
+
+    def inc_evictions(self, size=1):
+        self.evicted_size += size
+
+    def describe(self):
+        return []
+
+    def collect(self):
+        try:
+            if self._cache_type == "response_cache":
+                response_cache_size.labels(self._cache_name).set(len(self._cache))
+                response_cache_hits.labels(self._cache_name).set(self.hits)
+                response_cache_evicted.labels(self._cache_name).set(self.evicted_size)
+                response_cache_total.labels(self._cache_name).set(
+                    self.hits + self.misses
+                )
+            else:
+                cache_size.labels(self._cache_name).set(len(self._cache))
+                cache_hits.labels(self._cache_name).set(self.hits)
+                cache_evicted.labels(self._cache_name).set(self.evicted_size)
+                cache_total.labels(self._cache_name).set(self.hits + self.misses)
+                if getattr(self._cache, "max_size", None):
+                    cache_max_size.labels(self._cache_name).set(self._cache.max_size)
+            if self._collect_callback:
+                self._collect_callback()
+        except Exception as e:
+            logger.warning("Error calculating metrics for %s: %s", self._cache_name, e)
+            raise
+
+
+def register_cache(
+    cache_type: str,
+    cache_name: str,
+    cache,
+    collect_callback: Optional[Callable] = None,
+    resizable: bool = True,
+    resize_callback: Optional[Callable] = None,
+) -> CacheMetric:
+    """Register a cache object for metric collection and resizing.
 
     Args:
-        cache_type (str):
-        cache_name (str): name of the cache
-        cache (object): cache itself
-        collect_callback (callable|None): if not None, a function which is called during
-            metric collection to update additional metrics.
+        cache_type
+        cache_name: name of the cache
+        cache: cache itself
+        collect_callback: If given, a function which is called during metric
+            collection to update additional metrics.
+        resizable: Whether this cache supports being resized.
+        resize_callback: A function which can be called to resize the cache.
 
     Returns:
         CacheMetric: an object which provides inc_{hits,misses,evictions} methods
     """
+    if resizable:
+        if not resize_callback:
+            resize_callback = getattr(cache, "set_cache_factor")
+        add_resizable_cache(cache_name, resize_callback)
 
-    # Check if the metric is already registered. Unregister it, if so.
-    # This usually happens during tests, as at runtime these caches are
-    # effectively singletons.
+    metric = CacheMetric(cache, cache_type, cache_name, collect_callback)
     metric_name = "cache_%s_%s" % (cache_type, cache_name)
-    if metric_name in collectors_by_name.keys():
-        REGISTRY.unregister(collectors_by_name[metric_name])
-
-    class CacheMetric(object):
-
-        hits = 0
-        misses = 0
-        evicted_size = 0
-
-        def inc_hits(self):
-            self.hits += 1
-
-        def inc_misses(self):
-            self.misses += 1
-
-        def inc_evictions(self, size=1):
-            self.evicted_size += size
-
-        def describe(self):
-            return []
-
-        def collect(self):
-            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)
-                if collect_callback:
-                    collect_callback()
-            except Exception as e:
-                logger.warning("Error calculating metrics for %s: %s", cache_name, e)
-                raise
-
-            yield GaugeMetricFamily("__unused", "")
-
-    metric = CacheMetric()
-    REGISTRY.register(metric)
     caches_by_name[cache_name] = cache
     collectors_by_name[metric_name] = metric
     return metric

synapse/util/caches/descriptors.py

@@ -13,6 +13,7 @@
 # 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 functools
 import inspect
 import logging
@@ -30,7 +31,6 @@ from twisted.internet import defer
 from synapse.logging.context import make_deferred_yieldable, preserve_fn
 from synapse.util import unwrapFirstError
 from synapse.util.async_helpers import ObservableDeferred
-from synapse.util.caches import get_cache_factor_for
 from synapse.util.caches.lrucache import LruCache
 from synapse.util.caches.treecache import TreeCache, iterate_tree_cache_entry
 
@@ -81,7 +81,6 @@ class CacheEntry(object):
 class Cache(object):
     __slots__ = (
         "cache",
-        "max_entries",
         "name",
         "keylen",
         "thread",
@@ -111,6 +110,10 @@ class Cache(object):
             collect_callback=self._metrics_collection_callback,
         )
 
+    @property
+    def max_entries(self):
+        return self.cache.max_size
+
     def _on_evicted(self, evicted_count):
         self.metrics.inc_evictions(evicted_count)
 
@@ -370,13 +373,11 @@ class CacheDescriptor(_CacheDescriptorBase):
             cache_context=cache_context,
         )
 
-        max_entries = int(max_entries * get_cache_factor_for(orig.__name__))
-
         self.max_entries = max_entries
         self.tree = tree
         self.iterable = iterable
 
-    def __get__(self, obj, objtype=None):
+    def __get__(self, obj, owner):
         cache = Cache(
             name=self.orig.__name__,
             max_entries=self.max_entries,

synapse/util/caches/expiringcache.py

@@ -18,6 +18,7 @@ from collections import OrderedDict
 
 from six import iteritems, itervalues
 
+from synapse.config import cache as cache_config
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.util.caches import register_cache
 
@@ -55,11 +56,12 @@ class ExpiringCache(object):
         """
         self._cache_name = cache_name
 
+        self.max_size = int(max_len * cache_config.DEFAULT_CACHE_SIZE_FACTOR)
+        self._original_max_size = max_len
+
         self._clock = clock
 
-        self._max_len = max_len
         self._expiry_ms = expiry_ms
-
         self._reset_expiry_on_get = reset_expiry_on_get
 
         self._cache = OrderedDict()
@@ -82,9 +84,11 @@ class ExpiringCache(object):
     def __setitem__(self, key, value):
         now = self._clock.time_msec()
         self._cache[key] = _CacheEntry(now, value)
+        self.evict()
 
+    def evict(self):
         # Evict if there are now too many items
-        while self._max_len and len(self) > self._max_len:
+        while self.max_size and len(self) > self.max_size:
             _key, value = self._cache.popitem(last=False)
             if self.iterable:
                 self.metrics.inc_evictions(len(value.value))
@@ -170,6 +174,23 @@ class ExpiringCache(object):
         else:
             return len(self._cache)
 
+    def set_cache_factor(self, factor: float) -> bool:
+        """
+        Set the cache factor for this individual cache.
+
+        This will trigger a resize if it changes, which may require evicting
+        items from the cache.
+
+        Returns:
+            bool: Whether the cache changed size or not.
+        """
+        new_size = int(self._original_max_size * factor)
+        if new_size != self.max_size:
+            self.max_size = new_size
+            self.evict()
+            return True
+        return False
+
 
 class _CacheEntry(object):
     __slots__ = ["time", "value"]

synapse/util/caches/lrucache.py

@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
 import threading
 from functools import wraps
 
@@ -76,6 +75,11 @@ class LruCache(object):
         """
         cache = cache_type()
         self.cache = cache  # Used for introspection.
+
+        # Save the original max size, and apply the default size factor.
+        self._original_max_size = max_size
+        self.max_size = int(max_size)
+
         list_root = _Node(None, None, None, None)
         list_root.next_node = list_root
         list_root.prev_node = list_root
@@ -83,7 +87,7 @@ class LruCache(object):
         lock = threading.Lock()
 
         def evict():
-            while cache_len() > max_size:
+            while cache_len() > self.max_size:
                 todelete = list_root.prev_node
                 evicted_len = delete_node(todelete)
                 cache.pop(todelete.key, None)
@@ -236,6 +240,7 @@ class LruCache(object):
             return key in cache
 
         self.sentinel = object()
+        self._on_resize = evict
         self.get = cache_get
         self.set = cache_set
         self.setdefault = cache_set_default
@@ -266,3 +271,20 @@ class LruCache(object):
 
     def __contains__(self, key):
         return self.contains(key)
+
+    def set_cache_factor(self, factor: float) -> bool:
+        """
+        Set the cache factor for this individual cache.
+
+        This will trigger a resize if it changes, which may require evicting
+        items from the cache.
+
+        Returns:
+            bool: Whether the cache changed size or not.
+        """
+        new_size = int(self._original_max_size * factor)
+        if new_size != self.max_size:
+            self.max_size = new_size
+            self._on_resize()
+            return True
+        return False

synapse/util/caches/response_cache.py

@@ -38,7 +38,7 @@ class ResponseCache(object):
         self.timeout_sec = timeout_ms / 1000.0
 
         self._name = name
-        self._metrics = register_cache("response_cache", name, self)
+        self._metrics = register_cache("response_cache", name, self, resizable=False)
 
     def size(self):
         return len(self.pending_result_cache)

synapse/util/caches/stream_change_cache.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import logging
+import math
 
 from six import integer_types
 
@@ -35,17 +36,37 @@ class StreamChangeCache(object):
     """
 
     def __init__(self, name, current_stream_pos, max_size=10000, prefilled_cache=None):
-        self._max_size = int(max_size * caches.CACHE_SIZE_FACTOR)
+        self._original_max_size = max_size
+        self.max_size = math.floor(max_size)
         self._entity_to_key = {}
         self._cache = SortedDict()
         self._earliest_known_stream_pos = current_stream_pos
         self.name = name
-        self.metrics = caches.register_cache("cache", self.name, self._cache)
+        self.metrics = caches.register_cache(
+            "cache", self.name, self._cache, resize_callback=self.set_cache_factor
+        )
 
         if prefilled_cache:
             for entity, stream_pos in prefilled_cache.items():
                 self.entity_has_changed(entity, stream_pos)
 
+    def set_cache_factor(self, factor: float) -> bool:
+        """
+        Set the cache factor for this individual cache.
+
+        This will trigger a resize if it changes, which may require evicting
+        items from the cache.
+
+        Returns:
+            bool: Whether the cache changed size or not.
+        """
+        new_size = math.floor(self._original_max_size * factor)
+        if new_size != self.max_size:
+            self.max_size = new_size
+            self._evict()
+            return True
+        return False
+
     def has_entity_changed(self, entity, stream_pos):
         """Returns True if the entity may have been updated since stream_pos
         """
@@ -133,13 +154,13 @@ class StreamChangeCache(object):
                 self._cache.pop(old_pos, None)
             self._cache[stream_pos] = entity
             self._entity_to_key[entity] = stream_pos
+            self._evict()
 
-            while len(self._cache) > self._max_size:
-                k, r = self._cache.popitem(0)
-                self._earliest_known_stream_pos = max(
-                    k, self._earliest_known_stream_pos
-                )
-                self._entity_to_key.pop(r, None)
+    def _evict(self):
+        while len(self._cache) > self.max_size:
+            k, r = self._cache.popitem(0)
+            self._earliest_known_stream_pos = max(k, self._earliest_known_stream_pos)
+            self._entity_to_key.pop(r, None)
 
     def get_max_pos_of_last_change(self, entity):
         """Returns an upper bound of the stream id of the last change to an

synapse/util/caches/ttlcache.py

@@ -38,7 +38,7 @@ class TTLCache(object):
 
         self._timer = timer
 
-        self._metrics = register_cache("ttl", cache_name, self)
+        self._metrics = register_cache("ttl", cache_name, self, resizable=False)
 
     def set(self, key, value, ttl):
         """Add/update an entry in the cache

synmark/__main__.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import sys
+from argparse import REMAINDER
 from contextlib import redirect_stderr
 from io import StringIO
 
@@ -21,7 +22,7 @@ import pyperf
 from synmark import make_reactor
 from synmark.suites import SUITES
 
-from twisted.internet.defer import ensureDeferred
+from twisted.internet.defer import Deferred, ensureDeferred
 from twisted.logger import globalLogBeginner, textFileLogObserver
 from twisted.python.failure import Failure
 
@@ -40,7 +41,8 @@ def make_test(main):
         file_out = StringIO()
         with redirect_stderr(file_out):
 
-            d = ensureDeferred(main(reactor, loops))
+            d = Deferred()
+            d.addCallback(lambda _: ensureDeferred(main(reactor, loops)))
 
             def on_done(_):
                 if isinstance(_, Failure):
@@ -50,6 +52,7 @@ def make_test(main):
                 return _
 
             d.addBoth(on_done)
+            reactor.callWhenRunning(lambda: d.callback(True))
             reactor.run()
 
         return d.result
@@ -62,11 +65,13 @@ if __name__ == "__main__":
     def add_cmdline_args(cmd, args):
         if args.log:
             cmd.extend(["--log"])
+        cmd.extend(args.tests)
 
     runner = pyperf.Runner(
-        processes=3, min_time=2, show_name=True, add_cmdline_args=add_cmdline_args
+        processes=3, min_time=1.5, show_name=True, add_cmdline_args=add_cmdline_args
     )
     runner.argparser.add_argument("--log", action="store_true")
+    runner.argparser.add_argument("tests", nargs=REMAINDER)
     runner.parse_args()
 
     orig_loops = runner.args.loops
@@ -79,6 +84,11 @@ if __name__ == "__main__":
             )
         setupdb()
 
+    if runner.args.tests:
+        SUITES = list(
+            filter(lambda x: x[0].__name__.split(".")[-1] in runner.args.tests, SUITES)
+        )
+
     for suite, loops in SUITES:
         if loops:
             runner.args.loops = loops

synmark/suites/__init__.py

@@ -1,3 +1,9 @@
-from . import logging
+from . import logging, lrucache, lrucache_evict
 
-SUITES = [(logging, 1000), (logging, 10000), (logging, None)]
+SUITES = [
+    (logging, 1000),
+    (logging, 10000),
+    (logging, None),
+    (lrucache, None),
+    (lrucache_evict, None),
+]

synmark/suites/lrucache.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# 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 pyperf import perf_counter
+
+from synapse.util.caches.lrucache import LruCache
+
+
+async def main(reactor, loops):
+    """
+    Benchmark `loops` number of insertions into LruCache without eviction.
+    """
+    cache = LruCache(loops)
+
+    start = perf_counter()
+
+    for i in range(loops):
+        cache[i] = True
+
+    end = perf_counter() - start
+
+    return end

synmark/suites/lrucache_evict.py

@@ -0,0 +1,35 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# 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 pyperf import perf_counter
+
+from synapse.util.caches.lrucache import LruCache
+
+
+async def main(reactor, loops):
+    """
+    Benchmark `loops` number of insertions into LruCache where half of them are
+    evicted.
+    """
+    cache = LruCache(loops // 2)
+
+    start = perf_counter()
+
+    for i in range(loops):
+        cache[i] = True
+
+    end = perf_counter() - start
+
+    return end

tests/config/test_cache.py

@@ -0,0 +1,125 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 Matrix.org Foundation C.I.C.
+#
+# 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 synapse.config._base import Config, RootConfig
+from synapse.config.cache import CacheConfig, add_resizable_cache
+from synapse.util.caches.lrucache import LruCache
+
+from tests.unittest import TestCase
+
+
+class FakeServer(Config):
+    section = "server"
+
+
+class TestConfig(RootConfig):
+    config_classes = [FakeServer, CacheConfig]
+
+
+class CacheConfigTests(TestCase):
+    def setUp(self):
+        CacheConfig._reset()
+
+    def test_individual_caches_from_environ(self):
+        """
+        Individual cache factors will be loaded from the environment.
+        """
+        config = {}
+        t = TestConfig()
+        t.caches._environ = {
+            "SYNAPSE_CACHE_FACTOR_SOMETHING_OR_OTHER": "2",
+            "SYNAPSE_NOT_CACHE": "BLAH",
+        }
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(dict(t.caches.cache_factors), {"something_or_other": 2.0})
+
+    def test_config_overrides_environ(self):
+        """
+        Individual cache factors defined in config will take precedence over
+        ones in the environment.
+        """
+        config = {"caches": {"per_cache_factors": {"foo": 2, "bar": 3}}}
+        t = TestConfig()
+        t.caches._environ = {
+            "SYNAPSE_CACHE_FACTOR_SOMETHING_OR_OTHER": "2",
+            "SYNAPSE_CACHE_FACTOR_FOO": 1,
+        }
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(
+            dict(t.caches.cache_factors),
+            {"foo": 2.0, "bar": 3.0, "something_or_other": 2.0},
+        )
+
+    def test_individual_instantiated_before_config_load(self):
+        """
+        If a cache is instantiated before the config is read, it will be given
+        the default cache size in the interim, and then resized once the config
+        is loaded.
+        """
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 50)
+
+        config = {"caches": {"per_cache_factors": {"foo": 3}}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(cache.max_size, 300)
+
+    def test_individual_instantiated_after_config_load(self):
+        """
+        If a cache is instantiated after the config is read, it will be
+        immediately resized to the correct size given the per_cache_factor if
+        there is one.
+        """
+        config = {"caches": {"per_cache_factors": {"foo": 2}}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 200)
+
+    def test_global_instantiated_before_config_load(self):
+        """
+        If a cache is instantiated before the config is read, it will be given
+        the default cache size in the interim, and then resized to the new
+        default cache size once the config is loaded.
+        """
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 50)
+
+        config = {"caches": {"global_factor": 4}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        self.assertEqual(cache.max_size, 400)
+
+    def test_global_instantiated_after_config_load(self):
+        """
+        If a cache is instantiated after the config is read, it will be
+        immediately resized to the correct size given the global factor if there
+        is no per-cache factor.
+        """
+        config = {"caches": {"global_factor": 1.5}}
+        t = TestConfig()
+        t.read_config(config, config_dir_path="", data_dir_path="")
+
+        cache = LruCache(100)
+        add_resizable_cache("foo", cache.set_cache_factor)
+        self.assertEqual(cache.max_size, 150)

tests/storage/test__base.py

@@ -25,8 +25,8 @@ from synapse.util.caches.descriptors import Cache, cached
 from tests import unittest
 
 
-class CacheTestCase(unittest.TestCase):
-    def setUp(self):
+class CacheTestCase(unittest.HomeserverTestCase):
+    def prepare(self, reactor, clock, homeserver):
         self.cache = Cache("test")
 
     def test_empty(self):
@@ -96,7 +96,7 @@ class CacheTestCase(unittest.TestCase):
         cache.get(3)
 
 
-class CacheDecoratorTestCase(unittest.TestCase):
+class CacheDecoratorTestCase(unittest.HomeserverTestCase):
     @defer.inlineCallbacks
     def test_passthrough(self):
         class A(object):
@@ -239,7 +239,7 @@ class CacheDecoratorTestCase(unittest.TestCase):
         callcount2 = [0]
 
         class A(object):
-            @cached(max_entries=4)  # HACK: This makes it 2 due to cache factor
+            @cached(max_entries=2)
             def func(self, key):
                 callcount[0] += 1
                 return key

tests/storage/test_appservice.py

@@ -43,7 +43,7 @@ class ApplicationServiceStoreTestCase(unittest.TestCase):
         )
 
         hs.config.app_service_config_files = self.as_yaml_files
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         self.as_token = "token1"
@@ -110,7 +110,7 @@ class ApplicationServiceTransactionStoreTestCase(unittest.TestCase):
         )
 
         hs.config.app_service_config_files = self.as_yaml_files
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         self.as_list = [
@@ -422,7 +422,7 @@ class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
         )
 
         hs.config.app_service_config_files = [f1, f2]
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         database = hs.get_datastores().databases[0]
@@ -440,7 +440,7 @@ class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
         )
 
         hs.config.app_service_config_files = [f1, f2]
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         with self.assertRaises(ConfigError) as cm:
@@ -464,7 +464,7 @@ class ApplicationServiceStoreConfigTestCase(unittest.TestCase):
         )
 
         hs.config.app_service_config_files = [f1, f2]
-        hs.config.event_cache_size = 1
+        hs.config.caches.event_cache_size = 1
         hs.config.password_providers = []
 
         with self.assertRaises(ConfigError) as cm:

tests/storage/test_base.py

@@ -51,7 +51,8 @@ class SQLBaseStoreTestCase(unittest.TestCase):
 
         config = Mock()
         config._disable_native_upserts = True
-        config.event_cache_size = 1
+        config.caches = Mock()
+        config.caches.event_cache_size = 1
         hs = TestHomeServer("test", config=config)
 
         sqlite_config = {"name": "sqlite3"}

tests/test_metrics.py

@@ -15,6 +15,7 @@
 # limitations under the License.
 
 from synapse.metrics import REGISTRY, InFlightGauge, generate_latest
+from synapse.util.caches.descriptors import Cache
 
 from tests import unittest
 
@@ -129,3 +130,36 @@ class BuildInfoTests(unittest.TestCase):
         self.assertTrue(b"osversion=" in items[0])
         self.assertTrue(b"pythonversion=" in items[0])
         self.assertTrue(b"version=" in items[0])
+
+
+class CacheMetricsTests(unittest.HomeserverTestCase):
+    def test_cache_metric(self):
+        """
+        Caches produce metrics reflecting their state when scraped.
+        """
+        CACHE_NAME = "cache_metrics_test_fgjkbdfg"
+        cache = Cache(CACHE_NAME, max_entries=777)
+
+        items = {
+            x.split(b"{")[0].decode("ascii"): x.split(b" ")[1].decode("ascii")
+            for x in filter(
+                lambda x: b"cache_metrics_test_fgjkbdfg" in x,
+                generate_latest(REGISTRY).split(b"\n"),
+            )
+        }
+
+        self.assertEqual(items["synapse_util_caches_cache_size"], "0.0")
+        self.assertEqual(items["synapse_util_caches_cache_max_size"], "777.0")
+
+        cache.prefill("1", "hi")
+
+        items = {
+            x.split(b"{")[0].decode("ascii"): x.split(b" ")[1].decode("ascii")
+            for x in filter(
+                lambda x: b"cache_metrics_test_fgjkbdfg" in x,
+                generate_latest(REGISTRY).split(b"\n"),
+            )
+        }
+
+        self.assertEqual(items["synapse_util_caches_cache_size"], "1.0")
+        self.assertEqual(items["synapse_util_caches_cache_max_size"], "777.0")

tests/util/test_expiring_cache.py

@@ -21,7 +21,7 @@ from tests.utils import MockClock
 from .. import unittest
 
 
-class ExpiringCacheTestCase(unittest.TestCase):
+class ExpiringCacheTestCase(unittest.HomeserverTestCase):
     def test_get_set(self):
         clock = MockClock()
         cache = ExpiringCache("test", clock, max_len=1)

tests/util/test_lrucache.py

@@ -22,7 +22,7 @@ from synapse.util.caches.treecache import TreeCache
 from .. import unittest
 
 
-class LruCacheTestCase(unittest.TestCase):
+class LruCacheTestCase(unittest.HomeserverTestCase):
     def test_get_set(self):
         cache = LruCache(1)
         cache["key"] = "value"
@@ -84,7 +84,7 @@ class LruCacheTestCase(unittest.TestCase):
         self.assertEquals(len(cache), 0)
 
 
-class LruCacheCallbacksTestCase(unittest.TestCase):
+class LruCacheCallbacksTestCase(unittest.HomeserverTestCase):
     def test_get(self):
         m = Mock()
         cache = LruCache(1)
@@ -233,7 +233,7 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
         self.assertEquals(m3.call_count, 1)
 
 
-class LruCacheSizedTestCase(unittest.TestCase):
+class LruCacheSizedTestCase(unittest.HomeserverTestCase):
     def test_evict(self):
         cache = LruCache(5, size_callback=len)
         cache["key1"] = [0]

tests/util/test_stream_change_cache.py

@@ -1,11 +1,9 @@
-from mock import patch
-
 from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 from tests import unittest
 
 
-class StreamChangeCacheTests(unittest.TestCase):
+class StreamChangeCacheTests(unittest.HomeserverTestCase):
     """
     Tests for StreamChangeCache.
     """
@@ -46,7 +44,6 @@ class StreamChangeCacheTests(unittest.TestCase):
         self.assertTrue(cache.has_entity_changed("user@foo.com", 0))
         self.assertTrue(cache.has_entity_changed("not@here.website", 0))
 
-    @patch("synapse.util.caches.CACHE_SIZE_FACTOR", 1.0)
     def test_has_entity_changed_pops_off_start(self):
         """
         StreamChangeCache.entity_has_changed will respect the max size and

tests/utils.py

@@ -164,6 +164,7 @@ def default_config(name, parse=False):
         # disable user directory updates, because they get done in the
         # background, which upsets the test runner.
         "update_user_directory": False,
+        "caches": {"global_factor": 1},
     }
 
     if parse: