diff options
Diffstat (limited to 'synapse/util/caches')
| -rw-r--r-- | synapse/util/caches/__init__.py | 144 | ||||
| -rw-r--r-- | synapse/util/caches/descriptors.py | 36 | ||||
| -rw-r--r-- | synapse/util/caches/expiringcache.py | 29 | ||||
| -rw-r--r-- | synapse/util/caches/lrucache.py | 52 | ||||
| -rw-r--r-- | synapse/util/caches/response_cache.py | 2 | ||||
| -rw-r--r-- | synapse/util/caches/stream_change_cache.py | 33 | ||||
| -rw-r--r-- | synapse/util/caches/ttlcache.py | 2 |
7 files changed, 206 insertions, 92 deletions
diff --git a/synapse/util/caches/__init__.py b/synapse/util/caches/__init__.py index da5077b471..4b8a0c7a8f 100644 --- a/synapse/util/caches/__init__.py +++ b/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. @@ -15,27 +15,17 @@ # 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 - -logger = logging.getLogger(__name__) - -CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.5)) +import attr +from prometheus_client.core import Gauge +from synapse.config.cache import add_resizable_cache -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 - +logger = logging.getLogger(__name__) 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 diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py index 2e8f6543e5..cd48262420 100644 --- a/synapse/util/caches/descriptors.py +++ b/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", @@ -89,7 +88,29 @@ class Cache(object): "_pending_deferred_cache", ) - def __init__(self, name, max_entries=1000, keylen=1, tree=False, iterable=False): + def __init__( + self, + name: str, + max_entries: int = 1000, + keylen: int = 1, + tree: bool = False, + iterable: bool = False, + apply_cache_factor_from_config: bool = True, + ): + """ + Args: + name: The name of the cache + max_entries: Maximum amount of entries that the cache will hold + keylen: The length of the tuple used as the cache key + tree: Use a TreeCache instead of a dict as the underlying cache type + iterable: If True, count each item in the cached object as an entry, + rather than each cached object + apply_cache_factor_from_config: Whether cache factors specified in the + config file affect `max_entries` + + Returns: + Cache + """ cache_type = TreeCache if tree else dict self._pending_deferred_cache = cache_type() @@ -99,6 +120,7 @@ class Cache(object): cache_type=cache_type, size_callback=(lambda d: len(d)) if iterable else None, evicted_callback=self._on_evicted, + apply_cache_factor_from_config=apply_cache_factor_from_config, ) self.name = name @@ -111,6 +133,10 @@ 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 +396,11 @@ 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, diff --git a/synapse/util/caches/expiringcache.py b/synapse/util/caches/expiringcache.py index cddf1ed515..2726b67b6d 100644 --- a/synapse/util/caches/expiringcache.py +++ b/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 @@ -51,15 +52,16 @@ class ExpiringCache(object): an item on access. Defaults to False. iterable (bool): If true, the size is calculated by summing the sizes of all entries, rather than the number of entries. - """ self._cache_name = cache_name + self._original_max_size = max_len + + self._max_size = int(max_len * cache_config.properties.default_factor_size) + 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"] diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py index 1536cb64f3..29fabac3cd 100644 --- a/synapse/util/caches/lrucache.py +++ b/synapse/util/caches/lrucache.py @@ -13,10 +13,11 @@ # See the License for the specific language governing permissions and # limitations under the License. - import threading from functools import wraps +from typing import Callable, Optional, Type, Union +from synapse.config import cache as cache_config from synapse.util.caches.treecache import TreeCache @@ -52,17 +53,18 @@ class LruCache(object): def __init__( self, - max_size, - keylen=1, - cache_type=dict, - size_callback=None, - evicted_callback=None, + max_size: int, + keylen: int = 1, + cache_type: Type[Union[dict, TreeCache]] = dict, + size_callback: Optional[Callable] = None, + evicted_callback: Optional[Callable] = None, + apply_cache_factor_from_config: bool = True, ): """ Args: - max_size (int): + max_size: The maximum amount of entries the cache can hold - keylen (int): + keylen: The length of the tuple used as the cache key cache_type (type): type of underlying cache to be used. Typically one of dict @@ -73,9 +75,23 @@ class LruCache(object): evicted_callback (func(int)|None): if not None, called on eviction with the size of the evicted entry + + apply_cache_factor_from_config (bool): If true, `max_size` will be + multiplied by a cache factor derived from the homeserver config """ 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 + # We previously didn't apply the cache factor here, and as such some caches were + # not affected by the global cache factor. Add an option here to disable applying + # the cache factor when a cache is created + if apply_cache_factor_from_config: + self.max_size = int(max_size * cache_config.properties.default_factor_size) + else: + 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 +99,7 @@ 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 +252,7 @@ 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 +283,20 @@ 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 diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py index b68f9fe0d4..a6c60888e5 100644 --- a/synapse/util/caches/response_cache.py +++ b/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) diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py index e54f80d76e..2a161bf244 100644 --- a/synapse/util/caches/stream_change_cache.py +++ b/synapse/util/caches/stream_change_cache.py @@ -14,6 +14,7 @@ # limitations under the License. import logging +import math from typing import Dict, FrozenSet, List, Mapping, Optional, Set, Union from six import integer_types @@ -46,7 +47,8 @@ class StreamChangeCache: max_size=10000, prefilled_cache: Optional[Mapping[EntityType, int]] = 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 = {} # type: Dict[EntityType, int] # map from stream id to the a set of entities which changed at that stream id. @@ -58,12 +60,31 @@ class StreamChangeCache: # 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: EntityType, stream_pos: int) -> bool: """Returns True if the entity may have been updated since stream_pos """ @@ -171,6 +192,7 @@ class StreamChangeCache: e1 = self._cache[stream_pos] = set() e1.add(entity) self._entity_to_key[entity] = stream_pos + self._evict() # if the cache is too big, remove entries while len(self._cache) > self._max_size: @@ -179,6 +201,13 @@ class StreamChangeCache: for entity in r: del self._entity_to_key[entity] + 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) + for entity in r: + self._entity_to_key.pop(entity, None) + def get_max_pos_of_last_change(self, entity: EntityType) -> int: """Returns an upper bound of the stream id of the last change to an diff --git a/synapse/util/caches/ttlcache.py b/synapse/util/caches/ttlcache.py index 99646c7cf0..6437aa907e 100644 --- a/synapse/util/caches/ttlcache.py +++ b/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 |