From 7cb8b4bc67042a39bd1b0e05df46089a2fce1955 Mon Sep 17 00:00:00 2001 From: Amber Brown Date: Tue, 12 May 2020 03:45:23 +1000 Subject: Allow configuration of Synapse's cache without using synctl or environment variables (#6391) --- synapse/util/caches/lrucache.py | 52 ++++++++++++++++++++++++++++++++++------- 1 file changed, 43 insertions(+), 9 deletions(-) (limited to 'synapse/util/caches/lrucache.py') 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 -- cgit 1.5.1 From eefc6b3a0d08cd2a64be7c78c0a4a651cc965be9 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 27 May 2020 12:04:37 +0100 Subject: Don't apply cache factor to event cache. (#7578) This is already correctly done when we instansiate the cache, but wasn't when it got reloaded (which always happens at least once on startup). --- changelog.d/7578.bugfix | 1 + synapse/util/caches/lrucache.py | 4 ++++ tests/config/test_cache.py | 16 ++++++++++++++++ 3 files changed, 21 insertions(+) create mode 100644 changelog.d/7578.bugfix (limited to 'synapse/util/caches/lrucache.py') diff --git a/changelog.d/7578.bugfix b/changelog.d/7578.bugfix new file mode 100644 index 0000000000..cd29307361 --- /dev/null +++ b/changelog.d/7578.bugfix @@ -0,0 +1 @@ +Fix cache config to not apply cache factor to event cache. Regression in v1.14.0rc1. diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py index 29fabac3cd..df4ea5901d 100644 --- a/synapse/util/caches/lrucache.py +++ b/synapse/util/caches/lrucache.py @@ -81,6 +81,7 @@ class LruCache(object): """ cache = cache_type() self.cache = cache # Used for introspection. + self.apply_cache_factor_from_config = apply_cache_factor_from_config # Save the original max size, and apply the default size factor. self._original_max_size = max_size @@ -294,6 +295,9 @@ class LruCache(object): Returns: bool: Whether the cache changed size or not. """ + if not self.apply_cache_factor_from_config: + return False + new_size = int(self._original_max_size * factor) if new_size != self.max_size: self.max_size = new_size diff --git a/tests/config/test_cache.py b/tests/config/test_cache.py index 2920279125..b45e0cc536 100644 --- a/tests/config/test_cache.py +++ b/tests/config/test_cache.py @@ -125,3 +125,19 @@ class CacheConfigTests(TestCase): cache = LruCache(100) add_resizable_cache("foo", cache_resize_callback=cache.set_cache_factor) self.assertEqual(cache.max_size, 150) + + def test_apply_cache_factor_from_config(self): + """Caches can disable applying cache factor updates, mainly used by + event cache size. + """ + + config = {"caches": {"event_cache_size": "10k"}} + t = TestConfig() + t.read_config(config, config_dir_path="", data_dir_path="") + + cache = LruCache( + max_size=t.caches.event_cache_size, apply_cache_factor_from_config=False, + ) + add_resizable_cache("event_cache", cache_resize_callback=cache.set_cache_factor) + + self.assertEqual(cache.max_size, 10240) -- cgit 1.5.1