Make TRACK_MEMORY_USAGE configurable

synapse/app/generic_worker.py

@@ -452,6 +452,7 @@ def start(config_options):
         config.server.update_user_directory = False
 
     synapse.events.USE_FROZEN_DICTS = config.use_frozen_dicts
+    synapse.util.caches.lrucache.TRACK_MEMORY_USAGE = config.caches.track_memory_usage
 
     hs = GenericWorkerServer(
         config.server_name,

synapse/app/homeserver.py

@@ -339,6 +339,7 @@ def setup(config_options):
         sys.exit(0)
 
     events.USE_FROZEN_DICTS = config.use_frozen_dicts
+    synapse.util.caches.lrucache.TRACK_MEMORY_USAGE = config.caches.track_memory_usage
 
     hs = SynapseHomeServer(
         config.server_name,

synapse/config/cache.py

@@ -17,6 +17,8 @@ import re
 import threading
 from typing import Callable, Dict
 
+from synapse.python_dependencies import DependencyException, check_requirements
+
 from ._base import Config, ConfigError
 
 # The prefix for all cache factor-related environment variables
@@ -189,6 +191,15 @@ class CacheConfig(Config):
                 )
             self.cache_factors[cache] = factor
 
+        self.track_memory_usage = cache_config.get("track_memory_usage", False)
+        if self.track_memory_usage:
+            try:
+                check_requirements("cache_memory")
+            except DependencyException as e:
+                raise ConfigError(
+                    e.message  # noqa: B306, DependencyException.message is a property
+                )
+
         # Resize all caches (if necessary) with the new factors we've loaded
         self.resize_all_caches()
 

synapse/python_dependencies.py

@@ -121,7 +121,7 @@ CONDITIONAL_REQUIREMENTS = {
     # hiredis is not a *strict* dependency, but it makes things much faster.
     # (if it is not installed, we fall back to slow code.)
     "redis": ["txredisapi>=1.4.7", "hiredis"],
-    "cache_memroy": ["pympler"],
+    "cache_memory": ["pympler"],
 }
 
 ALL_OPTIONAL_REQUIREMENTS = set()  # type: Set[str]

synapse/util/caches/lrucache.py

@@ -60,7 +60,7 @@ except ImportError:
 
 
 # Whether to track estimated memory usage of the LruCaches.
-TRACK_MEMORY_USAGE = True
+TRACK_MEMORY_USAGE = False
 
 
 # Function type: the type used for invalidation callbacks