1 files changed, 6 insertions, 0 deletions
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index a37d1934ec..6caf7b3356 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -16,6 +16,8 @@ import logging
 
 from synapse.api.errors import StoreError
 from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
+from synapse.util.caches import CACHE_SIZE_FACTOR
+from synapse.util.caches.dictionary_cache import DictionaryCache
 from synapse.util.caches.descriptors import Cache
 from synapse.storage.engines import PostgresEngine
 import synapse.metrics
@@ -178,6 +180,10 @@ class SQLBaseStore(object):
         self._get_event_cache = Cache("*getEvent*", keylen=3,
                                       max_entries=hs.config.event_cache_size)
 
+        self._state_group_cache = DictionaryCache(
+            "*stateGroupCache*", 100000 * CACHE_SIZE_FACTOR
+        )
+
         self._event_fetch_lock = threading.Condition()
         self._event_fetch_list = []
         self._event_fetch_ongoing = 0