diff --git a/synapse/util/caches/__init__.py b/synapse/util/caches/__init__.py
index 42f6abb5e1..9387632d0d 100644
--- a/synapse/util/caches/__init__.py
+++ b/synapse/util/caches/__init__.py
@@ -20,9 +20,11 @@ from sys import intern
from typing import Any, Callable, Dict, List, Optional, Sized, TypeVar
import attr
+from prometheus_client import REGISTRY
from prometheus_client.core import Gauge
from synapse.config.cache import add_resizable_cache
+from synapse.util.metrics import DynamicCollectorRegistry
logger = logging.getLogger(__name__)
@@ -30,27 +32,62 @@ logger = logging.getLogger(__name__)
# Whether to track estimated memory usage of the LruCaches.
TRACK_MEMORY_USAGE = False
+# We track cache metrics in a special registry that lets us update the metrics
+# just before they are returned from the scrape endpoint.
+CACHE_METRIC_REGISTRY = DynamicCollectorRegistry()
caches_by_name: Dict[str, Sized] = {}
-collectors_by_name: Dict[str, "CacheMetric"] = {}
-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", "reason"])
-cache_total = Gauge("synapse_util_caches_cache:total", "", ["name"])
-cache_max_size = Gauge("synapse_util_caches_cache_max_size", "", ["name"])
+cache_size = Gauge(
+ "synapse_util_caches_cache_size", "", ["name"], registry=CACHE_METRIC_REGISTRY
+)
+cache_hits = Gauge(
+ "synapse_util_caches_cache_hits", "", ["name"], registry=CACHE_METRIC_REGISTRY
+)
+cache_evicted = Gauge(
+ "synapse_util_caches_cache_evicted_size",
+ "",
+ ["name", "reason"],
+ registry=CACHE_METRIC_REGISTRY,
+)
+cache_total = Gauge(
+ "synapse_util_caches_cache", "", ["name"], registry=CACHE_METRIC_REGISTRY
+)
+cache_max_size = Gauge(
+ "synapse_util_caches_cache_max_size", "", ["name"], registry=CACHE_METRIC_REGISTRY
+)
cache_memory_usage = Gauge(
"synapse_util_caches_cache_size_bytes",
"Estimated memory usage of the caches",
["name"],
+ registry=CACHE_METRIC_REGISTRY,
)
-response_cache_size = Gauge("synapse_util_caches_response_cache:size", "", ["name"])
-response_cache_hits = Gauge("synapse_util_caches_response_cache:hits", "", ["name"])
+response_cache_size = Gauge(
+ "synapse_util_caches_response_cache_size",
+ "",
+ ["name"],
+ registry=CACHE_METRIC_REGISTRY,
+)
+response_cache_hits = Gauge(
+ "synapse_util_caches_response_cache_hits",
+ "",
+ ["name"],
+ registry=CACHE_METRIC_REGISTRY,
+)
response_cache_evicted = Gauge(
- "synapse_util_caches_response_cache:evicted_size", "", ["name", "reason"]
+ "synapse_util_caches_response_cache_evicted_size",
+ "",
+ ["name", "reason"],
+ registry=CACHE_METRIC_REGISTRY,
)
-response_cache_total = Gauge("synapse_util_caches_response_cache:total", "", ["name"])
+response_cache_total = Gauge(
+ "synapse_util_caches_response_cache", "", ["name"], registry=CACHE_METRIC_REGISTRY
+)
+
+
+# Register our custom cache metrics registry with the global registry
+REGISTRY.register(CACHE_METRIC_REGISTRY)
class EvictionReason(Enum):
@@ -160,7 +197,7 @@ def register_cache(
resize_callback: A function which can be called to resize the cache.
Returns:
- CacheMetric: an object which provides inc_{hits,misses,evictions} methods
+ an object which provides inc_{hits,misses,evictions} methods
"""
if resizable:
if not resize_callback:
@@ -170,7 +207,7 @@ def register_cache(
metric = CacheMetric(cache, cache_type, cache_name, collect_callback)
metric_name = "cache_%s_%s" % (cache_type, cache_name)
caches_by_name[cache_name] = cache
- collectors_by_name[metric_name] = metric
+ CACHE_METRIC_REGISTRY.register_hook(metric_name, metric.collect)
return metric
|
