feat: modified MultiConsumerLruCache to track inMemory usage (#14034)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

crates/rpc/rpc-eth-types/src/cache/metrics.rs

@@ -14,4 +14,6 @@ pub(crate) struct CacheMetrics {
     pub(crate) hits_total: Counter,
     /// The number of cache misses.
     pub(crate) misses_total: Counter,
+    /// The memory usage of the cache.
+    pub(crate) memory_usage: Gauge,
 }

crates/rpc/rpc-eth-types/src/cache/multi_consumer.rs

@@ -1,16 +1,15 @@
 //! Metered cache, which also provides storage for senders in order to queue queries that result in
 //! a cache miss.
 
+use super::metrics::CacheMetrics;
+use reth_primitives_traits::InMemorySize;
+use schnellru::{ByLength, Limiter, LruMap};
 use std::{
     collections::{hash_map::Entry, HashMap},
     fmt::{self, Debug, Formatter},
     hash::Hash,
 };
 
-use schnellru::{ByLength, Limiter, LruMap};
-
-use super::metrics::CacheMetrics;
-
 /// A multi-consumer LRU cache.
 pub struct MultiConsumerLruCache<K, V, L, S>
 where
@@ -23,6 +22,8 @@ where
     queued: HashMap<K, Vec<S>>,
     /// Cache metrics
     metrics: CacheMetrics,
+    // Tracked heap usage
+    memory_usage: usize,
 }
 
 impl<K, V, L, S> Debug for MultiConsumerLruCache<K, V, L, S>
@@ -35,6 +36,7 @@ where
             .field("cache_length", &self.cache.len())
             .field("cache_memory_usage", &self.cache.memory_usage())
             .field("queued_length", &self.queued.len())
+            .field("memory_usage", &self.memory_usage)
             .finish()
     }
 }
@@ -62,8 +64,13 @@ where
     }
 
     /// Remove consumers for a given key, this will also remove the key from the cache.
-    pub fn remove(&mut self, key: &K) -> Option<Vec<S>> {
-        let _ = self.cache.remove(key);
+    pub fn remove(&mut self, key: &K) -> Option<Vec<S>>
+    where
+        V: InMemorySize,
+    {
+        self.cache
+            .remove(key)
+            .inspect(|value| self.memory_usage = self.memory_usage.saturating_sub(value.size()));
         self.queued
             .remove(key)
             .inspect(|removed| self.metrics.queued_consumers_count.decrement(removed.len() as f64))
@@ -89,14 +96,22 @@ where
     pub fn insert<'a>(&mut self, key: L::KeyToInsert<'a>, value: V) -> bool
     where
         L::KeyToInsert<'a>: Hash + PartialEq<K>,
+        V: InMemorySize,
     {
-        self.cache.insert(key, value)
+        let size = value.size();
+        if self.cache.insert(key, value) {
+            self.memory_usage = self.memory_usage.saturating_add(size);
+            true
+        } else {
+            false
+        }
     }
 
     /// Update metrics for the inner cache.
     #[inline]
     pub fn update_cached_metrics(&self) {
         self.metrics.cached_count.set(self.cache.len() as f64);
+        self.metrics.memory_usage.set(self.memory_usage as f64);
     }
 }
 
@@ -110,6 +125,7 @@ where
             cache: LruMap::new(ByLength::new(max_len)),
             queued: Default::default(),
             metrics: CacheMetrics::new_with_labels(&[("cache", cache_id.to_string())]),
+            memory_usage: 0,
         }
     }
 }

etc/grafana/dashboards/overview.json

@@ -8309,6 +8309,57 @@
           "refId": "D",
           "useBackend": false
         },
+        {
+          "datasource": {
+              "type": "prometheus",
+              "uid": "${DS_PROMETHEUS}"
+          },
+          "disableTextWrap": false,
+          "editorMode": "builder",
+          "expr": "reth_rpc_eth_cache_memory_usage{instance=\"$instance\", cache=\"receipts\"}",
+          "fullMetaSearch": false,
+          "hide": false,
+          "includeNullMetadata": true,
+          "instant": false,
+          "legendFormat": "Receipts cache memory usage",
+          "range": true,
+          "refId": "D",
+          "useBackend": false
+      },
+      {
+          "datasource": {
+              "type": "prometheus",
+              "uid": "${DS_PROMETHEUS}"
+          },
+          "disableTextWrap": false,
+          "editorMode": "builder",
+          "expr": "reth_rpc_eth_cache_memory_usage{instance=\"$instance\", cache=\"blocks\"}",
+          "fullMetaSearch": false,
+          "hide": false,
+          "includeNullMetadata": true,
+          "instant": false,
+          "legendFormat": "Blocks cache memory usage",
+          "range": true,
+          "refId": "E",
+          "useBackend": false
+      },
+      {
+          "datasource": {
+              "type": "prometheus",
+              "uid": "${DS_PROMETHEUS}"
+          },
+          "disableTextWrap": false,
+          "editorMode": "builder",
+          "expr": "reth_rpc_eth_cache_memory_usage{instance=\"$instance\", cache=\"headers\"}",
+          "fullMetaSearch": false,
+          "hide": false,
+          "includeNullMetadata": true,
+          "instant": false,
+          "legendFormat": "Headers cache memory usage",
+          "range": true,
+          "refId": "F",
+          "useBackend": false
+      },
         {
           "datasource": {
             "type": "prometheus",