add da cache metrics

beacon_node/beacon_chain/src/data_availability_checker.rs

@@ -454,6 +454,24 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
     pub fn persist_all(&self) -> Result<(), AvailabilityCheckError> {
         self.availability_cache.write_all_to_disk()
     }
+
+    /// Collects metrics from the data availability checker.
+    pub fn metrics(&self) -> DataAvailabilityCheckerMetrics {
+        DataAvailabilityCheckerMetrics {
+            processing_cache_size: self.processing_cache.read().len(),
+            num_store_entries: self.availability_cache.num_store_entries(),
+            state_cache_size: self.availability_cache.state_cache_size(),
+            block_cache_size: self.availability_cache.block_cache_size(),
+        }
+    }
+}
+
+/// Helper struct to group data availability checker metrics.
+pub struct DataAvailabilityCheckerMetrics {
+    pub processing_cache_size: usize,
+    pub num_store_entries: usize,
+    pub state_cache_size: usize,
+    pub block_cache_size: usize,
 }
 
 pub fn start_availability_cache_maintenance_service<T: BeaconChainTypes>(

beacon_node/beacon_chain/src/data_availability_checker/overflow_lru_cache.rs

@@ -363,6 +363,16 @@ impl<T: BeaconChainTypes> Critical<T> {
             }
         }
     }
+
+    /// Returns the number of pending component entries in memory.
+    pub fn num_blocks(&self) -> usize {
+        self.in_memory.len()
+    }
+
+    /// Returns the number of entries that have overflowed to disk.
+    pub fn num_store_entries(&self) -> usize {
+        self.store_keys.len()
+    }
 }
 
 /// This is the main struct for this module. Outside methods should
@@ -671,6 +681,21 @@ impl<T: BeaconChainTypes> OverflowLRUCache<T> {
     pub fn state_lru_cache(&self) -> &StateLRUCache<T> {
         &self.state_cache
     }
+
+    /// Number of states stored in memory in the cache.
+    pub fn state_cache_size(&self) -> usize {
+        self.state_cache.lru_cache().read().len()
+    }
+
+    /// Number of pending component entries in memory in the cache.
+    pub fn block_cache_size(&self) -> usize {
+        self.critical.read().num_blocks()
+    }
+
+    /// Returns the number of entries in the cache that have overflowed to disk.
+    pub fn num_store_entries(&self) -> usize {
+        self.critical.read().num_store_entries()
+    }
 }
 
 impl ssz::Encode for OverflowKey {

beacon_node/beacon_chain/src/data_availability_checker/processing_cache.rs

@@ -38,6 +38,9 @@ impl<E: EthSpec> ProcessingCache<E> {
         }
         roots_missing_components
     }
+    pub fn len(&self) -> usize {
+        self.processing_cache.len()
+    }
 }
 
 #[derive(Debug, Clone)]

beacon_node/beacon_chain/src/data_availability_checker/state_lru_cache.rs

@@ -190,8 +190,7 @@ impl<T: BeaconChainTypes> StateLRUCache<T> {
             })
     }
 
-    /// returns the state cache for inspection in tests
-    #[cfg(test)]
+    /// returns the state cache for inspection
     pub fn lru_cache(&self) -> &RwLock<LruCache<Hash256, BeaconState<T::EthSpec>>> {
         &self.states
     }

beacon_node/beacon_chain/src/metrics.rs

@@ -1128,6 +1128,31 @@ lazy_static! {
         // Create a custom bucket list for greater granularity in block delay
         Ok(vec![0.1, 0.2, 0.3,0.4,0.5,0.75,1.0,1.25,1.5,1.75,2.0,2.5,3.0,3.5,4.0,5.0,6.0,7.0,8.0,9.0,10.0,15.0,20.0])
     );
+
+
+    /*
+    * Data Availability cache metrics
+    */
+    pub static ref DATA_AVAILABILITY_PROCESSING_CACHE_SIZE: Result<IntGauge> =
+        try_create_int_gauge(
+            "data_availability_processing_cache_size",
+            "Number of entries in the data availability processing cache."
+        );
+    pub static ref DATA_AVAILABILITY_OVERFLOW_MEMORY_BLOCK_CACHE_SIZE: Result<IntGauge> =
+        try_create_int_gauge(
+            "data_availability_overflow_memory_block_cache_size",
+            "Number of entries in the data availability overflow block memory cache."
+        );
+    pub static ref DATA_AVAILABILITY_OVERFLOW_MEMORY_STATE_CACHE_SIZE: Result<IntGauge> =
+        try_create_int_gauge(
+            "data_availability_overflow_memory_state_cache_size",
+            "Number of entries in the data availability overflow state memory cache."
+        );
+    pub static ref DATA_AVAILABILITY_OVERFLOW_STORE_CACHE_SIZE: Result<IntGauge> =
+        try_create_int_gauge(
+            "data_availability_overflow_store_cache_size",
+            "Number of entries in the data availability overflow store cache."
+        );
 }
 
 /// Scrape the `beacon_chain` for metrics that are not constantly updated (e.g., the present slot,
@@ -1155,6 +1180,24 @@ pub fn scrape_for_metrics<T: BeaconChainTypes>(beacon_chain: &BeaconChain<T>) {
         )
     }
 
+    let da_checker_metrics = beacon_chain.data_availability_checker.metrics();
+    set_gauge_by_usize(
+        &DATA_AVAILABILITY_PROCESSING_CACHE_SIZE,
+        da_checker_metrics.processing_cache_size,
+    );
+    set_gauge_by_usize(
+        &DATA_AVAILABILITY_OVERFLOW_MEMORY_BLOCK_CACHE_SIZE,
+        da_checker_metrics.block_cache_size,
+    );
+    set_gauge_by_usize(
+        &DATA_AVAILABILITY_OVERFLOW_MEMORY_STATE_CACHE_SIZE,
+        da_checker_metrics.state_cache_size,
+    );
+    set_gauge_by_usize(
+        &DATA_AVAILABILITY_OVERFLOW_STORE_CACHE_SIZE,
+        da_checker_metrics.num_store_entries,
+    );
+
     if let Some((size, num_lookups)) = beacon_chain.pre_finalization_block_cache.metrics() {
         set_gauge_by_usize(&PRE_FINALIZATION_BLOCK_CACHE_SIZE, size);
         set_gauge_by_usize(&PRE_FINALIZATION_BLOCK_LOOKUP_COUNT, num_lookups);