Re-added block_availability_delay and utilized it

Author: ackintosh

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -4322,6 +4322,9 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         payload_verification_status: PayloadVerificationStatus,
         current_slot: Slot,
     ) {
+        let block_delay_total =
+            get_slot_delay_ms(block_time_imported, block.slot(), &self.slot_clock);
+
         // Only present some metrics for blocks from the previous epoch or later.
         //
         // This helps avoid noise in the metrics during sync.
@@ -4331,6 +4334,11 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 block.body().attestations_len() as f64,
             );
 
+            metrics::set_gauge(
+                &metrics::BLOCK_AVAILABILITY_DELAY,
+                block_delay_total.as_secs() as i64,
+            );
+
             if let Ok(sync_aggregate) = block.body().sync_aggregate() {
                 metrics::set_gauge(
                     &metrics::BLOCK_SYNC_AGGREGATE_SET_BITS,
@@ -4339,9 +4347,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             }
         }
 
-        let block_delay_total =
-            get_slot_delay_ms(block_time_imported, block.slot(), &self.slot_clock);
-
         // Do not write to the cache for blocks older than 2 epochs, this helps reduce writes to
         // the cache during sync.
         if block_delay_total < self.slot_clock.slot_duration() * 64 {

beacon_node/beacon_chain/src/metrics.rs

@@ -1835,6 +1835,16 @@ pub static BLOCK_PRODUCTION_BLOBS_VERIFICATION_TIMES: LazyLock<Result<Histogram>
     },
 );
 
+/*
+ * Availability related metrics
+ */
+pub static BLOCK_AVAILABILITY_DELAY: LazyLock<Result<IntGauge>> = LazyLock::new(|| {
+    try_create_int_gauge(
+        "block_availability_delay",
+        "Duration between start of the slot and the time at which all components of the block are available.",
+    )
+});
+
 /*
  * Data Availability cache metrics
  */