Improve FB metrics even more (#380)

* Add counter metrics
Fix histogram to show correct distr

* Add counter metrics
Fix histogram to show correct distr

Author: SozinM

crates/rollup-boost/src/flashblocks/metrics.rs

@@ -28,6 +28,32 @@ pub struct FlashblocksServiceMetrics {
     #[metric(describe = "Number of messages processed by the service")]
     pub messages_processed: Counter,
 
-    #[metric(describe = "Number of flashblocks used to build a block")]
-    pub flashblocks_used: Histogram,
+    #[metric(describe = "Total number of used flashblocks")]
+    pub flashblocks_gauge: Gauge,
+
+    #[metric(describe = "Total number of used flashblocks")]
+    pub flashblocks_counter: Counter,
+
+    #[metric(describe = "Reduction in flashblocks issued.")]
+    pub flashblocks_missing_histogram: Histogram,
+
+    #[metric(describe = "Reduction in flashblocks issued.")]
+    pub flashblocks_missing_gauge: Gauge,
+
+    #[metric(describe = "Reduction in flashblocks issued.")]
+    pub flashblocks_missing_counter: Counter,
+}
+
+impl FlashblocksServiceMetrics {
+    pub fn record_flashblocks(&self, flashblocks_count: u64, max_flashblocks: u64) {
+        let reduced_flashblocks = max_flashblocks.saturating_sub(flashblocks_count);
+        self.flashblocks_gauge.set(flashblocks_count as f64);
+        self.flashblocks_counter.increment(flashblocks_count);
+        self.flashblocks_missing_histogram
+            .record(reduced_flashblocks as f64);
+        self.flashblocks_missing_gauge
+            .set(reduced_flashblocks as f64);
+        self.flashblocks_missing_counter
+            .increment(reduced_flashblocks);
+    }
 }

crates/rollup-boost/src/flashblocks/service.rs

@@ -22,6 +22,7 @@ use reth_optimism_payload_builder::payload_id_optimism;
 use serde::{Deserialize, Serialize};
 use std::io;
 use std::sync::Arc;
+use std::sync::atomic::{AtomicU64, Ordering};
 use thiserror::Error;
 use tokio::sync::RwLock;
 use tokio::sync::mpsc;
@@ -187,7 +188,12 @@ pub struct FlashblocksService {
     /// Websocket publisher for sending valid pre-confirmations to clients.
     ws_pub: Arc<WebSocketPublisher>,
 
+    /// Metrics
     metrics: FlashblocksServiceMetrics,
+
+    /// Atomic to track absolute maximum number of flashblocks used is block building.
+    /// This used to measures the reduction in flashblocks issued.
+    max_flashblocks: Arc<AtomicU64>,
 }
 
 impl FlashblocksService {
@@ -200,6 +206,7 @@ impl FlashblocksService {
             best_payload: Arc::new(RwLock::new(FlashblockBuilder::new())),
             ws_pub,
             metrics: Default::default(),
+            max_flashblocks: Arc::new(AtomicU64::new(0)),
         })
     }
 
@@ -219,10 +226,13 @@ impl FlashblocksService {
         // consume the best payload and reset the builder
         let payload = {
             let mut builder = self.best_payload.write().await;
-            let flashblocks_number = builder.flashblocks.len();
+            let flashblocks_number = builder.flashblocks.len() as u64;
+            let max_flashblocks = self
+                .max_flashblocks
+                .fetch_max(flashblocks_number, Ordering::Relaxed)
+                .max(flashblocks_number);
             self.metrics
-                .flashblocks_used
-                .record(flashblocks_number as f64);
+                .record_flashblocks(flashblocks_number, max_flashblocks);
             tracing::Span::current().record("flashblocks_count", flashblocks_number);
             // Take payload and place new one in its place in one go to avoid double locking
             std::mem::replace(&mut *builder, FlashblockBuilder::new()).into_envelope(version)?