feat(eth-sender): metrics for finalized and safe L1 block numbers (#972)

https://linear.app/matterlabs/issue/PLA-751/metrics-for-l1-block-heights

core/lib/zksync_core/src/eth_sender/eth_tx_manager.rs

@@ -5,7 +5,7 @@ use tokio::sync::watch;
 use zksync_config::configs::eth_sender::SenderConfig;
 use zksync_dal::{ConnectionPool, StorageProcessor};
 use zksync_eth_client::{
-    BoundEthInterface, Error, ExecutedTxStatus, RawTransactionBytes, SignedCallResult,
+    BoundEthInterface, Error, EthInterface, ExecutedTxStatus, RawTransactionBytes, SignedCallResult,
 };
 use zksync_types::{
     eth_sender::EthTx,
@@ -37,6 +37,7 @@ struct OperatorNonce {
 
 #[derive(Debug, Clone, Copy)]
 pub(super) struct L1BlockNumbers {
+    pub safe: L1BlockNumber,
     pub finalized: L1BlockNumber,
     pub latest: L1BlockNumber,
 }
@@ -300,7 +301,22 @@ impl EthTxManager {
             .await?
             .as_u32()
             .into();
-        Ok(L1BlockNumbers { finalized, latest })
+
+        let safe = self
+            .ethereum_gateway
+            .block(BlockId::Number(BlockNumber::Safe), "eth_tx_manager")
+            .await?
+            .expect("Safe block must be present on L1")
+            .number
+            .expect("Safe block must contain number")
+            .as_u32()
+            .into();
+
+        Ok(L1BlockNumbers {
+            finalized,
+            latest,
+            safe,
+        })
     }
 
     // Monitors the in-flight transactions, marks mined ones as confirmed,
@@ -310,9 +326,7 @@ impl EthTxManager {
         storage: &mut StorageProcessor<'_>,
         l1_block_numbers: L1BlockNumbers,
     ) -> Result<Option<(EthTx, u32)>, ETHSenderError> {
-        METRICS
-            .last_known_l1_block
-            .set(l1_block_numbers.latest.0.into());
+        METRICS.track_block_numbers(&l1_block_numbers);
         let operator_nonce = self.get_operator_nonce(l1_block_numbers).await?;
         let inflight_txs = storage.eth_sender_dal().get_inflight_txs().await.unwrap();
         METRICS.number_of_inflight_txs.set(inflight_txs.len());

core/lib/zksync_core/src/eth_sender/metrics.rs

@@ -7,7 +7,10 @@ use zksync_dal::StorageProcessor;
 use zksync_types::{aggregated_operations::AggregatedActionType, eth_sender::EthTx};
 use zksync_utils::time::seconds_since_epoch;
 
-use crate::metrics::{BlockL1Stage, BlockStage, APP_METRICS};
+use crate::{
+    eth_sender::eth_tx_manager::L1BlockNumbers,
+    metrics::{BlockL1Stage, BlockStage, APP_METRICS},
+};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, EncodeLabelSet, EncodeLabelValue)]
 #[metrics(label = "kind", rename_all = "snake_case")]
@@ -18,6 +21,15 @@ pub(super) enum PubdataKind {
     RepeatedWritesCompressed,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, EncodeLabelSet, EncodeLabelValue)]
+#[metrics(label = "block_number_variant", rename_all = "snake_case")]
+#[allow(clippy::enum_variant_names)]
+pub(super) enum BlockNumberVariant {
+    Latest,
+    Finalized,
+    Safe,
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, EncodeLabelSet, EncodeLabelValue)]
 #[metrics(label = "type")]
 pub(super) struct ActionTypeLabel(AggregatedActionType);
@@ -76,20 +88,28 @@ pub(super) struct EthSenderMetrics {
     #[metrics(buckets = FEE_BUCKETS)]
     pub used_priority_fee_per_gas: Histogram<u64>,
     /// Last L1 block observed by the Ethereum sender.
-    pub last_known_l1_block: Gauge<u64>,
+    pub last_known_l1_block: Family<BlockNumberVariant, Gauge<usize>>,
     /// Number of in-flight txs produced by the Ethereum sender.
     pub number_of_inflight_txs: Gauge<usize>,
     #[metrics(buckets = GAS_BUCKETS)]
     pub l1_gas_used: Family<ActionTypeLabel, Histogram<f64>>,
     #[metrics(buckets = Buckets::LATENCIES)]
     pub l1_tx_mined_latency: Family<ActionTypeLabel, Histogram<Duration>>,
-    #[metrics(buckets = &[1.0, 2.0, 3.0, 5.0, 7.0, 10.0, 20.0, 30.0, 50.0])]
+    #[metrics(buckets = & [1.0, 2.0, 3.0, 5.0, 7.0, 10.0, 20.0, 30.0, 50.0])]
     pub l1_blocks_waited_in_mempool: Family<ActionTypeLabel, Histogram<u64>>,
     /// Number of L1 batches aggregated for publishing with a specific reason.
     pub block_aggregation_reason: Family<AggregationReasonLabels, Counter>,
 }
 
 impl EthSenderMetrics {
+    pub fn track_block_numbers(&self, l1_block_numbers: &L1BlockNumbers) {
+        self.last_known_l1_block[&BlockNumberVariant::Latest]
+            .set(l1_block_numbers.latest.0 as usize);
+        self.last_known_l1_block[&BlockNumberVariant::Finalized]
+            .set(l1_block_numbers.finalized.0 as usize);
+        self.last_known_l1_block[&BlockNumberVariant::Safe].set(l1_block_numbers.safe.0 as usize);
+    }
+
     pub async fn track_eth_tx_metrics(
         &self,
         connection: &mut StorageProcessor<'_>,

core/lib/zksync_core/src/eth_sender/tests.rs

@@ -134,7 +134,11 @@ impl EthSenderTester {
     async fn get_block_numbers(&self) -> L1BlockNumbers {
         let latest = self.gateway.block_number("").await.unwrap().as_u32().into();
         let finalized = latest - Self::WAIT_CONFIRMATIONS as u32;
-        L1BlockNumbers { finalized, latest }
+        L1BlockNumbers {
+            finalized,
+            latest,
+            safe: finalized,
+        }
     }
 }