feat: add forkchoice data structures metrics

packages/beacon-node/src/chain/chain.ts

@@ -284,7 +284,9 @@ export class BeaconChain implements IBeaconChain {
       new PrepareNextSlotScheduler(this, this.config, metrics, this.logger, signal);
     }
 
-    metrics?.opPool.aggregatedAttestationPoolSize.addCollect(() => this.onScrapeMetrics());
+    if (metrics) {
+      metrics.opPool.aggregatedAttestationPoolSize.addCollect(() => this.onScrapeMetrics(metrics));
+    }
 
     // Event handlers. emitter is created internally and dropped on close(). Not need to .removeListener()
     clock.addListener(ClockEvent.slot, this.onClockSlot.bind(this));
@@ -652,17 +654,25 @@ export class BeaconChain implements IBeaconChain {
     this.logger.debug("Persisted invalid ssz object", {id: suffix, filepath});
   }
 
-  private onScrapeMetrics(): void {
+  private onScrapeMetrics(metrics: Metrics): void {
     const {attestationCount, attestationDataCount} = this.aggregatedAttestationPool.getAttestationCount();
-    this.metrics?.opPool.aggregatedAttestationPoolSize.set(attestationCount);
-    this.metrics?.opPool.aggregatedAttestationPoolUniqueData.set(attestationDataCount);
-    this.metrics?.opPool.attestationPoolSize.set(this.attestationPool.getAttestationCount());
-    this.metrics?.opPool.attesterSlashingPoolSize.set(this.opPool.attesterSlashingsSize);
-    this.metrics?.opPool.proposerSlashingPoolSize.set(this.opPool.proposerSlashingsSize);
-    this.metrics?.opPool.voluntaryExitPoolSize.set(this.opPool.voluntaryExitsSize);
-    this.metrics?.opPool.syncCommitteeMessagePoolSize.set(this.syncCommitteeMessagePool.size);
-    this.metrics?.opPool.syncContributionAndProofPoolSize.set(this.syncContributionAndProofPool.size);
-    this.metrics?.opPool.blsToExecutionChangePoolSize.set(this.opPool.blsToExecutionChangeSize);
+    metrics.opPool.aggregatedAttestationPoolSize.set(attestationCount);
+    metrics.opPool.aggregatedAttestationPoolUniqueData.set(attestationDataCount);
+    metrics.opPool.attestationPoolSize.set(this.attestationPool.getAttestationCount());
+    metrics.opPool.attesterSlashingPoolSize.set(this.opPool.attesterSlashingsSize);
+    metrics.opPool.proposerSlashingPoolSize.set(this.opPool.proposerSlashingsSize);
+    metrics.opPool.voluntaryExitPoolSize.set(this.opPool.voluntaryExitsSize);
+    metrics.opPool.syncCommitteeMessagePoolSize.set(this.syncCommitteeMessagePool.size);
+    metrics.opPool.syncContributionAndProofPoolSize.set(this.syncContributionAndProofPool.size);
+    metrics.opPool.blsToExecutionChangePoolSize.set(this.opPool.blsToExecutionChangeSize);
+
+    const forkChoiceMetrics = this.forkChoice.getMetrics();
+    metrics.forkChoice.votes.set(forkChoiceMetrics.votes);
+    metrics.forkChoice.queuedAttestations.set(forkChoiceMetrics.queuedAttestations);
+    metrics.forkChoice.validatedAttestationDatas.set(forkChoiceMetrics.validatedAttestationDatas);
+    metrics.forkChoice.balancesLength.set(forkChoiceMetrics.balancesLength);
+    metrics.forkChoice.nodes.set(forkChoiceMetrics.nodes);
+    metrics.forkChoice.indices.set(forkChoiceMetrics.indices);
   }
 
   private onClockSlot(slot: Slot): void {

packages/beacon-node/src/metrics/metrics/beacon.ts

@@ -83,6 +83,30 @@ export function createBeaconMetrics(register: RegistryMetricCreator) {
         // Add buckets up to 100 to capture high depth re-orgs. Above 100 things are going really bad.
         buckets: [1, 2, 3, 5, 7, 10, 20, 30, 50, 100],
       }),
+      votes: register.gauge({
+        name: "beacon_fork_choice_votes_count",
+        help: "Current count of votes in fork choice data structures",
+      }),
+      queuedAttestations: register.gauge({
+        name: "beacon_fork_choice_queued_attestations_count",
+        help: "Current count of queued_attestations in fork choice data structures",
+      }),
+      validatedAttestationDatas: register.gauge({
+        name: "beacon_fork_choice_validated_attestation_datas_count",
+        help: "Current count of validatedAttestationDatas in fork choice data structures",
+      }),
+      balancesLength: register.gauge({
+        name: "beacon_fork_choice_balances_length",
+        help: "Current length of balances in fork choice data structures",
+      }),
+      nodes: register.gauge({
+        name: "beacon_fork_choice_nodes_count",
+        help: "Current count of nodes in fork choice data structures",
+      }),
+      indices: register.gauge({
+        name: "beacon_fork_choice_indices_count",
+        help: "Current count of indices in fork choice data structures",
+      }),
     },
 
     parentBlockDistance: register.histogram({

packages/fork-choice/src/forkChoice/forkChoice.ts

@@ -39,6 +39,7 @@ import {
   EpochDifference,
   AncestorResult,
   AncestorStatus,
+  ForkChoiceMetrics,
 } from "./interface.js";
 import {IForkChoiceStore, CheckpointWithHex, toCheckpointWithHex, JustifiedBalances} from "./store.js";
 
@@ -112,6 +113,17 @@ export class ForkChoice implements IForkChoice {
     this.balances = this.fcStore.justified.balances;
   }
 
+  getMetrics(): ForkChoiceMetrics {
+    return {
+      votes: this.votes.length,
+      queuedAttestations: this.queuedAttestations.size,
+      validatedAttestationDatas: this.validatedAttestationDatas.size,
+      balancesLength: this.balances.length,
+      nodes: this.protoArray.nodes.length,
+      indices: this.protoArray.indices.size,
+    };
+  }
+
   /**
    * Returns the block root of an ancestor of `blockRoot` at the given `slot`.
    * (Note: `slot` refers to the block that is *returned*, not the one that is supplied.)

packages/fork-choice/src/forkChoice/interface.ts

@@ -37,8 +37,19 @@ export type AncestorResult =
   | {code: AncestorStatus.NoCommonAncenstor}
   | {code: AncestorStatus.BlockUnknown};
 
+export type ForkChoiceMetrics = {
+  votes: number;
+  queuedAttestations: number;
+  validatedAttestationDatas: number;
+  balancesLength: number;
+  nodes: number;
+  indices: number;
+};
+
 export interface IForkChoice {
   irrecoverableError?: Error;
+
+  getMetrics(): ForkChoiceMetrics;
   /**
    * Returns the block root of an ancestor of `block_root` at the given `slot`. (Note: `slot` refers
    * to the block that is *returned*, not the one that is supplied.)

packages/fork-choice/src/index.ts

@@ -10,7 +10,14 @@ export {
 } from "./protoArray/interface.js";
 
 export {ForkChoice, ForkChoiceOpts, assertValidTerminalPowBlock} from "./forkChoice/forkChoice.js";
-export {IForkChoice, PowBlockHex, EpochDifference, AncestorResult, AncestorStatus} from "./forkChoice/interface.js";
+export {
+  IForkChoice,
+  PowBlockHex,
+  EpochDifference,
+  AncestorResult,
+  AncestorStatus,
+  ForkChoiceMetrics,
+} from "./forkChoice/interface.js";
 export {ForkChoiceStore, IForkChoiceStore, CheckpointWithHex, JustifiedBalancesGetter} from "./forkChoice/store.js";
 export {
   InvalidAttestation,