From 7f24c6eacd0519a0dc47a07504039140e158dabc Mon Sep 17 00:00:00 2001
From: dapplion <35266934+dapplion@users.noreply.github.com>
Date: Wed, 12 Jul 2023 12:45:15 +0200
Subject: [PATCH] Track participants of produced aggregates

---
 .../src/api/impl/validator/index.ts           |  8 +++++++
 .../chain/produceBlock/produceBlockBody.ts    |  7 +++---
 .../src/metrics/metrics/lodestar.ts           | 24 +++++++++++++++++++
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/packages/beacon-node/src/api/impl/validator/index.ts b/packages/beacon-node/src/api/impl/validator/index.ts
index def416fc963a..face5456394f 100644
--- a/packages/beacon-node/src/api/impl/validator/index.ts
+++ b/packages/beacon-node/src/api/impl/validator/index.ts
@@ -374,6 +374,11 @@ export function getValidatorApi({
 
       const contribution = chain.syncCommitteeMessagePool.getContribution(subcommitteeIndex, slot, beaconBlockRoot);
       if (!contribution) throw new ApiError(500, "No contribution available");
+
+      metrics?.production.producedSyncContributionParticipants.observe(
+        contribution.aggregationBits.getTrueBitIndexes().length
+      );
+
       return {data: contribution};
     },
 
@@ -538,6 +543,9 @@ export function getValidatorApi({
 
       await waitForSlot(slot); // Must never request for a future slot > currentSlot
 
+      const aggregate = chain.attestationPool.getAggregate(slot, attestationDataRoot);
+      metrics?.production.producedAggregateParticipants.observe(aggregate.aggregationBits.getTrueBitIndexes().length);
+
       return {
         data: chain.attestationPool.getAggregate(slot, attestationDataRoot),
       };
diff --git a/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts b/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts
index e8a76ffc64b1..04b5760a4a71 100644
--- a/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts
+++ b/packages/beacon-node/src/chain/produceBlock/produceBlockBody.ts
@@ -130,10 +130,11 @@ export async function produceBlockBody<T extends BlockType>(
   const blockEpoch = computeEpochAtSlot(blockSlot);
 
   if (blockEpoch >= this.config.ALTAIR_FORK_EPOCH) {
-    (blockBody as altair.BeaconBlockBody).syncAggregate = this.syncContributionAndProofPool.getAggregate(
-      parentSlot,
-      parentBlockRoot
+    const syncAggregate = this.syncContributionAndProofPool.getAggregate(parentSlot, parentBlockRoot);
+    this.metrics?.production.producedSyncAggregateParticipants.observe(
+      syncAggregate.syncCommitteeBits.getTrueBitIndexes().length
     );
+    (blockBody as altair.BeaconBlockBody).syncAggregate = syncAggregate;
   }
 
   const fork = currentState.config.getForkName(blockSlot);
diff --git a/packages/beacon-node/src/metrics/metrics/lodestar.ts b/packages/beacon-node/src/metrics/metrics/lodestar.ts
index fb2d540abb45..439b5c563094 100644
--- a/packages/beacon-node/src/metrics/metrics/lodestar.ts
+++ b/packages/beacon-node/src/metrics/metrics/lodestar.ts
@@ -221,6 +221,30 @@ export function createLodestarMetrics(
       }),
     },
 
+    production: {
+      producedAggregateParticipants: register.histogram({
+        name: "lodestar_produced_aggregate_participants",
+        help: "API impl produced aggregates histogram of participatns",
+        // We care more about tracking low quality aggregates with low participation
+        // Max committee sizes are: 0.5e6 vc: 244, 1e6 vc: 488
+        buckets: [1, 5, 20, 50, 100, 200, 400],
+      }),
+      producedSyncContributionParticipants: register.histogram({
+        name: "lodestar_produced_sync_contribution_participants",
+        help: "API impl produced sync contribution histogram of participatns",
+        // We care more about tracking low quality aggregates with low participation
+        // Max committee sizes fixed to 512/4 = 128
+        buckets: [1, 5, 20, 50, 128],
+      }),
+      producedSyncAggregateParticipants: register.histogram({
+        name: "lodestar_produced_sync_aggregate_participants",
+        help: "API impl produced sync aggregate histogram of participatns",
+        // We care more about tracking low quality aggregates with low participation
+        // Max committee sizes fixed to 512
+        buckets: [1, 5, 20, 50, 100, 200, 512],
+      }),
+    },
+
     // Beacon state transition metrics
 
     epochTransitionTime: register.histogram({