feat: remove unfinalized pubkey cache (#7230)

* Remove unfinalized pubkey cache

* lint

* Fix unit test

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

@@ -1047,9 +1047,6 @@ export class BeaconChain implements IBeaconChain {
     metrics.forkChoice.balancesLength.set(forkChoiceMetrics.balancesLength);
     metrics.forkChoice.nodes.set(forkChoiceMetrics.nodes);
     metrics.forkChoice.indices.set(forkChoiceMetrics.indices);
-
-    const headState = this.getHeadState();
-    metrics.headState.unfinalizedPubkeyCacheSize.set(headState.epochCtx.unfinalizedPubkey2index.size);
   }
 
   private onClockSlot(slot: Slot): void {
@@ -1139,27 +1136,8 @@ export class BeaconChain implements IBeaconChain {
       this.opPool.pruneAll(headBlock, headState);
     }
 
-    const cpEpoch = cp.epoch;
-
     if (headState === null) {
       this.logger.verbose("Head state is null");
-    } else if (cpEpoch >= this.config.ELECTRA_FORK_EPOCH) {
-      // Get the validator.length from the state at cpEpoch
-      // We are confident the last element in the list is from headEpoch
-      // Thus we query from the end of the list. (cpEpoch - headEpoch - 1) is negative number
-      const pivotValidatorIndex = headState.epochCtx.getValidatorCountAtEpoch(cpEpoch);
-
-      if (pivotValidatorIndex !== undefined) {
-        // Note EIP-6914 will break this logic
-        const newFinalizedValidators = headState.epochCtx.unfinalizedPubkey2index.filter(
-          (index, _pubkey) => index < pivotValidatorIndex
-        );
-
-        // Populate finalized pubkey cache and remove unfinalized pubkey cache
-        if (!newFinalizedValidators.isEmpty()) {
-          this.regen.updateUnfinalizedPubkeys(newFinalizedValidators);
-        }
-      }
     }
 
     // TODO-Electra: Deprecating eth1Data poll requires a check on a finalized checkpoint state.

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

@@ -1,6 +1,6 @@
 import {routes} from "@lodestar/api";
 import {IForkChoice, ProtoBlock} from "@lodestar/fork-choice";
-import {CachedBeaconStateAllForks, UnfinalizedPubkeyIndexMap, computeEpochAtSlot} from "@lodestar/state-transition";
+import {CachedBeaconStateAllForks, computeEpochAtSlot} from "@lodestar/state-transition";
 import {BeaconBlock, Epoch, RootHex, Slot, phase0} from "@lodestar/types";
 import {Logger, toRootHex} from "@lodestar/utils";
 import {Metrics} from "../../metrics/index.js";
@@ -206,54 +206,6 @@ export class QueuedStateRegenerator implements IStateRegenerator {
     return this.checkpointStateCache.updatePreComputedCheckpoint(rootHex, epoch);
   }
 
-  /**
-   * Remove `validators` from all unfinalized cache's epochCtx.UnfinalizedPubkey2Index,
-   * and add them to epochCtx.pubkey2index and epochCtx.index2pubkey
-   */
-  updateUnfinalizedPubkeys(validators: UnfinalizedPubkeyIndexMap): void {
-    let numStatesUpdated = 0;
-    const states = this.blockStateCache.getStates();
-    const cpStates = this.checkpointStateCache.getStates();
-
-    // Add finalized pubkeys to all states.
-    const addTimer = this.metrics?.regenFnAddPubkeyTime.startTimer();
-
-    // We only need to add pubkeys to any one of the states since the finalized caches is shared globally across all states
-    const firstState = (states.next().value ?? cpStates.next().value) as CachedBeaconStateAllForks | undefined;
-
-    if (firstState !== undefined) {
-      firstState.epochCtx.addFinalizedPubkeys(validators, this.metrics?.epochCache ?? undefined);
-    } else {
-      this.logger.warn("Attempt to delete finalized pubkey from unfinalized pubkey cache. But no state is available");
-    }
-
-    addTimer?.();
-
-    // Delete finalized pubkeys from unfinalized pubkey cache for all states
-    const deleteTimer = this.metrics?.regenFnDeletePubkeyTime.startTimer();
-    const pubkeysToDelete = Array.from(validators.keys());
-
-    for (const s of states) {
-      s.epochCtx.deleteUnfinalizedPubkeys(pubkeysToDelete);
-      numStatesUpdated++;
-    }
-
-    for (const s of cpStates) {
-      s.epochCtx.deleteUnfinalizedPubkeys(pubkeysToDelete);
-      numStatesUpdated++;
-    }
-
-    // Since first state is consumed from the iterator. Will need to perform delete explicitly
-    if (firstState !== undefined) {
-      firstState?.epochCtx.deleteUnfinalizedPubkeys(pubkeysToDelete);
-      numStatesUpdated++;
-    }
-
-    deleteTimer?.();
-
-    this.metrics?.regenFnNumStatesUpdated.observe(numStatesUpdated);
-  }
-
   /**
    * Get the state to run with `block`.
    * - State after `block.parentRoot` dialed forward to block.slot

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

@@ -34,7 +34,7 @@ export class BlockStateCacheImpl implements BlockStateCache {
     this.maxStates = maxStates;
     this.cache = new MapTracker(metrics?.stateCache);
     if (metrics) {
-      this.metrics = {...metrics.stateCache, ...metrics.epochCache};
+      this.metrics = metrics.stateCache;
       metrics.stateCache.size.addCollect(() => metrics.stateCache.size.set(this.cache.size));
     }
   }

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

@@ -124,13 +124,6 @@ export function createBeaconMetrics(register: RegistryMetricCreator) {
       }),
     },
 
-    headState: {
-      unfinalizedPubkeyCacheSize: register.gauge({
-        name: "beacon_head_state_unfinalized_pubkey_cache_size",
-        help: "Current size of the unfinalizedPubkey2Index cache in the head state",
-      }),
-    },
-
     parentBlockDistance: register.histogram({
       name: "beacon_imported_block_parent_distance",
       help: "Histogram of distance to parent block of valid imported blocks",

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

@@ -378,17 +378,6 @@ export function createLodestarMetrics(
       help: "Total count state.validators nodesPopulated is false on stfn for post state",
     }),
 
-    epochCache: {
-      finalizedPubkeyDuplicateInsert: register.gauge({
-        name: "lodestar_epoch_cache_finalized_pubkey_duplicate_insert_total",
-        help: "Total count of duplicate insert of finalized pubkeys",
-      }),
-      newUnFinalizedPubkey: register.gauge({
-        name: "lodestar_epoch_cache_new_unfinalized_pubkey_total",
-        help: "Total count of unfinalized pubkeys added",
-      }),
-    },
-
     // BLS verifier thread pool and queue
 
     bls: {

packages/beacon-node/test/sim/electra-interop.test.ts

@@ -375,17 +375,8 @@ describe("executionEngine / ExecutionEngineHttp", () => {
     if (headState.validators.length !== 33 || headState.balances.length !== 33) {
       throw Error("New validator is not reflected in the beacon state at slot 5");
     }
-    if (epochCtx.index2pubkey.length !== 32 || epochCtx.pubkey2index.size !== 32) {
-      throw Error("Finalized cache is modified.");
-    }
-    if (epochCtx.unfinalizedPubkey2index.size !== 1) {
-      throw Error(
-        `Unfinalized cache is missing the expected validator. Size: ${epochCtx.unfinalizedPubkey2index.size}`
-      );
-    }
-    // validator count at epoch 1 should be empty at this point since no epoch transition has happened.
-    if (epochCtx.getValidatorCountAtEpoch(1) !== undefined) {
-      throw Error("Historical validator lengths is modified");
+    if (epochCtx.index2pubkey.length !== 33 || epochCtx.pubkey2index.size !== 33) {
+      throw Error("Pubkey cache is not updated");
     }
 
     await new Promise<void>((resolve, _reject) => {
@@ -412,23 +403,7 @@ describe("executionEngine / ExecutionEngineHttp", () => {
       throw Error("New validator is not reflected in the beacon state.");
     }
     if (epochCtx.index2pubkey.length !== 33 || epochCtx.pubkey2index.size !== 33) {
-      throw Error("New validator is not in finalized cache");
-    }
-    if (!epochCtx.unfinalizedPubkey2index.isEmpty()) {
-      throw Error("Unfinalized cache still contains new validator");
-    }
-    // After 4 epochs, headState's finalized cp epoch should be 2
-    // epochCtx should only have validator count for epoch 3 and 4.
-    if (epochCtx.getValidatorCountAtEpoch(4) === undefined || epochCtx.getValidatorCountAtEpoch(3) === undefined) {
-      throw Error("Missing historical validator length for epoch 3 or 4");
-    }
-
-    if (epochCtx.getValidatorCountAtEpoch(4) !== 33 || epochCtx.getValidatorCountAtEpoch(3) !== 33) {
-      throw Error("Incorrect historical validator length for epoch 3 or 4");
-    }
-
-    if (epochCtx.getValidatorCountAtEpoch(2) !== undefined || epochCtx.getValidatorCountAtEpoch(1) !== undefined) {
-      throw Error("Historical validator length for epoch 1 or 2 is not dropped properly");
+      throw Error("New validator is not in pubkey cache");
     }
 
     if (headState.depositRequestsStartIndex === UNSET_DEPOSIT_REQUESTS_START_INDEX) {

packages/state-transition/package.json

@@ -69,8 +69,7 @@
     "@lodestar/params": "^1.23.0",
     "@lodestar/types": "^1.23.0",
     "@lodestar/utils": "^1.23.0",
-    "bigint-buffer": "^1.1.5",
-    "immutable": "^4.3.2"
+    "bigint-buffer": "^1.1.5"
   },
   "keywords": [
     "ethereum",