feat: proposer boost reorg

packages/api/src/beacon/routes/debug.ts

@@ -34,6 +34,7 @@ const protoNodeSszType = new ContainerType(
     parentRoot: stringType,
     stateRoot: stringType,
     targetRoot: stringType,
+    timeliness: ssz.Boolean,
     justifiedEpoch: ssz.Epoch,
     justifiedRoot: stringType,
     finalizedEpoch: ssz.Epoch,

packages/api/test/unit/beacon/testData/debug.ts

@@ -40,6 +40,7 @@ export const testData: GenericServerTestCases<Api> = {
           weight: 1,
           bestChild: "1",
           bestDescendant: "1",
+          timeliness: false,
         },
       ],
     },

packages/beacon-node/src/api/impl/validator/index.ts

@@ -323,10 +323,20 @@ export function getValidatorApi({
     {
       skipHeadChecksAndUpdate,
       commonBlockBody,
-    }: Omit<routes.validator.ExtraProduceBlockOps, "builderSelection"> & {
-      skipHeadChecksAndUpdate?: boolean;
-      commonBlockBody?: CommonBlockBody;
-    } = {}
+      parentBlockRoot: inParentBlockRoot,
+    }: Omit<routes.validator.ExtraProduceBlockOps, "builderSelection"> &
+      (
+        | {
+            skipHeadChecksAndUpdate: true;
+            commonBlockBody: CommonBlockBody;
+            parentBlockRoot: Root;
+          }
+        | {
+            skipHeadChecksAndUpdate?: false | undefined;
+            commonBlockBody?: undefined;
+            parentBlockRoot?: undefined;
+          }
+      ) = {}
   ): Promise<routes.validator.ProduceBlindedBlockRes> {
     const version = config.getForkName(slot);
     if (!isForkExecution(version)) {
@@ -344,6 +354,7 @@ export function getValidatorApi({
       throw Error("Execution builder disabled");
     }
 
+    let parentBlockRoot: Root;
     if (skipHeadChecksAndUpdate !== true) {
       notWhileSyncing();
       await waitForSlot(slot); // Must never request for a future slot > currentSlot
@@ -352,14 +363,17 @@ export function getValidatorApi({
       // forkChoice.updateTime() might have already been called by the onSlot clock
       // handler, in which case this should just return.
       chain.forkChoice.updateTime(slot);
-      chain.recomputeForkChoiceHead();
+      parentBlockRoot = fromHexString(chain.getProposerHead(slot).blockRoot);
+    } else {
+      parentBlockRoot = inParentBlockRoot;
     }
 
     let timer;
     try {
       timer = metrics?.blockProductionTime.startTimer();
       const {block, executionPayloadValue, consensusBlockValue} = await chain.produceBlindedBlock({
         slot,
+        parentBlockRoot,
         randaoReveal,
         graffiti: toGraffitiBuffer(graffiti || ""),
         commonBlockBody,
@@ -393,14 +407,21 @@ export function getValidatorApi({
       strictFeeRecipientCheck,
       skipHeadChecksAndUpdate,
       commonBlockBody,
-    }: Omit<routes.validator.ExtraProduceBlockOps, "builderSelection"> & {
-      skipHeadChecksAndUpdate?: boolean;
-      commonBlockBody?: CommonBlockBody;
-    } = {}
+      parentBlockRoot: inParentBlockRoot,
+    }: Omit<routes.validator.ExtraProduceBlockOps, "builderSelection"> &
+      (
+        | {
+            skipHeadChecksAndUpdate: true;
+            commonBlockBody: CommonBlockBody;
+            parentBlockRoot: Root;
+          }
+        | {skipHeadChecksAndUpdate?: false | undefined; commonBlockBody?: undefined; parentBlockRoot?: undefined}
+      ) = {}
   ): Promise<routes.validator.ProduceBlockOrContentsRes & {shouldOverrideBuilder?: boolean}> {
     const source = ProducedBlockSource.engine;
     metrics?.blockProductionRequests.inc({source});
 
+    let parentBlockRoot: Root;
     if (skipHeadChecksAndUpdate !== true) {
       notWhileSyncing();
       await waitForSlot(slot); // Must never request for a future slot > currentSlot
@@ -409,14 +430,17 @@ export function getValidatorApi({
       // forkChoice.updateTime() might have already been called by the onSlot clock
       // handler, in which case this should just return.
       chain.forkChoice.updateTime(slot);
-      chain.recomputeForkChoiceHead();
+      parentBlockRoot = fromHexString(chain.getProposerHead(slot).blockRoot);
+    } else {
+      parentBlockRoot = inParentBlockRoot;
     }
 
     let timer;
     try {
       timer = metrics?.blockProductionTime.startTimer();
       const {block, executionPayloadValue, consensusBlockValue, shouldOverrideBuilder} = await chain.produceBlock({
         slot,
+        parentBlockRoot,
         randaoReveal,
         graffiti: toGraffitiBuffer(graffiti || ""),
         feeRecipient,
@@ -484,7 +508,6 @@ export function getValidatorApi({
       // forkChoice.updateTime() might have already been called by the onSlot clock
       // handler, in which case this should just return.
       chain.forkChoice.updateTime(slot);
-      chain.recomputeForkChoiceHead();
 
       const fork = config.getForkName(slot);
       // set some sensible opts
@@ -529,8 +552,11 @@ export function getValidatorApi({
       };
 
       logger.verbose("Assembling block with produceEngineOrBuilderBlock", loggerContext);
+      const parentBlockRoot = fromHexString(chain.getProposerHead(slot).blockRoot);
+
       const commonBlockBody = await chain.produceCommonBlockBody({
         slot,
+        parentBlockRoot,
         randaoReveal,
         graffiti: toGraffitiBuffer(graffiti || ""),
       });
@@ -555,6 +581,7 @@ export function getValidatorApi({
             // skip checking and recomputing head in these individual produce calls
             skipHeadChecksAndUpdate: true,
             commonBlockBody,
+            parentBlockRoot,
           })
         : Promise.reject(new Error("Builder disabled"));
 
@@ -565,6 +592,7 @@ export function getValidatorApi({
             // skip checking and recomputing head in these individual produce calls
             skipHeadChecksAndUpdate: true,
             commonBlockBody,
+            parentBlockRoot,
           }).then((engineBlock) => {
             // Once the engine returns a block, in the event of either:
             // - suspected builder censorship

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

@@ -28,7 +28,7 @@ import {
   bellatrix,
   isBlindedBeaconBlock,
 } from "@lodestar/types";
-import {CheckpointWithHex, ExecutionStatus, IForkChoice, ProtoBlock} from "@lodestar/fork-choice";
+import {CheckpointWithHex, ExecutionStatus, IForkChoice, ProtoBlock, UpdateHeadOpt} from "@lodestar/fork-choice";
 import {ProcessShutdownCallback} from "@lodestar/validator";
 import {Logger, gweiToWei, isErrorAborted, pruneSetToMax, sleep, toHex} from "@lodestar/utils";
 import {ForkSeq, SLOTS_PER_EPOCH} from "@lodestar/params";
@@ -43,7 +43,14 @@ import {ensureDir, writeIfNotExist} from "../util/file.js";
 import {isOptimisticBlock} from "../util/forkChoice.js";
 import {BlockProcessor, ImportBlockOpts} from "./blocks/index.js";
 import {ChainEventEmitter, ChainEvent} from "./emitter.js";
-import {IBeaconChain, ProposerPreparationData, BlockHash, StateGetOpts, CommonBlockBody} from "./interface.js";
+import {
+  IBeaconChain,
+  ProposerPreparationData,
+  BlockHash,
+  StateGetOpts,
+  CommonBlockBody,
+  FindHeadFnName,
+} from "./interface.js";
 import {IChainOptions} from "./options.js";
 import {QueuedStateRegenerator, RegenCaller} from "./regen/index.js";
 import {initializeForkChoice} from "./forkChoice/index.js";
@@ -252,7 +259,8 @@ export class BeaconChain implements IBeaconChain {
       clock.currentSlot,
       cachedState,
       opts,
-      this.justifiedBalancesGetter.bind(this)
+      this.justifiedBalancesGetter.bind(this),
+      logger
     );
     const regen = new QueuedStateRegenerator({
       config,
@@ -475,22 +483,19 @@ export class BeaconChain implements IBeaconChain {
   }
 
   async produceCommonBlockBody(blockAttributes: BlockAttributes): Promise<CommonBlockBody> {
-    const {slot} = blockAttributes;
-    const head = this.forkChoice.getHead();
+    const {slot, parentBlockRoot} = blockAttributes;
     const state = await this.regen.getBlockSlotState(
-      head.blockRoot,
+      toHexString(parentBlockRoot),
       slot,
       {dontTransferCache: true},
       RegenCaller.produceBlock
     );
-    const parentBlockRoot = fromHexString(head.blockRoot);
 
     // TODO: To avoid breaking changes for metric define this attribute
     const blockType = BlockType.Full;
 
     return produceCommonBlockBody.call(this, blockType, state, {
       ...blockAttributes,
-      parentBlockRoot,
       parentSlot: slot - 1,
     });
   }
@@ -514,21 +519,26 @@ export class BeaconChain implements IBeaconChain {
 
   async produceBlockWrapper<T extends BlockType>(
     blockType: T,
-    {randaoReveal, graffiti, slot, feeRecipient, commonBlockBody}: BlockAttributes & {commonBlockBody?: CommonBlockBody}
+    {
+      randaoReveal,
+      graffiti,
+      slot,
+      feeRecipient,
+      commonBlockBody,
+      parentBlockRoot,
+    }: BlockAttributes & {commonBlockBody?: CommonBlockBody}
   ): Promise<{
     block: AssembledBlockType<T>;
     executionPayloadValue: Wei;
     consensusBlockValue: Wei;
     shouldOverrideBuilder?: boolean;
   }> {
-    const head = this.forkChoice.getHead();
     const state = await this.regen.getBlockSlotState(
-      head.blockRoot,
+      toHexString(parentBlockRoot),
       slot,
       {dontTransferCache: true},
       RegenCaller.produceBlock
     );
-    const parentBlockRoot = fromHexString(head.blockRoot);
     const proposerIndex = state.epochCtx.getBeaconProposer(slot);
     const proposerPubKey = state.epochCtx.index2pubkey[proposerIndex].toBytes();
 
@@ -648,10 +658,38 @@ export class BeaconChain implements IBeaconChain {
 
   recomputeForkChoiceHead(): ProtoBlock {
     this.metrics?.forkChoice.requests.inc();
-    const timer = this.metrics?.forkChoice.findHead.startTimer();
+    const timer = this.metrics?.forkChoice.findHead.startTimer({entrypoint: FindHeadFnName.recomputeForkChoiceHead});
+
+    try {
+      return this.forkChoice.updateAndGetHead({mode: UpdateHeadOpt.GetCanonicialHead});
+    } catch (e) {
+      this.metrics?.forkChoice.errors.inc();
+      throw e;
+    } finally {
+      timer?.();
+    }
+  }
+
+  predictProposerHead(slot: Slot): ProtoBlock {
+    this.metrics?.forkChoice.requests.inc();
+    const timer = this.metrics?.forkChoice.findHead.startTimer({entrypoint: FindHeadFnName.predictProposerHead});
+
+    try {
+      return this.forkChoice.updateAndGetHead({mode: UpdateHeadOpt.GetPredictedProposerHead, slot});
+    } catch (e) {
+      this.metrics?.forkChoice.errors.inc();
+      throw e;
+    } finally {
+      timer?.();
+    }
+  }
+
+  getProposerHead(slot: Slot): ProtoBlock {
+    this.metrics?.forkChoice.requests.inc();
+    const timer = this.metrics?.forkChoice.findHead.startTimer({entrypoint: FindHeadFnName.getProposerHead});
 
     try {
-      return this.forkChoice.updateHead();
+      return this.forkChoice.updateAndGetHead({mode: UpdateHeadOpt.GetProposerHead, slot});
     } catch (e) {
       this.metrics?.forkChoice.errors.inc();
       throw e;

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

@@ -7,7 +7,7 @@ import {
   ForkChoiceStore,
   ExecutionStatus,
   JustifiedBalancesGetter,
-  ForkChoiceOpts,
+  ForkChoiceOpts as RawForkChoiceOpts,
 } from "@lodestar/fork-choice";
 import {
   CachedBeaconStateAllForks,
@@ -16,12 +16,16 @@ import {
   isMergeTransitionComplete,
 } from "@lodestar/state-transition";
 
+import {Logger} from "@lodestar/utils";
 import {computeAnchorCheckpoint} from "../initState.js";
 import {ChainEventEmitter} from "../emitter.js";
 import {ChainEvent} from "../emitter.js";
 import {GENESIS_SLOT} from "../../constants/index.js";
 
-export type {ForkChoiceOpts};
+export type ForkChoiceOpts = RawForkChoiceOpts & {
+  // for testing only
+  forkchoiceConstructor?: typeof ForkChoice;
+};
 
 /**
  * Fork Choice extended with a ChainEventEmitter
@@ -32,7 +36,8 @@ export function initializeForkChoice(
   currentSlot: Slot,
   state: CachedBeaconStateAllForks,
   opts: ForkChoiceOpts,
-  justifiedBalancesGetter: JustifiedBalancesGetter
+  justifiedBalancesGetter: JustifiedBalancesGetter,
+  logger?: Logger
 ): ForkChoice {
   const {blockHeader, checkpoint} = computeAnchorCheckpoint(config, state);
   const finalizedCheckpoint = {...checkpoint};
@@ -47,7 +52,11 @@ export function initializeForkChoice(
 
   const justifiedBalances = getEffectiveBalanceIncrementsZeroInactive(state);
 
-  return new ForkChoice(
+  // forkchoiceConstructor is only used for some test cases
+  // production code use ForkChoice constructor directly
+  const forkchoiceConstructor = opts.forkchoiceConstructor ?? ForkChoice;
+
+  return new forkchoiceConstructor(
     config,
 
     new ForkChoiceStore(
@@ -68,6 +77,7 @@ export function initializeForkChoice(
         parentRoot: toHexString(blockHeader.parentRoot),
         stateRoot: toHexString(blockHeader.stateRoot),
         blockRoot: toHexString(checkpoint.root),
+        timeliness: true, // Optimisitcally assume is timely
 
         justifiedEpoch: justifiedCheckpoint.epoch,
         justifiedRoot: toHexString(justifiedCheckpoint.root),
@@ -89,6 +99,7 @@ export function initializeForkChoice(
       currentSlot
     ),
 
+    logger,
     opts
   );
 }

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

@@ -62,6 +62,12 @@ export type StateGetOpts = {
   allowRegen: boolean;
 };
 
+export enum FindHeadFnName {
+  recomputeForkChoiceHead = "recomputeForkChoiceHead",
+  predictProposerHead = "predictProposerHead",
+  getProposerHead = "getProposerHead",
+}
+
 /**
  * The IBeaconChain service deals with processing incoming blocks, advancing a state transition
  * and applying the fork choice rule to update the chain head
@@ -180,6 +186,12 @@ export interface IBeaconChain {
 
   recomputeForkChoiceHead(): ProtoBlock;
 
+  /** When proposerBoostReorg is enabled, this is called at slot n-1 to predict the head block to build on if we are proposing at slot n */
+  predictProposerHead(slot: Slot): ProtoBlock;
+
+  /** When proposerBoostReorg is enabled and we are proposing a block, this is called to determine which head block to build on */
+  getProposerHead(slot: Slot): ProtoBlock;
+
   waitForBlock(slot: Slot, root: RootHex): Promise<boolean>;
 
   updateBeaconProposerData(epoch: Epoch, proposers: ProposerPreparationData[]): Promise<void>;

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

@@ -89,6 +89,7 @@ export const defaultChainOptions: IChainOptions = {
   blsVerifyAllMultiThread: false,
   disableBlsBatchVerify: false,
   proposerBoostEnabled: true,
+  proposerBoostReorgEnabled: false,
   computeUnrealized: true,
   safeSlotsToImportOptimistically: SAFE_SLOTS_TO_IMPORT_OPTIMISTICALLY,
   suggestedFeeRecipient: defaultValidatorOptions.suggestedFeeRecipient,