Skip to content

Commit

Permalink
Simplify Eth1MergeBlockTracker statuses
Browse files Browse the repository at this point in the history
  • Loading branch information
@dapplion
dapplion committed Aug 2, 2022
1 parent 6c5cd12 commit ba902cc
Show file tree
Hide file tree
Showing 3 changed files with 42 additions and 71 deletions.
103 changes: 42 additions & 61 deletions packages/beacon-node/src/eth1/eth1MergeBlockTracker.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,14 +13,12 @@ export enum StatusCode {
STOPPED = "STOPPED",
SEARCHING = "SEARCHING",
FOUND = "FOUND",
MERGE_COMPLETE = "MERGE_COMPLETE",
}

type Status =
| {code: StatusCode.STOPPED}
| {code: StatusCode.SEARCHING}
| {code: StatusCode.FOUND; mergeBlock: PowMergeBlock}
| {code: StatusCode.MERGE_COMPLETE};
| {code: StatusCode.FOUND; mergeBlock: PowMergeBlock};

/** For metrics, index order = declaration order of StatusCode */
const statusCodeIdx = enumToIndexMap(StatusCode);
Expand Down Expand Up @@ -117,10 +115,6 @@ export class Eth1MergeBlockTracker {

case StatusCode.FOUND:
return this.status.mergeBlock;

case StatusCode.MERGE_COMPLETE:
// For better debugging in case this module stops searching too early
throw Error("Must not request mergeBlock on MERGE_COMPLETE");
}
}

Expand All @@ -147,16 +141,6 @@ export class Eth1MergeBlockTracker {
}
}

/**
* Call when merge is irrevocably completed to stop polling unnecessary data from the eth1 node
*/
mergeCompleted(): void {
if (this.status.code !== StatusCode.MERGE_COMPLETE) {
this.status = {code: StatusCode.MERGE_COMPLETE};
this.close();
}
}

/**
* Get a POW block by hash checking the local cache first
*/
Expand Down Expand Up @@ -196,7 +180,12 @@ export class Eth1MergeBlockTracker {
});

const interval = setInterval(() => {
void this.pollTerminalPowBlockFromEth1();
// Pre-emptively try to find merge block and cache it if found.
// Future callers of getTerminalPowBlock() will re-use the cached found mergeBlock.
this.getTerminalPowBlockFromEth1().catch((e) => {
this.logger.error("Error on findMergeBlock", {}, e as Error);
this.metrics?.eth1.eth1PollMergeBlockErrors.inc();
});
}, this.config.SECONDS_PER_ETH1_BLOCK * 1000);

this.intervals.push(interval);
Expand All @@ -206,46 +195,41 @@ export class Eth1MergeBlockTracker {
this.intervals.forEach(clearInterval);
}

private setTerminalBlock(mergeBlock: PowMergeBlock): void {
if (this.status.code !== StatusCode.MERGE_COMPLETE) {
this.status = {code: StatusCode.FOUND, mergeBlock};
this.metrics?.eth1.eth1MergeBlockDetails.set(
{
terminalBlockHash: mergeBlock.blockHash,
// Convert all number/bigints to string labels
terminalBlockNumber: mergeBlock.number.toString(10),
terminalBlockTD: mergeBlock.totalDifficulty.toString(10),
},
1
);
}
}

private async pollTerminalPowBlockFromEth1(): Promise<void> {
try {
const mergeBlock = await this.getTerminalPowBlockFromEth1();
if (mergeBlock) {
this.logger.info("Terminal POW block found!", {
hash: mergeBlock.blockHash,
number: mergeBlock.number,
totalDifficulty: mergeBlock.totalDifficulty,
});
}
// It is possible for status to be updated to merge complete or found or stopped
if (this.status.code != StatusCode.SEARCHING) {
this.close();
}
} catch (e) {
this.logger.error("Error on findMergeBlock", {}, e as Error);
this.metrics?.eth1.eth1PollMergeBlockErrors.inc();
}
}

private async getTerminalPowBlockFromEth1(): Promise<PowMergeBlock | null> {
if (!this.getTerminalPowBlockFromEth1Promise) {
this.getTerminalPowBlockFromEth1Promise = this.unsafeGetTerminalPowBlockFromEth1().finally(() => {
this.getTerminalPowBlockFromEth1Promise = null;
});
this.getTerminalPowBlockFromEth1Promise = this.internalGetTerminalPowBlockFromEth1()
.then((mergeBlock) => {
// Persist found merge block here to affect both caller paths:
// - internal searcher
// - external caller if STOPPED
if (mergeBlock && this.status.code != StatusCode.FOUND) {
if (this.status.code === StatusCode.SEARCHING) {
this.close();
}

this.logger.info("Terminal POW block found!", {
hash: mergeBlock.blockHash,
number: mergeBlock.number,
totalDifficulty: mergeBlock.totalDifficulty,
});

this.status = {code: StatusCode.FOUND, mergeBlock};
this.metrics?.eth1.eth1MergeBlockDetails.set(
{
terminalBlockHash: mergeBlock.blockHash,
// Convert all number/bigints to string labels
terminalBlockNumber: mergeBlock.number.toString(10),
terminalBlockTD: mergeBlock.totalDifficulty.toString(10),
},
1
);
}

return mergeBlock;
})
.finally(() => {
this.getTerminalPowBlockFromEth1Promise = null;
});
} else {
// This should no happen, since getTerminalPowBlockFromEth1() should resolve faster than SECONDS_PER_ETH1_BLOCK.
// else something is wrong: the el-cl comms are two slow, or the backsearch got stuck in a deep search.
Expand All @@ -256,17 +240,16 @@ export class Eth1MergeBlockTracker {
}

/**
* **unsafe** since it can create multiple backward searches that overload the eth1 client.
* **internal** + **unsafe** since it can create multiple backward searches that overload the eth1 client.
* Must be called in a wrapper to ensure that there's only once concurrent call to this fn.
*/
private async unsafeGetTerminalPowBlockFromEth1(): Promise<PowMergeBlock | null> {
private async internalGetTerminalPowBlockFromEth1(): Promise<PowMergeBlock | null> {
// Search merge block by hash
// Terminal block hash override takes precedence over terminal total difficulty
const terminalBlockHash = toHexString(this.config.TERMINAL_BLOCK_HASH);
if (terminalBlockHash !== ZERO_HASH_HEX) {
const block = await this.getPowBlock(terminalBlockHash);
if (block) {
this.setTerminalBlock(block);
return block;
} else {
// if a TERMINAL_BLOCK_HASH other than ZERO_HASH is configured and we can't find it, return NONE
Expand Down Expand Up @@ -305,7 +288,6 @@ export class Eth1MergeBlockTracker {

// Allow genesis block to reach TTD https://github.com/ethereum/consensus-specs/pull/2719
if (block.parentHash === ZERO_HASH_HEX) {
this.setTerminalBlock(block);
return block;
}

Expand All @@ -319,7 +301,6 @@ export class Eth1MergeBlockTracker {
// block.td > TTD && parent.td < TTD => block is mergeBlock
if (parent.totalDifficulty < this.config.TERMINAL_TOTAL_DIFFICULTY) {
// Is terminal total difficulty block AND has verified block -> parent relationship
this.setTerminalBlock(block);
return block;
} else {
block = parent;
Expand Down
8 changes: 0 additions & 8 deletions packages/beacon-node/src/eth1/index.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -88,10 +88,6 @@ export class Eth1ForBlockProduction implements IEth1ForBlockProduction {
return block && fromHexString(block.blockHash);
}

mergeCompleted(): void {
this.eth1MergeBlockTracker.mergeCompleted();
}

getPowBlock(powBlockHash: string): Promise<PowMergeBlock | null> {
return this.eth1MergeBlockTracker.getPowBlock(powBlockHash);
}
Expand Down Expand Up @@ -125,10 +121,6 @@ export class Eth1ForBlockProductionDisabled implements IEth1ForBlockProduction {
return null;
}

mergeCompleted(): void {
// Ignore
}

/** Will not be able to validate the merge block */
async getPowBlock(_powBlockHash: string): Promise<PowMergeBlock | null> {
throw Error("eth1 must be enabled to verify merge block");
Expand Down
2 changes: 0 additions & 2 deletions packages/beacon-node/src/eth1/interface.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,8 +41,6 @@ export interface IEth1ForBlockProduction {

/** Returns the most recent POW block that satisfies the merge block condition */
getTerminalPowBlock(): Promise<Root | null>;
/** Call when merge is irrevocably completed to stop polling unnecessary data from the eth1 node */
mergeCompleted(): void;
/** Get a POW block by hash checking the local cache first */
getPowBlock(powBlockHash: string): Promise<PowMergeBlock | null>;

Expand Down

0 comments on commit ba902cc

Please sign in to comment.