fix(across-relayer): more accurately determine a safe last block numb…

…er to query (UMAprotocol#3856) * fix: more accurately determine a safe block number to query Signed-off-by: Matt Rice <[email protected]> * WIP Signed-off-by: Matt Rice <[email protected]>
Woodpile37 · Mar 23, 2022 · 02ea4c4 · 02ea4c4
1 parent 4f67e4d
commit 02ea4c4
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Showing 2 changed files with 66 additions and 5 deletions.
diff --git a/packages/financial-templates-lib/src/clients/InsuredBridgeL2Client.ts b/packages/financial-templates-lib/src/clients/InsuredBridgeL2Client.ts
@@ -36,7 +36,8 @@ export class InsuredBridgeL2Client {
     readonly chainId: number = 0,
     readonly startingBlockNumber: number = 0,
     readonly endingBlockNumber: number | null = null,
-    readonly redundantL2Web3s: Web3[] = [l2Web3]
+    readonly redundantL2Web3s: Web3[] = [l2Web3],
+    readonly maxBlockTimestampVariance: number = 300 // 5 minutes
   ) {
     this.bridgeDepositBox = (new l2Web3.eth.Contract(
       getAbi("BridgeDepositBox"),
@@ -65,7 +66,7 @@ export class InsuredBridgeL2Client {
     // Define a config to bound the queries by.
     const blockSearchConfig = {
       fromBlock: this.firstBlockToSearch,
-      toBlock: this.endingBlockNumber || (await this.l2Web3.eth.getBlockNumber()),
+      toBlock: this.endingBlockNumber || (await this.getLatestBlockNumber()),
     };
     if (blockSearchConfig.fromBlock > blockSearchConfig.toBlock) {
       this.logger.debug({
@@ -105,6 +106,30 @@ export class InsuredBridgeL2Client {
     });
   }
 
+  async getLatestBlockNumber(): Promise<number> {
+    const blocks = await Promise.all(this.redundantL2Web3s.map((web3) => web3.eth.getBlock("latest")));
+
+    // Sorts from smallest to largest.
+    const timestamps = blocks.map((block) => Number(block.timestamp));
+
+    // Throw if one of the blocks is too far back in time. This is used to detect providers that are hanging or blocked.
+    if (Math.max(...timestamps) - Math.min(...timestamps) > this.maxBlockTimestampVariance) {
+      const error = new Error(`Timestamps for chainId ${this.chainId} differ by too much time.`);
+
+      this.logger.error({
+        at: "InsuredBridgeL2Client",
+        message: "Timestamps from providers differ by too much time ⏰",
+        chainId: this.chainId,
+        error,
+      });
+      throw error;
+    }
+
+    const blockNumbers = blocks.map((block) => block.number);
+
+    return Math.min(...blockNumbers);
+  }
+
   async getBridgeDepositBoxEvents(eventSearchOptions: EventSearchOptions, eventName: string): Promise<EventData[]> {
     // Note: the primary l2Web3 is not used here because the main l2Web3 usually uses a combination of the list of
     // redundant providers. Including both would mean calling the same provider(s) twice.

diff --git a/packages/financial-templates-lib/test/clients/InsuredBridgeL2Client.js b/packages/financial-templates-lib/test/clients/InsuredBridgeL2Client.js
@@ -11,7 +11,7 @@ const sinon = require("sinon");
 
 // Client to test
 const { InsuredBridgeL2Client } = require("../../dist/clients/InsuredBridgeL2Client");
-const { ZERO_ADDRESS } = require("@uma/common");
+const { ZERO_ADDRESS, advanceBlockAndSetTime } = require("@uma/common");
 
 // Helper contracts
 const chainId = 10;
@@ -167,15 +167,17 @@ describe("InsuredBridgeL2Client", () => {
       transports: [new SpyTransport({ level: "debug" }, { spy: spy })],
     });
 
+    const ganacheWeb3 = new Web3(ganache.provider());
+
     // Construct new client where we pass in a fallback L2 web3.
-    const clientWithFallbackWeb3s = new InsuredBridgeL2Client(
+    let clientWithFallbackWeb3s = new InsuredBridgeL2Client(
       spyLogger,
       web3,
       depositBox.options.address,
       chainId,
       0,
       null,
-      [web3, new Web3(ganache.provider())] // Ganache provider will be different from hardhat provider that is already
+      [web3, ganacheWeb3] // Ganache provider will be different from hardhat provider that is already
       // connected to the BridgeDepositBox.
     );
 
@@ -211,6 +213,17 @@ describe("InsuredBridgeL2Client", () => {
       assert.equal(spy.getCall(-1).lastArg.eventName, "FundsDeposited");
     }
 
+    clientWithFallbackWeb3s = new InsuredBridgeL2Client(
+      spyLogger,
+      web3,
+      depositBox.options.address,
+      chainId,
+      0,
+      (await web3.eth.getBlock("latest")).number, // Ensure that we query to the end.
+      [web3, ganacheWeb3] // Ganache provider will be different from hardhat provider that is already
+      // connected to the BridgeDepositBox.
+    );
+
     // Update will throw an error.
     try {
       await clientWithFallbackWeb3s.update();
@@ -219,5 +232,28 @@ describe("InsuredBridgeL2Client", () => {
       assert.equal(lastSpyLogLevel(spy), "error");
       assert.isTrue(lastSpyLogIncludes(spy, "L2 RPC endpoint state disagreement"));
     }
+
+    // Set the ganache time past the latest block time to generate a different error.
+    await advanceBlockAndSetTime(ganacheWeb3, Number((await web3.eth.getBlock("latest")).timestamp + 1000));
+
+    clientWithFallbackWeb3s = new InsuredBridgeL2Client(
+      spyLogger,
+      web3,
+      depositBox.options.address,
+      chainId,
+      0,
+      null, // Allow the client to determine how far we query.
+      [web3, ganacheWeb3] // Ganache provider will be different from hardhat provider that is already
+      // connected to the BridgeDepositBox.
+    );
+
+    // Update will throw an error.
+    try {
+      await clientWithFallbackWeb3s.update();
+      assert.isTrue(false);
+    } catch (e) {
+      assert.equal(lastSpyLogLevel(spy), "error");
+      assert.isTrue(lastSpyLogIncludes(spy, "differ by too much time."));
+    }
   });
 });