chore: Deflake inactivity slash e2e test (#17090)

Attempt at fixing the flake on `inactivity_slash.test`. The test was
failing as sometimes other validator than the "offline" one was getting
slashed, due to inactivity during setup. We try addressing that by
setting up a long slashing grace period, so we can safely set up every
sequencer during that period, and then warping to after that to start
slashing.

We also try avoid slashing an active validator by bumping the inactivity
threshold on this PR.

Author: spalladino

yarn-project/end-to-end/src/e2e_p2p/inactivity_slash.test.ts

@@ -17,6 +17,7 @@ describe('e2e_p2p_inactivity_slash', () => {
     test = await P2PInactivityTest.create('e2e_p2p_inactivity_slash', {
       slashInactivityConsecutiveEpochThreshold: SLASH_INACTIVITY_CONSECUTIVE_EPOCH_THRESHOLD,
       inactiveNodeCount: 1,
+      keepInitialNode: false,
     }).then(t => t.setup());
   });
 

yarn-project/end-to-end/src/e2e_p2p/inactivity_slash_test.ts

@@ -22,6 +22,9 @@ const AZTEC_SLOT_DURATION = 8;
 const SLASHING_UNIT = BigInt(1e18);
 const SLASHING_AMOUNT = SLASHING_UNIT * 3n;
 
+// How many epochs it may take to set everything up, so we dont slash during this period
+const SETUP_EPOCH_DURATION = 5;
+
 export class P2PInactivityTest {
   public nodes!: AztecNodeService[];
   public activeNodes!: AztecNodeService[];
@@ -32,18 +35,20 @@ export class P2PInactivityTest {
 
   private dataDir: string;
   private inactiveNodeCount: number;
+  private keepInitialNode: boolean;
 
   constructor(
     public readonly test: P2PNetworkTest,
-    opts: { inactiveNodeCount: number },
+    opts: { inactiveNodeCount: number; keepInitialNode?: boolean },
   ) {
     this.dataDir = fs.mkdtempSync(path.join(os.tmpdir(), test.testName));
     this.inactiveNodeCount = opts.inactiveNodeCount;
+    this.keepInitialNode = opts.keepInitialNode ?? false;
   }
 
   static async create(
     testName: string,
-    opts: { slashInactivityConsecutiveEpochThreshold: number; inactiveNodeCount: number },
+    opts: { slashInactivityConsecutiveEpochThreshold: number; inactiveNodeCount: number; keepInitialNode?: boolean },
   ) {
     const test = await P2PNetworkTest.create({
       testName,
@@ -64,8 +69,8 @@ export class P2PInactivityTest {
         sentinelEnabled: true,
         slashingQuorum: SLASHING_QUORUM,
         slashingRoundSizeInEpochs: SLASHING_ROUND_SIZE_IN_EPOCHS,
-        slashInactivityTargetPercentage: 0.5,
-        slashGracePeriodL2Slots: EPOCH_DURATION, // do not slash during the first epoch
+        slashInactivityTargetPercentage: 0.8,
+        slashGracePeriodL2Slots: SETUP_EPOCH_DURATION * EPOCH_DURATION, // do not slash during setup
         slashAmountSmall: SLASHING_UNIT,
         slashAmountMedium: SLASHING_UNIT * 2n,
         slashAmountLarge: SLASHING_UNIT * 3n,
@@ -91,18 +96,21 @@ export class P2PInactivityTest {
     this.test.ctx.aztecNodeConfig.slashInactivityPenalty = SLASHING_AMOUNT;
     this.rollup = rollup;
 
-    // The initial validator that ran on this node is picked up by the first new node started below
-    await this.test.removeInitialNode();
+    if (!this.keepInitialNode) {
+      await this.test.ctx.aztecNode.stop();
+    }
 
     // Create all active nodes
     this.activeNodes = await createNodes(
       this.test.ctx.aztecNodeConfig,
       this.test.ctx.dateProvider,
       this.test.bootstrapNodeEnr,
-      NUM_NODES - this.inactiveNodeCount,
+      NUM_NODES - this.inactiveNodeCount - Number(this.keepInitialNode),
       BOOT_NODE_UDP_PORT,
       this.test.prefilledPublicData,
       this.dataDir,
+      undefined,
+      Number(this.keepInitialNode),
     );
 
     // And the ones with an initially disabled sequencer
@@ -119,7 +127,15 @@ export class P2PInactivityTest {
       NUM_NODES - this.inactiveNodeCount,
     );
 
-    this.nodes = [...this.activeNodes, ...this.inactiveNodes];
+    this.nodes = [
+      ...(this.keepInitialNode ? [this.test.ctx.aztecNode] : []),
+      ...this.activeNodes,
+      ...this.inactiveNodes,
+    ];
+
+    if (this.nodes.length !== NUM_NODES) {
+      throw new Error(`Expected ${NUM_NODES} nodes but got ${this.nodes.length}`);
+    }
 
     this.offlineValidators = this.test.validators
       .slice(this.test.validators.length - this.inactiveNodeCount)
@@ -130,6 +146,9 @@ export class P2PInactivityTest {
       offlineValidators: this.offlineValidators,
     });
 
+    this.test.logger.warn(`Advancing to epoch ${SETUP_EPOCH_DURATION + 1} to start slashing`);
+    await this.test.ctx.cheatCodes.rollup.advanceToEpoch(SETUP_EPOCH_DURATION + 1);
+
     return this;
   }
 

yarn-project/end-to-end/src/fixtures/utils.ts

@@ -573,7 +573,7 @@ export async function setup(
     await blobSink.start();
     config.blobSinkUrl = `http://localhost:${blobSinkPort}`;
 
-    logger.verbose('Creating and synching an aztec node...');
+    logger.verbose('Creating and synching an aztec node', config);
 
     const acvmConfig = await getACVMConfig(logger);
     if (acvmConfig) {

yarn-project/ethereum/src/test/rollup_cheat_codes.ts

@@ -112,14 +112,14 @@ export class RollupCheatCodes {
    * @param opts - Options
    */
   public async advanceToEpoch(
-    epoch: bigint,
+    epoch: bigint | number,
     opts: {
       /** Optional test date provider to update with the epoch timestamp */
       updateDateProvider?: TestDateProvider;
     } = {},
   ) {
     const { epochDuration: slotsInEpoch } = await this.getConfig();
-    const timestamp = await this.rollup.read.getTimestampForSlot([epoch * slotsInEpoch]);
+    const timestamp = await this.rollup.read.getTimestampForSlot([BigInt(epoch) * slotsInEpoch]);
     try {
       await this.ethCheatCodes.warp(Number(timestamp), { ...opts, silent: true, resetBlockInterval: true });
       this.logger.warn(`Warped to epoch ${epoch}`);