feat: delete attestations older than a slot (#10326)

Prune attestation pool

fixes: #7971

Author: Maddiaa0

yarn-project/foundation/src/config/env_var.ts

@@ -91,6 +91,7 @@ export type EnvVar =
   | 'P2P_TCP_LISTEN_ADDR'
   | 'P2P_TCP_ANNOUNCE_ADDR'
   | 'P2P_TX_POOL_KEEP_PROVEN_FOR'
+  | 'P2P_ATTESTATION_POOL_KEEP_FOR'
   | 'P2P_TX_PROTOCOL'
   | 'P2P_UDP_ANNOUNCE_ADDR'
   | 'P2P_UDP_LISTEN_ADDR'

yarn-project/p2p/src/client/p2p_client.test.ts

@@ -58,6 +58,7 @@ describe('In-Memory P2P Client', () => {
       addAttestations: jest.fn(),
       deleteAttestations: jest.fn(),
       deleteAttestationsForSlot: jest.fn(),
+      deleteAttestationsOlderThan: jest.fn(),
       getAttestationsForSlot: jest.fn().mockReturnValue(undefined),
     };
 
@@ -326,5 +327,22 @@ describe('In-Memory P2P Client', () => {
     });
   });
 
-  // TODO(https://github.com/AztecProtocol/aztec-packages/issues/7971): tests for attestation pool pruning
+  describe('Attestation pool pruning', () => {
+    it('deletes attestations older than the number of slots we want to keep in the pool', async () => {
+      const advanceToProvenBlockNumber = 20;
+      const keepAttestationsInPoolFor = 12;
+
+      blockSource.setProvenBlockNumber(0);
+      (client as any).keepAttestationsInPoolFor = keepAttestationsInPoolFor;
+      await client.start();
+      expect(attestationPool.deleteAttestationsOlderThan).not.toHaveBeenCalled();
+
+      await advanceToProvenBlock(advanceToProvenBlockNumber);
+
+      expect(attestationPool.deleteAttestationsOlderThan).toHaveBeenCalledTimes(1);
+      expect(attestationPool.deleteAttestationsOlderThan).toHaveBeenCalledWith(
+        BigInt(advanceToProvenBlockNumber - keepAttestationsInPoolFor),
+      );
+    });
+  });
 });

yarn-project/p2p/src/client/p2p_client.ts

@@ -202,6 +202,9 @@ export class P2PClient extends WithTracer implements P2P {
   private attestationPool: AttestationPool;
   private epochProofQuotePool: EpochProofQuotePool;
 
+  /** How many slots to keep attestations for. */
+  private keepAttestationsInPoolFor: number;
+
   private blockStream;
 
   /**
@@ -224,7 +227,9 @@ export class P2PClient extends WithTracer implements P2P {
   ) {
     super(telemetry, 'P2PClient');
 
-    const { blockCheckIntervalMS, blockRequestBatchSize } = getP2PConfigFromEnv();
+    const { blockCheckIntervalMS, blockRequestBatchSize, keepAttestationsInPoolFor } = getP2PConfigFromEnv();
+
+    this.keepAttestationsInPoolFor = keepAttestationsInPoolFor;
 
     this.blockStream = new L2BlockStream(l2BlockSource, this, this, {
       batchSize: blockRequestBatchSize,
@@ -615,7 +620,9 @@ export class P2PClient extends WithTracer implements P2P {
 
     const firstBlockNum = blocks[0].number;
     const lastBlockNum = blocks[blocks.length - 1].number;
+    const lastBlockSlot = blocks[blocks.length - 1].header.globalVariables.slotNumber.toBigInt();
 
+    // If keepProvenTxsFor is 0, we delete all txs from all proven blocks.
     if (this.keepProvenTxsFor === 0) {
       await this.deleteTxsFromBlocks(blocks);
     } else if (lastBlockNum - this.keepProvenTxsFor >= INITIAL_L2_BLOCK_NUM) {
@@ -626,12 +633,19 @@ export class P2PClient extends WithTracer implements P2P {
       await this.deleteTxsFromBlocks(blocksToDeleteTxsFrom);
     }
 
+    // We delete attestations older than the last block slot minus the number of slots we want to keep in the pool.
+    const lastBlockSlotMinusKeepAttestationsInPoolFor = lastBlockSlot - BigInt(this.keepAttestationsInPoolFor);
+    if (lastBlockSlotMinusKeepAttestationsInPoolFor >= BigInt(INITIAL_L2_BLOCK_NUM)) {
+      await this.attestationPool.deleteAttestationsOlderThan(lastBlockSlotMinusKeepAttestationsInPoolFor);
+    }
+
     await this.synchedProvenBlockNumber.set(lastBlockNum);
     this.log.debug(`Synched to proven block ${lastBlockNum}`);
     const provenEpochNumber = await this.l2BlockSource.getProvenL2EpochNumber();
     if (provenEpochNumber !== undefined) {
       this.epochProofQuotePool.deleteQuotesToEpoch(BigInt(provenEpochNumber));
     }
+
     await this.startServiceIfSynched();
   }
 

yarn-project/p2p/src/config.ts

@@ -92,6 +92,9 @@ export interface P2PConfig extends P2PReqRespConfig {
   /** How many blocks have to pass after a block is proven before its txs are deleted (zero to delete immediately once proven) */
   keepProvenTxsInPoolFor: number;
 
+  /** How many slots to keep attestations for. */
+  keepAttestationsInPoolFor: number;
+
   /**
    * The interval of the gossipsub heartbeat to perform maintenance tasks.
    */
@@ -230,6 +233,11 @@ export const p2pConfigMappings: ConfigMappingsType<P2PConfig> = {
       'How many blocks have to pass after a block is proven before its txs are deleted (zero to delete immediately once proven)',
     ...numberConfigHelper(0),
   },
+  keepAttestationsInPoolFor: {
+    env: 'P2P_ATTESTATION_POOL_KEEP_FOR',
+    description: 'How many slots to keep attestations for.',
+    ...numberConfigHelper(96),
+  },
   gossipsubInterval: {
     env: 'P2P_GOSSIPSUB_INTERVAL_MS',
     description: 'The interval of the gossipsub heartbeat to perform maintenance tasks.',

yarn-project/p2p/src/mem_pools/attestation_pool/attestation_pool.ts

@@ -21,6 +21,15 @@ export interface AttestationPool {
    */
   deleteAttestations(attestations: BlockAttestation[]): Promise<void>;
 
+  /**
+   * Delete Attestations with a slot number smaller than the given slot
+   *
+   * Removes all attestations associated with a slot
+   *
+   * @param slot - The oldest slot to keep.
+   */
+  deleteAttestationsOlderThan(slot: bigint): Promise<void>;
+
   /**
    * Delete Attestations for slot
    *

yarn-project/p2p/src/mem_pools/attestation_pool/memory_attestation_pool.test.ts

@@ -3,6 +3,7 @@ import { Secp256k1Signer } from '@aztec/foundation/crypto';
 import { Fr } from '@aztec/foundation/fields';
 import { NoopTelemetryClient } from '@aztec/telemetry-client/noop';
 
+import { jest } from '@jest/globals';
 import { type MockProxy, mock } from 'jest-mock-extended';
 
 import { type PoolInstrumentation } from '../instrumentation.js';
@@ -30,6 +31,11 @@ describe('MemoryAttestationPool', () => {
     (ap as any).metrics = metricsMock;
   });
 
+  const createAttestationsForSlot = (slotNumber: number) => {
+    const archive = Fr.random();
+    return signers.map(signer => mockAttestation(signer, slotNumber, archive));
+  };
+
   it('should add attestations to pool', async () => {
     const slotNumber = 420;
     const archive = Fr.random();
@@ -171,4 +177,29 @@ describe('MemoryAttestationPool', () => {
     const retreivedAttestationsAfterDelete = await ap.getAttestationsForSlot(BigInt(slotNumber), proposalId);
     expect(retreivedAttestationsAfterDelete.length).toBe(0);
   });
+
+  it('Should delete attestations older than a given slot', async () => {
+    const slotNumbers = [1, 2, 3, 69, 72, 74, 88, 420];
+    const attestations = slotNumbers.map(slotNumber => createAttestationsForSlot(slotNumber)).flat();
+    const proposalId = attestations[0].archive.toString();
+
+    await ap.addAttestations(attestations);
+
+    const attestationsForSlot1 = await ap.getAttestationsForSlot(BigInt(1), proposalId);
+    expect(attestationsForSlot1.length).toBe(signers.length);
+
+    const deleteAttestationsSpy = jest.spyOn(ap, 'deleteAttestationsForSlot');
+
+    await ap.deleteAttestationsOlderThan(BigInt(73));
+
+    const attestationsForSlot1AfterDelete = await ap.getAttestationsForSlot(BigInt(1), proposalId);
+    expect(attestationsForSlot1AfterDelete.length).toBe(0);
+
+    expect(deleteAttestationsSpy).toHaveBeenCalledTimes(5);
+    expect(deleteAttestationsSpy).toHaveBeenCalledWith(BigInt(1));
+    expect(deleteAttestationsSpy).toHaveBeenCalledWith(BigInt(2));
+    expect(deleteAttestationsSpy).toHaveBeenCalledWith(BigInt(3));
+    expect(deleteAttestationsSpy).toHaveBeenCalledWith(BigInt(69));
+    expect(deleteAttestationsSpy).toHaveBeenCalledWith(BigInt(72));
+  });
 });

yarn-project/p2p/src/mem_pools/attestation_pool/memory_attestation_pool.ts

@@ -58,6 +58,27 @@ export class InMemoryAttestationPool implements AttestationPool {
     return total;
   }
 
+  public async deleteAttestationsOlderThan(oldestSlot: bigint): Promise<void> {
+    const olderThan = [];
+
+    // Entries are iterated in insertion order, so we can break as soon as we find a slot that is older than the oldestSlot.
+    // Note: this will only prune correctly if attestations are added in order of rising slot, it is important that we do not allow
+    // insertion of attestations that are old. #(https://github.com/AztecProtocol/aztec-packages/issues/10322)
+    const slots = this.attestations.keys();
+    for (const slot of slots) {
+      if (slot < oldestSlot) {
+        olderThan.push(slot);
+      } else {
+        break;
+      }
+    }
+
+    for (const oldSlot of olderThan) {
+      await this.deleteAttestationsForSlot(oldSlot);
+    }
+    return Promise.resolve();
+  }
+
   public deleteAttestationsForSlot(slot: bigint): Promise<void> {
     // We count the number of attestations we are removing
     const numberOfAttestations = this.#getNumberOfAttestationsInSlot(slot);

yarn-project/p2p/src/service/reqresp/reqresp.integration.test.ts

@@ -63,6 +63,7 @@ const makeMockPools = () => {
       addAttestations: jest.fn(),
       deleteAttestations: jest.fn(),
       deleteAttestationsForSlot: jest.fn(),
+      deleteAttestationsOlderThan: jest.fn(),
       getAttestationsForSlot: jest.fn().mockReturnValue(undefined),
     },
     epochProofQuotePool: {