feat: merge-train/spartan (#20620)

BEGIN_COMMIT_OVERRIDE
fix: Fix the epoch long proving test (#20617)
feat: disabling peer scoring for block proposals topic (#20577)
END_COMMIT_OVERRIDE

Author: AztecBot

yarn-project/end-to-end/src/e2e_epochs/epochs_long_proving_time.test.ts

@@ -24,7 +24,12 @@ describe('e2e_epochs/epochs_long_proving_time', () => {
     const { aztecSlotDuration } = EpochsTestContext.getSlotDurations({ aztecEpochDuration });
     const epochDurationInSeconds = aztecSlotDuration * aztecEpochDuration;
     const proverTestDelayMs = (epochDurationInSeconds * 1000 * 3) / 4;
-    test = await EpochsTestContext.setup({ aztecEpochDuration, aztecProofSubmissionEpochs: 8, proverTestDelayMs });
+    test = await EpochsTestContext.setup({
+      aztecEpochDuration,
+      aztecProofSubmissionEpochs: 1000, // Effectively don't re-org
+      proverTestDelayMs,
+      proverNodeMaxPendingJobs: 1, // We test for only a single job at once
+    });
     ({ logger, monitor, L1_BLOCK_TIME_IN_S } = test);
     logger.warn(`Initialized with prover delay set to ${proverTestDelayMs}ms (epoch is ${epochDurationInSeconds}s)`);
   });
@@ -34,7 +39,7 @@ describe('e2e_epochs/epochs_long_proving_time', () => {
     await test.teardown();
   });
 
-  it.skip('generates proof over multiple epochs', async () => {
+  it('generates proof over multiple epochs', async () => {
     const targetProvenEpochs = process.env.TARGET_PROVEN_EPOCHS ? parseInt(process.env.TARGET_PROVEN_EPOCHS) : 1;
     const targetProvenBlockNumber = targetProvenEpochs * test.epochDuration;
     logger.info(`Waiting for ${targetProvenEpochs} epochs to be proven at ${targetProvenBlockNumber} L2 blocks`);

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

@@ -216,6 +216,7 @@ export type EnvVar =
   | 'SEQ_L1_PUBLISHING_TIME_ALLOWANCE_IN_SLOT'
   | 'SEQ_ATTESTATION_PROPAGATION_TIME'
   | 'SEQ_BLOCK_DURATION_MS'
+  | 'SEQ_EXPECTED_BLOCK_PROPOSALS_PER_SLOT'
   | 'SEQ_BUILD_CHECKPOINT_IF_EMPTY'
   | 'SEQ_SECONDS_BEFORE_INVALIDATING_BLOCK_AS_COMMITTEE_MEMBER'
   | 'SEQ_SECONDS_BEFORE_INVALIDATING_BLOCK_AS_NON_COMMITTEE_MEMBER'

yarn-project/p2p/src/config.ts

@@ -38,7 +38,7 @@ export interface P2PConfig
     ChainConfig,
     TxCollectionConfig,
     TxFileStoreConfig,
-    Pick<SequencerConfig, 'blockDurationMs'> {
+    Pick<SequencerConfig, 'blockDurationMs' | 'expectedBlockProposalsPerSlot'> {
   /** A flag dictating whether the P2P subsystem should be enabled. */
   p2pEnabled: boolean;
 

yarn-project/p2p/src/services/gossipsub/README.md

@@ -40,7 +40,7 @@ We configure all parameters (P1-P4) with values calculated dynamically from netw
 | P3b: meshFailurePenalty | -34 per topic | Sticky penalty after pruning |
 | P4: invalidMessageDeliveries | -20 per message | Attack detection |
 
-**Important:** P1 and P2 are only enabled on topics with P3 enabled (block_proposal, checkpoint_proposal, checkpoint_attestation). The tx topic has all scoring disabled except P4, to prevent free positive score accumulation that would offset penalties from other topics.
+**Important:** P1 and P2 are only enabled on topics with P3 enabled. By default, P3 is enabled for checkpoint_proposal and checkpoint_attestation (2 topics). Block proposal scoring is controlled by `expectedBlockProposalsPerSlot` (current default: `0`, including when env var is unset, so disabled) - see [Block Proposals](#block-proposals-block_proposal) for details. The tx topic has all scoring disabled except P4, to prevent free positive score accumulation that would offset penalties from other topics.
 
 ## Exponential Decay
 
@@ -217,7 +217,21 @@ Transactions are submitted unpredictably by users, so we cannot set meaningful d
 
 ### Block Proposals (block_proposal)
 
-In Multi-Block-Per-Slot (MBPS) mode, N-1 block proposals are gossiped per slot (the last block is bundled with the checkpoint). In single-block mode, this is 0.
+Block proposal scoring is controlled by the `expectedBlockProposalsPerSlot` config (`SEQ_EXPECTED_BLOCK_PROPOSALS_PER_SLOT` env var):
+
+| Config Value | Behavior |
+|-------------|----------|
+| `0` (current default) | Block proposal P3 scoring is **disabled** |
+| Positive number | Uses the provided value as expected proposals per slot |
+| `undefined` | Falls back to `blocksPerSlot - 1` (MBPS mode: N-1, single block: 0) |
+
+**Current behavior note:** In the current implementation, if `SEQ_EXPECTED_BLOCK_PROPOSALS_PER_SLOT` is not set, config mapping applies `0` by default (scoring disabled). The `undefined` fallback above is currently reachable only if the value is explicitly provided as `undefined` in code.
+
+**Future intent:** Once throughput is stable, we may change env parsing/defaults so an unset env var resolves to `undefined` again (re-enabling automatic fallback to `blocksPerSlot - 1`).
+
+**Why disabled by default?** In MBPS mode, gossipsub expects N-1 block proposals per slot. When transaction throughput is low (as expected at launch), fewer blocks are actually built, causing peers to be incorrectly penalized for under-delivering block proposals. The default of 0 disables this scoring. Set to a positive value when throughput increases and block production is consistent.
+
+In MBPS mode (when enabled), N-1 block proposals are gossiped per slot (the last block is bundled with the checkpoint). In single-block mode, this is 0.
 
 ### Checkpoint Proposals (checkpoint_proposal)
 
@@ -241,6 +255,7 @@ The scoring parameters depend on:
 | `targetCommitteeSize` | L1RollupConstants | 48 |
 | `heartbeatInterval` | P2PConfig.gossipsubInterval | 700ms |
 | `blockDurationMs` | P2PConfig.blockDurationMs | undefined (single block) |
+| `expectedBlockProposalsPerSlot` | P2PConfig.expectedBlockProposalsPerSlot | 0 (disabled; current unset-env behavior) |
 
 ## Invalid Message Handling (P4)
 
@@ -320,9 +335,9 @@ Conversely, if topic scores are low, a peer slightly above the disconnect thresh
 
 Topic scores provide **burst response** to attacks, while app score provides **stable baseline**:
 
-- P1 (time in mesh): Max +8 per topic (+24 across 3 topics)
-- P2 (first deliveries): Max +25 per topic (+75 across 3 topics, but decays fast)
-- P3 (under-delivery): Max -34 per topic (-102 across 3 topics in MBPS; -68 in single-block mode)
+- P1 (time in mesh): Max +8 per topic (+16 default, +24 with block proposal scoring enabled)
+- P2 (first deliveries): Max +25 per topic (+50 default, +75 with block proposal scoring, but decays fast)
+- P3 (under-delivery): Max -34 per topic (-68 default with 2 topics, -102 with block proposal scoring enabled)
 - P4 (invalid messages): -20 per invalid message, can spike to -2000+ during attacks
 
 Example attack scenario:
@@ -373,21 +388,21 @@ When a peer is pruned from the mesh:
 3. **P3b captures the penalty**: The P3 deficit at prune time becomes P3b, which decays slowly
 
 After pruning, the peer's score consists mainly of P3b:
-- **Total P3b across 3 topics: -102** (max)
+- **Total P3b: -68** (default, 2 topics) or **-102** (with block proposal scoring enabled, 3 topics)
 - **Recovery time**: P3b decays to ~1% over one decay window (2-5 slots = 2-6 minutes)
 - **Grafting eligibility**: Peer can be grafted when score ≥ 0, but asymptotic decay means recovery is slow
 
 ### Why Non-Contributors Aren't Disconnected
 
-With P3b capped at -102 total after pruning (MBPS mode). In single-block mode, the cap is -68:
+With P3b capped at -68 (default, 2 topics) or -102 (with block proposal scoring, 3 topics) after pruning:
 
 | Threshold | Value | P3b Score | Triggered? |
 |-----------|-------|-----------|------------|
-| gossipThreshold | -500 | -102 (MBPS) / -68 (single) | No |
-| publishThreshold | -1000 | -102 (MBPS) / -68 (single) | No |
-| graylistThreshold | -2000 | -102 (MBPS) / -68 (single) | No |
+| gossipThreshold | -500 | -68 (default) / -102 (block scoring on) | No |
+| publishThreshold | -1000 | -68 (default) / -102 (block scoring on) | No |
+| graylistThreshold | -2000 | -68 (default) / -102 (block scoring on) | No |
 
-**A score of -102 (MBPS) or -68 (single-block) is well above -500**, so non-contributing peers:
+**A score of -68 or -102 is well above -500**, so non-contributing peers:
 - Are pruned from mesh (good - stops them slowing propagation)
 - Still receive gossip (can recover by reconnecting/restarting)
 - Are NOT disconnected unless they also have application-level penalties
@@ -547,7 +562,7 @@ What happens when a peer experiences a network outage and stops delivering messa
 While the peer is disconnected:
 
 1. **P3 penalty accumulates**: The message delivery counter decays toward 0, causing increasing P3 penalty
-2. **Max P3 penalty reached**: Once counter drops below threshold, penalty hits -34 per topic (-102 total in MBPS; -68 single-block)
+2. **Max P3 penalty reached**: Once counter drops below threshold, penalty hits -34 per topic (-68 default, -102 with block proposal scoring)
 3. **Mesh pruning**: Topic score goes negative → peer is pruned from mesh
 4. **P3b captures penalty**: The P3 deficit at prune time becomes P3b (sticky penalty)
 
@@ -569,13 +584,13 @@ Note: If the peer just joined the mesh, P3 penalties only start after
 During a network outage, the peer:
 - **Does NOT send invalid messages** → No P4 penalty
 - **Does NOT violate protocols** → No application-level penalty
-- **Only accumulates topic-level penalties** → Max -102 (P3b, MBPS) or -68 (single-block)
+- **Only accumulates topic-level penalties** → Max -68 (default) or -102 (with block proposal scoring)
 
 This is the crucial difference from malicious behavior:
 
 | Scenario | App Score | Topic Score | Total | Threshold Hit |
 |----------|-----------|-------------|-------|---------------|
-| Network outage | 0 | -102 (MBPS) / -68 (single) | -102 / -68 | None |
+| Network outage | 0 | -68 (default) / -102 (block scoring on) | -68 / -102 | None |
 | Validation failure | -50 | -20 | -520 | gossipThreshold |
 | Malicious peer | -100 | -2000+ | -2100+ | graylistThreshold |
 

yarn-project/p2p/src/services/gossipsub/topic_score_params.test.ts

@@ -12,6 +12,7 @@ import {
   createAllTopicScoreParams,
   createTopicScoreParamsForTopic,
   getDecayWindowSlots,
+  getEffectiveBlockProposalsPerSlot,
   getExpectedMessagesPerSlot,
 } from './topic_score_params.js';
 
@@ -148,18 +149,47 @@ describe('Topic Score Params', () => {
     });
   });
 
+  describe('getEffectiveBlockProposalsPerSlot', () => {
+    it('returns undefined when override is 0 (disabled)', () => {
+      expect(getEffectiveBlockProposalsPerSlot(5, 0)).toBeUndefined();
+    });
+
+    it('returns override value when positive', () => {
+      expect(getEffectiveBlockProposalsPerSlot(5, 3)).toBe(3);
+      expect(getEffectiveBlockProposalsPerSlot(1, 7)).toBe(7);
+    });
+
+    it('falls back to blocksPerSlot - 1 when override is undefined', () => {
+      expect(getEffectiveBlockProposalsPerSlot(5, undefined)).toBe(4);
+      expect(getEffectiveBlockProposalsPerSlot(3, undefined)).toBe(2);
+    });
+
+    it('returns undefined when override is undefined and single block mode', () => {
+      expect(getEffectiveBlockProposalsPerSlot(1, undefined)).toBeUndefined();
+    });
+  });
+
   describe('getExpectedMessagesPerSlot', () => {
     it('returns undefined for tx topic (unpredictable)', () => {
       expect(getExpectedMessagesPerSlot(TopicType.tx, 48, 5)).toBeUndefined();
     });
 
-    it('returns N-1 for block_proposal in MBPS mode', () => {
+    it('returns N-1 for block_proposal when override is undefined (fallback)', () => {
       expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 5)).toBe(4);
       expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 3)).toBe(2);
     });
 
-    it('returns 0 for block_proposal in single block mode', () => {
-      expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 1)).toBe(0);
+    it('returns undefined for block_proposal in single block mode without override', () => {
+      expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 1)).toBeUndefined();
+    });
+
+    it('returns undefined for block_proposal when override is 0 (disabled)', () => {
+      expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 5, 0)).toBeUndefined();
+    });
+
+    it('returns override value for block_proposal when positive', () => {
+      expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 1, 3)).toBe(3);
+      expect(getExpectedMessagesPerSlot(TopicType.block_proposal, 48, 5, 7)).toBe(7);
     });
 
     it('returns 1 for checkpoint_proposal', () => {
@@ -207,10 +237,35 @@ describe('Topic Score Params', () => {
         expect(params.meshFailurePenaltyWeight).toBe(0);
       });
 
-      it('enables P3/P3b for block_proposal in MBPS mode', () => {
+      it('disables P3/P3b for block_proposal in MBPS mode when expectedBlockProposalsPerSlot is 0', () => {
+        const factory = new TopicScoreParamsFactory({
+          ...standardParams,
+          blockDurationMs: 10000,
+          expectedBlockProposalsPerSlot: 0,
+        });
+        const params = factory.createForTopic(TopicType.block_proposal);
+
+        expect(params.meshMessageDeliveriesWeight).toBe(0);
+        expect(params.meshFailurePenaltyWeight).toBe(0);
+      });
+
+      it('enables P3/P3b for block_proposal when expectedBlockProposalsPerSlot is positive', () => {
+        const factory = new TopicScoreParamsFactory({
+          ...standardParams,
+          blockDurationMs: 10000,
+          expectedBlockProposalsPerSlot: 3,
+        });
+        const params = factory.createForTopic(TopicType.block_proposal);
+
+        expect(params.meshMessageDeliveriesWeight).toBeLessThan(0);
+        expect(params.meshFailurePenaltyWeight).toBeLessThan(0);
+      });
+
+      it('falls back to blocksPerSlot - 1 for block_proposal when expectedBlockProposalsPerSlot is undefined', () => {
         const factory = new TopicScoreParamsFactory({ ...standardParams, blockDurationMs: 10000 });
         const params = factory.createForTopic(TopicType.block_proposal);
 
+        // MBPS mode with no override: falls back to blocksPerSlot - 1 > 0, so P3 is enabled
         expect(params.meshMessageDeliveriesWeight).toBeLessThan(0);
         expect(params.meshFailurePenaltyWeight).toBeLessThan(0);
       });
@@ -447,33 +502,42 @@ describe('Topic Score Params', () => {
       expect(Math.abs(maxP3)).toBeGreaterThan(maxP1 + maxP2);
     });
 
-    it('total P3b across all topics is approximately -102', () => {
-      const factory = new TopicScoreParamsFactory(standardParams);
+    it('total P3b is -102 when block proposal scoring is enabled (3 topics)', () => {
+      const factory = new TopicScoreParamsFactory({
+        ...standardParams,
+        blockDurationMs: 4000,
+        expectedBlockProposalsPerSlot: 3,
+      });
 
-      // Topics with P3 enabled: checkpoint_proposal, checkpoint_attestation, block_proposal (in MBPS)
-      const mbpsParams = { ...standardParams, blockDurationMs: 4000 };
-      const mbpsFactory = new TopicScoreParamsFactory(mbpsParams);
+      expect(factory.numP3EnabledTopics).toBe(3);
+      expect(factory.totalMaxP3bPenalty).toBeCloseTo(-102, 0);
 
       const checkpointParams = factory.createForTopic(TopicType.checkpoint_proposal);
       const attestationParams = factory.createForTopic(TopicType.checkpoint_attestation);
-      const blockParams = mbpsFactory.createForTopic(TopicType.block_proposal);
+      const blockParams = factory.createForTopic(TopicType.block_proposal);
 
-      // Calculate max P3 for each topic
       const p3Checkpoint =
         checkpointParams.meshMessageDeliveriesThreshold ** 2 * checkpointParams.meshMessageDeliveriesWeight;
       const p3Attestation =
         attestationParams.meshMessageDeliveriesThreshold ** 2 * attestationParams.meshMessageDeliveriesWeight;
       const p3Block = blockParams.meshMessageDeliveriesThreshold ** 2 * blockParams.meshMessageDeliveriesWeight;
 
-      // Each should be approximately -34
       expect(p3Checkpoint).toBeCloseTo(-34, 0);
       expect(p3Attestation).toBeCloseTo(-34, 0);
       expect(p3Block).toBeCloseTo(-34, 0);
-
-      // Total should be approximately -102
       expect(p3Checkpoint + p3Attestation + p3Block).toBeCloseTo(-102, 0);
     });
 
+    it('total P3b is -68 when block proposal scoring is disabled (2 topics)', () => {
+      const factory = new TopicScoreParamsFactory({
+        ...standardParams,
+        expectedBlockProposalsPerSlot: 0,
+      });
+
+      expect(factory.numP3EnabledTopics).toBe(2);
+      expect(factory.totalMaxP3bPenalty).toBeCloseTo(-68, 0);
+    });
+
     it('non-contributing peer has negative topic score and gets pruned', () => {
       const factory = new TopicScoreParamsFactory(standardParams);
       const params = factory.createForTopic(TopicType.checkpoint_proposal);