Attestation Processing Performance Bottleneck - [Phase0]

[EchoAlice]

Description

epoch_processing::get_inclusion_delay_deltas() creates a significant performance bottleneck in state_transition(). At slot 3,200, processing takes ~3.92 days due to inefficient attestation iteration.

Impact

• Blocks epoch boundary processing
• Affects validator reward calculations
• Prevents timely consensus

Current Implementation

// O(validators × pending_attestations)
for validator in unslashed_validators {
    for attestation in pending_attestations {
        // Process attestations
    }
}

Metrics

(at slot 3,200)

• 20,488 validators
• 225 pending attestations
• 4.6M attestation batches
• 73.5ms per batch

0.0735 x 4,600,000 = ~3.92 days

Proposed Solution

Restructure to single-pass attestation processing.