Problem

Currently lacks granular timing metrics for newPayload processing phases, making it difficult to identify performance bottlenecks.

Cannot measure:

• Time until execution starts
• Prewarming effectiveness
• Individual phase durations (validation, execution, state root)
• State root algorithm performance

Current implementation:
https://github.com/paradigmxyz/reth/blob/main/crates/engine/tree/src/tree/mod.rs#L504-L600

Solution

do we have enough observability for the entire newPayload process?

what would help us is like a time diagram to see

• Phase A: Pre-execution (entry → execution start)
• Phase B: Prewarming initialization
• Phase C: Block execution
• Phase D: Post-execution validation
• Phase E: State root computation
• Phase F: Post-processing

Implementation locations

• crates/engine/tree/src/tree/metrics.rs - Add NewPayloadPhaseMetrics struct
• crates/engine/tree/src/tree/mod.rs#L504 - Instrument on_new_payload
• crates/engine/tree/src/tree/payload_validator.rs#L288 - Instrument validation phases

Expected outcome

• Enable time diagram generation for analysis
• Metrics

Additional context