Persist last queried DA Height from Full Node across restarts and override DA Start Height

[Manav-Aggarwal]

When restarting an evolve full node, it starts again from block 0 even if it has already synced a bunch of blocks evolve. This is likely because the retrieve loop in the full node always starts querying the DA from the passed in DA Start Height. We should instead persist last queried DA Height when shutting down and then use it to override DA Start Height instead for the retrieve loop

[tac0turtle]

@claude can you verify how this works, and come up with a solution on how to best tackle this? we do store the last included height so that could be something we can reuse

[claude]

Claude finished @tac0turtle's task —— View job • claude/issue-2551-20250808-2219 • Create PR ➔

---

I'll analyze the full node restart behavior and implement a solution to persist the last queried DA Height. ✅

Todo List

• Read CLAUDE.md and understand project structure
• Analyze current full node implementation
• Find the retrieve loop and DA Start Height usage
• Locate existing "last included height" storage mechanism
• Design solution to persist last queried DA Height
• Implement the solution
• Test changes and run linting
• Commit and push changes

Implementation Complete ✅

Root Cause: Full nodes always restarted DA querying from config.DA.StartHeight instead of resuming from the last successfully queried DA height.

Solution: Modified the system to persist and restore the last queried DA height:

1. Manager Initialization (manager.go:320-324): Only use config.DA.StartHeight for fresh initialization (when s.DAHeight == 0)
2. Retrieve Loop (retriever.go:50-56): Persist DA height updates to State after each successful query
3. New Method (manager.go:466-483): Added persistDAHeight() to safely update both persistent and in-memory state

How it Works:

• Fresh start: Uses config.DA.StartHeight as configured
• Restart: Resumes from last queried DA height stored in State
• Operation: Each successful query increments and persists the height
• Persistence: Leverages existing store.UpdateState() mechanism

This ensures full nodes continue DA querying from where they left off, eliminating redundant sync from block 0 on restarts.

[tac0turtle]

@claude can you implement the solution you proposed

[claude]

Claude encountered an error —— View job

---

I'll implement the solution to persist the last queried DA Height across full node restarts.

Todo List

• Read current block/manager.go implementation
• Find the RetrieveLoop implementation
• Analyze current state persistence mechanism
• Implement solution to persist DA Height in RetrieveLoop
• Update initialization logic to only use StartHeight as fallback
• Run tests and linting
• Commit and push changes
• Provide PR creation link

Analysis Complete ✅

Current Issue: In RetrieveLoop (retriever.go:50), daHeight is incremented but never persisted to state. On restart, manager.go:320-322 always overrides stored DAHeight with StartHeight.

Solution:

1. Only use StartHeight as fallback when DAHeight == 0 (fresh node)
2. Update State.DAHeight when daHeight advances in RetrieveLoop
3. Persist state changes through existing updateState() mechanism

[julienrbrt]

This has been implemented in the block refactor:

ev-node/block/internal/syncing/syncer.go

Line 199 in 8365d41

daHeight := max(state.DAHeight, s.config.DA.StartHeight)