Single Sequencer
A single sequencer is the simplest sequencing architecture for a Rollkit-based rollup. In this model, one node (the sequencer) is responsible for ordering transactions, producing blocks, and submitting data to the data availability (DA) layer.
How the Single Sequencer Model Works
Transaction Submission:
- Users submit transactions directly to the sequencer node via RPC or other interfaces.
Transaction Ordering:
- The sequencer collects transactions from users and orders them into blocks according to the rollup's rules.
Block Production:
- The sequencer produces new blocks at regular intervals or when enough transactions are collected.
- Each block contains a batch of ordered transactions and metadata.
Data Availability Posting:
- The sequencer posts the block data to the configured DA layer (e.g., Celestia, Avail, etc.).
- This ensures that anyone can access the data needed to reconstruct the rollup state.
State Update:
- The sequencer updates the rollup state based on the new block and makes the updated state available to light clients and full nodes.
Advantages
- Simplicity: Easy to set up and operate, making it ideal for development, testing, and small-scale deployments.
- Low Latency: Fast block production and transaction inclusion, since there is no consensus overhead among multiple sequencers.
Use Cases
- Production rollups seeking simplicity and performance
- Prototyping and development
- Private or permissioned rollups
- Projects that value deterministic ordering and operational control