SUI News Today: Sui's Mysticeti v2 Merges Validation Into Consensus to Boost Efficiency

Sui Network has launched Mysticeti v2, a major upgrade to its Directed Acyclic Graph (DAG)-based consensus protocol, reducing transaction latency by 35% and enhancing overall efficiency. The update integrates transaction validation directly into the consensus process, eliminating redundant steps that previously added computational overhead and delays, according to the Mysticeti v2 post. The new version also introduces the Transaction Driver, a streamlined client mechanism that simplifies transaction submission and confirmation, as reported in a Blockonomi article. Early results show significant latency reductions, particularly in Asia and Europe, with Asia-based nodes experiencing a drop from ~1.00s to ~0.65s (see the Mysticeti v2 post).

Mysticeti, first deployed on Sui's mainnet in July 2024, was designed to decouple transaction dissemination from ordering, enabling high throughput and censorship resistance, as described in the Mysticeti v2 post. However, the initial implementation retained a pre-consensus validation step, where validators voted on transaction acceptance. While this ensured security, it introduced latency for non-fastpath transactions—those involving shared objects rather than solely owned ones, per the Mysticeti v2 post.

Mysticeti v2 merges this validation phase into the consensus process, allowing transactions to be finalized concurrently with block commits. A transaction is now finalized once it achieves a quorum of certificates, while blocks follow the original DAG commit rules, the Blockonomi article notes. This change eliminates the need for separate validation rounds, reducing both computational load and time to finality.

The Transaction Driver further optimizes transaction flow by replacing the previous Quorum Driver system. Under the old model, transactions were broadcast to all validators, requiring multiple signature aggregations and consuming significant bandwidth and CPU resources, according to the Mysticeti v2 post. The new driver submits transactions to a single validator, which coordinates certification through the network. Signatures are batched within consensus blocks, slashing bandwidth usage and computational overhead, the Blockonomi article explains. Smart validator selection based on historical latency ensures faster confirmations, while graceful retries and DoS protections enhance resilience, as the Mysticeti v2 post describes.

Performance benchmarks from Mysten Labs and partner nodes confirm the improvements. Asia-based full nodes saw a 35% latency reduction, while European nodes improved by 25%, data reported in the Mysticeti v2 post. The Transaction Driver is now the default in Sui node v1.60, with future updates targeting further optimizations. These include reducing the median number of message rounds needed to commit transactions (from four to three) and enabling direct streaming of consensus blocks to full nodes, as outlined in the Mysticeti v2 post. Additionally, protocol-level adjustments aim to prevent "deadlocks" in object execution, ensuring seamless transaction processing across all use cases, the Blockonomi article adds.

The upgrade underscores Sui's commitment to maintaining its fastpath finality model, where transactions involving only owned objects can be confirmed without full consensus, as explained in the Mysticeti v2 post. By streamlining validation and submission processes, Mysticeti v2 brings the network closer to its theoretical performance limits while preserving security and scalability.