Optimistic Aborts for Geo-distributed Transactions

TL;DR

The paper introduces optimistic abort, a technique that reduces latency in geo-distributed transactional systems by early aborts of likely-to-fail transactions, implemented in the Gotthard system using programmable network devices.

Contribution

It presents a novel network-based optimistic abort method for high-contention, write-heavy workloads, enhancing latency and throughput in geo-distributed transactions.

Findings

Significantly reduces transaction latency.

Improves throughput for high-contention workloads.

Effectively identifies transactions likely to abort.

Abstract

Network latency can have a significant impact on the performance of transactional storage systems, particularly in wide area or geo-distributed deployments. To reduce latency, systems typically rely on a cache to service read-requests closer to the client. However, caches are not effective for write-heavy workloads, which have to be processed by the storage system in order to maintain serializability. This paper presents a new technique, called optimistic abort, which reduces network latency for high-contention, write-heavy workloads by identifying transactions that will abort as early as possible, and aborting them before they reach the store. We have implemented optimistic abort in a system called Gotthard, which leverages recent advances in network data plane programmability to execute transaction processing logic directly in network devices. Gotthard examines network traffic to observe and log transaction requests. If Gotthard suspects that a transaction is likely to be aborted at the store, it aborts the transaction early by re-writing the packet header, and routing the packets back to the client. Gotthard significantly reduces the overall latency and improves the throughput for high-contention workloads.