Why NetEase’s Open‑Source Curve Beats Ceph by 84% in Performance

On July 16, NetEase’s cloud service unit NetEase Shufan announced the open‑source release of Curve, a high‑performance distributed storage system that the company claims can achieve 1.84× the performance of Ceph.

Curve is positioned as a high‑performance, low‑latency storage foundation on which enterprises can build various storage solutions such as block storage, object storage, and cloud‑native databases. The current implementation provides a high‑performance block storage system.

High performance : The Curve team drew inspiration from leading open‑source storage projects and designed a new architecture. It uses brpc for high‑throughput network communication, braft for low‑latency multi‑replica consistency, and optimizes braft snapshots. Disk I/O is improved by finer‑grained address‑space hashing, increased concurrency, and a chunk‑file pool to reduce amplification.

Benchmark results released by NetEase show that in single‑volume tests Curve’s 4 KB random read/write IOPS are 1.84× and 1.58× higher than Ceph respectively, while latency is reduced by 48.39 % for reads and 37.50 % for writes.

High availability : Curve’s core components tolerate partial instance failures without affecting overall cluster availability. Client I/O remains unaffected by single‑node storage failures or system scaling, and common anomalies such as disk hot‑swap or process interruption cause minimal I/O jitter.

Autonomy : The system supports one‑click deployment and upgrade, requiring minimal manual intervention. It integrates open‑source projects like bvar, Prometheus, and Grafana to provide comprehensive metrics and alerting.

Curve’s high‑performance block storage is already used in NetEase’s core services, supporting snapshot cloning, QEMU virtual machines, and NBD devices for physical machines. After more than 400 days in production, it has reported no data inconsistency, loss, or major failures.

Future work includes fine‑grained hashing and an io_uring‑based write path, which the team expects to boost performance by another 30 % in the next release.

NetEase hopes the open‑source release will invite the community to adopt and contribute to Curve, addressing the current lack of high‑performance, low‑latency distributed storage solutions in the open‑source ecosystem.