English

ZhaoTao (Tom) — ten years building authoritative and recursive DNS data planes, four production systems, three of them on DPDK. Now working on L4 gateways and hardware offload.

ZhaoTao / 赵涛

Software engineer at Baidu, cloud infrastructure. I build and operate L4 gateways (network load balancers) and DNS.

For ten years I have been doing variations on one problem: rebuilding DNS from protocol handling down to data-plane performance. Four production systems — a carrier recursive cache, an internet-facing authoritative service, an in-VPC authoritative and forwarding cache, and an internet-facing authoritative service together with its control system. The last three run on self-built DPDK data planes, mostly in C. Since 2024 I have moved to L4 gateways and hardware offload.

Most of this blog is in Chinese. These pages are the English subset — the ones where the engineering travels better than the language.

  • About — background, systems I have built, and how to reach me
  • 中文主站 — the full blog: DNS, DPDK data planes, AI gateways

Writing

Making Authoritative DNS Fast Is the Easy Part

August 23, 2026

Kernel bypass gets an authoritative DNS server to millions of queries per second without much heroism. What it actually costs you is everything the kernel used to do for free — and the failure mode that follows does not page you.

Elsewhere