# Offloading I/O to Dedicated Cores: An Asymmetric io\_uring Backend for Seastar and ScyllaDB

DevFeed: [Offloading I/O to Dedicated Cores: An Asymmetric io\_uring Backend for Seastar and ScyllaDB](<https://devfeed.tech/articles/offloading-i-o-to-dedicated-cores-an-asymmetric-io-uring-backend-for-seastar-and-scylladb-4875.md>)

Original publisher: [Read original article](<https://www.scylladb.com/2026/07/22/asymmetric-io_uring-backend-seastar/>)

Author: Cynthia Dunlop

Published: 2026-07-22T18:03:10Z

Content type: article

Language: en

Sources: [ScyllaDB](<https://devfeed.tech/sources/scylladb.md>)

Topics: [IO](<https://devfeed.tech/topics/io.md>), [io\_uring](<https://devfeed.tech/topics/io-uring.md>), [Architecture & Design](<https://devfeed.tech/topics/architecture-design.md>), [C++](<https://devfeed.tech/topics/c-plus-plus.md>), [distributed-systems](<https://devfeed.tech/topics/distributed-systems.md>), [Linux](<https://devfeed.tech/topics/linux.md>), [networking](<https://devfeed.tech/topics/networking.md>), [Latency](<https://devfeed.tech/topics/latency.md>)

Tags: [aio](<https://devfeed.tech/tags/aio.md>), [architecture](<https://devfeed.tech/tags/architecture.md>), [c-plus-plus](<https://devfeed.tech/tags/c-plus-plus.md>), [cpu](<https://devfeed.tech/tags/cpu.md>), [design](<https://devfeed.tech/tags/design.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [i](<https://devfeed.tech/tags/i.md>), [io-uring](<https://devfeed.tech/tags/io-uring.md>), [latency](<https://devfeed.tech/tags/latency.md>), [linux](<https://devfeed.tech/tags/linux.md>), [networking](<https://devfeed.tech/tags/networking.md>), [performance](<https://devfeed.tech/tags/performance.md>), [seastar](<https://devfeed.tech/tags/seastar.md>), [systems](<https://devfeed.tech/tags/systems.md>)

## AI overview

This article presents Seastar's asymmetric io_uring backend, which moves low-level I/O work from application cores to dedicated cores. It explains the shared-nothing architecture, the motivations for offloading I/O, the design trade-offs, and the comparison with Seastar's existing linux-aio backend.

## Source excerpt

We moved low-level I/O execution off application cores to dedicated networking cores using Seastar's new asymmetric_io_uring backend. Explore the architecture design, trade-offs, and benchmark results.