# scylladb/seastar

High performance server-side application framework

Repository: https://github.com/scylladb/seastar
Canonical: https://ross.abutalabs.com/products/seastar
Homepage: http://seastar.io
Language: C++
License: Apache-2.0
License Family: permissive
Topics: c-plus-plus, seastar, dpdk, async, aio
Last push: 2026-08-26T20:01:53+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 4398, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 9342, forks 1704 (observed 2026-08-28T04:10:30.678250+00:00)

## What it is
Seastar is an open-source C++ framework for building high-performance, non-blocking, asynchronous server-side applications. It uses a shared-nothing, shard-per-core architecture with futures/promises, message passing between cores, and optional DPDK user-space networking.

## Use cases
- write a high-performance async HTTP server in C++
- build a low-latency network service that scales across all CPU cores
- use DPDK user-space networking for a fast server application
- avoid locks by sharing state via message passing between cores
- build a database or cache server like Scylla or Memcached replacement

## When to choose
- you need maximum server performance on modern multi-core Linux hardware
- you are comfortable with C++ and futures/continuation-style async code
- you want a shared-nothing design without locks or threads sharing state

## When to avoid
- you need a quick general-purpose web app with rich ecosystem support
- your team is not experienced with C++ and low-level async programming
- you need portability beyond Linux/OSv or heavy third-party library integration

## Facets
- artifact type: framework
- maturity: stable
- function: web-framework, http-server, concurrency, networking, rpc
- domain: backend, web-development, developer-tools, performance, microservices
- platform: cpp, cross-platform
- tags: shared-nothing, futures-and-promises, dpdk, shard-per-core, async, event-driven, server-side, linux

## Member repositories
- scylladb/seastar (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:30.678250+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:22:27.765261+00:00, confidence not recorded.
  - readme: https://github.com/scylladb/seastar (fetched 2026-08-28T04:10:30.678250+00:00, sha 7f6f59028812)
  - homepage: http://seastar.io (fetched 2026-08-29T08:22:27.551160+00:00, sha a58367bfb248)
  - site_page: http://docs.seastar.io (fetched 2026-08-29T08:22:27.560626+00:00, sha 2e540b6995c9)
  - site_page: https://seastar.io/faq (fetched 2026-08-29T08:22:27.562357+00:00, sha da3ab523f2c0)
- Data as of 2026-08-30T08:39:29.467469+00:00.