seaweedfs/rust/volume_server/DEV_PLAN.md

Rust Volume Server Rewrite Dev Plan

Goal

Build a Rust implementation of SeaweedFS volume server that is behavior-compatible with the current Go implementation and can pass the existing integration suites under /Users/chris/dev/seaweedfs2/test/volume_server/http and /Users/chris/dev/seaweedfs2/test/volume_server/grpc.

Compatibility Target

• CLI compatibility for volume-server startup flags used by integration harness.
• HTTP and gRPC behavioral parity for tested paths.
• Drop-in process integration with current Go master in transition phases.

Phases

Phase 0: Bootstrap and Harness Integration

• Add Rust volume-server crate.
• Implement Rust launcher that can run as a volume-server process entrypoint.
• Add integration harness switches so tests can run with:
  • Go master + Go volume (default)
  • Go master + Rust volume (VOLUME_SERVER_IMPL=rust or VOLUME_SERVER_BINARY=...)
• Add CI smoke coverage for Rust volume-server mode.

Phase 1: Native Rust Control Plane Skeleton

• Native Rust HTTP server with admin endpoints:
  • GET /status
  • GET /healthz
  • static/UI endpoints used by tests
• Native Rust gRPC server with basic lifecycle/state RPCs:
  • GetState, SetState, VolumeServerStatus, Ping, VolumeServerLeave
• Flag/config parser parity for currently exercised startup options.

Phase 2: Native Data Path (HTTP + core gRPC)

• HTTP read/write/delete parity:
  • path variants, conditional headers, ranges, auth, throttling
  • chunk manifest read/delete behavior
  • image and compression transform branches
• gRPC data RPC parity:
  • ReadNeedleBlob, ReadNeedleMeta, WriteNeedleBlob
  • BatchDelete, ReadAllNeedles
  • copy/receive/sync baseline

Phase 3: Advanced gRPC Surface

• Vacuum RPC family.
• Tail sender/receiver.
• Erasure coding family.
• Tiering/remote fetch family.
• Query/Scrub family.

Phase 4: Hardening and Cutover

• Determinism/flake hardening in integration runtime.
• Performance and resource-baseline checks versus Go.
• Optional dual-run diff tooling for payload/header parity.
• Default harness/CI mode switch to Rust volume server once parity threshold is met.

Integration Test Mapping

• HTTP suite: /Users/chris/dev/seaweedfs2/test/volume_server/http
• gRPC suite: /Users/chris/dev/seaweedfs2/test/volume_server/grpc
• Harness: /Users/chris/dev/seaweedfs2/test/volume_server/framework

Progress Log

• Date: 2026-02-15
• Change: Created Rust volume-server crate (weed-volume-rs) as compatibility launcher and wired harness binary selection (VOLUME_SERVER_IMPL/VOLUME_SERVER_BINARY).
• Validation: local Rust-mode smoke and full-suite runs passed:
  • VOLUME_SERVER_IMPL=rust go test ./test/volume_server/http ./test/volume_server/grpc