Files
seaweedfs/seaweed-volume
Eliah RusinandClaude Fable 5.1 799c495226 rust volume: one positional read helper; never seek a dup'd handle on Windows (#11342)
* rust volume: one positional read helper; never seek a dup'd handle on Windows

Positional read-exact was hand-rolled four times: the complete
cross-platform version in needle_map/sorted_file.rs, a Windows-only half
in volume.rs whose unix half was inlined as a
cfg(unix)/cfg(windows)/compile_error! triple at three call sites, a
byte-identical Windows-only copy in ec_volume.rs, and read_full_at in
ec_bitrot.rs. Three more sites -- EcVolumeShard::read_at,
EcLocalShard::read_at and ec_encoder::read_at_most -- hand-rolled the
short-read-permitted variant with a cfg(not(unix)) arm that
try_clone()s the handle and seeks it.

That last arm is wrong. A duplicated descriptor shares one kernel file
offset with the original, so seek-then-read is two syscalls against
state another thread can move in between: a concurrent reader or an
append repositions the offset and the read returns bytes from somewhere
else entirely. EcLocalShard::read_at documents that it must never seek,
one line above the seek. Windows seek_read carries its own offset in a
single call, so that window does not exist.

All seven now go through storage::io::{read_exact_at, read_at}, whose
module doc records why duplicating a handle is not a way to get a
private file position -- opening the file again is, as
Volume::dat_scan_plan already does. read_at_most keeps its own
fill-until-EOF loop; only the per-iteration positional read changes.

Behaviour on unix is unchanged: every unix arm was already
FileExt::read_exact_at or FileExt::read_at. The one exception is
ec_bitrot::verify_shard_blocks, which now retries on EINTR (std's
read_exact_at does; the loop it replaces did not) and, on unix, reports
the standard "failed to fill whole buffer" text instead of "short read
on shard block". The Windows arm still says "unexpected EOF in
seek_read"; both carry ErrorKind::UnexpectedEof, as before.

NeedleStreamSource::read_exact_at and Volume::read_exact_at_backend keep
their signatures; only their bodies shrink.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* rust volume: retry Interrupted in Windows read_exact_at

Unix std's FileExt::read_exact_at ignores ErrorKind::Interrupted and
retries, but the Windows seek_read loop propagated it, so the shared
exact-read contract differed by platform. seek_read can surface
ERROR_OPERATION_ABORTED, which std maps to Interrupted.

---------

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
2026-09-17 11:47:38 -07:00
..
2026-09-09 12:55:47 -07:00

SeaweedFS Volume Server (Rust)

A drop-in replacement for the SeaweedFS Go volume server, rewritten in Rust. It uses binary-compatible storage formats (.dat, .idx, .vif) and speaks the same HTTP and gRPC protocols, so it works with an unmodified Go master server.

Building

Requires Rust 1.91.1+ (2024 edition), matching rust-version in Cargo.toml. The patch release matters: 1.91.0 does not build. The edition itself only needs 1.85; the higher floor comes from the dependency tree — chiefly the AWS SDK — so it moves with those crates. CI builds on the latest stable.

cd seaweed-volume
cargo build --release

The binary is produced at target/release/seaweed-volume.

Running

Start a Go master server first, then point the Rust volume server at it:

# Minimal
seaweed-volume --port 8080 --master localhost:9333 --dir /data/vol1 --max 7

# Multiple data directories
seaweed-volume --port 8080 --master localhost:9333 \
  --dir /mnt/ssd1,/mnt/ssd2 --max 100,100 --disk ssd

# With datacenter/rack topology
seaweed-volume --port 8080 --master localhost:9333 --dir /data/vol1 --max 7 \
  --dataCenter dc1 --rack rack1

# With JWT authentication
seaweed-volume --port 8080 --master localhost:9333 --dir /data/vol1 --max 7 \
  --securityFile /etc/seaweedfs/security.toml

# With TLS (configured in security.toml via [https.volume] and [grpc.volume] sections)
seaweed-volume --port 8080 --master localhost:9333 --dir /data/vol1 --max 7 \
  --securityFile /etc/seaweedfs/security.toml

Common flags

Flag Default Description
--port 8080 HTTP listen port
--port.grpc port+10000 gRPC listen port
--master localhost:9333 Comma-separated master server addresses
--dir /tmp Comma-separated data directories
--max 8 Max volumes per directory (comma-separated)
--ip auto-detect Server IP / identifier
--ip.bind same as --ip Bind address
--dataCenter Datacenter name
--rack Rack name
--disk Disk type tag: hdd, ssd, or custom
--index memory Needle map type: memory, leveldb, leveldbMedium, leveldbLarge
--readMode proxy Non-local read mode: local, proxy, redirect
--fileSizeLimitMB 256 Max upload file size
--minFreeSpace 1 (percent) Min free disk space before marking volumes read-only
--securityFile Path to security.toml for JWT keys and TLS certs
--metricsPort 0 (disabled) Prometheus metrics endpoint port
--whiteList Comma-separated IPs with write permission
--preStopSeconds 10 Graceful drain period before shutdown
--compactionMBps 0 (unlimited) Compaction I/O rate limit
--pprof false Enable pprof HTTP handlers

Set RUST_LOG=debug (or trace, info, warn) for log level control. Set SEAWEED_WRITE_QUEUE=1 to enable batched async write processing.

Features

  • Binary compatible -- reads and writes the same .dat/.idx/.vif files as the Go server; seamless migration with no data conversion.
  • HTTP + gRPC -- full implementation of the volume server HTTP API and all gRPC RPCs including streaming operations (copy, tail, incremental copy, vacuum).
  • Master heartbeat -- bidirectional streaming heartbeat with the Go master server; volume and EC shard registration, leader failover, graceful shutdown deregistration.
  • JWT authentication -- signing key configuration via security.toml with token source precedence (query > header > cookie), file_id claims validation, and separate read/write keys.
  • TLS -- HTTPS for the HTTP API and mTLS for gRPC, configured through security.toml.
  • Erasure coding -- Reed-Solomon EC shard management: mount/unmount, read, rebuild, copy, delete, and shard-to-volume reconstruction.
  • S3 remote storage -- FetchAndWriteNeedle reads from any S3-compatible backend (AWS, MinIO, Wasabi, Backblaze, etc.) and writes locally. Supports VolumeTierMoveDatToRemote/FromRemote for tiered storage.
  • Needle map backends -- in-memory HashMap, LevelDB (via rusty-leveldb), or redb (pure Rust disk-backed) needle maps.
  • Image processing -- on-the-fly resize/crop, JPEG EXIF orientation auto-fix, WebP support.
  • Streaming reads -- large files (>1MB) are streamed via spawn_blocking to avoid blocking the async runtime.
  • Auto-compression -- compressible file types (text, JSON, CSS, JS, SVG, etc.) are gzip-compressed on upload.
  • Prometheus metrics -- counters, histograms, and gauges exported at a dedicated metrics port; optional push gateway support.
  • Graceful shutdown -- SIGINT/SIGTERM handling with configurable preStopSeconds drain period.

Testing

Rust unit tests

cd seaweed-volume
cargo test

Go integration tests

The Go test suite can target either the Go or Rust volume server via the VOLUME_SERVER_IMPL environment variable:

# Run all HTTP + gRPC integration tests against the Rust server
VOLUME_SERVER_IMPL=rust go test -v -count=1 -timeout 1200s \
  ./test/volume_server/grpc/... ./test/volume_server/http/...

# Run a single test
VOLUME_SERVER_IMPL=rust go test -v -count=1 -timeout 60s \
  -run "TestName" ./test/volume_server/http/...

# Run S3 remote storage tests
VOLUME_SERVER_IMPL=rust go test -v -count=1 -timeout 180s \
  -run "TestFetchAndWriteNeedle" ./test/volume_server/grpc/...

Load testing

A load test harness is available at test/volume_server/loadtest/. See that directory for usage instructions and scenarios.

Architecture

The server runs three listeners concurrently:

  • HTTP (Axum 0.7) -- admin and public routers for file upload/download, status, and stats endpoints.
  • gRPC (Tonic 0.12) -- all VolumeServer RPCs from the SeaweedFS protobuf definition.
  • Metrics (optional) -- Prometheus scrape endpoint on a separate port.

Key source modules:

Path Description
src/main.rs Entry point, server startup, signal handling
src/config.rs CLI parsing and configuration resolution
src/server/volume_server.rs HTTP router setup and middleware
src/server/handlers.rs HTTP request handlers (read, write, delete, status)
src/server/grpc_server.rs gRPC service implementation
src/server/heartbeat.rs Master heartbeat loop
src/storage/volume.rs Volume read/write/delete logic
src/storage/needle.rs Needle (file entry) serialization
src/storage/store.rs Multi-volume store management
src/security.rs JWT validation and IP whitelist guard
src/remote_storage/ S3 remote storage backend

See DEV_PLAN.md for the full development history and feature checklist.