* test(volume_server): reproduce #9184 ReceiveFile truncating a mounted shard ReceiveFile for an EC shard calls os.Create(filePath) which opens the path with O_TRUNC. When the shard is already mounted, the in-memory EcVolume holds a file descriptor against the same inode, so a second ReceiveFile call for the same (volume, shard) truncates the live shard file beneath the reader. Reproducer: generate and mount shard 0 for a populated volume, capture the on-disk size, then send a smaller payload for the same shard via ReceiveFile. The current handler accepts the overwrite and leaves the shard truncated in place; this test pins that behavior. When the fix lands the server should reject (or rename-then-swap) and this test must be inverted. * fix(volume_server): refuse ReceiveFile overwrite of mounted EC shard ReceiveFile used os.Create on EC shard paths, which opens with O_TRUNC and truncates in place. When an EC shard is already mounted, the in-memory EcVolume holds file descriptors against the same inodes, so the truncation corrupts the live shard beneath any ongoing read. On retries of an EC task this produced the "missing parts" class of errors in #9184. The fix rejects any ReceiveFile for an EC volume that currently has mounted shards. The caller must unmount before retrying — silent truncation is never an acceptable outcome. Non-EC writes and ReceiveFile for volumes that have never been mounted on this server continue to work as before. Tests: - TestReceiveFileRejectsOverwriteOfMountedEcShard: mounts a shard, attempts an overwrite, asserts the error response and that the on-disk file and live reads are undisturbed. - TestReceiveFileAllowsEcShardWhenNoMount: pins the common-case contract that a first write to a target still succeeds. * fix(volume-rust): refuse ReceiveFile overwrite of mounted EC shard Mirror the Go-side change: reject receive_file for any EC volume that currently has mounted shards on this server. std::fs::File::create truncates in place and the in-memory EcVolume holds fds on the same inodes, so an overwrite would corrupt live readers.
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 1.75+ (2021 edition).
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/.viffiles 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.tomlwith 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 --
FetchAndWriteNeedlereads from any S3-compatible backend (AWS, MinIO, Wasabi, Backblaze, etc.) and writes locally. SupportsVolumeTierMoveDatToRemote/FromRemotefor 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_blockingto 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
preStopSecondsdrain 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
VolumeServerRPCs 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.