* ec: refuse to mount a 0-byte shard file when the index has entries The startup scan already skips (and eventually deletes) zero-sized shard files as residue of a failed copy, but the mount RPC path opens the file directly with no size check, so an explicit VolumeEcShardsMount over a truncated file registers a size-0 claim. A registered empty shard serves nothing while advertising ownership: with placement pinned to the owning disk, it would keep attracting re-copies to a file that was never valid. The one legitimate 0-byte shard is the empty volume's: encoding a volume with no live needles produces a 0-byte .ecx and 0-byte shards, and that mount must keep working (TestMountEcShards_EmptyEcxMountsSuccessfully). So the gate compares against the index: AddEcVolumeShard (Go) and EcVolume::add_shard (Rust) refuse a 0-byte shard file only when the volume's .ecx has entries. Go's AddEcVolumeShard grows an error return for this; the loader cleans up the refused shard and, when it just created the EcVolume, unregisters that too. The mount loop already collects non-ENOENT failures per disk and keeps scanning, so a sibling disk holding a real copy still wins. Regression tests in both trees: an empty shard beside an index with entries is refused and leaves nothing registered; an empty shard of an empty volume still mounts. Claude-Session: https://claude.ai/code/session_01AWpefvdi4U3HLng18x5CJ9 * ec: release the duplicate shard when a mount retry re-loads it Review follow-up: AddEcVolumeShard keeps the existing shard and reports added=false for a shard this disk already registered, but the loader discarded that result, so every retried LoadEcShard leaked the duplicate it had just opened — an fd and a mount-gauge increment per retry. Release both and return the existing volume. Regression test pins the gauge. Claude-Session: https://claude.ai/code/session_01AWpefvdi4U3HLng18x5CJ9 * ec: close the test DiskLocation instead of only its EC volumes Review follow-up: DiskLocation.Close() also stops the background goroutine NewDiskLocation starts; closeEcVolumes left it running for the rest of the test process. Both uses are this PR's own tests. Claude-Session: https://claude.ai/code/session_01AWpefvdi4U3HLng18x5CJ9 * rust: unregister the just-created EcVolume when its first mount is refused Review follow-up: when the first mount of a volume rejects its shard (e.g. the new 0-byte-beside-nonempty-index refusal), the Rust mount path had already inserted the EcVolume and propagated the error without removing it — a zero-shard registration advertising a mount that serves no data while pinning the .ecx/.ecj descriptors (and, since placement's mounted tier keys off it, steering shard placement at this disk). Remove it on the way out, exactly as the Go loader already does; a volume that already holds shards keeps them (the RPC's first-error-aborts contract). Regression test covers both. Claude-Session: https://claude.ai/code/session_01AWpefvdi4U3HLng18x5CJ9 * rust: skip already mounted shards on a mount retry Review follow-up: EcVolume::add_shard replaces self.shards[id] for a shard the volume already holds, and the mount loop then bumps the ec_shards gauge although the mounted count did not grow — gauge drift on every mount retry, and a serving fd swapped for no reason. Skip shard ids the volume already reports, mirroring Go's AddEcVolumeShard added=false handling. Regression test pins the gauge across a duplicate mount (unique collection label: the gauge is process-global and tests run in parallel). Claude-Session: https://claude.ai/code/session_01AWpefvdi4U3HLng18x5CJ9
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.