* volume: split the write path into reusable steps do_write_request ran its pre-append checks, the append, the sync rollback, the index publish and the post-write bookkeeping inline, so a batched write could only reuse it one needle at a time. Pull the steps out (check_writable, prepare_write, undo_unsynced_append, publish_write, finish_write) and the store's volume lookup plus disk-space check (writable_volume_mut). do_write_request composes them in the same order with the same early returns; no behaviour change. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> * volume server: group-commit fsync writes in the write queue The write queue holds one store lock for a batch of up to 128 needles but wrote them one at a time, so every fsync needle paid its own .dat sync and its own .idx sync: 2N syncs per batch. Add Volume::write_needles_grouped, after Go's processBatch. A volume's entries are split into runs of distinct needle ids (a repeated id starts a new run, so its dedup and cookie checks see the earlier write). A run with a durable entry appends everything with append_at_ns chained through a local, syncs the .dat once, and only then publishes the entries and syncs the .idx once. A failed .dat sync truncates the .dat back to the run start (marking the volume unavailable if that fails), leaves last_append_at_ns and last_modified untouched, and fails every entry of the run. Runs with no durable entry go through the unchanged per-needle path. Store::write_volume_needles is the queue's entry point; the handlers' non-queue path is unchanged. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> * volume server: fail closed when a failed append's rollback fails append_needle discarded the truncate-back result, so a partial write that could not be rolled back left unindexed bytes on the .dat while the volume stayed writable; the next append would bury them mid-file, past the load-time tail check. Route the rollback through undo_unsynced_append, which marks the volume unavailable when the truncate fails, so nothing more is appended over an unverified tail. * volume server: keep a grouped run's I/O error streak from later appends A synced run stages every append before any entry finishes, so the success reset in finish_write ran after the failed appends queued behind the last write to land and erased their media-error streak. Sent one at a time, those errors would have counted and quarantined the volume. Skip the reset when an append after the last landed write added to the streak. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> * volume server: replay a grouped run's I/O error streak in queue order Skipping the run's success reset whenever an append after the last landed write failed kept the errors from before that write as well, so a run like [EIO, EIO, landed, EIO] reached the quarantine count that the same writes one at a time (one error) do not. Mark the streak where each entry is staged and record the run's success at the last landed write's mark: errors before it are cleared, the ones after it still count. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> * volume server: replay a run's I/O error streak in one atomic step Reads record their outcomes on the tracker without the volume's write lock, so record_success_at's separate load and store could drop an error a read counted in between, or restore errors a read had just cleared. Keep the count and the clear counter in one atomic word and apply the replay with a single fetch_update. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com> Co-authored-by: Chris Lu <chris.lu@gmail.com>
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/.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.