* volume: verify before destroy in VolumeCopy and replication repair Four data-safety fixes around copy/repair paths that could destroy or resurrect data before verifying the source or survivors. (a) VolumeCopy no longer deletes a pre-existing local replica up front. The delete is deferred until ReadVolumeFileStatus on the source succeeds, so a transient source outage (or a retry after one) can no longer wipe a healthy destination replica. Gated on source readability only; size/count comparisons are intentionally not used because they invert legitimately after divergent vacuum/compaction. Mirrored in the Rust volume server. (b) volume.check.disk no longer resurrects vacuumed-deleted needles. A key present-and-live on the source but entirely absent on the target is ambiguous: it may be a genuine missing write, or a needle deleted on the target and then vacuumed (its index entry and any tombstone are gone). An individual needle AppendAtNs has no monotonic relation to a vacuum watermark, so the old cutoff heuristic could not tell them apart. Without positive proof the absence is a missing write, the safe default is to NOT push it back. Tradeoff: a real missing write may go unrepaired until a tombstone-aware path exists, but we never raise back deleted data. (c) Over-replication trim no longer resurrects needles or removes the wrong replica. The pre-delete sync now runs read-only (divergence check only) instead of writing the doomed replica's needles into the survivor. pickOneReplicaToDelete only ever removes the smallest of multiple healthy writable replicas; it refuses the trim when doing so would leave only read-only/integrity-flagged survivors, since file_count>0 alone cannot prove the survivor's .dat is readable. (d) Incomplete-volume (.note) cleanup keeps the shared .vif when an .ecx for the same vid coexists on the disk, so removing an interrupted regular copy cannot strip a coexisting EC volume's info file. VolumeCopy now surfaces .note write/remove errors instead of ignoring them. In the Rust volume server (where a persisting note is actually reachable) the .note check moves below the empty-stub sweep and EC validation, keeps the .vif on EC coexistence, and the mount path fails when a .note still persists. * shell: scope the over-replication writable-survivor guard to the trim path only The writable-survivor guard (never trim down to a read-only survivor) lived inside the shared pickOneReplicaToDelete, so it also gated the misplaced-volume relocation via pickOneMisplacedVolume -- a misplaced read-only volume (e.g. a full one) would silently stop being rebalanced. Extract pickSmallestReplica for the relocation path (which deletes-and-recreates and must act on read-only replicas), and keep the writable-survivor guard only in pickOneReplicaToDelete used by the over-replication trim. * seaweed-volume: recompute keep_vif after invalid-EC cleanup in the .note path keep_vif used the pre-validation ecx_exists snapshot, so when the EC-validation step above removed the invalid .ecx/shards, the .note cleanup still preserved a now-orphaned .vif. Re-check .ecx existence at cleanup time, matching the Go hasEcxFile re-check. * shell: keep placement when picking an over-replication victim to delete The trim picked the smallest writable replica without regard to placement, so it could delete the only replica in a required failure domain (e.g. with "100" and replicas dc1 + two in dc2, deleting dc1 leaves both survivors in dc2). Prefer a writable replica whose removal still satisfies placement, falling back to the smallest writable only when none does.
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.