* Reconstruct an EC shard from the shards already on this server recoverOneRemoteEcShardInterval only ever fanned out to the cached shard locations, so a server holding shards of the volume still fetched them over gRPC from itself -- and when the peers were unreachable it could not reconstruct at all, even holding the whole volume on local disk. Seed the Reed-Solomon buffers from the locally mounted shards first; each one is a peer round trip, and an interval-sized buffer, the fan-out no longer needs. Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN * Fetch only the EC shards reconstruction still needs The recovery fan-out read every surviving shard, so a 10+4 volume pulled 13 interval-sized buffers to feed Reed-Solomon 10 -- a third more memory held, and a third more load asked of peers that were, by definition, already having trouble. Fetch what is missing, and widen only when some of those reads fail. A shard reporting the needle deleted ends the walk: the rest would only answer the same. Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN * Bound the bytes EC recovery holds in flight Recovery is the one read path that multiplies the served bytes: it holds an interval-sized buffer per shard until Reed-Solomon runs, and a peer that is slow to fail keeps them all alive for the whole gRPC timeout. Nothing bounded how many of those fan-outs ran at once, so a transient problem between volume servers turned every read into a DataShards-fold allocation and the server died of it -- 64 concurrent 4MB intervals pin 3.6GB, and that is a small burst. Charge each recovery against a process-wide budget, so a burst queues on the semaphore instead of on the heap. Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN * Answer a deleted EC needle as deleted, not as a failed recovery A holder reporting the needle deleted is authoritative: deletes are never invented and never undone. Recovery already collected that flag, then dropped it on the branch where too few shards came back -- so a read of a deleted needle that had to recover surfaced as "cannot recover shard", and the volume server answered 500 where it owed a 404. Carry the flag out of the shortfall, and let it decide ahead of the error it came with. Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN * Check the encode run of a locally seeded EC shard in Rust The Rust recovery seeded Reed-Solomon straight from the mounted shards, without the encode-run check the remote reads and Go's readLocalEcShardInterval both apply. A volume remounted from a newer encode between the read's snapshot and its recovery would have fed mixed-generation bytes into the reconstruction. Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN * Say what the recovery budget actually guarantees Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN * Seed Rust EC recovery from shards on every local disk find_ec_volume returns the first disk's EcVolume, so a reconciled volume whose shards are split across data dirs had the siblings ignored and could report "cannot recover" while holding enough shards locally. Resolve each shard together with the disk that owns it, the way Go's recovery already does, and check that owner's encode run. Claude-Session: https://claude.ai/code/session_01SM5ARdPvFcnvGWNpBPgNRN
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.