* pb: let a heartbeat carry only the volumes that changed A partial list cannot travel in volumes: a master that did not understand it would read the absences as deletions. So changes get their own field, used only once the master has said it compares digests and can tell when it has fallen behind. * master: apply the volumes a heartbeat reports as changed Only the named volumes are touched. A full report says the server holds exactly these; a changed report says nothing about the ones it leaves out, so absence must not read as removal. Also advertises that the master compares digests, which is what lets a server stop sending its whole list. Advertising it once per connection means a server reconnecting to a master that does not is back to full lists straight away. * volume: send only the volumes that changed once the master accepts them The whole list goes on every heartbeat until the master says it compares digests, and again whenever it asks, so a master that cannot tell when it has fallen behind never has to. has_no_volumes stays derived from a full list alone. Deriving it from what a heartbeat happens to carry would make a quiet one read as a server that had lost every volume, and the master would drop them all. The digest still covers every volume held rather than the ones sent, which is what lets the master confirm that applying the changes left it current. Reporting state is per-connection: a server that reconnects, or reaches a different master, starts again from the full list. * volume: let the zero reporting state stand for having told no master anything A Store built as a literal, which tests do, left the reporting state nil and panicked on the first heartbeat. As a value its zero form already means nothing has been reported to anyone, which is exactly the state that sends the whole list. * rust: send only the volumes that changed once the master accepts them Mirrors the Go volume server, with one hazard the Go side does not have: mount and unmount deltas here are derived by diffing successive heartbeats, so a heartbeat that carries a partial list would report every volume it left out as unmounted. Collecting now returns the full set alongside the message, and every site that diffs uses that rather than what went on the wire. * volume: do not let a full-list request be lost to the heartbeat it raced The request arrived while a heartbeat was already being built as a delta, and committing that heartbeat cleared it, so the master waited for another digest mismatch before asking again. Count the requests and clear only the one the heartbeat answered. * rust: stop marking volumes reported by a heartbeat that is thrown away The state-notify path collected a heartbeat only to diff its volume list, then sent a delta message of its own and dropped the one it had collected. Once collecting recorded what the master had been told, every mount or unmount silently marked the changed volumes as sent, and the master learned of them only after a digest mismatch. Snapshotting no longer records anything, and no longer expires ec volumes whose deletion that path was already discarding. * master: announce only the volumes a change actually brought Every changed volume was broadcast as a new location. Volumes grow constantly and growth moves no location, so on a busy cluster that told every connected client about volumes it could already reach, filling bounded broadcast queues and pushing out the topology updates that matter. * master: ask for the full list when only one can repair the master Delta heartbeats stop the full report, and with it the only thing that re-registers a volume the lookup index lost. The volume server cannot see that divergence and its digest cannot show it, so the master now checks its own two indexes agree and asks for the list when they do not. A node reporting one volume id twice is kept on full lists for the same reason rather than merely skipped: its digest can never be verified, so nothing else would tell the master what it had stopped holding. * master: keep the volume options on every heartbeat response A volume server takes them from whatever response arrives, and preallocate is a bare bool with no way to tell off from unmentioned. A response sent to ask for the volume list therefore turned preallocation off until the server reconnected. Responses sent mid-stream now start from the configured options rather than being built field by field. * master: announce a volume the lookup index had lost Repairing the index makes the volume servable again, but clients were told it went when the node dropped out and nothing told them otherwise: the disk map still held it, so it did not count as an arrival. Reaching the lookup index is what makes a volume servable, so recovering an entry there is an arrival as far as clients are concerned, on both the full report and the changed-volume path.
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.