Files
seaweedfs/seaweed-volume
563c729e70 rust volume: stream the tail scan and release the store lock (#11275)
* rust volume: add a .dat scan plan that runs without the store lock

DatScanPlan captures a fresh .dat handle, the version, the start offset
and an end bound while the caller holds a store guard, then visits one
record at a time with positional reads that never touch the Volume, the
way Go's ScanVolumeFileFrom feeds a scanner.

The handle pins the inode the offset was resolved against: a vacuum
commit renames .cpd over .dat and destroy unlinks it, and neither
rewrites the pinned bytes. The end bound is read while no writer can
hold store.write(), so the scan never meets a partial append. It is a
fresh open, not try_clone, because on Windows read_exact_at uses
seek_read, which moves a cursor a clone shares with the writer.

A header whose size is negative, or does not fit before the end bound,
ends the pass before the body length is computed or anything is
allocated. In today's scan a negative size reaches needle_body_length
and either overflows the buffer size or walks the scan from a wrong
offset. A size near i32::MAX overflows padding_length's i32 arithmetic,
which panics in debug builds.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018VF7E9SHPihG1jC1grU9H3

* rust volume: stream the tail scan with the store lock released

volume_tail_sender read every needle from the start offset to EOF into a
Vec while holding store.read(). volume.merge tails from zero, so that was
the whole volume in memory. And because needle writes and the heartbeat
take store.write() on a lock that prefers writers, the whole node stopped
serving until the scan finished: the failure #11235 fixed for EC scrub.

Each pass now runs on a blocking thread. Under one store guard it
resolves the start offset and captures a DatScanPlan, then drops the
guard and sends each needle as it is read, as Go's
VolumeFileScanner4Tailing does. This replaces the one-guard-across-
search-and-scan rule from the previous commit with a stronger invariant:
the offset, the handle and the end bound come from the same guard, and
the handle pins the inode, so a vacuum commit mid-scan cannot point the
offset into the compacted file.

A scan error now ends the stream with Status::internal instead of a
clean EOF, as Go's `streamFollow: %w` does. Once needles stream, a clean
EOF after a partial pass would let volume.move treat a truncated tail as
complete. A panic in the pass is reported the same way. A receiver that
hangs up is also noticed between skipped needles, not only on a send.

Unchanged: the append_at_ns filter, the header on every 2MB chunk, the
caught-up heartbeat without a scan, and the draining countdown.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018VF7E9SHPihG1jC1grU9H3

* rust volume: fail the tail pass on a short read below the snapshot end

DatScanPlan::scan treated an UnexpectedEof on the header or body read as
the end of the data and returned Ok. Every byte below the captured end
existed when the plan was taken, so a short read there can only mean the
inode was truncated under the plan: an unmount followed by a VolumeCopy
of the same volume id reopens .dat with truncate(true). The pass then
reported Scanned, the next pass found the volume gone, and the stream
ended cleanly after a prefix of the planned records, which volume.move
would take as a complete tail.

Both short-read arms now fail the scan with an I/O error that names the
offset and the snapshot end, so tail_pass reports Status::internal as it
does for every other read failure. The break arms were carried over from
scan_raw_needles_from, where the whole scan ran under the store guard and
nothing could truncate the file.

Found by the Devin and Greptile reviews on #11275.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* rust volume: sum the needle padding in i64 so a corrupt size cannot overflow

padding_length added the header, checksum and timestamp widths to the
needle size in i32. A size read from a corrupt header can sit near
i32::MAX, and that sum then overflows: a panic with overflow checks, a
wrapped padding without. DatScanPlan::scan bounds the size against the
bytes left before computing the body length, but that only keeps such a
size out of the arithmetic while under 2 GiB of the file remains, so on a
large volume the scan could still reach the overflow and, in release,
size a buffer from garbage.

Sum in i64 in both version branches. The result is at most
NEEDLE_PADDING_SIZE, so it still fits Size. The scan comment no longer
claims the bound check prevents the overflow.

Found by the CodeRabbit review on #11275.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

* rust volume: propagate dat scan parse failures

---------

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: Chris Lu <chris.lu@gmail.com>
2026-09-15 14:40:06 -07:00
..
2026-09-09 12:55:47 -07:00

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/.vif files 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.toml with 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 -- FetchAndWriteNeedle reads from any S3-compatible backend (AWS, MinIO, Wasabi, Backblaze, etc.) and writes locally. Supports VolumeTierMoveDatToRemote/FromRemote for 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_blocking to 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 preStopSeconds drain 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 VolumeServer RPCs 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.