Files
seaweedfs/seaweed-volume
Chris Lu 349576b63e backup: resume incremental copies by index position instead of appendAtNs (#12228)
* volume server: add last-entry cursor fields to VolumeIncrementalCopy

* backup: resume incremental copies by index position instead of appendAtNs

appendAtNs is stamped by whichever replica received the write, so the
same needle carries a different timestamp on every replica. A backup
that resumes from a different replica than last time can append the
last needle again or skip needles written inside the clock gap.

Send the local copy's index entry count and last entry identity (key,
size, cookie) with VolumeIncrementalCopy. The replica verifies the same
record sits at that position and streams from the next index entry, so
the resume no longer depends on any replica's clock. When the boundary
record does not match, or the local copy is ahead, the replica returns
FailedPrecondition and the backup rebuilds the local copy from scratch.

Old servers ignore the new fields and keep the timestamp behavior.

* rust volume server: mirror positional resume in VolumeIncrementalCopy

* volume server: add entries_hash prefix checksum to VolumeIncrementalCopy

* backup: verify the whole index prefix, not just the boundary entry

* rust volume server: verify the index prefix hash in resume_by_last_entry

* backup: keep the source's compaction revision on rebuilt copies

* backup: diverge on a zero-offset boundary entry

A remote-tier tombstone lives in the .idx with no .dat record, so
readNeedleAt(0) parses the superblock and its error bypassed the
ErrIncrementalCopyDiverged mapping; the backup got a generic failure
instead of FailedPrecondition and never rebuilt.

* rust volume server: mirror zero-offset boundary divergence

* rust volume server: gate the empty-dat early return on entry_count

With a positional resume the Go handler still reaches ResumeByLastEntry,
so an empty replica reports divergence; the Rust early return answered a
clean empty stream and weed backup kept a stale copy.

* backup: hash the index entry's size field, not trailing offset bytes

In a 5BytesOffset build the offset occupies bytes 8-12 and the size
starts at byte 13, so the hash folded in one byte of the offset.
Matching records at different offsets then hashed differently and a
valid backup was reported diverged and rebuilt.

* backup: read the index in whole-entry chunks for the prefix hash

When entries are 17 bytes a 1 MiB read buffer does not end on an entry
boundary: the partial tail entry was skipped by the loop but still
counted as consumed, so every later chunk was hashed at a misaligned
position.

* rust volume server: hash the index entry's size field after the offset

Mirrors the Go hashIndexEntries change: with the 5bytes feature the
offset occupies bytes 8-12, so starting the size slice at byte 12
folded one offset byte into the hash and matching records at different
offsets compared diverged.

* rust volume server: read the index in whole-entry chunks for the prefix hash

Mirrors the Go change. With 17-byte entries a 1 MiB buffer does not
end on an entry boundary, so slicing the partial tail entry panicked
once a backup held 61681 entries.

* rust volume server: default the new incremental copy request fields in tests
2026-10-29 18:56:25 -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
--compactionMaxParallelCommits 0 (unlimited) Max concurrent vacuum commits
--pprof false Enable pprof HTTP handlers

Set RUST_LOG=debug (or trace, info, warn) for log level control.

Durable (fsync=true) uploads always go through per-volume batching workers that share one .dat/.idx sync per batch, matching the Go volume server; non-fsync writes take the synchronous path.

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.