Files
seaweedfs/seaweed-volume
Chris Lu 339a597e7e fix(vacuum): crash-safe compaction commit with a durable .cpc marker, fsync-before-rename, and a reload fence (#9944)
* storage: make vacuum/compaction commit crash-safe with a durable .cpc marker

A crash mid-compaction-commit could lose or corrupt volume data. The
two-rename commit (.cpd->.dat, .cpx->.idx) was not atomic, fsync results
were discarded before renaming over a healthy .dat, a stale .ldb could
poison the needle map, and a duplicate/late commit could delete the live
.dat/.idx outright.

Introduce a durable .cpc commit marker so the swap is atomic across a
crash:

- CommitCompact writes and fsyncs the .cpc marker after makeupDiff
  fsyncs the .cpd/.cpx, then runs applyCompactSwap: an existence-guarded
  rename of .cpd->.dat and .cpx->.idx, a directory fsync, removal of the
  stale .ldb/.rdb, and finally removal of the marker.
- reconcileCompactState recovers an interrupted commit on load: roll
  forward (finish the renames) when the marker is present, roll back
  (delete the orphan .cpd/.cpx) when it is absent. It runs from a
  directory pre-pass keyed on .cpd/.cpc existence, since the per-volume
  loader is keyed on .idx/.vif and misses the marker-only and
  already-renamed-.idx states.
- applyCompactSwap verifies BOTH .cpd and .cpx exist before touching the
  live files, so a stale-state commit (including the Windows
  RemoveAll-then-rename path) errors without deleting anything.
- Error-check the fsyncs that gate the swap: the .cpd close-fsync and
  .cpx fsync in copyDataBasedOnIndexFile, the makeupDiff .idx fsync, and
  MemDb.SaveToIdx.
- generateLevelDbFile rebuilds from offset 0 when the stored watermark
  sits past the end of the .idx, instead of replaying zero entries and
  poisoning the needle map.
- removeVolumeFiles and cleanupCompact sweep the .cpc marker; cleanup
  refuses to unlink the temp files while a marker is present.

Mirror the commit-marker, fsync-before-rename, guard, and
load/reconcile logic in the Rust volume server.

* storage: don't reconcile an already-loaded volume's compaction state on reload

reconcileCompactStates runs in loadExistingVolumes, which is re-invoked at
runtime on SIGHUP (Store.LoadNewVolumes). For a volume that is already loaded
and mid-vacuum, its .cpd/.cpx are live temp files, not crash leftovers --
rolling them back would clobber the in-flight compaction (and remove a live
.ldb out from under an open handle). Skip any vid already present in the
volume map; genuine startup recovery runs before any volume is loaded, so the
map is empty then. Mirrored in the Rust volume server.

Also drop the .note keepVif change that crept into this branch; it belongs to
the replica-copy/verify workstream and is restored to master's behavior here
so the two changes don't collide.

* storage: roll a compaction commit forward per-file, not all-or-nothing

A crash after the .cpd->.dat rename but before .cpx->.idx leaves .cpd gone,
.cpx and .cpc present, and a stale .idx. The roll-forward required BOTH temp
files, so it skipped the swap and cleared the marker, pairing the fresh .dat
with the stale .idx (index corruption). Finish whichever temp file remains:
extract finishCompactSwap to rename .cpd->.dat and/or .cpx->.idx independently;
applyCompactSwap keeps the both-present guard for the normal commit. Existence
in the Rust mirror is checked robustly so a transient error never skips the swap.

* seaweed-volume: propagate directory fsync failures on the compaction commit path

fsync_dir dropped every sync_all error, so the commit could proceed with an
undurable marker or rename and a later restart could recover the wrong
generation. Return the error and check it at the commit call sites (marker write
and the swap), matching the Go fsyncDir which already propagates. Directory
fsync stays a no-op on Windows, where it is unsupported.

* storage: overflow-safe stale-watermark check when rebuilding the leveldb index

watermark*NeedleMapEntrySize can overflow uint64 for a corrupted watermark and
wrap below the file size, defeating the stale-.ldb guard. Compare in entries
(watermark > size/NeedleMapEntrySize) instead, which is equivalent and cannot
overflow. LevelDb-backed needle map is Go-only; no Rust mirror.

* storage: propagate idxFile.Close error when writing the compacted index

SaveToIdx writes the .cpx that is renamed to .idx at commit; a discarded Close
error (buffered data not flushed) could leave a partially-written index after a
crash. Surface it in the same durability gate as the fsync.
2026-06-13 20:06:24 -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 1.75+ (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/.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.