Files
seaweedfs/seaweed-volume
Chris LuandGitHub 77bf2a3ab0 volume.balance: gate on real physical disk usage (fixes #10160) (#10162)
* shell: add volume.balance -byDiskUsage to balance by actual data

The default balancer ranks servers by slot density, dividing used volumes by
MaxVolumeCount. When MaxVolumeCount is configured higher than the disk can hold,
a physically near-full server looks nearly empty and gets picked as the move
target, so balancing drains less-full servers onto an already-full one.

-byDiskUsage ranks servers by the actual data they hold (sum of volume sizes)
instead, so the fullest-by-data server is treated as full and balancing drains
it. It assumes comparable disk sizes per disk type and still respects each
server's free volume slots. Default behavior is unchanged.

* plumb physical disk usage into topology, gate volume.balance on it

Volume servers now report each disk's filesystem total/free bytes in the
heartbeat, and the master stores them in DiskInfo. volume.balance uses them to
skip any move target whose disk is already near full (-maxDiskUsagePercent,
default 90), so an over-configured maxVolumeCount can no longer make a
physically full server look empty and get drained onto. The gate judges each
server against its own disk, so heterogeneous disk sizes are fine; servers that
do not report bytes fall back to slot-only behavior.

Rust seaweed-volume mirrors the heartbeat reporting.

* admin: report real physical disk capacity when volume servers provide it

The dashboard estimated server capacity as maxVolumeCount * volumeSizeLimit,
which overstates it when maxVolumeCount is set higher than the disk holds.
Prefer the filesystem capacity now reported per disk, falling back to the
estimate for servers that do not report it.

* worker: gate automatic balance on physical disk fullness too

The maintenance balance worker selects the least slot-utilized server as the
move destination, so an over-configured maxVolumeCount makes a physically full
server look empty and get drained onto — the same defect as the shell command.
Now that DiskInfo carries real disk bytes, skip any destination whose disk is
at/above 90% used (per server, against its own disk); a full server can still be
a source. When every candidate destination is full, create no tasks. Servers
that do not report disk bytes are not gated.

* balance: share the physical-disk-fullness gate between shell and worker

The shell volume.balance command and the maintenance balance worker each grew
their own copy of the disk-fullness gate (targetDiskTooFull / destinationDiskTooFull)
and a maxDiskUsagePercent=90 constant. Pull both into weed/topology/balancer
(DiskTooFullAfter + DefaultMaxDiskUsagePercent) so the policy has one home and the
two balancers can't drift.

* balance: harden the physical-disk gate

Guard against a nil DiskInfo in the byte/slot lookups. Let a zero disk-capacity
report clear previously stored bytes (0 means "not reported" for bytes, unlike
maxVolumeCount), so a server that stops reporting falls back to slot-only instead
of trusting stale capacity. In the worker, charge each planned move's bytes to
its destination within a detection cycle so the gate sees a target fill up rather
than only its heartbeat-time free space. Note the per-location capacity summing
assumes one location per filesystem (the used ratio the gate relies on stays
correct regardless; absolute capacity can over-report).
2026-06-30 19:31:12 -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.