Files
seaweedfs/seaweed-volume
Chris Lu 41d6c821ba feat(topology): report empty disks (per-disk type + capacity in heartbeat) (#10166)
* fix(topology): keep physical disk 0 distinct in SplitByPhysicalDisk

DiskId 0 doubles as the first physical disk (Locations[0]) and the
protobuf "unset" default. SplitByPhysicalDisk folded every DiskId-0
record onto the aggregate DiskId whenever that was non-zero, so on a
multi-disk node the first disk's volumes merged into whichever disk
held volumes[0]: the node reported one fewer disk, the sibling showed
~2x volumes, and per-disk max was smeared across the survivors. This
surfaced as cluster.status and volume.list undercounting disks.

Only treat 0 as unset when no record carries a non-zero DiskId; with a
mix, 0 is a real disk and keeps its own entry.

* fix(admin): resolve physical disk 0 in active-topology indexes

rebuildIndexes re-derived each volume/EC record's physical disk id with
the same "DiskId 0 means unset" heuristic SplitByPhysicalDisk used, so
the two agreed only by sharing the bug. Now that SplitByPhysicalDisk
keeps disk 0 distinct, the duplicated heuristic would fold disk-0 records
onto a sibling while at.disks kept them on disk 0; GetVolumeLocations and
GetECShardLocations then matched no record and silently dropped every
volume and EC shard on the first disk, starving balance and EC tasks.

Build the indexes from the same SplitByPhysicalDisk reconstruction that
builds at.disks, so the keys always resolve. One source of truth instead
of a parallel normalize.

* fix(ec): allow physical disk 0 as preferred EC shard target

pickBestDiskOnNode gated its result on bestDiskId != 0, but 0 is both a
valid physical disk and the uint32 zero value, so a best-scoring disk 0
was discarded and the non-matching fallback returned instead. Gate on
bestScore.

* test(admin): cover EC-shard index resolution for physical disk 0

rebuildIndexes builds ecShardIndex the same way as volumeIndex; pin the EC
path too so a shard on disk 0 keeps resolving via GetECShardLocations.

* proto: per-disk type/capacity in DiskTag, DiskInfo.physical_disks

DiskTag gains type + max_volume_count so the heartbeat can describe every
physical disk, including ones holding no volumes or EC shards. DiskInfo
gains physical_disks so the master can hand the full per-type disk set to
per-physical-disk consumers.

* feat(volume): report each physical disk's type and capacity

CollectHeartbeat fills DiskTag.type and the per-disk effective max for
every location, so the master can account for disks that hold no volumes
or EC shards yet. Rust heartbeat mirrors it.

* feat(master): surface empty disks in the per-physical-disk view

The master records each disk's type and max from DiskTags and lists them
on DiskInfo.physical_disks per type, including disks with no volumes or
EC shards. SplitByPhysicalDisk enumerates that full set and gives each
disk its exact max, so cluster.status, volume.list and the admin
topology count and can target empty disks. Without physical_disks the
even-split fallback is unchanged.

* fix(master): clamp per-disk free at zero for over-allocated disks

In the exact-max path FreeVolumeCount could go negative when a disk holds
more volumes than its max; a negative would reduce the node's summed free
and block placement on healthy disks. Clamp at 0.

* fix(master): rebuild disk tags fresh each heartbeat

DiskTags is the full authoritative per-disk list every heartbeat, so
rebuild dn.diskTags from scratch like dn.diskBackends; merging left stale
entries for removed disks.

* fix(master): keep zero-capacity disks in physical_disks

A disk reporting max 0 (an unavailable disk) is a valid physical disk,
not a signal to drop it. List every disk of the type, but only emit
physical_disks when the node reports real per-disk capacity, so an older
server sending all zeros still falls back to the aggregate split.

* test(volume): cover disk-space-low per-disk max in heartbeat

Assert DiskTag.max_volume_count follows the used-slots override when a
location is low on space, matching the per-type max_volume_counts.

* chore: trim comments on the empty-disk change

Drop narration; keep only the non-obvious why (disk-0 sentinel, exact-max
free clamp, EC slots not subtracted, all-zeros fallback).

* refactor(master): merge per-disk tags and capacity into one map

diskTags and diskBackends were parallel maps keyed by the same DiskId and
filled together from DiskTags. Fold them into one diskMetas map of
{tags, type, max}.

* refactor(proto): per-disk max as a map keyed by disk id

physical_disks was a repeated {disk_id, max_volume_count} whose fields
duplicated DiskInfo's own disk_id/max_volume_count. A map<uint32,int64>
keyed by disk id expresses "max per disk" directly, drops the extra
PhysicalDiskInfo message, and the consumer reads it as the disk set.

* docs(proto): note DiskInfo.disk_id's two meanings

Identity on a per-physical-disk DiskInfo (from SplitByPhysicalDisk),
representative fallback on the type-keyed aggregate.
2026-06-30 18:45:44 -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.