Files
seaweedfs/seaweed-volume
Chris Lu eed3c27d15 volume: cut the memory a server holding millions of volumes still uses (#10999)
* volume: stop the .vif guard depending on which entry the scan handed over

A volume has both an .idx and a .vif, and loadExistingVolume skipped a .vif
next to an .ecx as EC shard metadata. That was only ever correct because
os.ReadDir sorted .idx ahead of .vif: an interrupted encode, where the .idx is
still there, has to reach validateEcVolume to be reclaimed. Ask for the .idx
instead of trusting the order.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy

* volume: walk volume directories in batches instead of listing them whole

os.ReadDir builds, and sorts, a slice of every entry before the caller sees
the first one. A disk holding millions of volumes has a .dat, .idx and .vif
per volume, so each startup scan costs hundreds of MB of peak heap that the
runtime is slow to hand back -- and there are several of them before the
first volume loads.

Walk in batches instead, and keep only the entries each scan acts on:
loadAllEcShards now sorts and stats the shard and index files alone rather
than every file on the disk.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy

* volume: skip the sibling-.dat scan when no EC volume is loaded

pruneIncompleteEcWithSiblingDat only ever prunes EC volumes that are loaded,
but it first walks every disk and keys a map by every .dat on the server. On
a store with no EC volumes at all that is millions of map entries built to
answer no question.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy

* volume: stop keeping a departure message for every volume

The report state held a VolumeShortInformationMessage per volume copy so a
departure could be named, but almost no volume ever departs. Hold a handle to
the identity instead -- volumes share very few distinct ones -- and build the
message on the way out.

Measured over a populated report state: 195 -> 83 bytes per volume.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy

* rust volume: stop keeping a whole volume message per volume held

The send loop kept a VolumeInformationMessage for every volume just to notice
mounts and unmounts, and rebuilt the map from scratch on every beat. Keep the
identity a delta names, which is what the Go report state keeps for the same
reason.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy

* rust volume: keep only the EC files the shard scan acts on

load_all_ec_shards named every file on the disk twice -- once in the dedup set
and once in the sorted vector -- before deciding it only wanted .ec?? and .ecx.
Filter while reading instead. Mirrors the same change in loadAllEcShards.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy

* volume: share the strings every .vif repeats

A tiered volume's .vif names its replication and its backend, and every decode
allocates a fresh copy, so a server holding millions of them holds millions of
copies of the same handful of names. Route them through the interning table
the volume info decode already uses. The remote key names one volume and is
left alone.

Claude-Session: https://claude.ai/code/session_01NWpFUwAJcR2KUENrhLc9Sy
2026-08-27 22:25:15 -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.