Files
seaweedfs/seaweed-volume
Chris Lu d51454adf4 rust(seaweed-volume): distributed EC read across peer servers (#9516)
* feat(seaweed-volume): distributed EC read across peer servers

EcVolume::read_ec_shard_needle previously errored with NotFound when
any interval's shard wasn't local. In an RS(10,4)-across-N deployment
each server holds one shard, so every read needed >=9 peer fetches and
post-EC GETs returned 404 on volumes whose shards lived on more than
one server.

Mirror of weed/storage/store_ec.go's readOneEcShardInterval ->
readRemoteEcShardInterval -> recoverOneRemoteEcShardInterval chain:

  * server/store_ec.rs (new): entry point
    read_ec_shard_needle_distributed. Snapshots locate-needle + local
    reads under the Store sync lock, drops the lock, then async-fetches
    missing intervals via the peer's VolumeEcShardRead RPC. Falls back
    to Reed-Solomon reconstruction (read every other shard at the same
    (shard_offset, size) and run rs.reconstruct) when the direct peer
    read fails. Refreshes the per-EcVolume shard_locations cache from
    the master's LookupEcVolume RPC using Go's freshness thresholds
    (11s / 7min / 37min).
  * erasure_coding/ec_volume.rs: shard_locations now sits behind a
    std::sync::RwLock so the read path can refresh the map without
    holding the Store write lock. Adds shard_locations_refresh_time
    (Mutex<Option<Instant>>) for the staleness heuristic. Mirrors Go's
    ShardLocationsLock / ShardLocationsRefreshTime fields. set/get
    helpers updated for interior mutability.
  * server/handlers.rs: GET handler now tries the local-only fast
    path first, then falls through to the distributed path on
    NotFound.

* review: address PR 9516 feedback on distributed EC read

Five of the six PR-review comments addressed; the sixth (JWT on
outgoing peer gRPC) is deferred with an explicit TODO because the
crate-wide outgoing-JWT signing surface doesn't exist yet — adding it
in this one call site would split the credential plumbing across
peer paths that already lack it (copy_file_from_source, batch_delete,
…). Revisit when an outgoing-JWT helper lands.

Fixed in this commit:

  * Handlers: drop the two-tier (local-first, then distributed)
    read in handlers.rs. read_ec_shard_needle_distributed already
    does the local-first pass under the same store read lock; the
    redundant outer attempt re-read local intervals twice for any
    needle that spanned mixed-locality shards.
  * Scanner snapshot: replace inline locate-needle math with
    `ecv.locate_needle(needle_id)`. Same routine the local-only
    read path uses, so byte-identical on shard-size + interval
    boundaries.
  * EcVolume::set_shard_locations also advances
    shard_locations_refresh_time so the staleness check honors
    callers that populate the cache directly without going through
    the master LookupEcVolume RPC.
  * parse_grpc_address moved from grpc_server.rs into
    grpc_client.rs as `pub` and is reused by both grpc_server.rs
    and the new store_ec module. Single source of truth for the
    HTTP↔gRPC port-offset convention.
  * Reconstruction (recover_one_remote_ec_shard_interval) now seeds
    bufs from locally-mounted survivor shards BEFORE the remote
    fan-out. Previously the fan-out was remote-only, so when the
    shard_locations cache was cold or the master lookup failed,
    reconstruction errored even though enough siblings were on
    local disk to recover the missing interval.

* review: tighten parse_grpc_address; atomic shard-locations cache swap

Two follow-up findings from the PR 9516 review round 2:

  * `parse_grpc_address` now validates BOTH port components in the
    dotted form (`host:port.grpcPort`) — previously a non-numeric
    HTTP port like `host:abc.18080` slipped through and tripped a
    less-useful downstream URI parse error. The implicit form
    (`host:port` → port + 10000) also gains an overflow check so
    inputs like `host:60000` (which silently wrap past u16) are
    rejected here instead of producing an opaque connection
    failure later. Six unit tests cover each rejection path.

  * `EcVolume::set_shard_locations` no longer bumps the per-volume
    refresh timestamp. The previous fix introduced a freshness
    race: a multi-shard population that inserts shard-by-shard
    would flip `needs_refresh == false` on the first write, letting
    a concurrent reader observe a half-populated map already
    marked "fresh" and return NotFound for the not-yet-inserted
    shards. Added `EcVolume::replace_shard_locations(map)` for the
    atomic bulk swap; `write_back_shard_locations` in the
    distributed-read path uses it so the cache transitions
    old → fresh in a single observable step.
2026-05-16 20:44:28 -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.