Files
rustfs/crates/ecstore
houseme fe682e16e9 feat(ecstore): run one io_uring ring per shard on each disk (backlog#1145) (#4653)
A buffered read that hits the page cache completes inline inside
`io_uring_enter`, so the thread driving a ring performs that read's
memcpy. One ring per disk therefore capped cache-hit reads at a single
core's memory bandwidth: measured on a 16-core host, one driver thread sat
pinned at 100% CPU while throughput stayed flat at ~5 GB/s regardless of
read size, against 50 GB/s for the blocking-pool baseline.

rustfs/uring#6 taught the driver to hold N independent rings, each with its
own thread, pending table, backpressure semaphore, and eventfd. Wire it up:
`UringBackend::try_new` now calls `probe_and_start_sharded`, and
`RUSTFS_IO_URING_SHARDS` selects the count per disk.

The default is a quarter of the available parallelism clamped to `1..=4`,
because the cost is `disks × shards` driver threads (each normally blocked
in `poll(2)`). Any override is clamped to `1..=16`, so a mistyped value can
neither disable the driver (0) nor spawn threads without bound; an
unparseable value falls back to the default.

Effect (warm page cache, 16-core, rustfs/uring's concurrent_pread_bench):

  1 MiB, conc 8:    1 shard  4911 MB/s -> 8 shards 47361 MB/s (9.6x);
                    the blocking-pool baseline is 50662 MB/s
  64 KiB, conc 32:  StdBackend 153678 IOPS, p999 3030 us
                    8 shards   345402 IOPS, p999  897 us
  64 KiB, conc 128: StdBackend 135155 IOPS, p999 10716 us
                    8 shards    389047 IOPS, p999  4092 us

Sharding removes the throughput deficit *and* keeps io_uring's tail-latency
advantage, rather than trading one for the other.

Unchanged: io_uring read stays gray-off by default
(`RUSTFS_IO_URING_READ_ENABLE`), reads are byte-for-byte identical to
StdBackend, the per-disk degradation latches and probe cache (backlog#1101)
and the O_DIRECT tiered fallback (backlog#1102) all still apply. Rings stay
per-disk, so a stalled disk cannot starve another disk's rings
(backlog#1055). Bumps the rustfs-uring pin to the merged #6 commit.

Verified on a real Linux host (16-core, real io_uring): cargo clippy
--tests -D warnings clean; disk::local tests 132 passed, 0 failed —
including the existing io_uring and O_DIRECT cases now running on the
sharded driver, plus a new test covering the shard-count default, override,
and clamping.

Co-authored-by: heihutu <heihutu@gmail.com>
2026-07-10 07:41:11 +00:00
..

RustFS

RustFS ECStore - Erasure Coding Storage

High-performance erasure coding storage engine for RustFS distributed object storage

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📖 Overview

RustFS ECStore provides erasure coding storage capabilities for the RustFS distributed object storage system. For the complete RustFS experience, please visit the main RustFS repository.

Features

  • Reed-Solomon erasure coding implementation
  • Configurable redundancy levels (N+K schemes)
  • Automatic data healing and reconstruction
  • Multi-drive support with intelligent placement
  • Parallel encoding/decoding for performance
  • Efficient disk space utilization

📚 Documentation

For comprehensive documentation, examples, and usage guides, please visit the main RustFS repository.

📄 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Copyright 2024 RustFS Team

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

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All other trademarks are the property of their respective owners.

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