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Zhengchao An
05a5be51ce
A superseded cycle is the expected outcome of the dirty-usage fast path, not a signal of pathological load: a write burst marks buckets dirty, the scanner wakes within milliseconds, and the still-landing writes then supersede the snapshot it just took. Charging that first race SUPERSEDED_RETRY_BASE_INTERVAL = 60s meant the burst surfaced in usage and quota accounting roughly two cycles late. Measured on an idle single-node instance (fresh data dir, 10 PUTs, polling /rustfs/admin/v3/datausageinfo every 5s): the dirty-usage wake fires 0.3s after the PUTs, its cycle is superseded 0.2s later, and the retry was then scheduled 55.6s out; usage first became visible at t+120s. With the base at 5s the retry is scheduled 4.7s out and usage becomes visible at t+70s. The exponential growth in retry_interval is what protects against a persistently hot bucket driving an unbroken full-scan loop, so the base does not need to be a whole cycle: 5s, 10s, 20s, 40s ... still reaches minute-scale backoff within a handful of consecutive supersedes and keeps the SUPERSEDED_RETRY_MAX_INTERVAL cap. A configured cycle shorter than the base still wins, since retrying faster than the operator's own cadence buys nothing. Verification: cargo test -p rustfs-scanner --lib (444 passed) with the three superseded-backoff tests updated to the new schedule; make pre-commit green; end-to-end probe above.
RustFS Scanner
RustFS Scanner is the background maintenance scan loop. It handles usage accounting, lifecycle expiry and transition admission, bucket replication repair admission, scanner-driven heal/bitrot checks, and namespace alerts.
For operator-facing runtime controls, status fields, and tuning workflows, see Scanner Runtime Controls. For repeatable scanner-pressure validation, see Scanner Benchmark Runbook.
Chinese documentation is available in README.zh-CN.md.
Development
Build
cargo build --package rustfs-scanner
Test
cargo test --package rustfs-scanner
License
Apache License 2.0