docs(object-data-cache): state the correctness boundary and the timing channel
The crate doc still described itself as "a minimal skeleton for the initial
rollout phase", which stopped being true several releases ago, and neither
the crate nor the operator-facing env constant said anything about what the
cache does or does not guarantee.
Record two things a reader has to know.
The correctness boundary: a hit is sound because the key matched metadata the
caller just resolved from a read quorum, not because invalidation ran.
Process-local invalidation is hygiene that frees capacity; the key is what
keeps a stale body from being served. Anyone tempted to weaken the key should
meet this sentence first.
The timing side channel: a hit skips the erasure read, bitrot verify and
decode, so it is reliably faster than a miss. A principal authorized to read
an object can time a single GET and learn whether someone read that object
within the entry's lifetime. This crosses no authorization boundary — the
probe needs read access to that exact object, checked before the cache is
consulted — but it does disclose a co-tenant's recent access pattern. Say so
where operators look: on RUSTFS_OBJECT_DATA_CACHE_ENABLE. Timing noise would
cost precisely the latency the cache exists to save, so the mitigation is to
leave the cache off for buckets where access-pattern confidentiality matters.
Refs: backlog#1139
Co-authored-by: heihutu <heihutu@gmail.com>
* feat(cache): add object data cache engine
* feat(cache): wire app-layer object cache flow
* refactor(cache): streamline app-layer cache flow
* refactor(cache): tighten cache flow internals
* refactor: address final clippy cleanup
* chore(deps): update quick-xml to 0.41.0
* feat(cache): wire object data cache env config
* fix(cache): gate materialize fill by cache plan
* chore(cache): add object data cache benchmark gate
* fix(cache): guard object cache fill size mismatches
* refactor(cache): streamline object cache body planning
* fix(cache): align object cache rollout config
* test(cache): cover buffered object cache benchmark
* test(cache): isolate object cache benchmark metrics
* test(cache): mark materialize rollout experimental
* test(cache): tighten object cache benchmark gate
* fix(cache): address review findings for object data cache
- singleflight: clean up leader entry on cancellation (Drop impl) so a dropped GET future can no longer wedge all subsequent fills for the same key; switch the fill map to a std Mutex and add a regression test
- adapter: honor RUSTFS_OBJECT_DATA_CACHE_ENABLE=true by defaulting to hit_only when no explicit mode is set (explicit mode still wins)
- planner: treat nil version UUIDs as "no value" per repo convention so unversioned objects key under the canonical "null" instead of fragmenting the key space
- multipart: invalidate the object cache on the quota-exceeded rollback delete after complete-multipart, closing a stale-cache window
- layering: move the disabled-cache fallback into app::context and drop the new infra->app layer-dependency baseline entry
* fix(cache): close invalidation races and drop full-cache scan on writes
- index: make identity-index insert/remove/prune atomic via starshard compute_if_present/compute_if_absent so concurrent fills can no longer drop each other's keys (lost keys made entries unreachable to invalidation until TTL); add a concurrency regression test
- fill: register the key in the identity index before the entry becomes visible in the cache and re-check the index afterwards, undoing the fill when an invalidation raced in between (new skipped_invalidation_race fill result)
- invalidate: with the index now authoritative, remove the full-cache iter() fallback that made every PUT/DELETE of a never-cached object O(total cache entries) (two scans per PUT, 2N per batch delete)
- materialize-fill: fail the GET instead of falling back to the partially consumed stream after a mid-read error (the fallback would send a body missing its prefix under a full-length Content-Length), and log the same size-mismatch warning as the sibling buffering paths
Co-Authored-By: heihutu <heihutu@gmail.com>
* test(storage): fix media-dependent buffer clamp expectation
test_concurrency_manager_multi_factor_strategy_buffer_clamp asserted media_cap.min(MI_B), but the implementation's final safety clamp is [32KiB, media_cap.max(MI_B)] — deliberately so a media cap above 1MiB (NVMe's 2MiB default) stays effective. The test only passed on machines detected as SSD/Unknown (cap == 1MiB) and failed on NVMe-backed CI runners with 2MiB != 1MiB. Assert the media cap itself, which is what the strategy actually guarantees on every environment.
Co-Authored-By: heihutu <heihutu@gmail.com>
* test(storage): format buffer clamp assertion
* chore(logging): update tier guardrail path
---------
Signed-off-by: houseme <housemecn@gmail.com>
Co-authored-by: cxymds <cxymds@gmail.com>
Co-authored-by: overtrue <anzhengchao@gmail.com>
Co-authored-by: heihutu <heihutu@gmail.com>
houseme