FA-73814 / Rate limiter algorithms / Member archive

Combined per-second and per-minute fixed windows: minute window computed from milliseconds as seconds · case 04

The minute counter resets every 60 ms and the minute limit is never effective.

Member previewVariant 4 · 3 implementations · 6 checks per implementation

Case contract

Input {per_second, per_minute, requests [t_ms]} with nondecreasing t. Second windows are t div 1000 and minute windows t div 60000, each resetting its own counter only when its own window changes. The second limit is checked first ("deny-second"), then the minute limit ("deny-minute"); only admitted requests are counted, in both windows. Return [decisions, second count, minute count].

Why this case matters

Public APIs commonly publish several simultaneous limits; coupling their resets or charging denied requests to one of them breaks the published contract.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
minute budget spans seconds	`[["allow", "allow", "allow", "allow", "allow", "allow", "allow", "allow"], 1, 1]`	`[["allow", "allow", "allow", "allow", "allow", "deny-minute", "deny-minute", "deny-minute"], 0, 5]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.