FA-854 / Queues / Member archive

Assign a partition during consumer rebalance: The new consumer starts while the old owner remains active · case 04

The partition rebalance operation is admitted even though the new consumer starts while the old owner remains active.

Member previewVariant 4 · 3 implementations · 9 checks per implementation

Case contract

Return a Boolean admission decision for assign a partition during consumer rebalance. The record r must satisfy all of: r['revocation_complete'] is True; r['assignment_epoch'][0] > r['assignment_epoch'][1]; r['checkpoint_available'] is not None; r['subscription_match'][0] in r['subscription_match'][1]; r['capacity_limit'][0]+r['capacity_limit'][1] <= r['capacity_limit'][2]. Extra tracing fields are ignored; validation does not mutate the record.

Why this case matters

A deterministic local contract for queues. Each negative fixture violates exactly one invariant. No transport timing, persistence, cryptographic verification, or full protocol implementation is claimed.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
The new consumer starts while the old owner remains active	`true`	`false`	Failed

MEMBER ARCHIVE

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