BZLZHH 82de3f6826 [Docs] (P12): the ring-1024 experiment - every deferred answer comes back (readfail 8,872 -> 0), so eviction was the whole cause and the residency budget is now the brake ...

One-line experiment before writing the retention table: StreamLink's kReplyRing 8 -> 1024,
nothing else changed, same load frame on the same device.

                       ring = 8 (today)   ring = 1024
    readfail                    8,872              0
    taken                          63          4,499 / 4,500
    blocked (fell back)         4,435              0
    by_op 2                     9,071          3,443
    wall                        27.9 s         23.04 s
    frame-sent        create 4,536, records 103,097   identical per op

TWO CONCLUSIONS. First, eviction was the ONLY cause: with a buffer deep enough, every
deferred answer was read back and not one create fell through to the blocking path.
The wedge (want=310) and the useless budget (budget=4,451) were two faces of "eight
slots is not enough". Second, what brakes now is the BUDGET, not the buffer: by_op 2 =
3,443 matches the number of times the budget forced an early read (3,395), i.e. every
one of those is a real blocking wait. Its constant is 7, sized for the 8-slot pool, so
against a 1,024-deep buffer it became the only throttle and the wall only moved 27.9 ->
23.0 s.

WHAT IT MEANS FOR THE DESIGN. Once the answers are RETAINED until read, correctness no
longer depends on how long one survives in a bounded buffer, so the budget must be
sized to the RETENTION CAPACITY rather than to the pool - or be replaced by "retained
means safe". by_op 2 = records/W then puts W=2 at ~2,268 waits and the wall at ~15 s,
which is the goal's own success criterion.

Experiment reverted (ring back to 8, probes deleted); 172 + 13 + 22 + 103 green.

2026-09-26 02:44:30 +08:00

..

CS_Refactor

[Feat] (MG_Remote): a record can tell the server its answer will never be read - the bit works and cuts a frame's replies by 92%, and it proves the window's real blocker is the FIFO drain, not the pool depth

2026-09-26 02:00:44 +08:00

Disaggregated

[Docs] (P12): the ring-1024 experiment - every deferred answer comes back (readfail 8,872 -> 0), so eviction was the whole cause and the residency budget is now the brake

2026-09-26 02:44:30 +08:00