On 04/19/2017 08:06 AM, Loic Dachary wrote: > On 04/19/2017 03:53 PM, Alex Rousskov wrote:
>> On 04/18/2017 01:00 AM, Loic Dachary wrote: >> >>> It turns out [CARP] performs as well as CRUSH >> On 04/19/2017 06:51 AM, Loic Dachary wrote: >> >>> I found one use case where CRUSH behaves significantly better than CARP. >> FYI, here is how the above statements can be interpreted: "It is all a >> mystery to us. Sometimes CRUSH and CARP are about the same, sometimes >> one of the algorithms wins, but we cannot tell you when to use CARP or >> CRUSH because we cannot generalize their differences. Our experimental >> data does not suggest any clear trends." >> >> That unpredictability may be the nature of the beast, of course, but I >> currently see no reasoning or experimental data to confirm or deny that >> sad hypothesis. > CRUSH is no mystery [...] CARP is somewhat mysterious You may know exactly how each algorithm works, but that does not really matter in this context. What matters here is the _relative_ strengths and weaknesses of an algorithm. That part is still a mystery (to me). When is CRUSH better than CARP? When is CARP better than CRUSH? > Please let me know if that is of interest to Squid As of 04/18/2017, my personal answer to that question is "why bother?". As of 04/19/2017, my personal answer to that question is "maybe": One out of 2+ random(?) tests shows about the same CARP and CRUSH results. Another test shows better CRUSH performance. It is not clear to me whether some other tests will show better CARP performance. I hope the above clarifies my position. Others may have a completely different opinion, of course, and my current position does not block CRUSH acceptance. Thank you, Alex. _______________________________________________ squid-dev mailing list [email protected] http://lists.squid-cache.org/listinfo/squid-dev
