[SCIP] Fscip run time

[Vladimir V. Voloshinov]

Dear colleagues,
excuse me to interfere into your conversation, but I had the same problem
(with SCIP 8.0.3) and reported about it in April 2023,
http://listserv.zib.de/pipermail/scip/2023-April/004626.html.
After a month, I got the answer that the problem was serious, but Yuji
Shinano was busy and the decision was postponed, ... unfortunately! See,
http://listserv.zib.de/pipermail/scip/2023-May/004627.html.

Sincerely yours,
Vladimir

On Fri, Jan 19, 2024 at 8:47 PM Pedro Matias Carrancio <
pedro.carrancio at gmail.com> wrote:

> Thorsten,thank you very much for you response.
>
> What you say is true, but with harder problems the same thing happens.
>
> Pyscipopt log:
>
>   222s| 13100 |  4121 |  1221k|  93.0 |     0  |  72 | 920 | 186 | 981 |
> 756k|  0 |   0 |   0 | 5.367782e-04 | 5.083094e-04 |   5.60%|  47.53%
> (node 13111) solution of LP 139849 not optimal (pfeas=1, dfeas=0) --
> solving again with tighter feasibility tolerance
>
> SCIP Status        : solving was interrupted [gap limit reached]
> Solving Time (sec) : 222.53
> Solving Nodes      : 13111
> Primal Bound       : +5.08309438454586e-04 (48 solutions)
> Dual Bound         : +5.36773734174404e-04
> Gap                : 5.60 %
>
>
> Fscip Log  (-sth 30)
>
>  314          34120         505        30           0.0005
> 0.0005      5.59%           0.0005      5.59%
>       320          34127          37        23           0.0005
> 0.0005      5.59%           0.0005      5.59%
>       325          34138          37        12           0.0005
> 0.0005      5.59%           0.0005      5.59%
> SCIP Status        : solving was interrupted [given gap reached]
> Total Time         : 328.70
>   solving          : 328.70
>   presolving       : 0.06 (included in solving)
> B&B Tree           :
>   nodes (total)    : 34149
> Solution           :
>   Solutions found  : 2
>   Primal Bound     : +5.08310004133510e-04
>   Dual Bound       : +5.36729879827307e-04
> Gap                : 5.59105 %
>
> I used this params in fscip (normal ramp-up)
>
> RacingStatBranching = FALSE
> RampUpPhaseProcess = 0
>
> In racing ramp-up the time is greater.
>
> Maybe I'm missing some additional configuration. I don´t know.
>
> Thanks for you help.
>
> Pedro Carrancio.
>
>
>
>
>
>
> El mié, 17 ene 2024 a las 18:02, Thorsten Koch (<koch at zib.de>) escribió:
>
>> Hi Pedro,
>>
>> this problem is too small and easy to profit from Fiber SCIP.
>>
>> You only have 1 or 3 nodes. fscip parallelizes on a node basis. There is
>> nothing to parallelize.
>>
>> BR Thorsten
>>
>> Am 17.01.24 um 20:49 schrieb Pedro Matias Carrancio:
>> > Hello Scip Team.
>> >
>> > I  solved a MINLP by running scip in python with Pyscipopt.
>> >
>> > It ran ok , I had optimal response in 25 seconds. I exported the model
>> in attached file. (modelMM.cip)
>> >
>> > image.png
>> >
>> > Now, I´m trying to solve the same MINLP with fscip.
>> >
>> > It run well too, but it takes longer.
>> >
>> > -sth 1
>> >
>> > image.png
>> >
>> > image.png
>> >
>> > And the greater the number of threads, the greater the delay.
>> >
>> > -sth 3
>> >
>> > image.png
>> >
>> > image.png
>> >
>> >
>> > It´s right? I expected that with more threads the time would improve
>> and that with one thread the time would be similar to that of pysicpopt.
>> >
>> > Any help is appreciated.
>> >
>> > Thanks.
>> >
>> >
>> > Pedro Carrancio.
>> >
>> >
>> >
>> > _______________________________________________
>> > Scip mailing list
>> > Scip at zib.de
>> > https://listserv.zib.de/mailman/listinfo/scip
>>
>> --
>> The important thing is not to stop questioning.
>> Curiosity has its own reason for existing.          -- Albert Einstein
>> ______________________________________________________________________
>> Prof. Dr. Thorsten Koch /       Technische Universität Berlin
>> www.zib.de/koch        /                   and
>> koch at zib.de           /          Zuse Institute Berlin (ZIB)
>> _____________________/       Takustraße 7, 14195 Berlin, Germany
>>         and also                Phone +49-30-84185-213, Fax -269
>> Kooperativer Bibliotheksverbund Berlin Brandenburg (KOBV)
>> Forschungs- und Kompetenzzentrum Digitalisierung Berlin (digiS)
>> ______________________________________________________________________
>>
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