[Cbc] two minor issues in cbc (maxtime and log)

[Matthew Galati]

Wall clock and cpu are pretty close here. I suspect CBC is just not checking maxtime often enough (inside some expensive operation). 

Sent from my iPhone

> On Jan 22, 2018, at 9:48 PM, Andrew Wald <andrewjohnwald at gmail.com> wrote:
> 
> Hi Matthew,
> 
> It seems like your problem is pretty large and spent a lot of time pre-processing... 
> 
> Not sure if this will help since I don't have your files to test, but this might be something to try. What about constraining by the wall clock like this when you call it up:
> cbc -solve -quit -seconds 1300 -timeMode elapsed
> 
> - Andrew
> 
> 
>> On Mon, Jan 22, 2018 at 8:06 PM, Matthew Galati <Matthew.Galati at sas.com> wrote:
>> Two minor issues. This is through the C++ CBCModel API using the latest CBC.
>> 
>>  
>> 
>> I set max time (1300 seconds), but CBC did not stop until after 19,900 seconds.
>> This is a maximization problem, but the final summary states “Lower bound” for the bound. It might be cleaner to just say “bound” – to avoid confusion.
>>  
>> 
>> command line - cbc -solve -quit -seconds 1300 (default strategy 1)
>> 
>> Continuous objective value is 1.88508e+09 - 855.75 seconds
>> 
>> Cgl0005I 998000 SOS with 13941976 members
>> 
>> Cgl0004I processed model has 999000 rows, 13941976 columns (13941976 integer (13                                                                                                 941976 of which binary)) and 26887952 elements
>> 
>> Cutoff increment increased from 1e-05 to 0.9999
>> 
>> Cbc0020I Exiting on maximum time
>> 
>> Cbc0005I Partial search - best objective 1e+50 (best possible -1.885078e+09), to                                                                                                 ok 0 iterations and 0 nodes (19624.31 seconds)
>> 
>> Cbc0035I Maximum depth 0, 0 variables fixed on reduced cost
>> 
>> Cuts at root node changed objective from -1.88508e+09 to -1.88508e+09
>> 
>> Probing was tried 0 times and created 0 cuts of which 0 were active after adding                                                                                                  rounds of cuts (0.000 seconds)
>> 
>> Gomory was tried 0 times and created 0 cuts of which 0 were active after adding                                                                                                  rounds of cuts (0.000 seconds)
>> 
>> Knapsack was tried 0 times and created 0 cuts of which 0 were active after addin                                                                                                 g rounds of cuts (0.000 seconds)
>> 
>> Clique was tried 0 times and created 0 cuts of which 0 were active after adding                                                                                                  rounds of cuts (0.000 seconds)
>> 
>> MixedIntegerRounding2 was tried 0 times and created 0 cuts of which 0 were activ                                                                                                 e after adding rounds of cuts (0.000 seconds)
>> 
>> FlowCover was tried 0 times and created 0 cuts of which 0 were active after addi                                                                                                 ng rounds of cuts (0.000 seconds)
>> 
>> TwoMirCuts was tried 0 times and created 0 cuts of which 0 were active after add                                                                                                 ing rounds of cuts (0.000 seconds)
>> 
>>  
>> 
>> Result - Stopped on time limit
>> 
>>  
>> 
>> No feasible solution found
>> 
>> Lower bound:                    1885078031.000
>> 
>> Enumerated nodes:               0
>> 
>> Total iterations:               0
>> 
>> Time (CPU seconds):             19928.34
>> 
>> Time (Wallclock seconds):       19973.07
>> 
>>  
>> 
>> Total time (CPU seconds):       19930.87   (Wallclock seconds):       19975.64
>> 
>> 
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