Very slow on infeasible problem #381
Description
Hello,
I found the following in my server logs. Unfortunately, I don't have the exact corresponding problem.
It looks like cbc determined in less than one second that the problem was infeasible, but still ran for over 7 minutes before returning the result.
2021-04-07T13:10:54.285756111Z app[web.1]: Welcome to the CBC MILP Solver
2021-04-07T13:10:54.285815602Z app[web.1]: Version: 2.9.9
2021-04-07T13:10:54.285819954Z app[web.1]: Build Date: Aug 21 2017
2021-04-07T13:10:54.285823272Z app[web.1]:
2021-04-07T13:10:54.285827023Z app[web.1]: command line - Cbc_C_Interface -solve -quit (default strategy 1)
2021-04-07T13:10:54.285830493Z app[web.1]: Presolve determined that the problem was infeasible with tolerance of 1e-08
2021-04-07T13:10:54.285833993Z app[web.1]: Analysis indicates model infeasible or unbounded
2021-04-07T13:10:54.285849206Z app[web.1]: 1 infeasibilities
2021-04-07T13:10:54.285853240Z app[web.1]: Analysis indicates model infeasible or unbounded
2021-04-07T13:10:54.285856954Z app[web.1]: Perturbing problem by 0.001 %% of 16961.932 - largest nonzero change 9.7912192e-05 (%% 0.047165003) - largest zero change 9.7911624e-05
2021-04-07T13:10:54.285878894Z app[web.1]: 0 Obj 0 Primal inf 40000000 (8760)
2021-04-07T13:10:54.285882211Z app[web.1]: 1000 Obj 28.066767 Primal inf 39609818 (8760
[...] hundreds and hundreds of similar lines: XXX Obj XX.XXX Primal inf XXX (XXX)
2021-04-07T13:17:18.032751255Z app[web.1]: 44884 Obj 1800339.8 Primal inf 15620000 (4380)
2021-04-07T13:17:18.032774648Z app[web.1]: 44884 Obj 1800000 Primal inf 15620000 (4380)
2021-04-07T13:17:18.032779753Z app[web.1]: Primal infeasible - objective value 1800000
2021-04-07T13:17:18.032784399Z app[web.1]: PrimalInfeasible objective 1800000 - 44884 iterations time 355.052
2021-04-07T13:17:18.032788853Z app[web.1]:
2021-04-07T13:17:18.032793113Z app[web.1]: Result - Linear relaxation infeasible
2021-04-07T13:17:18.032797385Z app[web.1]:
2021-04-07T13:17:18.032801554Z app[web.1]: Enumerated nodes: 0
2021-04-07T13:17:18.032805787Z app[web.1]: Total iterations: 0
2021-04-07T13:17:18.032827804Z app[web.1]: Time (CPU seconds): 355.05
2021-04-07T13:17:18.032849672Z app[web.1]: Time (Wallclock Seconds): 387.95
2021-04-07T13:17:18.032856381Z app[web.1]:
2021-04-07T13:17:18.032861313Z app[web.1]: Total time (CPU seconds): 355.05 (Wallclock seconds): 387.95