What version of OR-Tools and what language are you using?
Version: 9.15.6755
Language: Python
Which solver are you using (e.g. CP-SAT, Routing Solver, GLOP, BOP, Gurobi)
CP-SAT
What operating system (Linux, Windows, ...) and version?
Ubuntu 24.04.3 LTS
What did you do?
I ran a particular CP-SAT model (1.1M+ variables) from python, allowing 64 workers.
What did you expect to see
Based on the logs, it seems that the optimum was identified and proven optimal in under 600 seconds. Ideally, the solver would terminate shortly after this point.
What did you see instead?
The solver continues on for another ~1.5 hours before returning result, apparently related to the three variables_shaving subsolvers. (Note: The issue is more obvious if I specify solver.parameters.max_time_in_seconds = 600.0. The time limit is not respected and the solver continues on for an additional ~1.5 hours.)
I've attached the full log, which includes the task timing details.
CP-SAT.variables_shaving.performance_issue.txt
Anything else we should know about your project / environment
I suspect my model is so large that individual calls to CopyModelConnectedToVar() could be taking a significant amount of time. That function doesn't currently seem to include any checks to shared_->SearchIsDone() or shared_->time_limit->LimitReached(), so I think it may effectively become a "zombie process". (Perhaps checks for completed-search / time-limit-reached would be appropriate, maybe around L518-519?)
What version of OR-Tools and what language are you using?
Version: 9.15.6755
Language: Python
Which solver are you using (e.g. CP-SAT, Routing Solver, GLOP, BOP, Gurobi)
CP-SAT
What operating system (Linux, Windows, ...) and version?
Ubuntu 24.04.3 LTS
What did you do?
I ran a particular CP-SAT model (1.1M+ variables) from python, allowing 64 workers.
What did you expect to see
Based on the logs, it seems that the optimum was identified and proven optimal in under 600 seconds. Ideally, the solver would terminate shortly after this point.
What did you see instead?
The solver continues on for another ~1.5 hours before returning result, apparently related to the three
variables_shavingsubsolvers. (Note: The issue is more obvious if I specifysolver.parameters.max_time_in_seconds = 600.0. The time limit is not respected and the solver continues on for an additional ~1.5 hours.)I've attached the full log, which includes the task timing details.
CP-SAT.variables_shaving.performance_issue.txt
Anything else we should know about your project / environment
I suspect my model is so large that individual calls to CopyModelConnectedToVar() could be taking a significant amount of time. That function doesn't currently seem to include any checks to
shared_->SearchIsDone()orshared_->time_limit->LimitReached(), so I think it may effectively become a "zombie process". (Perhaps checks for completed-search / time-limit-reached would be appropriate, maybe around L518-519?)