Gurobi stuck after solution found

進行中

Jingyuan Hu

2022年08月02日 23:29

• 
• 
• 

Hi, 

I am currently working on a large-scale mixed-integer programming problem and I set the optimality gap to 1%. However, I got the following outputs

 

This is weird because I had a similar problem before and gurobi has no problem solving it (took 2 hours), but for this instance it got stuck for about 3 hours even though the gap is already 0.12%, which is lower than 1%. I wonder why this is happening and is there anything I can do to speed it up?

 

0

• 正式なコメント

  

  Simranjit Kaur

  • Gurobi Staff

  2025年11月16日 23:31

  This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum, or try Gurobot, our chatbot interface offering instant, expert-level support.
• 

  Matthias Miltenberger

  • Gurobi Staff

  2022年08月03日 09:42

  Hi!

  This is a pretty large problem instance and Gurobi performs a lot of presolving reductions to reduce its size. After the final solution is found, these reductions need to be reverted to compute a solution for the original space and this could take some time. It should still only take a fraction of the presolving time to perform that transformation, though.

  Let's further inspect this issue in an internal ticket.

  Best regards,
  Matthias

  0

投稿コメントは受け付けていません。