how to set the memory parameter in a Gurobi model

Question

I would like to allocate a large memory for a model created using Python API. When I try to set MemLimit parameter, I do receive an error.

import gurobipy as gp
from gurobipy import GRB

my_model = gp.Model('myModel')
my_model.setParam('MemLimit', 1e+11)

gurobipy.GurobiError: Unable to modify parameter MemLimit after environment started

Could soemone show how to create an empty enviroment, set the memory parameter and then connect that with the model please?

Answer 1

There are two default behaviors that prevent you from setting the MemLimit parameter in the the Gurobi Python API (gurobipy):

1. gurobipy creates a default Gurobi environment
2. You cannot set the MemLimit parameter once the environment has been created

There are two alternate ways to handle this:

1. Use an environment file: Create a gurobi.env file in your working directory that contains the line:

MemLimit 1e11

2. Use an explicit Gurobi Env object like this:

import gurobipy as gp
from gurobipy import GRB

e = gp.Env("gurobi.log", params={'MemLimit': 1e11})
my_model = gp.Model('myModel', env=e)