Model too large for size-limited license despite WLS license

Answered

Alexandre Touzet

• January 08, 2024 10:58
• Edited

Hello, 

I have a web application that makes use of a WLS license to create and solve optimization models, and until 2 weeks ago everything was working perfectly. I didn't use my application for two weeks, and now I am getting the following error, even though nothing changed: "An error occurred during optimization: Model too large for size-limited license; visit https://www.gurobi.com/free-trial for a full license".

The license expires in March 2024. I pass the credentials via parameters to the Gurobi environment directly, and when I write them down it shows the credentials of the license perfectly. I even tried generating a new license file with new credentials but it didn't change anything.

I pass the parameters as follows:

def read_gurobi_license_from_secrets():
    license_data = {
        'WLSACCESSID': st.secrets['WLSACCESSID'],
        'WLSSECRET': st.secrets['WLSSECRET'],
        'LICENSEID': int(st.secrets['LICENSEID'])  # Cast to int because secrets are loaded as strings
    }
    return license_data
    
def init_gurobi_env_from_secrets():
    license_data = read_gurobi_license_from_secrets()
    env = gp.Env(params=license_data)
    return env

env = init_gurobi_env_from_secrets()

[...]

trains_scheduling_ordered, equipment_scheduling = milp_stage_1_and_2_app(df1,earliest_arrival,end_date_latest_arrival,env)

And the function milp_stage_1_and_2_app is defined as follows:

def milp_stage_1_and_2_app(df1,earliest_arrival,end_date_latest_arrival,env):
    
    [rest of the code to create and solve the model]

    return(trains_scheduling_ordered,equipment_scheduling)

It was working perfectly until now so I really don't know what is going wrong... Any help would be extremely appreciated. Thank you! 

Related to

• License

0

• 

  Mario Ruthmair

  Gurobi Staff

  • January 08, 2024 11:56

  Hi Alexandre,

  Could you show us the Gurobi output? Does it show license messages referring to your WLS license?
  Could you also show us the line that creates the model?

  Best regards,
  Mario

  0
• 

  Alexandre Touzet

  • January 08, 2024 13:11

  

  

  Thanks to your message I found the problem! 

  I was creating the model with:

  m = gp.Model("multi_objective_model")

  And not:

  m = gp.Model("multi_objective_model",env=env)

  Thank you!

  0
• 

  Mario Ruthmair

  Gurobi Staff

  • January 08, 2024 13:31

  Thanks for reporting the solution! This might be helpful for others, too!

  0

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