# CBC and CLP solver version with JuMP

**URL:** <https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795>\
**Category:** Optimization (Mathematical)\
**Tags:** optimization\
**Created:** [March 10, 2020, 11:13am UTC](https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795 "2020-03-10T11:13:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bandaya](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bandaya/32/12956_2.png) [@bandaya](https://discourse.julialang.org/u/bandaya)\
**Post date:** [March 10, 2020, 11:13am UTC](https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795/1 "2020-03-10T11:13:49Z")

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I am running an optimization problem with CBC solver but it is taking forever with around 1100 binary variables. The same problem is solved in about 2 minutes if I reduce the number of variables to 900. I suspect that this could be due to version of the CBC solver available with JuMP is not up to date. The same problem with CLP solver gets solved in a fraction of a second if binary restriction on the variables is relaxed.

I have following questions:  
1- Is the CBC solver up to date?  
2- The CBC solver gives me the same answer as CLP solver for LP. Is the CBC solver already embedded with CLP solver or do I need to use the CLP solver separately?  
3- How can I specify feasibility tolerance for constraints violation? Using the following code results in an error message  
`Model = Model(Clp.Optimizer, PrimalTolerance =1e-9, DualTolerance =1e-9)`

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**Author:** ![odow](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/odow/32/28685_2.png) [@odow](https://discourse.julialang.org/u/odow)\
**Post date:** [March 10, 2020, 2:26pm UTC](https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795/2 "2020-03-10T14:26:15Z")

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Mixed-integer linear programs are hard to solve, and run-times can increase dramatically with small changes in the model.

You want: [Solvers · JuMP](https://www.juliaopt.org/JuMP.jl/stable/solvers/#JuMP.set_optimizer_attribute)

```nohighlight
model = Model(Clp.Optimizer)
set_optimizer_attribute(model, "PrimalTolerance", 1e-9)

```

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<div class="post-metadata">

**Author:** ![bandaya](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bandaya/32/12956_2.png) [@bandaya](https://discourse.julialang.org/u/bandaya)\
**Post date:** [March 10, 2020, 9:17pm UTC](https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795/3 "2020-03-10T21:17:33Z")

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Thanks.