# JuMP 0.21. How to stop the solver in callback?
**URL:** https://discourse.julialang.org/t/jump-0-21-how-to-stop-the-solver-in-callback/35028
**Category:** Optimization (Mathematical)
**Created:** [February 22, 2020, 7:42pm UTC](https://discourse.julialang.org/t/jump-0-21-how-to-stop-the-solver-in-callback/35028 "2020-02-22T19:42:14Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@mike\_k](https://discourse.julialang.org/u/mike_k)
#### Post date: [February 22, 2020, 7:42pm UTC](https://discourse.julialang.org/t/jump-0-21-how-to-stop-the-solver-in-callback/35028/1 "2020-02-22T19:42:14Z")
Dear community,
in older JuMP versions, one was able to stop the solving process in a callback with `JuMP.StopTheSolver`. However, I did not find something similar in the documentation of the current release 0.21. Do have any suggestions?
Thanks in advance.
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### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [February 25, 2020, 4:21am UTC](https://discourse.julialang.org/t/jump-0-21-how-to-stop-the-solver-in-callback/35028/2 "2020-02-25T04:21:20Z")
I don’t think we have a way to do this at present.
If you’re willing to use one particular solver, you can write a solver-dependent callback.
e.g., [JuMP.jl/callbacks.jl at 13ad5db156210f805699e8a1004610d60bc3be3b · jump-dev/JuMP.jl · GitHub](https://github.com/JuliaOpt/JuMP.jl/blob/13ad5db156210f805699e8a1004610d60bc3be3b/examples/callbacks.jl#L132-L149)
You would need to find the write `GLPK.ios_xxx` function to call though (from memory, it’s something like `ios_terminate(cb_data.tree)`).
If you’re using Gurobi or CPLEX, you can do something similar, but it isn’t well documented. The best thing to do is look in the `test/MOI_callbacks.jl` file in each repository.