# Using local module with @everywhere

**URL:** <https://discourse.julialang.org/t/using-local-module-with-everywhere/87163>\
**Category:** Julia at Scale\
**Tags:** distributed\
**Created:** [September 12, 2022, 9:04pm UTC](https://discourse.julialang.org/t/using-local-module-with-everywhere/87163 "2022-09-12T21:04:59Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![bojeryd91](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bojeryd91/32/42622_2.png) [@bojeryd91](https://discourse.julialang.org/u/bojeryd91)\
**Post date:** [September 12, 2022, 9:04pm UTC](https://discourse.julialang.org/t/using-local-module-with-everywhere/87163/1 "2022-09-12T21:04:59Z")

</div>

Hi, my goal is to within one script define a module only once in my local scope, and then read it to all my workers. However, I cannot figure out what to do. This is my MWE:

```julia
using Distributed

module myModule
export f
function f(x_in)
        return x_in^2.0
end
end

using .myModule
f(1.0) # This works as expected

addprocs(1)

@everywhere using .myModule # This throws error "myModule not defined"
@everywhere f(1.0)

```

If I put myModule in a separate myModule.jl, then the following works:

```julia
using Distributed

include("myModule.jl"); using .myModule
f(1.0)

addprocs(1)

@everywhere begin include("myModule.jl"); using .myModule end
@everywhere f(1.0)

```

This solution is OK, but I prefer to have everything in one script for reasons.

(The _actual_ goal is to conveniently load the function `f(x_in)` without having to use the solution in [Easy way to send custom function to distributed workers? - #2 by greg\_plowman](https://discourse.julialang.org/t/easy-way-to-send-custom-function-to-distributed-workers/22118/2))

---

<div class="post-metadata">

**Author:** ![nsajko](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nsajko/32/221187_2.png) [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Post date:** [September 12, 2022, 9:16pm UTC](https://discourse.julialang.org/t/using-local-module-with-everywhere/87163/2 "2022-09-12T21:16:34Z")

</div>

Seems you can define the module with `@everywhere`:

```julia
julia> using Distributed

julia> addprocs(1)
1-element Vector{Int64}:
 5

julia> @everywhere module SomeModuleName
         f() = 3
       end

julia> @everywhere using .SomeModuleName

julia> @everywhere println(SomeModuleName.f())
3
      From worker 5: 3

julia> 
julia> From worker 3: 3
      From worker 2: 3
julia> 

julia> 

```

But I have a feeling you’re going about things the wrong way.

---

<div class="post-metadata">

**Author:** ![bojeryd91](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bojeryd91/32/42622_2.png) [@bojeryd91](https://discourse.julialang.org/u/bojeryd91)\
**Post date:** [September 12, 2022, 9:38pm UTC](https://discourse.julialang.org/t/using-local-module-with-everywhere/87163/4 "2022-09-12T21:38:31Z")

</div>

OK, so what I thought before was that variables created with @everywhere were only accessible “by the workers” and not in my local scope. But I see now that if I want to only once define the module or the function `f()`, I should do it once using @everywhere.

Thanks!

```julia
using Distributed
addprocs(1)

@everywhere module myModule
        export f
        function f(x_in)
                return x_in^2.0
        end
end
@everywhere using .myModule
f(1.0)
@everywhere f(1.0)

```