# Using module does not work with SSH remote workers

**URL:** <https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825>\
**Category:** General Usage\
**Tags:** question\
**Created:** [December 18, 2017, 4:18am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825 "2017-12-18T04:18:12Z")\
**Posts on this page:** 12\
**Page:** 1

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 4:18am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/1 "2017-12-18T04:18:12Z")

</div>

From what I understand, `using Module` should use the module available on the master process, and send it to the workers. However, it is not working for me:

```julia
julia> addprocs([("admin@some.server",4)],exename="julia",dir="/home/admin",tunnel=true)
4-element Array{Int64,1}:
 2
 3
 4
 5

julia> using OrdinaryDiffEq
ERROR: On worker 2:
UndefVarError: ##694#696 not defined
#99 at ./event.jl:73
#remotecall_fetch#141(::Array{Any,1}, ::Function, ::Function, ::Base.Distributed.Worker) at .\distributed\remotecall.jl:354
remotecall_fetch(::Function, ::Base.Distributed.Worker) at .\distributed\remotecall.jl:346
#remotecall_fetch#144(::Array{Any,1}, ::Function, ::Function, ::Int64) at .\distributed\remotecall.jl:367
remotecall_fetch(::Function, ::Int64) at .\distributed\remotecall.jl:367
macro expansion at .\loading.jl:180 [inlined]
(::Base.##693#695)() at .\task.jl:335

...and 3 more exception(s).

Stacktrace:
 [1] sync_end() at .\task.jl:287
 [2] macro expansion at .\task.jl:303 [inlined]
 [3] _require_from_serialized(::Int64, ::Symbol, ::String, ::Bool) at .\loading.jl:177
 [4] _require_search_from_serialized(::Int64, ::Symbol, ::String, ::Bool) at .\loading.jl:236
 [5] _require(::Symbol) at .\loading.jl:441
 [6] require(::Symbol) at .\loading.jl:405

```

Am I missing anything obvious here or is it a Julia issue?

Thanks,  
Jeremy

---

<div class="post-metadata">

**Author:** ![vchuravy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/vchuravy/32/8_2.png) [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Post date:** [December 18, 2017, 4:29am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/2 "2017-12-18T04:29:11Z")

</div>

You will have to say `@everywhere using OrdinaryDiffEq`.

The manual says:

> using DummyModule causes the module to be loaded on all processes; however, the module is brought into scope only on the one executing the statement.

[https://docs.julialang.org/en/stable/manual/parallel-computing/#Code-Availability-and-Loading-Packages-1](https://docs.julialang.org/en/stable/manual/parallel-computing/#Code-Availability-and-Loading-Packages-1)

---

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 4:53am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/3 "2017-12-18T04:53:56Z")

</div>

That’s not the issue, like the passage you quoted says, `using Module` should be sufficient to load the code on the remote workers.

In any case, adding `@everywhere` produces the exact same error.

---

<div class="post-metadata">

**Author:** ![vchuravy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/vchuravy/32/8_2.png) [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Post date:** [December 18, 2017, 5:10am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/4 "2017-12-18T05:10:20Z")

</div>

It will load the code, but it will not bring the code into scope.

But it it seems that the error you are seeing is coming from somewhere else…  
On which Julia version are you? (`versioninfo()`)?

---

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 5:12am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/5 "2017-12-18T05:12:26Z")

</div>

I’m running 0.6.2 on the master and workers.

BTW, in this context, what does it mean for the code to not be in scope on the workers? I though that only meant that no functions were exported, but that the module name would still be available. Is that not correct?

---

<div class="post-metadata">

**Author:** ![vchuravy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/vchuravy/32/8_2.png) [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Post date:** [December 18, 2017, 5:27am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/6 "2017-12-18T05:27:55Z")

</div>

The fully-qualified module name will work, but none of the methods exported by it will be implicitly available. So in most cases you do want to do an `@everywhere using ...`.

Is this happening only for `OrdinaryDiffEq` or also for other modules?

---

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 5:30am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/7 "2017-12-18T05:30:17Z")

</div>

It happens with other modules as well.

What is the fully qualified module name? Is it Main.Module?

---

<div class="post-metadata">

**Author:** ![vchuravy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/vchuravy/32/8_2.png) [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Post date:** [December 18, 2017, 5:46am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/8 "2017-12-18T05:46:04Z")

</div>

And this is SSH worker specific and doesn’t occur with only local processes? Did you ever try this on 0.6.1?

This looks to me like a proper Julia bug and so I am trying to narrow down what is happening.

Yes `Main.X.func` is the fully-qualified name but `X.func` should work as well.

---

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 5:50am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/9 "2017-12-18T05:50:18Z")

</div>

Local workers work properly. I have not tried on 0.6.1, and I also have not tried with non-tunneled workers since I can’t get them to work.

Interestingly, I tried a few more packages and found that `using Compat` works.

---

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 5:54am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/10 "2017-12-18T05:54:14Z")

</div>

> [@jebej](#):
>
> Interestingly, I tried a few more packages and found that using Compat works.

That actually seems to be because `Compat` is automatically loaded on the workers.

---

<div class="post-metadata">

**Author:** ![juliohm](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/juliohm/32/215266_2.png) [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Post date:** [December 18, 2017, 6:23am UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/11 "2017-12-18T06:23:38Z")

</div>

@jebej thank you for reporting this. If you have the time/chance to try yet another module that makes use of multiple workers, please try to follow this notebook that I know was working with Julia v0.6.1 on my laptop at least. Please ignore the warnings as it is not fully implemented: [https://github.com/juliohm/GeoStats.jl/blob/master/examples/ParallelSimulation.ipynb](https://github.com/juliohm/GeoStats.jl/blob/master/examples/ParallelSimulation.ipynb)

---

<div class="post-metadata">

**Author:** ![jebej](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jebej/32/1784_2.png) [@jebej](https://discourse.julialang.org/u/jebej)\
**Post date:** [December 18, 2017, 6:36pm UTC](https://discourse.julialang.org/t/using-module-does-not-work-with-ssh-remote-workers/7825/12 "2017-12-18T18:36:36Z")

</div>

The problem is not with using the workers, it’s just with loading the code with `using`.

Loading the code with `@everywhere f(x,y) = x+y` works fine, and executes properly.