# Communication error between local processes and remote processes
**URL:** https://discourse.julialang.org/t/communication-error-between-local-processes-and-remote-processes/82903
**Category:** General Usage
**Tags:** parallel
**Created:** [June 17, 2022, 4:48am UTC](https://discourse.julialang.org/t/communication-error-between-local-processes-and-remote-processes/82903 "2022-06-17T04:48:17Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Isaia\_Nisoli](https://discourse.julialang.org/u/Isaia_Nisoli)
#### Post date: [June 17, 2022, 4:48am UTC](https://discourse.julialang.org/t/communication-error-between-local-processes-and-remote-processes/82903/1 "2022-06-17T04:48:17Z")
Hi,
I’m experimenting with a setup and I’m getting a strange behavior.
```julia
using Distributed
loc_proc = addprocs(4) # this adds processes 2 to 5 on the local machine
rem_proc = addprocs([("foo@remote_machine", :auto)]) # this adds processes 6 to 37 on a remote machine
rem_proc_2 = addprocs([("foo@remote_machine", :auto)]) # this add processes 38 to 45 on another remote machine
```
if I run
```julia
r = remotecall(rand, 6, 2, 2)
s = @spawnat 38 1 .+ fetch(r)
fetch(s)
```
everything works as expected, the remote workers are able to communicate between them.
If I try to mix remote and local processes as in
```julia
r = remotecall(rand, 2, 2, 2)
s = @spawnat 6 1 .+ fetch(r)
fetch(s)
```
I get the following error:
From worker 6: ┌ Error: Error on 6 while connecting to peer 2, exiting
From worker 6: │ exception =
From worker 6: │ IOError: connect: connection refused (ECONNREFUSED)
From worker 6: │ Stacktrace:
From worker 6: │ [1] wait\_connected(x::Sockets.TCPSocket)
From worker 6: │ @ Sockets /opt/julia-1.7.3/share/julia/stdlib/v1.7/Sockets/src/Sockets.jl:532
From worker 6: │ [2] connect
From worker 6: │ @ /opt/julia-1.7.3/share/julia/stdlib/v1.7/Sockets/src/Sockets.jl:567 [inlined]
From worker 6: │ [3] connect\_to\_worker(host::String, port::Int64)
From worker 6: │ @ Distributed /opt/julia-1.7.3/share/julia/stdlib/v1.7/Distributed/src/managers.jl:632
From worker 6: │ [4] connect\_w2w(pid::Int64, config::WorkerConfig)
From worker 6: │ @ Distributed /opt/julia-1.7.3/share/julia/stdlib/v1.7/Distributed/src/managers.jl:580
From worker 6: │ [5] connect(manager::Distributed.DefaultClusterManager, pid::Int64, config::WorkerConfig)
From worker 6: │ @ Distributed /opt/julia-1.7.3/share/julia/stdlib/v1.7/Distributed/src/managers.jl:512
From worker 6: │ [6] connect\_to\_peer(manager::Distributed.DefaultClusterManager, rpid::Int64, wconfig::WorkerConfig)
From worker 6: │ @ Distributed /opt/julia-1.7.3/share/julia/stdlib/v1.7/Distributed/src/process\_messages.jl:355
From worker 6: │ [7] (::Distributed.var"#121#123"{Int64, WorkerConfig})()
From worker 6: │ @ Distributed /opt/julia-1.7.3/share/julia/stdlib/v1.7/Distributed/src/process\_messages.jl:342
From worker 6: │ [8] exec\_conn\_func(w::Distributed.Worker)
From worker 6: │ @ Distributed /opt/julia-1.7.3/share/julia/stdlib/v1.7/Distributed/src/cluster.jl:181
From worker 6: │ [9] (::Distributed.var"#21#24"{Distributed.Worker})()
From worker 6: │ @ Distributed ./task.jl:429
From worker 6: └ @ Distributed /buildworker/worker/package\_linux64/build/usr/share/julia/stdlib/v1.7/Distributed/src/process\_messages.jl:362
I’m confused since I did not change the default topology, so I would expect that all processes would communicate with all processes.
---
### Author:  [@Isaia\_Nisoli](https://discourse.julialang.org/u/Isaia_Nisoli)
#### Post date: [June 17, 2022, 5:02am UTC](https://discourse.julialang.org/t/communication-error-between-local-processes-and-remote-processes/82903/2 "2022-06-17T05:02:14Z")
Ok, it seems that specifying
```julia
loc_proc = addprocs(4; restrict = false)
```
solves the issue.
As stated in the documentation
```julia
addprocs(np::Integer; restrict=true, kwargs...)
```
> Launches workers using the in-built `LocalManager` which only launches workers on the local host. This can be used to take advantage of multiple cores. `addprocs(4)` will add 4 processes on the local machine. If `restrict` is `true`, binding is restricted to `127.0.0.1`. Keyword args `dir`, `exename`, `exeflags`, `topology`, `lazy` and `enable_threaded_blas` have the same effect as documented for `addprocs(machines)`.