How to define remote calls in julia?

Please guide in defining remote call function:

log:

[root@srvr0 ~]# julia -p 4
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.6.4 (2021-11-19)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

julia> 

julia> using Distributed;

julia> r = remotecall(2, ones, 2, 2)
ERROR: MethodError: no method matching remotecall(::Int64, ::typeof(ones), ::Int64, ::Int64)
Closest candidates are:
  remotecall(::Any, ::Distributed.LocalProcess, ::Any...; kwargs...) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:357
  remotecall(::Any, ::Distributed.Worker, ::Any...; kwargs...) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:363
  remotecall(::Any, ::Integer, ::Any...; kwargs...) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.6/Distributed/src/remotecall.jl:376
  ...
Stacktrace:
 [1] top-level scope
   @ REPL[2]:1

julia> fetch(r)
ERROR: UndefVarError: r not defined
Stacktrace:
 [1] top-level scope
   @ REPL[3]:1

Solution

As the type signature in the error message ("Closest candidates") indicates, the worker process must be the second argument to the call. So the function you're calling, ones in this case, is the first argument instead.

julia> using Distributed

julia> r = remotecall(ones, 2, 2, 2)
Future(2, 1, 5, nothing)

julia> fetch(r)
2×2 Matrix{Float64}:
 1.0  1.0
 1.0  1.0