[R] parallel: socket connection behind a NAT router

[Henrik Bengtsson]

If you have SSH access to the workers, then

workers <- c("machine1.example.org", "machine2.example.org")
cl <- parallelly::makeClusterPSOCK(workers)

should do it.  It does this without admin rights and port forwarding.
See also the README in https://cran.r-project.org/package=parallelly.

/Henrik

On Mon, Jan 18, 2021 at 6:45 AM Jiefei Wang <szwjf08 using gmail.com> wrote:
>
> Hi all,
>
> I have a few cloud instances and I want to use them to do parallel
> computing. I would like to create a socket cluster on my local machine to
> control the remote instances. Here is my network setup:
>
> local machine -- NAT -- Internet -- cloud instances
>
> In the parallel package, the server needs to call `makeCluster()` and
> listens to the connection from the workers. In my case, the server is the
> local machine and the workers are the cloud instances. However, since the
> local machine is hidden behind the NAT, it does not have a public address
> and the worker cannot connect to it. Therefore, `makeCluster()` will never
> be able to see the connection from the workers and hang forever.
>
> One solution for letting the external machine to access the device inside
> the NAT is to use port forwarding. However, this would not work for my case
> as the NAT is set by the network provider(not my home router) so I do not
> have access to the router. As the cloud instances have public addresses,
> I'll wonder if there is any way to build the cluster by letting the server
> connect to the cloud? I have checked `?parallel::makeCluster` and
> `?snow::makeSOCKcluster` but I found no result. The only promising solution
> I can see now is to use TCP hole punching, but it is quite complicated and
> may not work for every case. Since building a connection from local to the
> remote is super easy, I would like to know if there exists any simple
> solution. I have searched it on Google for a week but find no answer. I'll
> appreciate it if you can provide me any suggestions!
>
> Best,
> Jiefei
>
>         [[alternative HTML version deleted]]
>
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