A remote future is a future that uses remote cluster evaluation, which means that its value is computed and resolved remotely in another process.

remote(
  ...,
  workers = NULL,
  revtunnel = TRUE,
  myip = NULL,
  persistent = TRUE,
  homogeneous = TRUE,
  envir = parent.frame()
)

Arguments

...

Additional named elements passed to Future().

workers

A cluster object, a character vector of host names, a positive numeric scalar, or a function. If a character vector or a numeric scalar, a cluster object is created using makeClusterPSOCK(workers). If a function, it is called without arguments when the future is created and its value is used to configure the workers. The function should return any of the above types.

revtunnel

If TRUE, reverse SSH tunneling is used for the PSOCK cluster nodes to connect back to the master R process. This avoids the hassle of firewalls, port forwarding and having to know the internal / public IP address of the master R session.

myip

The external IP address of this machine. If NULL, then it is inferred using an online service (default).

persistent

If FALSE, the evaluation environment is cleared from objects prior to the evaluation of the future.

homogeneous

If TRUE, all cluster nodes is assumed to use the same path to Rscript as the main R session. If FALSE, the it is assumed to be on the PATH for each node. If NULL, then parallelly::makeClusterPSOCK() will decide on TRUE or FALSE depending on workers.

envir

The environment from where global objects should be identified.

Value

A ClusterFuture.

Details

This function is not meant to be called directly. Instead, the typical usages are:

# Evaluate futures on remote machine 'server.example.org', and
# any nested ones sequentially (default) on that remote machine
plan(remote, workers = "server.example.org")

# Evaluate futures on remote machine 'server.example.org', and
# nested ones in parallel on that remote machine
plan(list(
   tweak(remote, workers = "server.example.org"),
   multisession
))

# Evaluate futures on remote machine 'server.example.org', and
# nested ones in parallel on the remote machines n1, n2, and n3.
plan(list(
  tweak(remote, workers = "server.example.org"),
  tweak(cluster, workers = c("n1", "n2", "n3"))
))

'remote' versus 'cluster'

The remote plan is a very similar to the cluster plan, but provides more convenient default argument values when connecting to remote machines. #' Specifically, remote uses persistent = TRUE by default, and it sets homogeneous, revtunnel, and myip "wisely" depending on the value of workers. ' See below for example on how remote and cluster are related.

Examples