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Launch Daemon

Source: R/launchers.R
launch_local.Rd

Launching a daemon is very much akin to launching a satellite. They are a way to deploy a daemon (in our case) on the desired machine. Once it executes, it connects back to the host process using its own communications.

launch_local deploys a daemon on the local machine in a new background Rscript process.

launch_remote returns the shell command for deploying daemons as a character vector. If an ssh_config(), cluster_config() or remote_config() configuration is supplied then this is used to launch the daemon on the remote machine.

Usage

launch_local(n = 1L, ..., tls = NULL, .compute = NULL)

launch_remote(
  n = 1L,
  remote = remote_config(),
  ...,
  tls = NULL,
  .compute = NULL
)

Arguments

n

integer number of daemons.

or for launch_remote only, a 'miraiCluster' or 'miraiNode'.

...

(optional) arguments passed through to daemon(). These include autoexit, cleanup, output, maxtasks, idletime and walltime. Only supply to override arguments originally provided to daemons(), otherwise those will be used instead.

tls

[default NULL] required for secure TLS connections over 'tls+tcp://'. Zero-configuration TLS certificates generated by daemons() are automatically passed to the daemon, without requiring to be specified here. Otherwise, supply either the character path to a file containing X.509 certificate(s) in PEM format, comprising the certificate authority certificate chain, or a length 2 character vector comprising [i] the certificate authority certificate chain and [ii] the empty string "".

.compute

[default NULL] character value for the compute profile to use (each has its own independent set of daemons), or NULL to use the 'default' profile.

remote

required only for launching remote daemons, a configuration generated by ssh_config(), cluster_config(), or remote_config(). An empty remote_config() does not perform any launches but returns the shell commands for deploying manually on remote machines.

Value

For launch_local: Integer number of daemons launched.

For launch_remote: A character vector of daemon launch commands, classed as 'miraiLaunchCmd'. The printed output may be copy / pasted directly to the remote machine.

Details

Daemons must already be set for launchers to work.

These functions may be used to re-launch daemons that have exited after reaching time or task limits.

For non-dispatcher daemons using the default seed strategy, the generated command contains the argument rs specifying the length 7 L'Ecuyer-CMRG random seed supplied to the daemon. The values will be different each time the function is called.

Examples

if (FALSE) { # interactive()
daemons(url = host_url(), dispatcher = FALSE)
status()
launch_local(1L, cleanup = FALSE)
launch_remote(1L, cleanup = FALSE)
Sys.sleep(1)
status()
daemons(0)

daemons(url = host_url(tls = TRUE))
status()
launch_local(2L, output = TRUE)
Sys.sleep(1)
status()
daemons(0)
}