Launch Daemon — launch

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.

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.

The generated command for non-dispatcher daemons contain 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. For dispatcher daemons, the equivalent random seed is obtained automatically from dispatcher, and hence rs is not specified in this case.

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)
}