make_cluster creates a cluster of type ‘miraiCluster’, which
may be used as a cluster object for any function in the parallel base
package such as clusterApply or
parLapply.
stop_cluster stops a cluster created by make_cluster.
Arguments
- n
integer number of nodes (automatically launched on the local machine unless ‘url’ is supplied).
- url
[default NULL] (specify for remote nodes) the character URL on the host for remote nodes to dial into, including a port accepting incoming connections, e.g. 'tcp://10.75.37.40:5555'. Specify a URL with the scheme ‘tls+tcp://’ to use secure TLS connections.
- remote
[default NULL] (specify to launch remote nodes) a remote launch configuration generated by
remote_configorssh_config. If not supplied, nodes may be deployed manually on remote resources.- ...
additional arguments passed onto
daemons.- cl
a ‘miraiCluster’.
Value
For make_cluster: An object of class ‘miraiCluster’ and ‘cluster’. Each ‘miraiCluster’ has an automatically assigned ID and ‘n’ nodes of class ‘miraiNode’. If ‘url’ is supplied but not ‘remote’, the shell commands for deployment of nodes on remote resources are printed to the console.
For stop_cluster: invisible NULL.
Note
The default behaviour of clusters created by this function is designed
to map as closely as possible to clusters created by the parallel
package. However, ‘...’ arguments are passed onto
daemons for additional customisation if desired, although
resultant behaviour may not always be supported.
Remote Nodes
Specify ‘url’ and ‘n’ to set up a host connection for remote nodes to dial into. ‘n’ defaults to one if not specified.
Also specify ‘remote’ to launch the nodes using a configuration
generated by remote_config or ssh_config. In this
case, the number of nodes is inferred from the configuration provided and
‘n’ is disregarded.
If ‘remote’ is not supplied, the shell commands for deploying nodes manually on remote resources are automatically printed to the console.
launch_remote may be called at any time on a
‘miraiCluster’ to return the shell commands for deployment of all
nodes, or on a ‘miraiNode’ to return the command for a single node.
Status
Call status on a ‘miraiCluster’ to check the number of
currently active connections as well as the host URL.
Errors
Errors are thrown by the ‘parallel’ mechanism if one or more nodes failed (quit unexpectedly). The resulting ‘errorValue’ returned is 19 (Connection reset). Other types of error, e.g. in evaluation, should result in the usual ‘miraiError’ being returned.
Examples
if (interactive()) {
# Only run examples in interactive R sessions
cl <- make_cluster(2)
cl
cl[[1L]]
Sys.sleep(0.5)
status(cl)
stop_cluster(cl)
}