Specification: Specification
| Specification | R Documentation |
Specification
Description
This class contains the information required to start a backend. An instance
of this class is used by the start method of the
BackendService interface.
Active bindings
coresThe number of nodes to use in the cluster creation.
typeThe type of cluster to create.
typesThe supported cluster types.
Methods
Public methods
Method set_cores()
Set the number of nodes to use in the cluster.
Usage
Specification$set_cores(cores)
Arguments
coresThe number of nodes to use in the cluster.
Details
This method also performs a validation of the requested number of
cores, ensuring that the the value lies between 1 and
parallel::detectCores() - 1.
Method set_type()
Set the type of cluster to create.
Usage
Specification$set_type(type)
Arguments
typeThe type of cluster to create. Possible values are
"fork"and"psock". Defaults to"psock".
Details
If no type is explicitly requested (i.e., type = NULL), the type is
determined based on the operating system. On Unix-like systems, the
type is set to "fork", while on Windows systems, the type is set to
"psock". If an unknown type is requested, a warning is issued and
the type is set to "psock".
Method clone()
The objects of this class are cloneable with this method.
Usage
Specification$clone(deep = FALSE)
Arguments
deepWhether to make a deep clone.
See Also
BackendService, Backend, SyncBackend,
and AsyncBackend.
Examples
# Create a specification object.
specification <- Specification$new()
# Set the number of cores.
specification$set_cores(cores = 4)
# Set the cluster type.
specification$set_type(type = "psock")
# Get the number of cores.
specification$cores
# Get the cluster type.
specification$type
# Attempt to set too many cores.
specification$set_cores(cores = 100)
# Check that the cores were reasonably set.
specification$cores
# Allow the object to determine the adequate cluster type.
specification$set_type(type = NULL)
# Check the type determined.
specification$type
# Attempt to set an invalid cluster type.
specification$set_type(type = "invalid")
# Check that the type was set to `psock`.
specification$type
