Dispatches tasks from a host to daemons for processing, using FIFO
scheduling, queuing tasks as required. Daemon / dispatcher settings may be
controlled by daemons and this function should not need to be
invoked directly.
Usage
dispatcher(
host,
url = NULL,
n = NULL,
...,
tls = NULL,
pass = NULL,
rs = NULL,
monitor = NULL
)Arguments
- host
the character host URL to dial (where tasks are sent from), including the port to connect to e.g. 'tcp://hostname:5555' or 'tcp://10.75.32.70:5555'.
- url
(optional) the character URL dispatcher should listen at (and daemons should dial in to), including the port to connect to e.g. 'tcp://hostname:5555' or 'tcp://10.75.32.70:5555'. Specify 'tls+tcp://' to use secure TLS connections.
- n
(optional) if specified, the integer number of daemons to launch. In this case, a local url is automatically generated.
- ...
(optional) additional arguments passed through to
daemon. These include ‘asyncdial’, ‘autoexit’, and ‘cleanup’.- tls
[default NULL] (required for secure TLS connections) either the character path to a file containing the PEM-encoded TLS certificate and associated private key (may contain additional certificates leading to a validation chain, with the TLS certificate first), or a length 2 character vector comprising [i] the TLS certificate (optionally certificate chain) and [ii] the associated private key.
- pass
[default NULL] (required only if the private key supplied to ‘tls’ is encrypted with a password) For security, should be provided through a function that returns this value, rather than directly.
- rs
[default NULL] the initial value of .Random.seed. This is set automatically using L'Ecuyer-CMRG RNG streams generated by the host process and should not be independently supplied.
- monitor
unused legacy parameter - do not specify this value.
Details
The network topology is such that a dispatcher acts as a gateway between the host and daemons, ensuring that tasks received from the host are dispatched on a FIFO basis for processing. Tasks are queued at the dispatcher to ensure tasks are only sent to daemons that can begin immediate execution of the task.