Create a controller with a local process launcher.

Create an R6 object to submit tasks and launch workers on local processes.

Usage

crew_controller_local(
  name = NULL,
  workers = 1L,
  host = "127.0.0.1",
  port = NULL,
  tls = crew::crew_tls(),
  tls_enable = NULL,
  tls_config = NULL,
  seconds_interval = 0.5,
  seconds_timeout = 60,
  seconds_launch = 30,
  seconds_idle = 300,
  seconds_wall = Inf,
  seconds_exit = NULL,
  retry_tasks = TRUE,
  tasks_max = Inf,
  tasks_timers = 0L,
  reset_globals = TRUE,
  reset_packages = FALSE,
  reset_options = FALSE,
  garbage_collection = FALSE,
  crashes_error = 5L,
  launch_max = NULL,
  r_arguments = c("--no-save", "--no-restore"),
  options_metrics = crew::crew_options_metrics(),
  options_local = crew::crew_options_local(),
  local_log_directory = NULL,
  local_log_join = NULL
)

Arguments

name: Name of the client object. If NULL, a name is automatically generated.
workers: Integer, maximum number of parallel workers to run.
host: IP address of the mirai client to send and receive tasks. If NULL, the host defaults to the local IP address.
port: TCP port to listen for the workers. If NULL, then an available ephemeral port is automatically chosen.
tls: A TLS configuration object from crew_tls().
tls_enable: Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.
tls_config: Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.
seconds_interval: Number of seconds between polling intervals waiting for certain internal synchronous operations to complete, such as checking mirai::status()
seconds_timeout: Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().
seconds_launch: Seconds of startup time to allow. A worker is unconditionally assumed to be alive from the moment of its launch until seconds_launch seconds later. After seconds_launch seconds, the worker is only considered alive if it is actively connected to its assign websocket.
seconds_idle: Maximum number of seconds that a worker can idle since the completion of the last task. If exceeded, the worker exits. But the timer does not launch until tasks_timers tasks have completed. See the idletime argument of mirai::daemon(). crew does not excel with perfectly transient workers because it does not micromanage the assignment of tasks to workers, so please allow enough idle time for a new worker to be delegated a new task.
seconds_wall: Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().
seconds_exit: Deprecated on 2023-09-21 in version 0.5.0.9002. No longer necessary.
retry_tasks: TRUE to automatically retry a task in the event of an unexpected worker exit. FALSE to give up on the first exit and return a mirai error code (code number 19). TRUE (default) is recommended in most situations. Use FALSE for debugging purposes, e.g. to confirm that a task is causing a worker to run out of memory or crash in some other way.
tasks_max: Maximum number of tasks that a worker will do before exiting. See the maxtasks argument of mirai::daemon(). crew does not excel with perfectly transient workers because it does not micromanage the assignment of tasks to workers, it is recommended to set tasks_max to a value greater than 1.
tasks_timers: Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().
reset_globals: TRUE to reset global environment variables between tasks, FALSE to leave them alone.
reset_packages: TRUE to unload any packages loaded during a task (runs between each task), FALSE to leave packages alone.
reset_options: TRUE to reset global options to their original state between each task, FALSE otherwise. It is recommended to only set reset_options = TRUE if reset_packages is also TRUE because packages sometimes rely on options they set at loading time.
garbage_collection: TRUE to run garbage collection between tasks, FALSE to skip.
crashes_error: Positive integer scalar. If a worker exits crashes_error times in a row without completing all its assigned tasks, then the launcher throws an informative error. The reason for crashes_error is to avoid an infinite loop where a task crashes a worker (through a segfault, maxing out memory, etc) but the worker always relaunches. To monitor the resources of crew workers, please see https://wlandau.github.io/crew/articles/logging.html.
launch_max: Deprecated on 2024-11-04 (version 0.10.1.9000). Use crashes_error instead.
r_arguments: Optional character vector of command line arguments to pass to Rscript (non-Windows) or Rscript.exe (Windows) when starting a worker. Example: r_arguments = c("--vanilla", "--max-connections=32").
options_metrics: Either NULL to opt out of resource metric logging for workers, or an object from crew_options_metrics() to enable and configure resource metric logging for workers. For resource logging to run, the autometric R package version 0.1.0 or higher must be installed.
options_local: An object generated by crew_options_local() with options specific to the local controller.
local_log_directory: Deprecated on 2024-10-08. Use options_local instead.
local_log_join: Deprecated on 2024-10-08. Use options_local instead.

Examples

if (identical(Sys.getenv("CREW_EXAMPLES"), "true")) {
controller <- crew_controller_local()
controller$start()
controller$push(name = "task", command = sqrt(4))
controller$wait()
controller$pop()
controller$terminate()
}

Usage

Arguments

See also

Examples