crew_launcher_local: Create a launcher with local process workers.
In crew: A Distributed Worker Launcher Framework

crew_launcher_local

R Documentation

Create a launcher with local process workers.

Description

Create an R6 object to launch and maintain local process workers.

Usage

crew_launcher_local(
  name = NULL,
  workers = 1L,
  seconds_interval = 1,
  seconds_timeout = 60,
  seconds_launch = 30,
  seconds_idle = Inf,
  seconds_wall = Inf,
  seconds_exit = NULL,
  tasks_max = Inf,
  tasks_timers = 0L,
  reset_globals = NULL,
  reset_packages = NULL,
  reset_options = NULL,
  garbage_collection = NULL,
  crashes_error = NULL,
  launch_max = NULL,
  tls = crew::crew_tls(),
  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`	Character string, name of the launcher. If the name is `NULL`, then a name is automatically generated when the launcher starts.
`workers`	Maximum number of workers to run concurrently when auto-scaling, excluding task retries and manual calls to `launch()`. Special workers allocated for task retries do not count towards this limit, so the number of workers running at a given time may exceed this maximum. A smaller number of workers may run if the number of executing tasks is smaller than the supplied value of the `workers` argument.
`seconds_interval`	Number of seconds between polling intervals waiting for certain internal synchronous operations to complete. In certain cases, exponential backoff is used with this argument passed to `seconds_max` in a `crew_throttle()` object.
`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.
`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`	Deprecated on 2025-05-30 (`crew` version 1.1.2.9004). Please use the `reset_globals` option of `crew_controller()` instead.
`reset_packages`	Deprecated on 2025-05-30 (`crew` version 1.1.2.9004). Please use the `reset_packages` option of `crew_controller()` instead.
`reset_options`	Deprecated on 2025-05-30 (`crew` version 1.1.2.9004). Please use the `reset_options` option of `crew_controller()` instead.
`garbage_collection`	Deprecated on 2025-05-30 (`crew` version 1.1.2.9004). Please use the `garbage_collection` option of `crew_controller()` instead.
`crashes_error`	Deprecated on 2025-01-13 (`crew` version 0.10.2.9002).
`launch_max`	Deprecated on 2024-11-04 (`crew` version 0.10.2.9002).
`tls`	A TLS configuration object from `crew_tls()`.
`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")) {
client <- crew_client()
client$start()
launcher <- crew_launcher_local(name = client$name)
launcher$start(url = client$url, profile = client$profile)
launcher$launch()
task <- mirai::mirai("result", .compute = client$profile)
mirai::call_mirai(task)
task$data
client$terminate()
}

crew documentation built on June 9, 2025, 5:09 p.m.