Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

IP address of the mirai client to send and receive tasks. If NULL, the host defaults to nanonext::ip_addr()[1].

TCP port to listen for the workers. If NULL, then an available ephemeral port is automatically chosen. Controllers running simultaneously on the same computer (as in a controller group) must not share the same TCP port.

A TLS configuration object from crew_tls().

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Either NULL (default) or an object produced by mirai::serial_config() to control the serialization of data sent to workers. This can help with either more efficient data transfers or to preserve attributes of otherwise non-exportable objects (such as torch tensors or arrow tables). See ?mirai::serial_config for details.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

Deprecated on 2023-09-21 in version 0.1.2.9000. No longer necessary.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

TRUE to reset global environment variables between tasks, FALSE to leave them alone.

TRUE to detach any packages loaded during a task (runs between each task), FALSE to leave packages alone. In either case, the namespaces are not detached.

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. for this and other reasons, reset_options only resets options that were nonempty at the beginning of the task. If your task sets an entirely new option not already in options(), then reset_options = TRUE does not delete the option.

TRUE to run garbage collection after each task task, FALSE to skip.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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").

In rare cases, a worker may exit unexpectedly before it completes its current task. If this happens, pop() returns a status of "crash" instead of "error" for the task. The controller does not automatically retry the task, but you can retry it manually by calling push() again and using the same task name as before. (However, targets pipelines running crew do automatically retry tasks whose workers crashed.)

crashes_max is a non-negative integer, and it sets the maximum number of allowable consecutive crashes for a given task. If a task's worker crashes more than crashes_max times in a row, then pop() throws an error when it tries to return the results of the task.

An optional crew controller object, or NULL to omit. If supplied, the backup controller runs any pushed tasks that have already reached crashes_max consecutive crashes. Using backup, you can create a chain of controllers with different levels of resources (such as worker memory and CPUs) so that a task that fails on one controller can retry using incrementally more powerful workers. All controllers in a backup chain should be part of the same controller group (see crew_controller_group()) so you can call the group-level pop() and collect() methods to make sure you get results regardless of which controller actually ended up running the task.

Limitations of backup: * crashes_max needs to be positive in order for backup to be used. Otherwise, every task would always skip the current controller and go to backup. * backup cannot be a controller group. It must be an ordinary controller.

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.

An options list from crew_options_lsf() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

IP address of the mirai client to send and receive tasks. If NULL, the host defaults to nanonext::ip_addr()[1].

TCP port to listen for the workers. If NULL, then an available ephemeral port is automatically chosen. Controllers running simultaneously on the same computer (as in a controller group) must not share the same TCP port.

A TLS configuration object from crew_tls().

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Either NULL (default) or an object produced by mirai::serial_config() to control the serialization of data sent to workers. This can help with either more efficient data transfers or to preserve attributes of otherwise non-exportable objects (such as torch tensors or arrow tables). See ?mirai::serial_config for details.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

Deprecated on 2023-09-21 in version 0.1.2.9000. No longer necessary.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

TRUE to reset global environment variables between tasks, FALSE to leave them alone.

TRUE to detach any packages loaded during a task (runs between each task), FALSE to leave packages alone. In either case, the namespaces are not detached.

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. for this and other reasons, reset_options only resets options that were nonempty at the beginning of the task. If your task sets an entirely new option not already in options(), then reset_options = TRUE does not delete the option.

TRUE to run garbage collection after each task task, FALSE to skip.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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").

In rare cases, a worker may exit unexpectedly before it completes its current task. If this happens, pop() returns a status of "crash" instead of "error" for the task. The controller does not automatically retry the task, but you can retry it manually by calling push() again and using the same task name as before. (However, targets pipelines running crew do automatically retry tasks whose workers crashed.)

crashes_max is a non-negative integer, and it sets the maximum number of allowable consecutive crashes for a given task. If a task's worker crashes more than crashes_max times in a row, then pop() throws an error when it tries to return the results of the task.

An optional crew controller object, or NULL to omit. If supplied, the backup controller runs any pushed tasks that have already reached crashes_max consecutive crashes. Using backup, you can create a chain of controllers with different levels of resources (such as worker memory and CPUs) so that a task that fails on one controller can retry using incrementally more powerful workers. All controllers in a backup chain should be part of the same controller group (see crew_controller_group()) so you can call the group-level pop() and collect() methods to make sure you get results regardless of which controller actually ended up running the task.

Limitations of backup: * crashes_max needs to be positive in order for backup to be used. Otherwise, every task would always skip the current controller and go to backup. * backup cannot be a controller group. It must be an ordinary controller.

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.

An options list from crew_options_pbs() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

IP address of the mirai client to send and receive tasks. If NULL, the host defaults to nanonext::ip_addr()[1].

TCP port to listen for the workers. If NULL, then an available ephemeral port is automatically chosen. Controllers running simultaneously on the same computer (as in a controller group) must not share the same TCP port.

A TLS configuration object from crew_tls().

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Either NULL (default) or an object produced by mirai::serial_config() to control the serialization of data sent to workers. This can help with either more efficient data transfers or to preserve attributes of otherwise non-exportable objects (such as torch tensors or arrow tables). See ?mirai::serial_config for details.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

Deprecated on 2023-09-21 in version 0.1.2.9000. No longer necessary.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

TRUE to reset global environment variables between tasks, FALSE to leave them alone.

TRUE to detach any packages loaded during a task (runs between each task), FALSE to leave packages alone. In either case, the namespaces are not detached.

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. for this and other reasons, reset_options only resets options that were nonempty at the beginning of the task. If your task sets an entirely new option not already in options(), then reset_options = TRUE does not delete the option.

TRUE to run garbage collection after each task task, FALSE to skip.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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").

In rare cases, a worker may exit unexpectedly before it completes its current task. If this happens, pop() returns a status of "crash" instead of "error" for the task. The controller does not automatically retry the task, but you can retry it manually by calling push() again and using the same task name as before. (However, targets pipelines running crew do automatically retry tasks whose workers crashed.)

crashes_max is a non-negative integer, and it sets the maximum number of allowable consecutive crashes for a given task. If a task's worker crashes more than crashes_max times in a row, then pop() throws an error when it tries to return the results of the task.

An optional crew controller object, or NULL to omit. If supplied, the backup controller runs any pushed tasks that have already reached crashes_max consecutive crashes. Using backup, you can create a chain of controllers with different levels of resources (such as worker memory and CPUs) so that a task that fails on one controller can retry using incrementally more powerful workers. All controllers in a backup chain should be part of the same controller group (see crew_controller_group()) so you can call the group-level pop() and collect() methods to make sure you get results regardless of which controller actually ended up running the task.

Limitations of backup: * crashes_max needs to be positive in order for backup to be used. Otherwise, every task would always skip the current controller and go to backup. * backup cannot be a controller group. It must be an ordinary controller.

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.

An options list from crew_options_sge() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

IP address of the mirai client to send and receive tasks. If NULL, the host defaults to nanonext::ip_addr()[1].

TCP port to listen for the workers. If NULL, then an available ephemeral port is automatically chosen. Controllers running simultaneously on the same computer (as in a controller group) must not share the same TCP port.

A TLS configuration object from crew_tls().

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Deprecated on 2023-09-15 in version 0.4.1. Use argument tls instead.

Either NULL (default) or an object produced by mirai::serial_config() to control the serialization of data sent to workers. This can help with either more efficient data transfers or to preserve attributes of otherwise non-exportable objects (such as torch tensors or arrow tables). See ?mirai::serial_config for details.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

Deprecated on 2023-09-21 in version 0.1.2.9000. No longer necessary.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

TRUE to reset global environment variables between tasks, FALSE to leave them alone.

TRUE to detach any packages loaded during a task (runs between each task), FALSE to leave packages alone. In either case, the namespaces are not detached.

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. for this and other reasons, reset_options only resets options that were nonempty at the beginning of the task. If your task sets an entirely new option not already in options(), then reset_options = TRUE does not delete the option.

TRUE to run garbage collection after each task task, FALSE to skip.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

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").

In rare cases, a worker may exit unexpectedly before it completes its current task. If this happens, pop() returns a status of "crash" instead of "error" for the task. The controller does not automatically retry the task, but you can retry it manually by calling push() again and using the same task name as before. (However, targets pipelines running crew do automatically retry tasks whose workers crashed.)

crashes_max is a non-negative integer, and it sets the maximum number of allowable consecutive crashes for a given task. If a task's worker crashes more than crashes_max times in a row, then pop() throws an error when it tries to return the results of the task.

An optional crew controller object, or NULL to omit. If supplied, the backup controller runs any pushed tasks that have already reached crashes_max consecutive crashes. Using backup, you can create a chain of controllers with different levels of resources (such as worker memory and CPUs) so that a task that fails on one controller can retry using incrementally more powerful workers. All controllers in a backup chain should be part of the same controller group (see crew_controller_group()) so you can call the group-level pop() and collect() methods to make sure you get results regardless of which controller actually ended up running the task.

Limitations of backup: * crashes_max needs to be positive in order for backup to be used. Otherwise, every task would always skip the current controller and go to backup. * backup cannot be a controller group. It must be an ordinary controller.

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.

An options list from crew_options_slurm() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_globals option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_packages option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_options option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the garbage_collection option of crew_controller() instead.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

A TLS configuration object from crew_tls().

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").

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.

List of options from a crew.cluster options function such as crew_options_slurm(). Make sure the cluster types of the launcher and options function match.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_globals option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_packages option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_options option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the garbage_collection option of crew_controller() instead.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

A TLS configuration object from crew_tls().

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").

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.

An options list from crew_options_lsf() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_globals option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_packages option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_options option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the garbage_collection option of crew_controller() instead.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

A TLS configuration object from crew_tls().

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").

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.

An options list from crew_options_pbs() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_globals option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_packages option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_options option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the garbage_collection option of crew_controller() instead.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

A TLS configuration object from crew_tls().

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").

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.

An options list from crew_options_sge() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character string, name of the launcher. If the name is NULL, then a name is automatically generated when the launcher starts.

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.

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.

Number of seconds until timing out while waiting for certain synchronous operations to complete, such as checking mirai::status().

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.

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.

Soft wall time in seconds. The timer does not launch until tasks_timers tasks have completed. See the walltime argument of mirai::daemon().

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.

Number of tasks to do before activating the timers for seconds_idle and seconds_wall. See the timerstart argument of mirai::daemon().

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_globals option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_packages option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the reset_options option of crew_controller() instead.

Deprecated on 2025-05-30 (crew version 1.1.2.9004). Please use the garbage_collection option of crew_controller() instead.

Deprecated on 2025-01-13 (crew version 0.10.2.9002).

A TLS configuration object from crew_tls().

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").

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.

An options list from crew_options_slurm() with cluster-specific configuration options.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated on 2024-01-08 (version 0.1.4.9001). Use command_terminate instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character of length 1, file path to the executable to list jobs.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character of length 1, file path to the executable to list jobs.

Deprecated. Use options_cluster instead.

Deprecated. Use options_cluster instead.

Character of length 1, file path to the executable to list jobs.

Deprecated. Use options_cluster instead.

Logical, whether to see console output and error messages when submitting worker.

Character of length 1, file path to the executable to submit a worker job.

Character of length 1, file path to the executable to terminate a worker job. Set to "" to skip manually terminating the worker. Unless there is an issue with the platform, the job should still exit thanks to the NNG-powered network programming capabilities of mirai. Still, if you set command_terminate = "", you are assuming extra responsibility for manually monitoring your jobs on the cluster and manually terminating jobs as appropriate.

Character of length 1, directory path to the job scripts. Just before each job submission, a job script is created in this folder. Script base names are unique to each launcher and worker, and the launcher deletes the script when the worker is manually terminated. tempdir() is the default, but it might not work for some systems. tools::R_user_dir("crew.cluster", which = "cache") is another reasonable choice.

Optional character vector of additional lines to be added to the job script just after the more common flags. An example would be script_lines = "module load R" if your cluster supports R through an environment module.

Logical, whether to see console output and error messages when submitting worker.

Character of length 1, file path to the executable to submit a worker job.

Character of length 1, file path to the executable to terminate a worker job. Set to "" to skip manually terminating the worker. Unless there is an issue with the platform, the job should still exit thanks to the NNG-powered network programming capabilities of mirai. Still, if you set command_terminate = "", you are assuming extra responsibility for manually monitoring your jobs on the cluster and manually terminating jobs as appropriate.

Character of length 1, directory path to the job scripts. Just before each job submission, a job script is created in this folder. Script base names are unique to each launcher and worker, and the launcher deletes the script when the worker is manually terminated. tempdir() is the default, but it might not work for some systems. tools::R_user_dir("crew.cluster", which = "cache") is another reasonable choice.

Optional character vector of additional lines to be added to the job script just after the more common flags. An example would be script_lines = "module load R" if your cluster supports R through an environment module.

Character of length 1, directory to launch the worker from (as opposed to the system default). cwd = "/home" translates to a line of ⁠#BSUB -cwd /home⁠ in the LSF job script. cwd = getwd() is the default, which launches workers from the current working directory. Set cwd = NULL to omit this line from the job script.

Character of length 1, file pattern to control the locations of the LSF worker log files. By default, both standard output and standard error go to the same file. log_output = "crew_log_%J.log" translates to a line of ⁠#BSUB -o crew_log_%J.log⁠ in the LSF job script, where ⁠%J⁠ is replaced by the job ID of the worker. The default is ⁠/dev/null⁠ to omit these logs. Set log_output = NULL to omit this line from the job script.

Character of length 1, file pattern for standard error. log_error = "crew_error_%J.err" translates to a line of ⁠#BSUB -e crew_error_%J.err⁠ in the LSF job script, where ⁠%J⁠ is replaced by the job ID of the worker. The default is ⁠/dev/null⁠ to omit these logs. Set log_error = NULL to omit this line from the job script.

Positive numeric scalar, memory limit in gigabytes of the worker. memory_gigabytes_limit = 4 translates to a line of ⁠#BSUB -M 4G⁠ in the LSF job script. memory_gigabytes_limit = NULL omits this line.

Positive numeric scalar, memory requirement in gigabytes. memory_gigabytes_required = 4 translates to a line of ⁠#BSUB -R 'rusage[mem=4G]'⁠ in the LSF job script. memory_gigabytes_required = NULL omits this line.

Optional positive integer scalar, number of CPU cores for the worker. cores = 4 translates to a line of ⁠#BSUB -n 4⁠ in the LSF job script. cores = NULL omits this line.

Logical, whether to see console output and error messages when submitting worker.

Character of length 1, file path to the executable to submit a worker job.

Character of length 1, file path to the executable to terminate a worker job. Set to "" to skip manually terminating the worker. Unless there is an issue with the platform, the job should still exit thanks to the NNG-powered network programming capabilities of mirai. Still, if you set command_terminate = "", you are assuming extra responsibility for manually monitoring your jobs on the cluster and manually terminating jobs as appropriate.

Character of length 1, directory path to the job scripts. Just before each job submission, a job script is created in this folder. Script base names are unique to each launcher and worker, and the launcher deletes the script when the worker is manually terminated. tempdir() is the default, but it might not work for some systems. tools::R_user_dir("crew.cluster", which = "cache") is another reasonable choice.

Optional character vector of additional lines to be added to the job script just after the more common flags. An example would be script_lines = "module load R" if your cluster supports R through an environment module.

Logical of length 1, whether to set the working directory of the worker to the working directory it was launched from. cwd = TRUE is translates to a line of ⁠cd "$O_WORKDIR"⁠ in the job script. This line is inserted after the content of script_lines to make sure the ⁠#PBS⁠ directives are above system commands. cwd = FALSE omits this line.

Character of length 1, file or directory path to PBS worker log files for standard output. log_output = "VALUE" translates to a line of ⁠#PBS -o VALUE⁠ in the PBS job script. The default is ⁠/dev/null⁠ to omit the logs. If you do supply a non-⁠/dev/null⁠ value, it is recommended to supply a directory path with a trailing slash so that each worker gets its own set of log files.

Character of length 1, file or directory path to PBS worker log files for standard error. log_error = "VALUE" translates to a line of ⁠#PBS -e VALUE⁠ in the PBS job script. The default of NULL omits this line. If you do supply a non-⁠/dev/null⁠ value, it is recommended to supply a directory path with a trailing slash so that each worker gets its own set of log files.

Logical, whether to join the stdout and stderr log files together into one file. log_join = TRUE translates to a line of ⁠#PBS -j oe⁠ in the PBS job script, while log_join = FALSE is equivalent to ⁠#PBS -j n⁠. If log_join = TRUE, then log_error should be NULL.

Optional positive numeric scalar, gigabytes of memory required to run the worker. memory_gigabytes_required = 2.4 translates to a line of ⁠#PBS -l mem=2.4gb⁠ in the PBS job script. memory_gigabytes_required = NULL omits this line.

Optional positive integer scalar, number of cores for the worker ("slots" in PBS lingo). cores = 4 translates to a line of ⁠#PBS -l ppn=4⁠ in the PBS job script. cores = NULL omits this line.

Numeric scalar, hours of wall time to request for the worker. walltime_hours = 23 translates to a line of ⁠#PBS -l walltime=23:00:00⁠ in the job script. walltime_hours = NULL omits this line.

Logical, whether to see console output and error messages when submitting worker.

Character of length 1, file path to the executable to submit a worker job.

Character of length 1, file path to the executable to terminate a worker job. Set to "" to skip manually terminating the worker. Unless there is an issue with the platform, the job should still exit thanks to the NNG-powered network programming capabilities of mirai. Still, if you set command_terminate = "", you are assuming extra responsibility for manually monitoring your jobs on the cluster and manually terminating jobs as appropriate.

Character of length 1, directory path to the job scripts. Just before each job submission, a job script is created in this folder. Script base names are unique to each launcher and worker, and the launcher deletes the script when the worker is manually terminated. tempdir() is the default, but it might not work for some systems. tools::R_user_dir("crew.cluster", which = "cache") is another reasonable choice.

Optional character vector of additional lines to be added to the job script just after the more common flags. An example would be script_lines = "module load R" if your cluster supports R through an environment module.

Logical of length 1, whether to launch the worker from the current working directory (as opposed to the user home directory). cwd = TRUE translates to a line of ⁠#$ -cwd⁠ in the SGE job script. cwd = FALSE omits this line.

Logical of length 1, whether to forward the environment variables of the current session to the SGE worker. envvars = TRUE translates to a line of ⁠#$ -V⁠ in the SGE job script. envvars = FALSE omits this line.

Character of length 1, file or directory path to SGE worker log files for standard output. log_output = "VALUE" translates to a line of ⁠#$ -o VALUE⁠ in the SGE job script. The default is ⁠/dev/null⁠ to omit the logs. If you do supply a non-⁠/dev/null⁠ value, it is recommended to supply a directory path with a trailing slash so that each worker gets its own set of log files.

Character of length 1, file or directory path to SGE worker log files for standard error. log_error = "VALUE" translates to a line of ⁠#$ -e VALUE⁠ in the SGE job script. The default of NULL omits this line. If you do supply a non-⁠/dev/null⁠ value, it is recommended to supply a directory path with a trailing slash so that each worker gets its own set of log files.

Logical, whether to join the stdout and stderr log files together into one file. log_join = TRUE translates to a line of ⁠#$ -j y⁠ in the SGE job script, while log_join = FALSE is equivalent to ⁠#$ -j n⁠. If log_join = TRUE, then log_error should be NULL.

Optional numeric scalar, maximum number of gigabytes of memory a worker is allowed to consume. If the worker consumes more than this level of memory, then SGE will terminate it. ⁠memory_gigabytes_limit = 5.7"⁠ translates to a line of "#$ -l h_rss=5.7G" in the SGE job script. memory_gigabytes_limit = NULL omits this line.

Optional positive numeric scalar, gigabytes of memory required to run the worker. memory_gigabytes_required = 2.4 translates to a line of ⁠#$ -l m_mem_free=2.4G⁠ in the SGE job script. memory_gigabytes_required = NULL omits this line.

Optional positive integer scalar, number of cores per worker ("slots" in SGE lingo). cores = 4 translates to a line of ⁠#$ -pe smp 4⁠ in the SGE job script. cores = NULL omits this line.

Optional integer scalar, number of GPUs to request for the worker. gpu = 1 translates to a line of "#$ -l gpu=1" in the SGE job script. gpu = NULL omits this line.

Logical, whether to see console output and error messages when submitting worker.

Character of length 1, file path to the executable to submit a worker job.

Character of length 1, file path to the executable to terminate a worker job. Set to "" to skip manually terminating the worker. Unless there is an issue with the platform, the job should still exit thanks to the NNG-powered network programming capabilities of mirai. Still, if you set command_terminate = "", you are assuming extra responsibility for manually monitoring your jobs on the cluster and manually terminating jobs as appropriate.

Character of length 1, directory path to the job scripts. Just before each job submission, a job script is created in this folder. Script base names are unique to each launcher and worker, and the launcher deletes the script when the worker is manually terminated. tempdir() is the default, but it might not work for some systems. tools::R_user_dir("crew.cluster", which = "cache") is another reasonable choice.

Optional character vector of additional lines to be added to the job script just after the more common flags. An example would be script_lines = "module load R" if your cluster supports R through an environment module.

Character of length 1, file pattern to control the locations of the SLURM worker log files. By default, both standard output and standard error go to the same file. log_output = "crew_log_%A.txt" translates to a line of ⁠#SBATCH --output=crew_log_%A.txt⁠ in the SLURM job script, where ⁠%A⁠ is replaced by the job ID of the worker. The default is ⁠/dev/null⁠ to omit these logs. Set log_output = NULL to omit this line from the job script.

Character of length 1, file pattern for standard error. log_error = "crew_log_%A.txt" translates to a line of ⁠#SBATCH --error=crew_log_%A.txt⁠ in the SLURM job script, where ⁠%A⁠ is replaced by the job ID of the worker. The default is ⁠/dev/null⁠ to omit these logs. Set log_error = NULL to omit this line from the job script.

Positive numeric scalar, total number of gigabytes of memory required per node. memory_gigabytes_required = 2.40123 translates to a line of ⁠#SBATCH --mem=2041M⁠ in the SLURM job script. memory_gigabytes_required = NULL omits this line.

Positive numeric scalar, gigabytes of memory required per CPU. memory_gigabytes_per_cpu = 2.40123 translates to a line of ⁠#SBATCH --mem-per-cpu=2041M⁠ in the SLURM job script. memory_gigabytes_per_cpu = NULL omits this line.

Optional positive integer scalar, number of CPUs for the worker. cpus_per_task = 4 translates to a line of ⁠#SBATCH --cpus-per-task=4⁠ in the SLURM job script. cpus_per_task = NULL omits this line.

Numeric scalar, number of minutes to designate as the wall time of crew each worker instance on the SLURM cluster. time_minutes = 60 translates to a line of ⁠#SBATCH --time=60⁠ in the SLURM job script. time_minutes = NULL omits this line.

Character string, name of the SLURM partition to create workers on. partition = "partition1,partition2" translates to a line of ⁠#SBATCH --partition=partition1,partition2⁠ in the SLURM job script. partition = NULL omits this line.

Numeric scalar, number of SLURM tasks to run within the job. n_tasks = 1 translates to a line of ⁠#SBATCH --ntasks=1⁠ in the SLURM job script. n_tasks = 0 omits this line.