Start a worker

Starts a worker. The function loads packages, initializes the RushWorker instance and invokes the worker loop. This function is called by $start_local_workers() or by the user after creating the worker script with $worker_script().

Usage

start_worker(
  worker_id = NULL,
  network_id,
  config = NULL,
  lgr_thresholds = NULL,
  lgr_buffer_size = 0,
  heartbeat_period = NULL,
  heartbeat_expire = NULL,
  message_log = NULL,
  output_log = NULL
)

Arguments

worker_id

(character(1))
Identifier of the worker. Keys in redis specific to the worker are prefixed with the worker id.

network_id

(character(1))
Identifier of the rush network. Manager and workers must have the same id. Keys in Redis are prefixed with the instance id.

config

(list())
Configuration for the Redis connection.

lgr_thresholds

(named character() | named numeric())
Logger threshold on the workers e.g. c("mlr3/rush" = "debug").

lgr_buffer_size

(integer(1))
By default (lgr_buffer_size = 0), the log messages are directly saved in the Redis data store. If lgr_buffer_size > 0, the log messages are buffered and saved in the Redis data store when the buffer is full. This improves the performance of the logging.

heartbeat_period

(integer(1))
Period of the heartbeat in seconds. The heartbeat is updated every heartbeat_period seconds. Must be at least 1 second.

heartbeat_expire

(integer(1))
Time to live of the heartbeat in seconds. The heartbeat key is set to expire after heartbeat_expire seconds. Must be at least heartbeat_period, otherwise a live worker is reaped as lost between two heartbeats. Set it larger than the longest pause a worker may experience, for example from garbage collection or swapping, because a live worker wrongly declared lost can leave a task in an inconsistent state.

message_log

(character(1))
Path to the message log files e.g. /tmp/message_logs/ The message log files are named message_<worker_id>.log. If NULL, no messages, warnings or errors are stored.

output_log

(character(1))
Path to the output log files e.g. /tmp/output_logs/ The output log files are named output_<worker_id>.log. If NULL, no output is stored.

Value

NULL

Note

The function initializes the connection to the Redis database. It loads the packages required by the worker loop. The function initialize the RushWorker instance and starts the worker loop.

Examples

# This example is not executed since Redis must be installed
if (FALSE) { # \dontrun{
  rush::start_worker(
    network_id = "test-rush",
    config = list(host = "127.0.0.1", port = "6379"))
} # }