startLocalWorkers: Start one or more background R worker processes on the local...

In doRedis: 'Foreach' Parallel Adapter Using the 'Redis' Database

Start one or more background R worker processes on the local system.

Description

Use startLocalWorkers to start one or more doRedis R worker processes in the background. The worker processes are started on the local system using the redisWorker function.

Usage

startLocalWorkers(
  n,
  queue,
  host = "localhost",
  port = 6379,
  iter = Inf,
  linger = 30,
  log = stdout(),
  Rbin = paste(R.home(component = "bin"), "R", sep = "/"),
  password,
  ...
)

Arguments

n	number of workers to start
queue	work queue name
host	Redis database host name or IP address
port	Redis database port number
iter	maximum number of tasks to process before exiting the worker loop
linger	timeout in seconds after which the work queue is deleted that the worker terminates
log	print messages to the specified file connection
Rbin	full path to the command-line R program
password	optional Redis database password
...	optional additional parameters passed to the redisWorker function

Details

Running workers self-terminate after a linger period if their work queues are deleted with the removeQueue function, or when network activity with Redis remains inactive for longer than the timeout period set in the redisConnect function. That value defaults internally to 3600 (one hour) in startLocalWorkers. You can increase it by including a timeout=n argument value.

Value

NULL is invisibly returned.

See Also

registerDoRedis, redisWorker

Examples

# Only run if a Redis server is running
if (redux::redis_available()) {
## The example assumes that a Redis server is running on the local host
## and standard port.

# Start a single local R worker process
startLocalWorkers(n=1, queue="R jobs", linger=1)

# Run a simple sampling approximation of pi:
registerDoRedis("R jobs")
print(foreach(j=1:10, .combine=sum, .multicombine=TRUE) %dopar%
        4 * sum((runif(1000000) ^ 2 + runif(1000000) ^ 2) < 1) / 10000000)

# Clean up
removeQueue("R jobs")
}

doRedis documentation built on May 2, 2023, 5:10 p.m.