startLocalWorkers: 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,
  ...
)

Value

NULL is invisibly returned.

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.

Examples

Run this code

# 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")
}