registerDoRedis: Register the doRedis parallel back end with foreach.

In cloudcell/doRedis111stable: Foreach parallel adapter for the rredis package

Description

The doRedis package supplies a simple and lightweight parallel back end for the foreach %dopar% function.

Usage

registerDoRedis(queue, host = "localhost", port = 6379, password=NULL)

Arguments

queue	A (character) work queue name.
host	The Redis server host or (character) I. P. address.
port	The Redis server port number.
password	The Redis server password.

Details

The doRedis package imlpements a simple but flexible parallel back end for foreach that uses Redis for inter-process communication. The work queue name specifies the base name of a small set of Redis keys that the master and worker processes use to exchange data.

Back-end worker R processes advertise their availablility for work with the redisWorker function.

The doRedis parallel back end tolerates faults among the worker processes and automatically resubmits failed tasks. It is also portable and supports heterogeneous sets of workers, even across operative systems. The back end supports dynamic pools of worker processes. New workers may be added to work queues at any time and can be immediately used by in-flight foreach computations.

Value

Nothing is returned.

Note

All doRedis functions require network access to a Redis server (not included with the doRedis package).

Author(s)

B. W. Lewis <[e-mail]>

References

http://cran.r-project.org/web/packages/foreach/index.html

See Also

redisWorker removeQueue

Examples

## Not run: 
## The example assumes that a Redis server is running on the local host
## and standard port.

## 1. Open one or more 'worker' R sessions and run:
require('doRedis')
redisWorker('jobs')

## 2. Open another R session acting as a 'master' and run this simple 
##    sampling approximation of pi:
require('doRedis')
registerDoRedis('jobs')
foreach(j=1:10,.combine=sum,.multicombine=TRUE) %dopar% 
          4*sum((runif(1000000)^2 + runif(1000000)^2)<1)/10000000
removeQueue('jobs')

## End(Not run)

cloudcell/doRedis111stable documentation built on May 13, 2019, 8:02 p.m.