rpc_cs_example: Example Functions of RPC Related to pbdCS
In snoweye/pbdRPC: Programming with Big Data -- Remote Procedure Call

Description Usage Arguments Details Value Examples

Example functions of RPC related to pbdCS

check_cs(machine, cmd = .pbd_env$RPC.CS$check)

kill_cs(machine, cmd = .pbd_env$RPC.CS$kill)

start_cs(machine, cmd = .pbd_env$RPC.CS$start,
  preload = .pbd_env$RPC.CS$preload)

`machine`	A machine configuration. See `?machine`.
`cmd`	the main command to be executed on the server.
`preload`	further commands preloaded before the main `command` is executed.

Using either ssh or plink to launch a pbdCS R cluster.

NO further input from stdin is expected. Outputs or errors may not be captured by R.

start_cs() starts a pbdCS R cluster on remote servers. Typical commands to launch a pbdCS R cluster is given in the example. The linux/unix commands are as the following:

1)nohup is for the non-stop call after disconnection.
2)mpiexec -np 4 is for launching 4 MPI instances.
3)Rscript -e 'pbdCS::pbdserver()' is for R to start the pbdCS R cluster within MPI in batch.
4)> .rrlog is to direct the stdout to a file .rrlog
5)2>&1 is to turn stderr to stdout which is the file .cslog.
6)< /dev/null is to get stdin from /dev/null which is nothing happen.
7)& is to put the batch command for the pbdCS R cluster in background.

check_cs() checks if there is a pbdCS R cluster on a remote server. Lunix/unix commands ps and grep are used.

kill_cs() kills the pbdCS R cluster if found. Lunix/unix commands ps, grep, awk, and kill are used.

Mainly the message received at the command line will be printed, but may not be captured by R.

## Not run: 
library(pbdRPC, quietly = TRUE)
# rpcopt_set(user = "snoweye", hostname = "192.168.56.101")
m <- machine(user = "snoweye", hostname = "192.168.56.101")

check_cs(m)    # pid 2857 (may differ)
kill_cs(m)     # all pbdCS pids are killed
check_cs(m)    # make sure no pbdCS R cluster is running

### use "; " to bypass multiple commands
preload <- "source ~/work-my/00_set_devel_R; "

### start a new pbdCS R cluster
start_cs(m, preload = preload)
check_cs(m)
kill_cs(m)

### Example: for module load on supercomputers
preload <- "module load r; "    # e.g. via module load r
start_cs(m, preload = preload)
check_cs(m)
kill_cs(m)

## End(Not run)