browser mode with foreach %dopar%

Question

Is there a way to enter browser mode in a parallel foreach call? I've tried to create a cluster using manual = TRUE. As expected, it requires me to manually launch instances of R. However, once the instance receive a task from the master process, its off the the races and doesn't seem to pause at the browser() command. I'd like to enter browser and inspect the state of R.

foreach( i = 1 : 5 ) %dopar% 
{
     browser()
}

Here's the Rscript call in manual mode:

c:/.../bin/x64/Rscript" -e "parallel:::.slaveRSOCK()" MASTER=localhost PORT=10187 OUT= TIMEOUT=2592000 METHODS=TRUE

score 0 · Answer 1 · answered Feb 28 '12 at 17:32

0

Though it's not stated in ?browser, I would expect that browser only works in interactive sessions.

answered Feb 28 '12 at 17:32

Joshua Ulrich

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Perhaps the rscript call that is displayed when manual=TRUE can be modified to make R run interactively? – Suraj Feb 28 '12 at 17:36
I added the rscript call to my original post – Suraj Feb 28 '12 at 17:45
@SFun28: You can't make R run interactively via Rscript. From `?Rscript`: "Options '--slave --no-restore' are always supplied: these imply '--no-save'". – Joshua Ulrich Feb 28 '12 at 19:00
ah...thanks! Sounds like I need to find a way to run this interactively – Suraj Feb 28 '12 at 23:05
Joshua - thanks for pointing me in the right direction. Posted the solution. – Suraj Feb 28 '12 at 23:45

score 0 · Accepted Answer · answered Feb 28 '12 at 23:44

0

The solution is to use manual = TRUE, load new instances of R (one for each node in your cluster), and execute the following:

timeout = 2592000
parallel:::.slaveRSOCK()

So basically ignore the RScript instructions.

answered Feb 28 '12 at 23:44

Suraj

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browser mode with foreach %dopar%

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