[R] Re: Sessioned R web interfaces

[Nathan Whitehouse]

Frank,

  Both RZope and Rho solve this problem.  
  
  RZope
(http://www.analytics.washington.edu/statcomp/projects/rzope/)solves
it by using *nix's fork command, which takes as much
time as a memcopy.  
 
  Rho(http://rho-project.org) solves it by maintaining
a pool of idling R processes, which it maintains
active & can pull to do a calculation immediately.

  Both of these are pretty immediate & allow
multistep/session calculations.(As compared to CGI
stuff)

  cheers,
  Nathan

Here's a related question:  Do any of the mentioned
R-web interfaces
(Rweb, R-Online, CGIwithR, RSPerl) support reusing the
same R process,
eliminating the startup overhead?  This would be
useful to me as well.

Currently I use such a method on my computing cluster:
 All 40 
compute nodes run an R process/compute server that
listens at a socket 
for
any 
connection and subsequent commands from another
computer. 
When the master process disconnects, the R processes
go back to 
listening
at the socket.  Connecting to the R compute servers
this way
takes < 2 milliseconds rather than the typical ~2
second R startup 
time.

Thanks for any tips.

-Frank

=====
Nathan Whitehouse
Statistics/Programming
Baylor College of Medicine
Houston, TX, USA
nlwhitehouse at yahoo.com
work: 1-713-798-9029
cell:    1-512-293-5840

http://rho-project.org: rho- open source web services for R.
http://franklin.imgen.bcm.tmc.edu: Shaw laboratory, bcm.