Dear all,

I've tested 'rgang', Fermilab's equivalent of runs_on but
_much_ faster. With the little testing I've done I can recommend it:

1. How to obtain it ?
   The latest version of rgang is v2_5 and is available at:
   ftp://linux-rep.fnal.gov/pub/rgang/

   Alternatively, you can also obtain it from
   /afs/cern.ch/user/b/bogaerts/public/rgangv2_5.tar
   or directory rgangv2_5

2. How to install it ?

   You must have python installed on the machine where you need
   to run rgang.

   Unpack rgangv2_5.tar. You want rgangv2_5/bin/rgang.py

   Edit the file to use ssh and scp instead of rsh and rcp:
   DFLT_RSH='rsh'  change into 'ssh'
   DFLT_RCP='rcp'  change into 'scp'

   Install rgang.py somewhere in your path and make it executable
   (chmod +x rgang.py)

   'rgang.py -h' should print 'help' information. Some documentation is
   also provided in the unpacked tar file. Read it (it is small enough).

3. Why do I like rgang.py ?

   It is parallel.
   It creates a thread for every remote node it makes an 'ssh' to.
   The documentation claims that this is good for up to ~ 200 nodes.

   You may make it even run faster by adding option --nway=2.
   This will create a binary tree and execute rgang.py from
   multiple nodes in a 'worm like' fashion.

   It is very powerful. It can copy files around machines.
   Probably, you'll wish to build customised scripts around rgang.py
   for specific tasks.

4. How to use it ?

   I've only very limited experience. The following commands
   worked for me on pcatb120-pcatb139:

   rgang.py -nn --nway=0 pcatb1{21-29},pcatb1{31-39} pwd
   rgang.py -nn --nway=2 pcatb1{21-29},pcatb1{31-39} pwd
   rgang.py -nn --farmlets="/home/bogaerts/farmlets" all pwd

   where all is a machine file located in /home/bogaerts/farmlets/

   Again, please read the few pages of documentation.


Best Regards, Andre



-----Original Message-----
From: Ron Rechenmacher [mailto:ron@fnapcf.fnal.gov]
Sent: 29 April 2004 18:56
To: Joannes Andreas Bogaerts
Cc: ron@fnapcf.fnal.gov; rhauser@fnal.gov
Subject: Re: FW: problems using rgang with the 'nway' option


Hi,

The latest version of rgang is v2_5 and is available at:

   ftp://linux-rep.fnal.gov/pub/rgang/

I would be happy to work with you to thoroughly test it.
The latest version has several features to add robust-ness, although there
are also 2 known bugs:
    1) node expansion gets confused in certain cases. i.e.
           rgang --list x{08-10}
       will produce an error. (note: "list" option is new)
    2) rgang bombs (as opposed to correctly reporting the error) when
       redirecting a >2GB file
       through stdin using --nway=2 and --input-to-all-branches when
       some portion of the destination nodes do not support >2GB files.
       When the --nway option is such that a tree is not formed and there is
       an error, the errors are correctly reported.

Anyway, please try the latest version and send the results.

Thanks,
Ron