[Beowulf] Remote procedure call (error)

Robert G. Brown rgb at phy.duke.edu
Wed Jan 28 11:42:05 EST 2004


On Wed, 28 Jan 2004, prakash borade wrote:

> rgb thanks for your support
> 
> well i am trying to wite an client server application 
> ( monitoring sofware ) for my beowulf cluster
> tell me what would be efficient either sockets or RPC

Raw sockets.  Eschew RPC.

You should also just visit

  http://www.phy.duke.edu/~rgb/Beowulf/beowulf.php

or brahma and pull xmlsysd and wulfstat.  It IS client/server monitoring
software, fully GPL, and will build and install and (hopefully) just
plain work for you.

If you are interested in this as a "learning project" and not because
you just need a monitoring package, consider using xmlsysd as a base and
contributing to the project rather than reinventing all the wheels that
it contains.  For example, it already contains forking daemon and xinetd
code (so the daemon part is "done".  It already knows how to open most
of the "interesting" files in /proc, read them and encapsulate their
contents in XML and send them to clients on demand, and even uses tricks
such as rewinding the files instead of closing and reopening them to
minimize the fairly significant overhead associated with opening a file
in the first place.

I think you'll find that xmlsysd is pretty efficiently written and
lightweight and stable and functional and non-leaky and (due to its use
of xml to encapsulate results) scalable and accessible to a variety of
clients.  It is even moderately extensible -- it is fairly easy to add a
new thing to be monitored, once you know the code (not quite "follow the
instructions" easy, though -- at this point I'm probably the only person
who could do it without extensively studying the code).

The thing that really needs to be done is develop more monitoring
(client) tools.  wulfstat isn't bad, really, especially for smallish
clusters, but it would be lovely to have "gwulfstat" (gtk) and
"wwulfstat" (web) monitoring tools.  It would also be lovely to have
some command line tools that could be backgrounded and poll results in a
timed loop and write them out to a named logfile (both as a historical
log trace of node load and to facilitate the creation of tools that
could graph the traces and generate reports).

SO if you are interested at all in helping out and joining the project,
I could certainly use the help.  I have too many projects running all at
the same time to give this one the full attention it deserves.

   rgb

> 
> would open socket on each machine put an extra load
> on the cluster or is it managable
> 
> --- "Robert G. Brown" <rgb at phy.duke.edu> wrote:
> > On Tue, 27 Jan 2004, prakash borade wrote:
> > 
> > > have any body tried RPC programing on Linux 
> > > i get
> > > rpc unknown protocol error 
> > > i am trying to diaply the message on the remote
> > host
> > 
> > To do rpm programming you probably need a bunch of
> > stuff configured and
> > running that might or might not be turned off for
> > security reasons.
> > Check, for example, to see if the portmapper is
> > running.  Also check
> > iptables and/or ipchains to see if they are running
> > and if so if any
> > rules block access to the portmapper.
> > 
> > rpcinfo is also your friend:
> > 
> > rgb at lilith|T:3#rpcinfo -p lilith
> >    program vers proto   port
> >     100000    2   tcp    111  portmapper
> >     100000    2   udp    111  portmapper
> >     100024    1   udp  32768  status
> >     100024    1   tcp  32768  status
> >     391002    2   tcp  32769  sgi_fam
> > 
> > As a general rule, I'd consider the portmapper and
> > rpc stuff to be a
> > moderate security risk; lilith lives inside
> > firewalls only.  I have had
> > direct experience of systems cracked in the past
> > through portmapper
> > bugs, which perhaps makes me a bit paranoid.
> > 
> > What exactly are you trying to do?
> > 
> >    rgb
> > 
> > > 
> > > __________________________________
> > > Do you Yahoo!?
> > > Yahoo! SiteBuilder - Free web site building tool.
> > Try it!
> > > http://webhosting.yahoo.com/ps/sb/
> > > _______________________________________________
> > > Beowulf mailing list, Beowulf at beowulf.org
> > > To change your subscription (digest mode or
> > unsubscribe) visit
> > http://www.beowulf.org/mailman/listinfo/beowulf
> > > 
> > 
> > -- 
> > Robert G. Brown	                      
> > http://www.phy.duke.edu/~rgb/
> > Duke University Dept. of Physics, Box 90305
> > Durham, N.C. 27708-0305
> > Phone: 1-919-660-2567  Fax: 919-660-2525    
> > email:rgb at phy.duke.edu
> > 
> > 
> > 
> > _______________________________________________
> > Beowulf mailing list, Beowulf at beowulf.org
> > To change your subscription (digest mode or
> > unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
> 
> __________________________________
> Do you Yahoo!?
> Yahoo! SiteBuilder - Free web site building tool. Try it!
> http://webhosting.yahoo.com/ps/sb/
> 

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu



_______________________________________________
Beowulf mailing list, Beowulf at beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf



More information about the Beowulf mailing list