Re: A proposal for a General Clustering Framework

[David Brower <David.Brower@oracle.com>]

Alan Robertson wrote:

> Unfrotuantely, XMLRPC is not nearly powerful enough.  I need to send
> basically arbitrarily complex data structures back and forth.  It doesn't
> have name/value pairs, or attributes, etc.  So, XML-RPC isn't very
> attractive thing to build on for clusters...

I don't understand this conclusion at all.  You can have pretty
much anything you want as a parameter, and XML is nothing but a big 
list of name value pairs.   The semantics of the parms (nvlist,
attribute,
etc. is up to the callers to agree upon; XML-RPC doesn't have an IDL
that enforces any semantics.    And I don't know what kind of complex
data structure can't be represented.  As with corba, you need to
understand
the abstraction to do linked lists or trees.  Since you can't send
pointers
(which are language dependant in all cases), you need to abstract the 
link references and resconstruct them in the appropriate way on the
receiving end.

Someone else observed that xml-rpc was "an expensive round trip" for
cases where one wished to use broadcast or multicast.   I think the
approach to take is that used by one interpretation of the corba
"oneway":  have the request contain a "no response needed" flag,
so that the receiver doesn't send a message back.

-dB

Linux-cluster: generic cluster infrastructure for Linux
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