From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: a last comment on xml-rpc Date: Fri, 10 Feb 2006 17:38:31 -0600 Message-ID: <43ED23F7.7040300@us.ibm.com> References: <43ED1615.7030209@lanl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <43ED1615.7030209@lanl.gov> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ronald G Minnich Cc: Matt Sottile , xen-devel List-Id: xen-devel@lists.xenproject.org Ronald G Minnich wrote: > I think Xen made the right decision, in the beginning, to use s-exprs. > We have heard from any number of places that learned the hard way that > XML is a really poor foundation for RPC. > > I hope you will reconsider going to XML-RPC. I don't think the > existence of python support is sufficient. The whole point of RPC, in > fact, is to let any client talk to any server, without regard to > language or environment. We know in practice that trivial C programs > can use s-expression based RPC; we've seen how awful the XML parsers > in C can be; do you really want to lock C out of this picture? I don't think that's fair at all. I've written the C code to interface with Xend using S-Expression/HTTP and it's painful (see libvirt). I've also written an XML-RPC interface to Xend in C using libxml2. It very little code and just works. Granted, parsing XML is more painful that parsing S-Expressions but there are so many libraries for so many languages that XML parsing is really a nop. I don't see any point in rolling out our own RPC mechanism when a standard one exists that is well supported in most languages. There is also a C library that provides support for XML-RPC (libxmlrpc_c) so interfacing with Xend using C would require no additional code on the client side. All the major high level languages I know of have XML-RPC support as part of the standard library. We're talking about a pretty significant reduction in code in Xend too by moving to XML-RPC. If Python supported a different RPC mechanism I would support moving to that simply to reduce the complexity of Xend. Regards, Anthony Liguori > thanks > > ron > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >