Re: XML support of strange languages

[Alan Robertson <alanr@unix.sh>]

Charly Jones wrote:
> 
> I am interested in the XML aspect of the Cluster Framework.
> I haven't yet studied XML, but I am going to.  Between now and
> when I finally do that, maybe someone would be kind enough to
> answer a few questions...

As best I can ;-)
 
> Is there a good open source version of an XML parser?


There are apparently several, but only two that I know of which are native
'C':
	libXML from the Gnome project - about 3 times the size of the current
			heartbeat cluster system
	expat - only about twice the size of the current heartbeat code

So, both are way too large to be locked into memory.  We have a prototype
XML parser which is 5% the size of libXML.  It looks pretty reasonable.

> Does XML support unicode?

Yes.  I don't plan on supporting any Unicode encoding except for UTF-8,
because it's so 'C' friendly, and much easier to program.

> Do you think the Cluster Framework should support configuration
> in a language other than English?

Without a doubt.

> If yes, and if we had a
> cluster with a node with a primary language of French, would
> you think it is reasonable to have another node in the same
> cluster that has a primary language of English?  If yes,
> would you think the entire cluster would have to be configured
> in one language, or would it be possible to configure one node
> in French and the other in English?

I have a different paradigm...

All cluster members are configured the the same (as nearly to identically as
possible).

Configuration does not necessarily take place on one of the cluster nodes. 
It probably takes place from a client which is not a member of the cluster. 
Otherwise remote administration can be difficult.  For example, it could be
done by Java programs/applets (like FailSafe).

Any given cluster configuration client program is configured in some
national language.  For example, if I'm running a configuration client on a
Java client on a desktop that's configured in French, then the APIs need to
support passing that config information (language = French) to the back end,
and acting on it.

If someone else is connected from a different client to the same node in the
same cluster, they could get a different set of messages.  This is
necessary, and should be controlled by the environment the
configuration/status client in - not the node in the cluster that's
servicing the request.

> Let me know if I am smoking bad dope...

I don't think so. ;-)

On a related subject:
I don't imagine that many (if any) messages between cluster nodes (over
cluster transport) will be sensitive to national language.  That is, they
wouldn't often contain such messages.  Those would occur most often between
a configuration client and the cluster.  I don't envision such communication
to occur over cluster message transport communication paths.

	-- Alan Robertson
	   alanr@unix.sh

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