Re: A proposal for a General Clustering Framework

["Jeff Darcy" <linuxguy@tambreet.com>]

From: "Greg Lindahl" <lindahl@conservativecomputer.com>
> I suspect most people here are using the non-RPC form of RPC, which
> would explain why they went "Huh?" to your note. And that's why
> there's more heat than light happening.

You're probably right about that part.  Some people seem to be using RPC -
"Remote Procedure Call" - in reference to separable representation issues,
or "Remote Coroutine" paradigms, or even to plain old vanilla messaging.

> > Every protocol that one might use -
> > e.g. for membership or consensus - has a very particular set of
requirements
> > regarding message reliability, ordering, etc.
>
> That's correct. And if you make these requirements explicit and
> available to the lower layers, they can provide appropriate
> services.

I sort of agree, but also sort of not.  Communications protocols are rarely
so modular that you can turn every individual feature on and off with a
switch.  That being the case, sometimes there's a mismatch that is only
highlighted but not solved by making the higher-level protocol's needs
explicit.

> Perhaps a better example is an application which does
> not require ordered delivery using a protocol which only provides
> ordered delivery.

Perhaps that is a better example.  It's certainly a common one, and sort of
what I was getting at when I mentioned lower-level protocols forcing
higher-level ones into less efficient modes or subsets.




Linux-cluster: generic cluster infrastructure for Linux
Archive:       http://mail.nl.linux.org/linux-cluster/