Re: available resource declaration language(s)

[Greg Lindahl <lindahl@conservativecomputer.com>]

On Fri, Mar 16, 2001 at 07:06:43PM -0600, David L. Nicol wrote:

> Could the way the clustered machines find out about each other be
> standardized?

I doubt it; existing protocols are quite diverse and attempts to
standardize it have not succeeded.

Legion, for example, has objects called "collections", which keep a
database of resource availability for a set of machines, updated by
both push and pull protocols. A machine may be in more than one
collection, and you can have meta-collections. This provides a very
flexible ability to create personalized collections for the hosts
you're allowed to use, etc etc.

Globus stores resource availability info in one or more LDAP
databases. I don't know if it's updated by push or pull.

In the clusters I build, resource availability is maintained by the
queue system (PBS), which periodically pulls the info from the
nodes. That's the traditional way to do it.

> Has anyone done any serious simulations of the efficiency of various
> discovery methods? For instance, it is easy to imagine a virtual
> ring architecture in which each node shares everything it knows
> about all other nodes in a larger packet which is sent around the
> ring

I suspect that other issues like reliability play a more important
role than efficiency.

> Thoughts?  Pointers to masters' theses?

I believe that both Legion and Globus have published papers about
their resource discovery and scheduling algorithms.

-- greg


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