[Spread-users] Load balancing with group communication

[Joshua Goodall]

On Wed, Jan 08, 2003 at 06:56:40AM -0800, Van Gale wrote:
> I have an application that I'd like to use Spread for messaging between
> components/objects.  Sometimes the components fit nicely into the Spread
> mold, like logging components or databse replication.  Sometimes though, I
> only want one member of the group to process the message.  In other words,
> more of a message queue model.
> 
> Unfortunately, the most promising looking paper, "S. Dolev, R. Segala, and
> A.A. Shvartsman, Dynamic Load Balancing with Group Communication, Proc. of
> 6th International Colloquium on Structured Information and Communication
> Complexity, 1999", seems to be unavailable online.
[snip]
> Anyone have any pointers or ideas to help me out here?

That paper is cited at least eight times:
http://citeseer.nj.nec.com/context/944702/0

The following general schemes occurred to me whilst flicking through
Tanenbaum's "Distributed Systems":

a) A coordinator-based system; requests are brokered through a lookup service
   (taking the form of a process or processes listening to a lookup group; the
   master lookup service is then the responding broker.  You could elect a master
   by simply choosing the first process in the group membership, which is
   globally the same in a stable view.)

   JavaSpaces as a reference point.

b) An offer-and-reject system; each process monitors a group for
   announcements of jobs-in-progress.  When a new job becomes available, a
   worker is selected from the known set by an appropriate algorithm, and
   the job is offered.  Rejection amounts to a back-off and retry.
   Acceptance results in announcement to the jobs-in-progress group.

c) An announce-and-offer system; new job is multicast to a group and available
   workers present themselves to the announcer.

d) Any dynamic combination of the above :)

e) Any dynamic combination of the above using virtual money to represent
   estimated job value and worker speed.

Joshua.