Information may be disseminated unsolicited, or it may be requested. It may be
stored in a central broker or trader which acts as a go-between to place
processes based on load information, or else it may be fully distributed.
There are two basic protocol approaches to distributing this information:
-
Broadcast/Multicast from each server to all others
-
Requested from each server by client.
The former approach is used for fault tolerance fully distributed (client
driven) load balancing systems. The latter might be coupled with the
nameservice or trading service to provide unified location and load
information.
Periodic broadcasts are a powerful way of disseminating any information, but
one must be aware of the danger of systems becoming synchronised and causing a
;SPM_quot;spike;SPM_quot; of traffic (this tendency must be counteracted by specific randomising
of the broadcasts over the interval). It can also be coupled with solicited
information, as the Address Resolution Protocol, where the solicitor broadcasts
a request for information, but also includes their own statistics in the
request so that everyone else is informed for free.