[jbosscache-dev] BuddyPool "exclusive"

[Brian Stansberry]

Was just editing some docs and realized our standard example use case
for buddy pools is bogus. ;)

The example is to use buddyPoolName to group servers so that a server
only chooses as a buddy a server on a separate rack with separate power
supply etc.

If you think about it, this only makes sense if each buddy pool only has
2 servers, one on each rack.  As soon as you have 3 servers in a pool,
the odds are only 50% that a server will pick one from the other rack as
its buddy.

Some kind of "exclusive" flag could help here -- i.e., pick my buddy
from among those where "this.buddyPoolName.equals(other.buddyPoolName)
== false".  So then those on rack #1 have buddyPoolName "rack1" and
those on rack #2 have buddyPoolName "rack2" and all buddies are on the
other rack.

Brian Stansberry
Lead, AS Clustering
JBoss, a division of Red Hat
Ph: 510-396-3864
skype: bstansberry