ISPN-263 Handle cluster partitions

https://issues.jboss.org/browse/ISPN-263

I added one more commit with some test fixes.
The definition of degraded is that we don't have all of the owners.  In the
case where we have 1 or more owners but not all we would be in degraded
mode and so would all the other nodes by definition.  I mentioned if we had
no owners then we would not allow the read.  Our is there some other car
you are thinking of?
On Aug 8, 2014 11:30 AM, "Dan Berindei" <notifications@github.com> wrote:

> In
> documentation/src/main/asciidoc/user_guide/chapter-32-Clustering_modes.adoc:
>
> > +bank account information). On the other hand, if Infinispan is used as an best-effort
> > +cache, e.g. to cache web pages in a proxy, the partitions are perfectly tolerable.
> > +
> > +The following sections describes the way Infinispan handles split brains and
> > +successive failures when partition handling is enabled, followed by a section on
> > +configuring the partition handling functionality.
> > +
> > +==== Split brain
> > +
> > +We assume a partition happens when *numOwners* or more nodes disappear at the
> > +same time. When this happen two (or more) partitions form which are not aware of
> > +each other. Each such partition does not start a rebalance, but enters in degraded mode:
> > +
> > +- request (read and writes) for entries that have all the copies on nodes within
> > +this partition are honoured
> > +- requests for entries that are partially or totally owned by nodes that disappeared
>
> Actually, I think it wouldn't be correct to allow reads, because we have
> no way to know that the other partition is also in degraded mode.
>
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> <https://github.com/infinispan/infinispan/pull/2785/files#r15998933>.
>