[infinispan-dev] Proposal: ISPN-1394 Manual rehashing in 5.2

[Mircea Markus]

> numOwners==2 is and will very likely remain the most common case,
> particularly for small clusters.
> 
> But if we have two sites, it makes sense to configure 2 owners per
> site. If only one node goes down, the surviving owner will supply
> state to the new owner. If both nodes go down, the new owners will
> fetch the data from the other site. So while 2 nodes going down will
> be quite costly, it should be infrequent enough that it's worth
> optimizing for the more frequent "1 node goes down and than comes
> back
> up" case.
> 
Agreed; this mixed batching (leaves with joins) makes sense for non-site clusters as well. 

> > For total shutdown, I guess we can use other means that rehash,
> > e.g. a specific command that would disable it and start flushing
> > to the store.
> >
> 
> I think just stopping the cache is enough to get it to flush data to
> the store with passivation enabled.
ATM, wouldn't the shutdown of a cluster of servers trigger a rehash storm?

> But for now any data saved to a
> private store in distributed mode is useless after restart, because
> we
> have no safe way to push data that we don't own to other nodes (and
> by
> safe I mean avoiding overwriting newer data or resurrecting deleted
> data).
I think that should work with a clustered cache store though.