[infinispan-dev] KeyAffinityService

[cotton-ben]

To be honest, Dan, your last post leaves me slightly concerned.

/
> Just to be clear, KAS doesn't really allow you to pin a key to a certain
> node. It only gives you a key that maps to the given node the moment you
> called KAS.getKeyForAddress(Address) - by the time you call  cache.put()
> with the "pinned" key, it may have already moved to a different node.

> Would that be enough for you?/

No.  that would be no good.

/> But it has been my impression that you want something that would keep the
key pinned to the same node as long as that node was alive. If that's the
case, then implementing it would require significant additional work./

Yes.  that is what I want.

/> I'm just wondering, wouldn't it be simpler if you created a custom
ConsistentHashFactory to map keys to nodes using the same mechanism you
already have? Not as easy as the API you proposed, but it wouldn't require a
separate cache either.../

I have no basis for commenting on this competently.  I am just not familiar
with ConsistentHashFactory, etc.  I do know the API I propose would be easy
for me.  But that is irrelevant if it is not doable.

/> With this solution, "pinned" keys could also move from the initial target
node to another node as the cache topology changes (and not all keys will
move to the same node).
/

Well, I guess I don't care if they move from pinnedNodeX to pinnedNodeY as
long as you gave me a reliable API that empowers me to answer for myself
"Where dey at?".  i.e. as long as this requested API works the way I want it
to work

*K getKeyForAddress(Address pinnedNodeAddress, K objectNaturalKey);
*

/> My main concern is that you actually want something more than the
KeyAffinityService is able to give you ATM - even if we did add the
"niceness" in the API, the keys still won't be pinned to a certain node for
as long as that node is alive./

Ok.  Greatly appreciate the candor of this comment.  Just sharing with you
my hopes for what I would like to see in an ideal API (if delivery of that
API is in fact possible).

BTW, how cool is it that a little ole ISPN user like me can come here and
get this kind of interactive dialog and support?  SUPERB!   And appreciated. 
:-)  Thanks.





--
View this message in context: http://infinispan-developer-list.980875.n3.nabble.com/KeyAffinityService-nice-2-recommendations-tp4027152p4027411.html
Sent from the Infinispan Developer List mailing list archive at Nabble.com.