[infinispan-dev] ISPN-359 and grouping entries for distribution

[Manik Surtani]

On 13 Apr 2010, at 10:54, Mircea Markus wrote:

>> 
>> since this will *not* work.  The cache still primarily is a collection of K -> V mappings and in the above case the last 2 lines will effectively overwrite the 1st 2 lines.
> "name" will only appear once in the cluster, (on different location though), right?

Yes, and hence the effective "overwriting" of the previous name.

> Generally speaking I'm curious on how this scenario is handled:
> node A: cache.inGroup("a").put("key","something");
> node B: . assertEquals("something" ,cache.get("key")); //this assert is correct

The interceptor would create these mappings on a put:

K -> G
G -> AtomicMap{K -> V}

and for a get:
return get(get(K)).get(K)

so in your example, after the put, you will find:

"key" -> "a"
"a" -> AtomicMap{"key" -> "something"}

Now when you do the get, the interceptor would:

grpId = get("key") 
atomicMap = get(grpId)
return atomicMap.get("key")


"All problems in computer science can be solved by another level of indirection" - David Wheeler

--
Manik Surtani
manik at jboss.org
Lead, Infinispan
Lead, JBoss Cache
http://www.infinispan.org
http://www.jbosscache.org