Re: [infinispan-dev] KeyAffinityService, GroupingConsistentHash et. al. Infinispan tactical APIs

Hi Infinispan-DEV team, Could anyone provide pointers to Infinispan API sample code that could assist us w/ our ambition to start building the attached distributed grid use-case? Any wiki "how-to" (or full code samples) would be especially helpful. Specifically, how to use KeyAffinityService, GroupingConsistentHash, JGroupsTopologyAwareAddress, etc.

would be ideal. Thanks,Ben / by Ben.Cotton(a)jpmorgan.com May 8, 2013 9:45 AM Ambition = on an Infinispan 5.3 grid of 4 nodes (4 x JVM, all nodes have same IP address, each node has a different socket port) I. distribute/partition a <K,V> set (call it set-A) uniformly across the grid and

II. pin a separate <K,V> set (call it set-B) at exactly 1 node on the grid.

How do I best do this in 5.3? Questions: JGroupsTopologyAwareAddress - is it configurable to include at least "ip_address+port"? what is the physical anatomy of a jGroupsTopologyAwareAddress?

GroupingConsistentHash - this looks like a good starting basis for achieving our ambition. Are there code samples that demonstrate how to use this?

KeyAffinityService - is this API intended to insulate the User from having to worry about JGroups specific details? i.e If I use the KeyAffinityService, can I get away without having to know how to code via JGroupsTopologyAwareAddress a/o GroupingConsistentHash?

Once we get our ambition realized in a running Infinispan 5.3 grid instance of 4 nodes: Assume that node #1 has set-B pinned to it (exclusively). Is there any way that nodes #2,#3,#4 can then operate on set-B *by reference* (sort of like RMI operations over a network-stub to the operand implementation), or is it necessary that nodes #2,#3,#4 must consume *by value* a copy of set-B into its' JVM address space before they can operate on set-B?

Thanks for any helpful insights, tactics and code samples. Thanks, Ben / *by Bela Ban on May 8, 2013 12:07 PM I'll try to address this in generic terms, for details (e.g. which classes to use etc) contact the Infinispan team. To distribute set A (more or less) evenly across a cluster, use mode=DIST. To ping set B to a single node, also use DIST, but set numOwners=1 and plug in your own consistent hashing function which pins all keys to a given node. E.g. if you have view {M,N,O,P}, the consistent hash could pin all keys to the first member of the list, M. This works because every member in a cluster has the same view (unless there's a split). However, this *will* lead to uneven distribution, so if set B is large, node M will bear more of the work than other nodes. Also, numOwners=1 is usually only advisable if you can fetch the data from somewhere, e.g. a DB, and use the cluster only as a front-end cache to a DB, for example. You could fix this by setting numOwners=2, and coming up with a consistent hash function which always pins the first of the 2 return values, e.g. [M->N], [M->O], [M->P], [M->N] etc. Once key set B is pinned to M, all access (using DIST) on other nodes will be routed to M. Note that you *could* use an L1 cache, which caches locally, but you stated you don't want to do that.* -- View this message in context: http://infinispan-developer-list.980875.n3.nabble.com/KeyAffinityService-... Sent from the Infinispan Developer List mailing list archive at Nabble.com. _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev