Re: [infinispan-dev] Hash calculation in DefaultConsistentHash

From: Manik Surtani <manik(a)jboss.org&gt; Subject: Re: [infinispan-dev] Hash calculation in DefaultConsistentHash To: "infinispan -Dev List" <infinispan-dev(a)lists.jboss.org&gt; Date: Thursday, October 1, 2009, 12:15 PM On 1 Oct 2009, at 17:55, Alex Kluge wrote: > Hi, > >  Thanks for the comments. > >  On item 1: >   I chose the way we use the hashing to fit in with the > current Dell-MessageOne use cases. It is an easy change to use > a different hash in the locate method , you just want to be careful > about getting uniform distributions of values, as this determines the > distribution of key/value pairs among the caches. So you exchange > one requirement for another. I could even implement a strategy pattern > here to make it very adaptable. > >  For generating the original bins in the constructor, however, it is > important to use a representation that is malliable, like a string, to > generate the virtual nodes. For the server class you also have  > complete > control so it is a reasonable restriction. Yes, this is fine for the Address type.  Just that we can't depend on  meaningful toString() impls on keys.  The only thing we can really  rely on (which we can reasonably expect users to implement) is hashcode ().  So what would be ideal is to take the hashcode() generated by the  user's algo, and use a bit spreader to ensure it is properly  distributed.  A bit like the way JDKs do with HashMap, etc.  I'm open  to suggestions as to the bit spreader algo to use. Cheers -- Manik Surtani manik(a)jboss.org Lead, Infinispan Lead, JBoss Cache http://www.infinispan.org http://www.jbosscache.org _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev