Regarding Consistent Hashing....

Dustin Sallings dustin at
Thu Aug 30 20:10:16 UTC 2007

On Aug 30, 2007, at 12:53 , Tobias Lütke wrote:

> I think standards are best when there is only one of them. Lets not
> add choices to the mix. We should find out what is the "less bad" of
> the two options or eliminate one at random with all things being
> equal. I'm certain that 99% of the memcached user base is not partial
> to either crc or fnv and the implementors probably appreciate crc
> because of the general availability of the algorithm ( there is a very
> fast implementation in zlib which is bundled and exposed in almost
> every scripting language ).

	My last job was in telecom, so I think ``standard'' is an antonym  
for ``innovation.''

	Choice can be confusing, but performance is often more valuable than  
interoperability here.  If you're in a java-only shop, java's native  
hash is going to be faster than anything else.  Strings are immutable  
and the hash is memoized.  If you have to interoperate, you can start  
making choices.

	It's way too early to be talking about standardization, anyway.   
There haven't been enough studies on the performance and  
appropriateness of different hash algorithms.  When people are  
interested in things, the last thing you want to do is standardize  
them.  They'll become standardized on their own once people are no  
longer interested.

Dustin Sallings

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