ketama - a consistent hashing algo for memcache clients
sgrimm at facebook.com
Tue Apr 10 17:00:29 UTC 2007
That was actually the next major thing on our memcached to-do list.
Thanks -- you may have saved us a bit of work there!
Richard Jones wrote:
> Every time we added memcached servers to the pool, the rehashing of all keys
> would kill our database while the cache filled up again. We implemented a
> consistent hashing algorithm that our memcached clients are now using to map
> keys to servers. Now we can add new memcached servers without causing
> chaos :)
> Here is the blurb and the code:
> Source download includes:
> libketama, a c library
> php_ketama, a php extension that uses the library
> a pure java implementation
> I'm interested in other approaches (or even if this is a concern for most
> people?). I read about the lots-of-virtual-buckets concept, but didn't find
> an implementation. Anyone already using consistent hashing for memcache?
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