Regarding Consistent Hashing....

dormando dormando at
Thu Aug 30 08:48:24 UTC 2007

A couple, I think ;)

Mikael, I think now's as good of a time as ever to decide on the hashing 
standard. Believe brad's asked a few times if anyone has any complaints 
with the Perl version, or any reasons/preferences as to one 
implementation or the other. There's no authority on this other than the 
people who respond here and have compelling arguments :)

I only know of (offhand):

- Yours
- libketama
- Set::ConsistentHash

... maybe Dustin wrote one? Maybe apr_memcache has one? I forget.

All that really matters is that an approach not everyone completely 
absolutely hates is decided on, so this can get into use. Based on MD5? 
Based on CRC32? What works best?


Mikael Johansson wrote:
> Hi,
> I believe there's already people using consistent hashing on large
> installs out there. As to the pecl/memcache client the code is not
> released and still in CVS, but it is stable (and certainly ready to be
> evaluated/tested), also a release is coming up so you can either wait
> for that or build from source like
>  cvs -d :pserver:cvsread at checkout pecl/memcache
>  cd pecl/memcache
>  phpize
>  ./configure
>  make && make install
> Enable it by setting an php.ini entry like
>  memcache.hash_strategy = consistent
> Please note that the consistent hashing implementation might still
> change in the future when a standard is reached on the subject.
> //Mikael
> Ajinkya Nahar wrote:
>> Hi all,
>> I want to know whether consistent hashing technique can be used in
>> production environment.
>> Is it still too young or is it of production quality?
>> Also, what configuration needs to be done in the PHP client when using
>> consistent hashing?
>> Please let me know.
>> Thanks in advance.
>> Regards,
>> Ajinkya

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