IP Upstream Hash
chateau.xiao at gmail.com
Thu Jul 21 03:11:59 UTC 2011
fist of all, 89, 113 and 6271 are all primes.
prime has a very import feature when we use to judge whether the bucket is
right place for the data to store.It simple made a hash more efficient and
the princple of "why prime" can be dicussed more detial in the URL below
On Thu, Jul 21, 2011 at 5:18 AM, Matthieu Tourne
<matthieu.tourne at gmail.com>wrote:
> Hi all,
> I was looking at the code in ngx_http_upstream_ip_hash_module.c
> And I'm not sure where the hashing algorithm for IPs is coming from,
> especially those lines :
> iphp->hash = 89;
> hash = (hash * 113 + iphp->addr[i]) % 6271;
> Just wondering if those constants are arbitrary chosen, or if there is
> something there to guarantee a good distribution ?
> If you have some links explaining this algorithm, it would be greatly
> Also, how would you get a good distribution on IPv6. Maybe it would make
> sense to use murmur ?
> Thank you,
> nginx-devel mailing list
> nginx-devel at nginx.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the nginx-devel