UpstreamConsistentHash, is it wrong?

[Markus Jelsma]

Hi,


I have a cluster with four memcache daemons and am using the current 
UpstreamConsistentHash [1] module with the latest 0.7 stable Nginx to balance 
between the nodes. Thanks to Valery's update on the eval module, i can now 
access two values in my location block. This works fine, hashing is consistent 
indeed but is not compatible with the current PHP (3.0.1-1) nor the current 
Python (1.40). 

I have set up two small PHP and Python scripts that both have the same pool 
definition as Nginx configuration has and both seem to want to store my two 
pieces test data in the first node. The Nginx module, however, believes the 
data should reside in the first and third node.

The order of memcache nodes is the same for both the scripts and the 
configuration, so at least that mistake is not the case. Also, searching in 
the ML archive wasn't quite helpful either. In one topic [2] the issue was 
solved by using this module, it seems it doesn't work for me that way.

Obviously i have no idea what's going and would like some advice on how to 
procede in fixing this issue.

Thanks in advance, any help is appreciated!


[1]: http://wiki.nginx.org/NginxHttpUpstreamConsistentHash
[2]: http://n2.nabble.com/Memcached-modules-behaviour-td3974859.html

Cheers,


Markus Jelsma - Technisch Architect - Buyways BV
http://www.linkedin.com/in/markus17
050-8536620 / 06-50258350