从多节点memcached群集AWS获取不一致的数据

Question

I am using Moodle 2.7.2 for our application on load balanced environment. I am using AWS elastic cache memcached cluster with multiple node.

Whenever i am doing any confrontational changes or database update, on front-end some times new changes reflects but some time old data are displayed.

I researched about this issue and found that i should set

memcached.sess_consistent_hash=On

I changes this and restarted the server but still i am getting inconsistent data.

Answer 1

I guess the problem you have to solve is the cache and permanent storage updates when you have dirty data.

The consistenthash parameter is for how the data should be distributed in cluster.

For your problem, there are various strategies for this like write-back, write-through, write-around. Typically if consistency and durability are important, one will choose write-through. Also, for lots of read and less write operations - write-through is a good fit.

Hope it helps!