I'm assuming, since memcached has server tables? Then the issue of synchronization with memcached, all the databases at sites 2,3,4 will sync?
No. Memcached is not a replicated cache. It is a distributed cache. There is no syncing.
The reason why I ask this, and I guess its maybe another question? Is that if a client goes to the load balancer, and the load balancer sends him to Site #2 the first connection, then after a few minutes, the client goes to Site #3 (because site #2 has high processes), the user will be able to access the same data? The concern is, if a user writes data to the database in Site #2, he won't be able to access the data again, if the load balancer redirects him to Site #3.
That is an issue that is outside of memcached IMO. memcached should only be used to speed up database operations. If a user makes a change in site #2, it is up to your backends to sync that data to the other locations. Memcached is a dumb, fast cache.
Also, I suspect the php session gets lost because of the load balancer, which is why we install msession??
Again, that is application logic and not related to memcached except that memcached is a storage area for that data.
-- Brian Moon Senior Developer ------------------------------ http://dealnews.com/ It's good to be cheap =)
