I have an Wordpress website, which was been set using AWS by a hosting provider. The hosting setup contains 2 EC2 instances, A memcached server, an amazon load balancer and a 2 seperate database servers (One is a master and one is a slave replication, using Hyper DB). The Wordpress site would also connect to a cloudfront CDN. The setup has the ability to autoscale spawning new EC2 servers when the load increases.
Currently I am in the middle of setting up the CDN using W3Total cache. However I have come across an issue where I have saved CDN settings to enable and when I reload the page responsible for enabling the CDN, it shows that the CDN is disabled.
Upon trying to set this a few times, I realised that the whenever I make any change to any W3Total cache setting, such as the CDN, they are only set to the instance that originally saved those settings. It does not propagate over to the other EC2 instances and I would have to repeat the same process to ensure consistency across all instances.
Then I'm also worried what would happen when my setup spawns new EC2 instances, if in this situation then I don't think the settings carry forward.
Can somebody please explain to me whether or not this is completely normal on cloud based setups, such as AWS, or is there really an underlying issue?
Would also it be possible have a situation where if I save my W3Total cache settings, it gets updated on all of my EC2 instances instead of having to change the cache settings one machine at a time?
Any feedback would be greatly appreciated. Thanks.
