Hello There,
I've checked your file and desired architecture and I have a couple of questions from you.
1. Why did you choose MySQL master-master over MariaDB Galera?
2. What is your web application type? Is it built on CMS/Framework?
3. Why did you choose Memcached over Redis in application Layer?
4. What is your plan for file changes, are you using distributed file system such GlusterFS, Ceph, etc.. ?
5. What is your main goal to design that type of architecture?
Little about me, I'm Daniel. A DevOps Engineer / Linux SysAdmin with 5 years experience. I'm expert in NGINX and manage LEMP Stacks. I've designed, implement and deploy HA architecture in various levels. (Web Server, Database, DNS, Virtualization, etc..)
I can offer you the best solution for your requirements.
Regards,
Daniel