How to setup a load balancing and failover back-end RDS for WordPress ?

WordPress is widely used to develop webs for multiple platforms. 
It is necessary to set up WordPress to deploy on a load balancing and failover backend RDS if you want to provide a service without any downtime for your customers.

How to get this  done ?

1. Create a Master and Slave database on RDS.

2.Import HyperDB Plugin into WordPress folder.

HyperDB can be download at below.
https://wordpress.org/plugins/hyperdb/


3. Setup the Master and Salve URL at HyperDB`s config file.


4. Performance Test 

The following info shows the test result on AWS.

EC2         Current session                RDS                                           

t2.micro            110 / s                     single master        

t2.medium         210 /s                       one master and one slave    


To conclude, using WordPress framework to develop the website can achieve a high performance at 210 current requests per second on EC2 with t2.medium spec; with t2.micro of EC2, the best throughput can also achieve 110 current requests per second. Thus, I think WordPress is good enough to build a high-performance website by PHP on AWS.