What to think when you want scale
- how to syncro the wp-content directory in s3 for use cloudfront
- syncro/update plugins , this change the php code that needs to be shared.
- sessions sharing or not
Very interesting article about scaling http://www.markomedia.com.au/scaling-wordpress-in-amazon-cloud/
Plugin for S3
https://wordpress.org/plugins/amazon-s3-and-cloudfront/installation/
Sessions
As is written in this article https://wordpress.org/support/topic/how-does-wordpress-handle-sessions-and-session-variables the core of wordpress don't use sessions but some plugins, e.g. wp-ecommerce, use it.
This article in the section "PHP Sessions" explain how to change the default path and share this in an nfs area.
A solution with GlusterFS and CloudFront
The article is interesting http://blog.celingest.com/en/2013/09/10/highly-available-wordpress-1/ explain some solutions with pro/contro propose at the end this solution with GlusterFS
OPSWorks
https://www.edge-cloud.net/2014/02/deploy-wordpress-aws-opsworks/ how to deploy a SINGLE instance in ops works with the recipe to give to chef .
To works you need also to personalize the chef recipe with the info of the db at least
the receipe to do this is here http://dev.mikamai.com/post/89353822489/wordpress-and-opsworks-pride-and-prejudice
Git to keep the status of the code with ElastickBeanstalk
in this article https://www.otreva.com/blog/deploying-wordpress-amazon-web-services-aws-ec2-rds-via-elasticbeanstalk/ there is an explanation how to create wordpress inside beanstalk and how to commit into git.
They propose every time the php code change to update the instance.