Elastic-Load-Balancer

Reading AWS’s recent announcement of the AWS Marketplace you would think that it provides a catalog of click-to-deploy, highly-available, scalable applications running on EC2. You’d be partially right: the applications available in the AWS Marketplace are deployable in only a few clicks. But highly-available and scalable services will be difficult to build using Marketplace images. Here’s why. Essential Ingredients of HA and Scalability on AWS AWS makes it easy to run scalable, HA applications via several features. Not all applications use all of these features, but it would be very difficult to provide scalable and highly available service without using at least one of these: ...

At long last, the most oft-requested feature for EC2’s Elastic Load Balancer is here: session affinity, also known as “sticky sessions”. What is session affinity? Why is this feature in such high demand? How can it be used with existing applications? Let’s take a look at these questions. But first, let’s explore what a session is - then we’ll cover why we want it to be sticky, and what ELB’s sticky session limitations are. [To skip directly to an explanation of how to use ELB sticky sessions, go toward the bottom of the article.] ...