A couple of months back a customer asked why we are proposing a three Availability Zone (AZ in short) architecture instead of two. Their main point was which failure modes 3 AZs guard against that 2 AZs can’t do. We gave the following two reasons:
- We proposed 3 AZs for improved availability. Also, since services and instances will be deployed across 3 AZs then if one AZ goes down then with 3 AZs you lose 1/3 capacity. With two AZs you can lose half the capacity.
- If there are services(like you want run your own Cassandra or something) where we need to manage quorum it is better to have three
They were not very convinced so we agreed to start with the two AZs solution.
Continue reading “Why an architecture with three Availability Zones is better than the one with two Availability Zones?”
Yesterday, I released hands-on guide to building Serverless applications using AWS Lambda and Serverless framework. The guide is open-source and available on Github. Checkout the guide and please give feedback.
Serverless is an overloaded word. Serverless means different things depending on the context. It could mean using third party managed services like Firebase, or it could mean an event driven architecture style or it could mean next generation compute service offered by cloud providers or it could mean a framework to build Serverless applications. This series will start with an introduction to Serverless compute and architecture. Once we learned the basics, we will start developing application in a step by manner.
Read more https://github.com/shekhargulati/hands-on-serverless-guide.