Building blocks for highly available systems
Thanks to the cloud, highly available systems are becoming the new standard. Creating an architecture offering high availability or even fault tolerance is affordable nowadays as you can use ready-to-use building blocks. On top of that, you can operate a highly available infrastructure in the cloud with almost no extra costs.
AWS offers managed services with built-in high availability or even fault tolerance:
- Load Balancer (ELB) is fault tolerant
- SQL database (RDS) is highly available on demand
- No-SQL database (DynamoDB) is fault tolerant
- Object Store (S3) is fault tolerant
The virtual server (EC2) itself is not high available or fault tolerant as the underlying virtualization or hardware might fail. But tools are helping you to build a high available infrastructure based on virtual servers.
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Subscribe now!Building blocks for high availability
The following figure shows a typical architecture for web applications offering high availability. The building blocks are:
- Load Balancer (ELB) fault tolerant by default routing requests to healthy virtual servers.
- Running virtual servers in different data centers (Availability Zone) in the same region.
- Running an SQL database which replicates all data from the master database to a standby database in another data center (Multi-AZ deployment).
All parts of this architecture are highly available. There is no single-point-of-failure left.
Andreas Wittig
I'm an independent consultant, technical writer, and programming founder. All these activities have to do with AWS. I'm writing this blog and all other projects together with my brother Michael.
In 2009, we joined the same company as software developers. Three years later, we were looking for a way to deploy our software—an online banking platform—in an agile way. We got excited about the possibilities in the cloud and the DevOps movement. It’s no wonder we ended up migrating the whole infrastructure of Tullius Walden Bank to AWS. This was a first in the finance industry, at least in Germany! Since 2015, we have accelerated the cloud journeys of startups, mid-sized companies, and enterprises. We have penned books like Amazon Web Services in Action and Rapid Docker on AWS, we regularly update our blog, and we are contributing to the Open Source community. Besides running a 2-headed consultancy, we are entrepreneurs building Software-as-a-Service products.
We are available for projects.
You can contact me via Email, Twitter, and LinkedIn.
