Nov 1, 2018

High Availability vs Scalability

Highly Available (by having multiple servers nodes to fail over to), does not mean scalable as well. Highly Available just means that, if the current processing node crashes, the request would be passed on or failed over to a different node in the cluster so that it can continue from where it started – that’s pretty much it!

Scalability is the ability to improve specific characteristics of the system (e.g. number of users, throughput, performance) by increasing the available resources (RAM, processor etc.) Even if the failed request is passed on to another node, you cannot guarantee that the application will behave correctly in that scenario