Episode 79 - Availability vs Scalability

This is the final episode of 2018. We will discuss the difference between Availability vs Scalability in software services.
Availability

What does it mean for my software to be available? 
software, service, application is designed in way so it can be available to consumers despite situation 
Will your service be available if

Host Failure
Maintenance 
Upgrading
Security updates


Available doesn’t necessarily mean performant.

Scalability

What does it mean for my software to be scalable? 
The ability for the software to handle the increase of workload or data growth
Assume photo sharing app, retrieving 1 photo with details. If in normal conditions you service can serve 100 requests per minute, will doubling resources double the output?u
If the volume of data increases will your query still perform?
A software is scalable when it is designed in a way so that adding more resources will handle more users