PERF 4. How do you ensure that the quantity of your instances matches demand?
The amount of demand placed on a system often varies over different cycles: product lifecycle, such as launch or growth; temporal cycles such a time of day, day of the week, or month; unpredictable cycles such as social media visibility; and predictable cycles such as television episodes. Insufficient instances to meet your workload can degrade user experience and, at worst, lead to system failure.
Best practices:
 Planned Plan based upon metrics and/or planned events.
 Automated - Scripted Use tools for automatic management.
 Automated - Auto Scaling Use Auto Scaling for automatic management.