Imagine you need to formulate a performance SLA for a new high-load system. It's not an easy task, bluntly speaking, especially for professionals who have never faced such a task before.
In this talk, I will try to show you how to approach the task step by step and make sure you don't get the wrong answer.
The talk will be useful for analysts and architects when writing SLA/NFR for systems.
- We will consider basic statistical metrics that are commonly used to describe this class of problems: min/max, average, median, percentile. We will try to find out the advantages and disadvantages of different approaches and when it is better to use them. In particular, we will analyze why intuitive averages can be misleading and percentiles should be used with caution.
- We will draw analogies in risk management and IT.
- We will discuss how and from where to derive approximate values for metrics. And with whom it is better to cooperate when writing SLAs.