Rally is intended to provide the community with a benchmarking tool that is capable of performing **specific**, **complicated** and **reproducible** test cases on **real deployment** scenarios.
If you are here, you are probably familiar with OpenStack and you also know that it's a really huge ecosystem of cooperative services. When something fails, performs slowly or doesn't scale, it's really hard to answer different questions on "what", "why" and "where" has happened. Another reason why you could be here is that you would like to build an OpenStack CI/CD system that will allow you to improve SLA, performance and stability of OpenStack continuously.
The OpenStack QA team mostly works on CI/CD that ensures that new patches don't break some specific single node installation of OpenStack. On the other hand it's clear that such CI/CD is only an indication and does not cover all cases (e.g. if a cloud works well on a single node installation it doesn't mean that it will continue to do so on a 1k servers installation under high load as well). Rally aims to fix this and help us to answer the question "How does OpenStack work at scale?". To make it possible, we are going to automate and unify all steps that are required for benchmarking OpenStack at scale: multi-node OS deployment, verification, benchmarking & profiling.
`Rally documentation on ReadTheDocs <https://rally.readthedocs.org/en/latest/>`_ is a perfect place to start learning about Rally. It provides you with an **easy** and **illustrative** guidance through this benchmarking tool. For example, check out the `Rally step-by-step tutorial <https://rally.readthedocs.io/en/latest/quick_start/tutorial.html>`_ that explains, in a series of lessons, how to explore the power of Rally in benchmarking your OpenStack clouds.
3.**Verification** - component that runs tempest (or another specific set of tests) against a deployed cloud, collects results & presents them in human readable form.
