-Use Cases and Scenarios
------------------------
+=========
+Use Cases
+=========
-This section describes the use cases and scenarios to verify the
-requirements of Escalator.
+This section describes the use cases in different system configuration
+to verify the requirements of Escalator.
-Scenarios
-~~~~~~~~~
-1. Upgrade a system with HA configuration
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+System Configurations
+=====================
+
+HA configuration
+^^^^^^^^^^^^^^^^
A HA configuration system is very popular in the operator's data centre.
It is a typical product environment. It is always running 7\*24 with VNFs
running on it to provide services to the end users.
-2. Upgrade a system with non-HA configuration
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Non-HA configuration
+^^^^^^^^^^^^^^^^^^^^
A non-HA configuration system is normally deployed for experimental or
development usages, such as a Vagrant/VM environment.
-Escalator supports the upgrade in this scenario, but it does not guarantee a
-smooth upgrade.
+Escalator supports the upgrade system in this configuration, but it may
+not guarantee a smooth upgrade.
Use cases
-~~~~~~~~~
+=========
+
Use case #1: Smooth upgrade in a HA configuration
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
For a system with HA configuration, the operator can use Escalator to
- Post-Conditions
1. The system is rolled-back successfully when the upgrade failed.
-