Using multi scenarios to generate load

Use Case

Rally should be able to generate real life load. Simultaneously create load on different components of OpenStack, e.g. simultaneously booting VM, uploading image and listing users.

Problem Description

At the moment Rally is able to run only 1 scenario per subtask. Scenario are quite specific (e.g. boot and delete VM for example) and can't actually generate real life load.

Writing a lot of specific subtask scenarios that produces more real life load will produce mess and a lot of duplication of code.

Possible solution

• Extend Rally subtask configuration in such way to support passing multiple scenarios in single subtask context
• Extend Rally task output format to support results of multiple scenarios in single subtask separately.
• Extend rally task plot2html and rally task detailed to show results separately for every scenario.