.. This work is licensed under a Creative Commons Attribution 4.0 International .. License. .. http://creativecommons.org/licenses/by/4.0 .. (c) 2016 Huawei Technologies Co.,Ltd and others ============ Architecture ============ Abstract ======== This chapter describes the yardstick framework software architecture. we will introduce it from Use-Case View, Logical View, Process View and Deployment View. More technical details will be introduced in this chapter. Overview ======== Architecture overview --------------------- Yardstick is mainly written in Python, and test configurations are made in YAML. Documentation is written in reStructuredText format, i.e. .rst files. Yardstick is inspired by Rally. Yardstick is intended to run on a computer with access and credentials to a cloud. The test case is described in a configuration file given as an argument. How it works: the benchmark task configuration file is parsed and converted into an internal model. The context part of the model is converted into a Heat template and deployed into a stack. Each scenario is run using a runner, either serially or in parallel. Each runner runs in its own subprocess executing commands in a VM using SSH. The output of each scenario is written as json records to a file or influxdb or http server, we use influxdb as the backend, the test result will be shown with grafana. Concept ------- **Benchmark** - assess the relative performance of something **Benchmark** configuration file - describes a single test case in yaml format **Context** - The set of Cloud resources used by a scenario, such as user names, image names, affinity rules and network configurations. A context is converted into a simplified Heat template, which is used to deploy onto the Openstack environment. **Data** - Output produced by running a benchmark, written to a file in json format **Runner** - Logic that determines how a test scenario is run and reported, for example the number of test iterations, input value stepping and test duration. Predefined runner types exist for re-usage, see `Runner types`_. **Scenario** - Type/class of measurement for example Ping, Pktgen, (Iperf, LmBench, ...) **SLA** - Relates to what result boundary a test case must meet to pass. For example a latency limit, amount or ratio of lost packets and so on. Action based on :term:`SLA` can be configured, either just to log (monitor) or to stop further testing (assert). The :term:`SLA` criteria is set in the benchmark configuration file and evaluated by the runner. Runner types ------------ There exists several predefined runner types to choose between when designing a test scenario: **Arithmetic:** Every test run arithmetically steps the specified input value(s) in the test scenario, adding a value to the previous input value. It is also possible to combine several input values for the same test case in different combinations. Snippet of an Arithmetic runner configuration: :: runner: type: Arithmetic iterators: - name: stride start: 64 stop: 128 step: 64 **Duration:** The test runs for a specific period of time before completed. Snippet of a Duration runner configuration: :: runner: type: Duration duration: 30 **Sequence:** The test changes a specified input value to the scenario. The input values to the sequence are specified in a list in the benchmark configuration file. Snippet of a Sequence runner configuration: :: runner: type: Sequence scenario_option_name: packetsize sequence: - 100 - 200 - 250 **Iteration:** Tests are run a specified number of times before completed. Snippet of an Iteration runner configuration: :: runner: type: Iteration iterations: 2 Use-Case View ============= Yardstick Use-Case View shows two kinds of users. One is the Tester who will do testing in cloud, the other is the User who is more concerned with test result and result analyses. For testers, they will run a single test case or test case suite to verify infrastructure compliance or bencnmark their own infrastructure performance. Test result will be stored by dispatcher module, three kinds of store method (file, influxdb and http) can be configured. The detail information of scenarios and runners can be queried with CLI by testers. For users, they would check test result with four ways. If dispatcher module is configured as file(default), there are two wa