add software Architecture chapter for user guide

this is a part of SWA, referenced with Per Holmgren's patch(9815).
Because Brahmaputra 2.0 is coming, Qiliang,Patrick,Mingjiang Lin
will work with me together to finish this chapter before doc freeze.

Change-Id: I1e6abe55658671fb1fcc66f2d81b5c2d0b364822
Signed-off-by: kubi <jean.gaoliang@huawei.com>
(cherry picked from commit bf1746e6432e18f17b6d8e890c72c93cd9ac928c)

3 files changed, 187 insertions, 0 deletions

diff --git a/docs/userguide/01-introduction.rst b/docs/userguide/01-introduction.rst
index 90c112a47..3c6100ae7 100644..100755
--- a/docs/userguide/01-introduction.rst
+++ b/docs/userguide/01-introduction.rst
@@ -41,6 +41,8 @@ This document consists of the following chapters:
 * Chapter :doc:`02-methodology` describes the methodology implemented by the
   Yardstick Project for :term:`NFVI` verification.
 
+* Chapter :doc:`architecture` provides information on the software architecture
+  of yardstick.
 * Chapter :doc:`04-vtc-overview` provides information on the :term:`VTC`.
 
 * Chapter :doc:`apexlake_installation` provides instructions to install the
diff --git a/docs/userguide/architecture.rst b/docs/userguide/architecture.rst
new file mode 100644
index 000000000..ccf8d482c
--- /dev/null
+++ b/docs/userguide/architecture.rst
@@ -0,0 +1,184 @@
+.. 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
+=============
+TBD(kubi)
+
+Logical View
+============
+TBD(Qiliang)
+
+Process View (Test execution flow)
+==================================
+TBD(Limingjiang)
+
+Deployment View
+===============
+TBD(Patrick)
+
+
+
+
+
+
+
+
+
+
+
+
+Yardstick Directory structure
+=============================
+
+**yardstick/** - Yardstick main directory.
+
+*ci/* - Used for continuous integration of Yardstick at different PODs and
+        with support for different installers.
+
+*docs/* - All documentation is stored here, such as configuration guides,
+          user guides and Yardstick descriptions.
+
+*etc/* - Used for test cases requiring specific POD configurations.
+
+*samples/* - test case samples are stored here, most of all scenario and
+             feature's samples are shown in this directory.
+
+*tests/* - Here both Yardstick internal tests (*functional/* and *unit/*) as
+           well as the test cases run to verify the NFVI (*opnfv/*) are stored.
+           Also configurations of what to run daily and weekly at the different
+           PODs is located here.
+
+*tools/* - Currently contains tools to build image for VMs which are deployed
+           by Heat. Currently contains how to build the yardstick-trusty-server
+           image with the different tools that are needed from within the image.
+
+*vTC/* - Contains the files for running the virtual Traffic Classifier tests.
+
+*yardstick/* - Contains the internals of Yardstick: Runners, Scenario, Contexts,
+               CLI parsing, keys, plotting tools, dispatcher and so on.
+
diff --git a/docs/userguide/index.rst b/docs/userguide/index.rst
index 3cad237e2..72a92a69f 100644
--- a/docs/userguide/index.rst
+++ b/docs/userguide/index.rst
@@ -12,6 +12,7 @@ Yardstick Overview
 
    01-introduction
    02-methodology
+   architecture
    04-vtc-overview
    apexlake_installation
    apexlake_api