2.4. Running the test

2.4.1. Overview

A default test will be run automatically when you launch the testing. The details and definition of that test are defined in file TST009_Throughput_64B_64F.test.

We will discuss the sections of such a test file and how this can be changed to accomodate the testing you want to execute. This will be done by creating your own test file and making sure it becomes part of your testcases.yaml, as will be shown below.

As the name of the default test file suggests, the test will find the throughput, latency and packet loss according to NFV-TST009, for packets that are 64 bytes long and for 64 different flows.

2.4.2. Test File Description

The test file has multiple sections. The first section is a generic section called TestParameters. Then there are 1 or more sections desribing the test machines we will be using in the test. The sections are named TestMx, where x is a number (starting with 1). The tests to be executed are described in a section called testy, where y is the number of the test to be executed, starting with 1. In this automated testing driven by Xtesting, we will typically only run 1 test. TestParameters

In this section, the name of the test is specified. This is only used in the reporting and has no influence on the actual testing.

name = Rapid_ETSINFV_TST009

The number of test that will be executed by this run and that will be described in the [testy] sections, is defined by the number_of_tests parameter. In the Xtesting framework that we are using here, this will typically be set to 1.

number_of_tests = 1

The total number of machines to be used in this testing will be defined by the parameter total_number_of_test_machines. The function that these machines have in this test will be described in the [TestMx] section. Typically, this number will be set to 2, but many more machines can particiapte in a test.

total_number_of_test_machines = 2

lat_percentile is a variable that is setting which percentile to use during the course of this test. This will be used to report the percentile round trip latency and is a better measurement for the high latencies during this test than the maximum latency which will also be reported. Note that we also report the total round trip latency histogram.

lat_percentile = 99 TestMx

In the TestMx sections, where x denotes the index of the machine, the function of the machine in the testing, will be described. The machine can be defined as a generator, or as a packet reflector (swap function). The machines can be any machine that is created upfront (See step 3 of the installation steps). Other functions can also be executed by the test machines and examples of test files can be found in rapid_location.

The first parameter is the name of the machine and is only used for referencing the machine. This will be the name of the PROX instance and will be shown in case you run the PROX UI. In this automated testing, this will be not be visible.

The config_file parameter defines which PROX config file is used by the PROX program and what PROX will be doing. For a generator, this will typically be gen.cfg. Multiple cfg files exist in the rapid_location.

The dest_vm parameter is used by a generator to find out to which VM he needs to send the packets. In the example below, the packets will be sent to TestM2.

The gencores parameter defines a list of cores to be used for the generator tasks. Note that if you specify more than 1 core, the interface will need to support as many tx queues as there are generator cores.

The latcores parameter specifies a list of cores to be used by the latency measurement tasks. You need as many rx queues on the interface as specified in the latcores parameter.

The default value for the bucket_size_exp parameter is 12. It is also its minimum value. In case most of the latency measurements in the histogram are falling in the last bucket, this number needs to be increased. Every time you increase this number by 1, the bucket size for the latency histogram is multiplied by 2. There are 128 buckets in the histogram.

cores is a parameter that will be used by non-generator configurations that don’t need a disctinction between generator and latency cores (e.g. swap.cfg).

Changing these parameters requires in depth knowledge of the PROX tool and is not something to start with.

name = Generator
config_file = gen.cfg
dest_vm = 2
gencores = [1]
latcores = [3]
#bucket_size_exp = 12 testy

In the testy sections, where y denotes the index of the test, the test that will be executed on the machines that were specified in the TestMx sections, will be described. Using Xtesting, we will typically only use 1 test. Parameter test is defining which test needs to be run. This is a hardcoded string and can only be one of the following [‘flowsizetest’, ‘TST009test’, ‘fixed_rate’, ‘increment_till_fail’, ‘corestats’, ‘portstats’, ‘impairtest’, ‘irqtest’, ‘warmuptest’]. In this project, we will use the TST009test testing. For examples of the other tests, please check out the other test files in rapid_location.

The pass_threshold parameter defines the success criterium for the test. When this test uses multiple combinations of packet size and flows, all combinations must be meeting the same threshold. If one of the combinations fails, the test will be reported as failed. The threshold is expressed in Mpps.

The imixs parameter defines the pakcet sizes that will be used. Each element in the imixs list will result in a separate test. Each element is on its turn a list of packet sizes which will be used during one test execution. If you only want to test 1 imix size, define imixs with only one element. For each element in the imixs list, the generator will iterate over the packet lengths and send them out in the order as specified in the list. An example of an imix list is [128, 256, 64, 64, 128]. In this case, 40% of the packets will have a size of 64 bytes, 40% will have a packet size of 128 and 20% will have a packet size of 256. When using this with Xtesting, we will typically only use 1 imix. When needing results for more sizes, one should create a specific test file per size and launch the different tests using Xtesting.

The flows parameter is a list of flow sizes. For each flow size, a test will be run with the specified amount of flows. The flow size needs to be a power of 2, max 2^30. If not a power of 2, we will use the lowest power of 2 that is larger than the requested number of flows. e.g. 9 will result in 16 flows. Same remark as for the imixs parameter: we will only use one element in the flows list. When more flows need to be tested, create a different test file and launch it using Xtesting.

The drop_rate_threshold parameter specifies the maximum ratio of packets than can be dropped while still considering the test run as succesful. Note that a value of 0 means an absolute zero packet loss: even if we lose 1 packet during a certain step in a test run, it will be marked as failed.

The lat_avg_threshold, lat_perc_threshold, lat_max_threshold parameters are thresholds to define the maximal acceptable round trip latency to mark the test step as successful. You can set this threshold for the average, the percentile and the maximum latency. Which percentile is being used is defined in the TestParameters section. All these thresholds are expressed in micro-seconds. You can also put the value to inf, which means the threshold will never be reached and hence the threshold value is not being used to define if the run is successful or not.

The MAXr, MAXz, MAXFramesPerSecondAllIngress and StepSize parameters are defined in NFV-TST009 and are used to control the binary search algorithm.

The ramp_step variable controls the ramping of the generated traffic. When not specified, the requested traffic for each step in the testing will be applied immediately. If specified, the generator will slowly go to the requested speed by increasing the traffic each second with the value specified in this parameter till it reaches the requested speed. This parameter is expressed in 100Mb/s.

imixs=[[128, 256, 64, 64, 128]]
drop_rate_threshold = 0
lat_avg_threshold = inf
lat_perc_threshold = inf
lat_max_threshold = inf
MAXr = 3
MAXz = 5000
MAXFramesPerSecondAllIngress = 12000000
StepSize = 10000
#ramp_step = 1

2.4.3. Modifying the test

In case you want to modify the parameters as specified in TST009_Throughput_64B_64F.test, it is best to create your own test file. Your test file will need to be uploaded to the test container. Hence you will have to rebuild your container, and add an extra copy command to the Dockerfile so that your new test file will be avaialble in the container. Then you will need to modify the testcases.yaml file. One of the args that you can specify is the test_file. Put your newly created test file as the new value for this argument. Now build and publish your test container as specified in steps 5 & 6 of the installation procedure.

Note that other arguments than test_file can be specified in testcases.yaml. For a list of arugments, please check out the test_params dictionary in the rapid_defaults.py that you can find in rapid_location. It is adviced not to change these parameters unless you have an in-depth knowledge of the code. The only 2 arguments that van be changed are the test_file which was already discussed and the runtime argument. This argument defines how long each test run will take and is expressed in seconds.