Neocortix Tutorial

In this tutorial, we will show you how to use Neocortix Cloud Services Scalable Compute to run a distributed LoadTest batch job, using a JMeter client, while monitoring the server with Dynatrace.

First, you need to sign up for a Dynatrace account. You can start with a free 15-day trial at https://www.dynatrace.com/trial/.

Next, please follow the steps in the tutorial Setting Up For Batch Jobs. After completion of the initial setup, you will have a directory with examples,

~/ncsexamples

In the subdirectory

~/ncsexamples/batchMode

you will find the runBatchDynatrace.py command. This script creates a set of instances running on mobile devices, one instance for each load generator. In the default example provided, we ask for 6 successful instances:

startFrame = 1,
endFrame = 6,
nWorkers = 10,

By setting

nWorkers = 10

, we slightly over-allocate instances to allow for some fraction to fail.

It will command the instances to install JMeter, and then run JMeter with a short (90 seconds) and simple

TestPlan_dynatrace.jmx

to send http requests to the target URL (currently

https://loadtest-target.neocortix.com

def frameCmd( self, frameNum ):
    cmd = 'date && apache-jmeter-5.3/bin/jmeter -n -t %s -l TestPlan_results_%03d.csv -D httpclient4.time_to_live=20000 -D httpclient.reset_state_on_thread_group_iteration=true' % (
        self.JMeterFilePath, frameNum
    )
    cmd += ' && cp -p jmeter.log jmeter_%03d.log' % frameNum
    return cmd

The output of each instance will be a .csv file

TestPlan_result_<n>.csv

containing request response timing information for each worker. The master will create several image files

WorldMap.png

DeliveredLoad.png

ResponseTimesByRegion.png

, and then terminate the instances.

Now you will configure

TestPlan_dynatrace.jmx

. After signing up for Dynatrace, you need to create an API access token by clicking on Left-Menu / Settings / Integration / Dynatrace API / Generate Token. Select the API v2 Ingest Metrics feature as shown:

Copy the generated token and then paste it into the

TestPlan_dynatrace.jmx

file in place of the "YourApiToken" placeholder. This field is called "dynatraceApiToken".

Next you need to set the "dynatraceMetricIngestUrl" field. When you signed up for dynatrace, they gave you a "monitoring instance" with a URL something like

https://abc99999.live.dynatrace.com/

. You will find it in the browser address bar:

In the

TestPlan_dynatrace.jmx

file, find where it says

https://xxxxx.live.dynatrace.com/api/v2/metrics/ingest

and replace the host part with the host part of your monitoring instance URL.

To test your own server, replace all occurrences of

loadtest-target.neocortix.com

with the URL of the web page you want to test (omitting the "https://" prefix).

Simply run

python3 ./runBatchDynatrace.py

When the program is done, the output files

TestPlan_results_<n>.csv

WorldMap.png

DeliveredLoad.png

ResponseTimesByRegion.png

, will be put in a directory

./data/dynatrace_<datestamp>

To see the metrics captured by Dynatrace,

browse to your monitoring url
create a dashboard (or use an existing dashboard)
add a custom chart
click on "try it out" in the banner at the top that says "Analyze multidimensional metrics from Prometheus, StatsD and others"
in the "Filter metrics by..." text box, enter "jmeter.usermetrics.transaction.success" (without quotes)
click "Add Metric"
in the second "Filter metrics by..." text box, enter "jmeter.usermetrics.transaction.meantime" (without quotes)
press enter
click "run query"
save the dashboard (so you won’t have to do these steps again)
You may want to click "run query" a number of times to refresh the displayed graph as data becomes available from the loadtest workers.

Example Command

Running a Longer Ramped Load Test

Example Outputs