Azure Load Testing client library for JavaScript - version 1.0.0

Article
03/07/2023

Azure Load Testing provides client library in JavaScript to the user by which they can interact natively with Azure Load Testing service. Azure Load Testing is a fully managed load-testing service that enables you to generate high-scale load. The service simulates traffic for your applications, regardless of where they're hosted. Developers, testers, and quality assurance (QA) engineers can use it to optimize application performance, scalability, or capacity.

Please rely heavily on our REST client docs to use this library

Documentation

Various documentation is available to help you get started

Getting started

Currently supported environments

Node.js version 14.x.x or higher

Prerequisites

You must have an Azure subscription and Azure Load Test Service Resource to use this package.

Install the `@azure-rest/load-testing` package

Install the AzureLoadTesting client REST client library for JavaScript with npm:

npm install @azure-rest/load-testing

Create and authenticate a `AzureLoadTesting` client

To use an Azure Active Directory (AAD) token credential, provide an instance of the desired credential type obtained from the @azure/identity library.

To authenticate with AAD, you must first npm install @azure/identity

After setup, you can choose which type of credential from @azure/identity to use. As an example, DefaultAzureCredential can be used to authenticate the client.

Set the values of the client ID, tenant ID, and client secret of the AAD application as environment variables: AZURE_CLIENT_ID, AZURE_TENANT_ID, AZURE_CLIENT_SECRET

import AzureLoadTesting, { AzureLoadTestingClient } from "@azure-rest/load-testing";
import { DefaultAzureCredential } from "@azure/identity";

const Client: AzureLoadTestingClient = AzureLoadTesting(Endpoint, new DefaultAzureCredential());

Key concepts

The following components make up the Azure Load Testing Service. The Azure Load Test client library for JavaScript allows you to interact with each of these components through the use of a dedicated client object.

Test

A test specifies the test script, and configuration settings for running a load test. You can create one or more tests in an Azure Load Testing resource.

App Component

When you run a load test for an Azure-hosted application, you can monitor resource metrics for the different Azure application components (server-side metrics). While the load test runs, and after completion of the test, you can monitor and analyze the resource metrics in the Azure Load Testing dashboard.

Metrics

During a load test, Azure Load Testing collects metrics about the test execution. There are two types of metrics:

Client-side metrics give you details reported by the test engine. These metrics include the number of virtual users, the request response time, the number of failed requests, or the number of requests per second.
Server-side metrics are available for Azure-hosted applications and provide information about your Azure application components. Metrics can be for the number of database reads, the type of HTTP responses, or container resource consumption.

Test Engine

A test engine is computing infrastructure that runs the Apache JMeter test script. You can scale out your load test by configuring the number of test engines. The test script runs in parallel across the specified number of test engines.

Test Run

A test run represents one execution of a load test. It collects the logs associated with running the Apache JMeter script, the load test YAML configuration, the list of app components to monitor, and the results of the test.

Data-Plane Endpoint

Data-plane of Azure Load Testing resources is addressable using the following URL format:

00000000-0000-0000-0000-000000000000.aaa.cnt-prod.loadtesting.azure.com

The first GUID 00000000-0000-0000-0000-000000000000 is the unique identifier used for accessing the Azure Load Testing resource. This is followed by aaa which is the Azure region of the resource.

The data-plane endpoint is obtained from Control Plane APIs.

Example: 1234abcd-12ab-12ab-12ab-123456abcdef.eus.cnt-prod.loadtesting.azure.com

In the above example, eus represents the Azure region East US.

Examples

Creating a load test

import { AzureLoadTestingClient } from "@azure-rest/load-testing";
import AzureLoadTesting from "@azure-rest/load-testing";
import { DefaultAzureCredential } from "@azure/identity";

var TEST_ID = "some-test-id";
var DISPLAY_NAME = "my-load-test";

const client: AzureLoadTestingClient = AzureLoadTesting("<Endpoint>", new DefaultAzureCredential());

await client.path("/tests/{testId}", TEST_ID).patch({
  contentType: "application/merge-patch+json",
  body: {
    displayName: DISPLAY_NAME,
    description: "",
    loadTestConfiguration: {
      engineInstances: 1,
      splitAllCSVs: false,
    },
    secrets: {},
    environmentVariables: {},
    passFailCriteria: { passFailMetrics: {} },
  },
});

Uploading .jmx file to a Test

import { AzureLoadTestingClient, getLongRunningPoller, isUnexpected } from "@azure-rest/load-testing";
import AzureLoadTesting from "@azure-rest/load-testing";
import { AbortController } from "@azure/abort-controller";
import { DefaultAzureCredential } from "@azure/identity";
import { createReadStream } from "fs";

const client: AzureLoadTestingClient = AzureLoadTesting("<Endpoint>", new DefaultAzureCredential());

var TEST_ID = "some-test-id";
const readStream = createReadStream("./sample.jmx");

const fileUploadResult = await client
  .path("/tests/{testId}/files/{fileName}", TEST_ID, "sample.jmx")
  .put({
    contentType: "application/octet-stream",
    body: readStream,
  });

if (isUnexpected(fileUploadResult)) {
  throw fileUploadResult.body.error;
}

let fileValidateResult;
const fileValidatePoller = await getLongRunningPoller(client, fileUploadResult);
try{
fileValidateResult = await fileValidatePoller.pollUntilDone({
  abortSignal: AbortController.timeout(120*1000), // timeout of 120 seconds
});} catch (ex: any) {
new Error("Error in polling file Validation" + ex.message); //polling timed out
}

if (fileValidatePoller.getOperationState().status != "succeeded" && fileValidateResult)
  throw new Error(
    "There is some issue in validation, please make sure uploaded file is a valid JMX." +
      fileValidateResult.body.validationFailureDetails
  );

Running a Test and fetching Metrics

import { AzureLoadTestingClient, getLongRunningPoller, isUnexpected } from "@azure-rest/load-testing";
import AzureLoadTesting from "@azure-rest/load-testing";
import { DefaultAzureCredential } from "@azure/identity";
import { AbortController } from "@azure/abort-controller";

const client: AzureLoadTestingClient = AzureLoadTesting("<Endpoint>", new DefaultAzureCredential());

var TEST_ID = "some-test-id";
var DISPLAY_NAME = "my-load-test";
var TEST_RUN_ID = "some-test-run-id";

// Creating/Updating the test run
const testRunCreationResult = await client.path("/test-runs/{testRunId}", TEST_RUN_ID).patch({
  contentType: "application/merge-patch+json",
  body: {
    testId: TEST_ID,
    displayName: DISPLAY_NAME,
  },
});

if (isUnexpected(testRunCreationResult)) {
  throw testRunCreationResult.body.error;
}

if (testRunCreationResult.body.testRunId === undefined)
  throw new Error("Test Run ID returned as undefined.");

const testRunPoller = await getLongRunningPoller(client, testRunCreationResult);
  let testRunResult;

  try {
    testRunResult = await testRunPoller.pollUntilDone({
      abortSignal: AbortController.timeout(60000), // timeout of 60 seconds
    });
  } catch (ex: any) {
    new Error("Error in polling test run completion" + ex.message); //polling timed out
  }

  if (testRunPoller.getOperationState().status != "succeeded")
    throw new Error("There is some issue in running the test, Error Response : " + testRunResult);

  if (testRunResult) {
    let testRunStarttime = testRunResult.body.startDateTime;
    let testRunEndTime = testRunResult.body.endDateTime;

    // get list of all metric namespaces and pick the first one
    const metricNamespaces = await client
      .path("/test-runs/{testRunId}/metric-namespaces", TEST_RUN_ID)
      .get();

    if (isUnexpected(metricNamespaces)) {
      throw metricNamespaces.body.error;
    }

    const metricNamespace = metricNamespaces.body.value[0];

    if (metricNamespace.name === undefined) {
      throw "No Metric Namespace name is defined.";
    }

    // get list of all metric definitions and pick the first one
    const metricDefinitions = await client
      .path("/test-runs/{testRunId}/metric-definitions", TEST_RUN_ID)
      .get({
        queryParameters: {
          metricNamespace: metricNamespace.name,
        },
      });

    if (isUnexpected(metricDefinitions)) {
      throw metricDefinitions.body.error;
    }

    const metricDefinition = metricDefinitions.body.value[0];

    if (metricDefinition.name === undefined) {
      throw "No Metric Namespace name is defined.";
    }

    // fetch client metrics using metric namespace and metric name
    const metricsResult = await client.path("/test-runs/{testRunId}/metrics", TEST_RUN_ID).post({
      queryParameters: {
        metricname: metricDefinition.name,
        metricNamespace: metricNamespace.name,
        timespan: testRunStarttime + "/" + testRunEndTime,
      },
    });

    console.log(metricsResult);
    console.log(testRunResult);
}

Troubleshooting

Logging

Enabling logging may help uncover useful information about failures. In order to see a log of HTTP requests and responses, set the AZURE_LOG_LEVEL environment variable to info. Alternatively, logging can be enabled at runtime by calling setLogLevel in the @azure/logger:

import { setLogLevel } from "@azure/logger";

setLogLevel("info");

For more detailed instructions on how to enable logs, you can look at the @azure/logger package docs.

Next steps

Azure Loading Testing JavaScript SDK samples are available to you in the SDK's GitHub repository. These samples provide example code for additional scenarios commonly encountered.

See Azure Load Testing samples.

Contributing

For details on contributing to this repository, see the contributing guide.

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request

Share via

Azure Load Testing client library for JavaScript - version 1.0.0

Documentation

Getting started

Currently supported environments

Prerequisites

Install the `@azure-rest/load-testing` package

Create and authenticate a `AzureLoadTesting` client

Key concepts

Test

App Component

Metrics

Test Engine

Test Run

Data-Plane Endpoint

Examples

Creating a load test

Uploading .jmx file to a Test

Running a Test and fetching Metrics

Troubleshooting

Logging

Next steps

Contributing

Additional resources

Share via

Azure Load Testing client library for JavaScript - version 1.0.0

Documentation

Getting started

Currently supported environments

Prerequisites

Install the @azure-rest/load-testing package

Create and authenticate a AzureLoadTesting client

Key concepts

Test

App Component

Metrics

Test Engine

Test Run

Data-Plane Endpoint

Examples

Creating a load test

Uploading .jmx file to a Test

Running a Test and fetching Metrics

Troubleshooting

Logging

Next steps

Contributing

Additional resources

Install the `@azure-rest/load-testing` package

Create and authenticate a `AzureLoadTesting` client