“Usage Of Datadog Synthetic Monitoring”

Reading Time: 5 minutes

Synthetic Monitoring allows you to observe how your systems and applications are performing using simulated requests and actions from around the globe. Datadog tracks the performance of your webpages and APIs from the backend to the frontend, and at various network levels (HTTPSSLDNSWebSocketTCPUDPICMP, and gRPC) in a controlled and stable way, alerting you about faulty behavior such as regressions, broken features, high response times, and unexpected status codes.

What is Synthetic Monitoring?

Synthetic testing, also known as synthetic monitoring or proactive monitoring, is a way to identify performance issues with key user journeys and application endpoints before they degrade the user experience. Datadog Synthetic Monitoring allows you to create code-free tests that proactively simulate user transactions on your applications and monitor key network endpoints across various layers of your systems. Quickly detect user-facing issues with API and browser tests—and jump-start system-wide investigations so you can optimize performance and enhance your end-user experience.

How Does Synthetic Monitoring Work?

Synthetic tests mimic real user traffic by sending simulated requests to your applications and services from different browsers, devices, and locations around the world. Synthetic tests can be used to monitor website transactions and application endpoints at various network layers, and the results of these tests can provide valuable information on uptime, response time, and regional performance issues.

Teams can run synthetic tests in production or in test environments to ensure new features are working properly before they are deployed. Typically, synthetic tests don’t carry high overhead, so they can run continuously, regardless of how much traffic an application is handling.

Synthetic Monitoring test types

Datadog offers API testsMultistep API testsBrowser tests, and Private Locations. API tests proactively monitor that your most important services are available at any time and from anywhere.

Single API tests come in eight subtypes that allow you to launch requests on the different network layers of your systems (HTTPSSLDNSWebSocketTCPUDPICMP, and gRPC). 

Multistep API tests enable you to run HTTP tests in sequence to monitor the uptime of key journeys at the API level.

Browser tests are scenarios that Datadog executes on your web applications. You can configure periodic intervals to run tests from multiple locations, devices, and browsers as well as execute them from your CI/CD pipelines.

Private locations allow you to monitor internal-facing applications or private URLs that aren’t accessible from the public internet.

Creating a single API test

HTTP tests monitor your API endpoints and alert you when response latency is high or fails to meet any conditions you define, such as expected HTTP status code, response headers, or response body content.

The example below demonstrates how to create an HTTP test, a subtype of single API tests.

Define request

  1. In the Datadog site, hover over UX Monitoring and select Synthetic Tests.
  2. Click New Test > New API test.
  3. Select the HTTP request type.
  4. Define your request:
  • Add the URL of the endpoint you want to monitor. For example, say https://www.knoldus.com. Defining the endpoint to test automatically populates the name of your test to Test on www.knoldus.com
  • You can select Advanced Options to set custom request options, certificates, authentication credentials, and more.
  • You can set tags such as env:prod on your test. Tags allow you to keep your test suite organized and quickly find tests you’re interested in on the homepage.

Define assertions

Clicking Test URL automatically populates basic assertions about your endpoint’s response. Assertions define what a successful test run is. Assertions are fully customizable. To add a custom assertion, click on elements of the response preview such as the headers or click New Assertion to define a new assertion from scratch.

Select locations

Select one or more Managed Locations or Private Locations to run your test from.

Managed locations allow you to test public-facing websites and endpoints. To test internal applications or simulate user behavior in discrete geographic regions, use private locations instead.

Specify test frequency

Select the frequency at which you want your test to execute. You can leave the default frequency of 1 minute.

Define alert conditions

You can define alert conditions to ensure your test does not trigger things like a sporadic network blip so that you only get alerted in case of real issues with your endpoint.

You can specify the number of consecutive failures that should happen before considering a location failed.

You can also configure your test to only trigger a notification when your endpoint goes down for a certain amount of time and a number of locations.

Notify your team

Design your alert message and add any email address you want your test to send alerts to. You can also use notifications integrations such as Slack, PagerDuty, Microsoft Teams, and webhooks. In order to trigger a Synthetic alert to these notification tools, you first need to set up the corresponding integration.

When you’re ready to run your test, click Save Test.

Why Is Synthetic Monitoring Important?

To address the challenges of understanding and tracking the performance of modern web applications, synthetic monitoring can be the perfect solution. The purpose of your specific web page or application determines the paths your users take. In synthetic monitoring, the behavioral paths of the end-users on a web app are scripted. Those scripts are run on set intervals, and, if necessary, from different checkpoints, and the performance, availability, functionality, and response time can be measured. 

Few benefits of synthetic monitoring:

  • Continuously monitor web page speed and load times, application performance and availability.
  • Set up and receive alerts when downtime or pre-defined performance thresholds are met.
  • Examine backend server/infrastructure performance and metrics.
  • Monitor third-party services and APIs.
  • Monitor user transactions/flows that are critical to the business.
  • Set baseline performance metrics and compare them against ongoing performance data.
  • Identify browser or device-specific issues.

Do You Really Need Synthetic Monitoring?

It is critical for a business that depends primarily on its websites and applications to have incredible uptime and performance, 24/7. Users who rely on your sites, applications, and APIs for their fundamental needs or entertainment, will not tolerate even a few seconds’ delays. Proactive detection and diagnosis of web application and page performance issues are necessary. Synthetic monitoring can occur at different global checkpoints and at different frequencies to make sure you are delivering the best experience to your users all the time.

Written by 

I am an DevOps engineer having experience working with the DevOps tool and technologies like Kubernetes, Docker, Ansible, AWS cloud, prometheus, grafana etc. Flexible towards new technologies and always willing to update skills and knowledge to increase productivity.