Run UDP and WebSocket API Tests to Monitor Latency-Critical Applications | Datadog

Run UDP and WebSocket API tests to monitor latency-critical applications

Author Kai Xin Tai

Published: November 11, 2021

Datadog Synthetic Monitoring allows you to proactively monitor your applications so that you can detect, troubleshoot, and resolve any availability or performance issues before they impact your end users. With our API test suite, you can send simulated HTTP requests to your API endpoints, check the validity of SSL certificates, verify the performance and correctness of DNS resolutions, test TCP connections, and ping endpoints to detect server connectivity issues.

We’re excited to announce that you can now conduct UDP and WebSocket API tests to ensure that your real-time applications, such as customer support chat platforms and video streaming services, are always able to meet their low-latency requirements. In this post, we’ll provide an overview of the UDP and WebSocket protocols and show you the key features of our API tests.

Ensure the availability and responsiveness of applications that depend on UDP and WebSocket

UDP is a transport layer protocol and a faster alternative to TCP. Unlike TCP, UDP does not require a client and server to first establish a connection before messages can be sent over the network. Although the lack of acknowledgment from the recipient removes any possible guarantee that packets will be delivered successfully or in order, UDP does enable faster data transmission. This fast delivery makes UDP well-suited for applications that prioritize speed over reliability, such as Voice over Internet Protocol (VoIP) services or video conferencing platforms.

WebSocket, on the other hand, is an application layer protocol that facilitates bidirectional client-server communication over a single, persistent TCP socket connection. Keeping an open connection, instead of establishing a new one for each client request, lowers latency and allows data to be exchanged at any time. This persistent channel makes WebSocket ideal for real-time applications like customer support chat platforms, social media feeds, and multi-player games.

Datadog Synthetic Monitoring lets you test the availability and responsiveness of your applications by sending simulated messages to UDP server ports and opening WebSocket connections. You can configure these tests to run on demand or periodically from globally distributed managed locations as well as private locations within your internal network. And with Datadog Synthetic CI/CD Testing, you can execute these tests directly from within your CI/CD pipelines, allowing you to detect and troubleshoot issues early.

If you’re notified of a failed test, you can examine the breakdown of network timings and verify that the response message and headers are consistent with your expectations. You can also see if any assertions have failed, which can serve as the starting point for an investigation. For instance, if a server takes too long to respond when a WebSocket connection is being established, as shown in the screenshot below, you will want to check for server configuration and network issues.

WebSocket test failed because it exceeded its expected response time

Start creating UDP and WebSocket tests today

Our new UDP and WebSocket tests help you stay ahead of any potential issues with your latency-critical applications so that you can deliver the best end-user experience. See our documentation for more information on how to start creating these tests today. If you’re not yet using Datadog to monitor your applications and infrastructure, you can get started with a 14-day .