Real User Monitoring vs. Synthetic Monitoring

Discover how Real User Monitoring (RUM) and Synthetic Monitoring can transform your API performance strategy. Learn their key differences, benefits, and how Treblle delivers real-time insights for smoother user experiences.

9 days ago   •   8 min read

By Rahul Khinchi
Table of contents

API monitoring involves tracking APIs' performance, availability, and reliability to ensure they function as expected. It helps businesses keep their digital services running smoothly, minimize downtime, and deliver the best possible user experience. It’s important for both technical and business teams to understand the monitoring options available, their various use cases, and the benefits of each.

There are several types of API monitoring, but in this blog post, we'll explore two essential methods: Synthetic Monitoring and Real User Monitoring (RUM)

Let me break down the distinctions and show how Treblle’s solution, which leverages RUM, provides more meaningful insights for your business.

But let’s start with the basics.

Why API Monitoring Matters

When building and maintaining APIs, you're primarily concerned with their functionality and whether they behave as expected in real-life situations.

Slow response times, frequent errors, and failures can frustrate users and lead to more significant problems later. 

No one wants a website to crash just when it's getting busy, right?

At this point, monitoring becomes essential. By monitoring how your API is performing, you can spot problems early, troubleshoot issues, and ensure that the overall experience remains smooth for your users.

Traditional monitoring tools might give you some insights but often miss the mark in providing a complete picture of what’s happening. That’s where Real User Monitoring (RUM) and Synthetic Monitoring make a difference. 

They each give you different perspectives on your API’s performance.

Understanding Synthetic Monitoring

Synthetic Monitoring is a proactive approach to testing the performance of an API or application. It involves creating automated tests that simulate fundamental user interactions, allowing businesses to track their APIs' behavior under different conditions.

How Does Synthetic Monitoring Work?

Synthetic monitoring works by simulating real user interactions with your API. Think of it as setting up a robot tester that requests your API at regular intervals, checking performance details like response time, data accuracy, and error rates. Synthetic monitoring is a form of active monitoring because it is controlled, it requires deployment, and the traffic generated does not represent actual users; the traffic is manually generated to collect specific data.

These tests run on a schedule, helping you monitor your API’s overall health even when there is no user traffic.

For example, a synthetic test might simulate a customer searching for a product on an e-commerce site through your API. The monitoring tool measures how long it takes to fetch the product details, checks if the data is correct, and confirms that the API responded without errors.

The Good Stuff:

  • Proactive Issue Detection: Spot issues like response-time spikes or request failures before they impact users.
  • Consistency: Scheduled tests let you benchmark performance over time and quickly see any dips after updates or new releases.
  • Test-Driven Prep: Simulate user traffic to see how your API handles peak load so you’re ready for high-demand times.

Where It Falls Short:

  • Simulated Conditions: Synthetic tests rely on simulated user conditions, which means they don't capture how APIs perform under real user conditions.
  • Controlled Environment: These tests don’t replicate real-world scenarios, like slow internet connections or high traffic bursts.
  • Limited Edge Case Coverage: Synthetic monitoring follows predefined traffic patterns, so it can miss edge cases that real users might experience due to specific devices, locations, or network quirks.

The Power of Real User Monitoring (RUM)

Real user monitoring, also known as digital experience monitoring, real user measurement, user monitoring, end-user experience monitoring, or simply RUM, focuses on monitoring actual user interactions with your API in real-time. RUM is a form of passive monitoring—it relies on services that constantly observe the system in the background, tracking responsiveness, functionality, and availability. Unlike synthetic monitoring, which simulates interactions, RUM truly represents how users interact with your system under normal conditions.

How Does RUM Work?

By collecting data from actual users interacting with the app or API in real-time, RUM provides a realistic view of the following:

  • API Response Times: How long does it take to respond?
  • User Device and Network Conditions: Which devices and networks are users on? Are there any network-specific slowdowns?
  • Geographical Location: Are there performance differences based on location?

Example: Say a user in New York opens an e-commerce site and requests product details. With RUM, Treblle captures the response time, any errors encountered, and conditions like the user’s network speed. This real-time feedback is essential. It’s like having a window into what users experience in the wild.

The Good Stuff:

  • Real-Time, Real-World Data: You get an accurate view of how users interact with your API under actual conditions. For example, if European users see slower load times than North American users, RUM will flag it.
  • Instant Alerts: When issues arise, RUM sends you a heads-up immediately. It lets you tackle performance problems, fix errors, and reduce latency as soon as they occur.
  • Performance Across Devices and Browsers: RUM shows you how the API works on various devices, operating systems, browsers, and network types. It means you’ll know if your API runs slower on older phones, outdated browsers, or slower mobile networks.

Where It Falls Short:

  • Post-Issue Detection: RUM only detects issues after they've affected users, meaning you’ll often react to problems rather than catch them early.
  • Data Overload: Real user data can pile up fast. Sorting through all that information to find valuable insights takes robust tools and intelligent filtering.

Synthetic Monitoring vs. RUM

Now that we understand what synthetic monitoring and RUM offer individually, let’s compare them head-to-head. Both approaches have their place but serve different purposes in your monitoring strategy.

Feature Synthetic Monitoring Real User Monitoring (RUM)
Data Source Simulated, controlled Real user interactions
Detection Method Proactive (alerts before issues happen) Reactive (alerts after problems occur)
Scope Limited, predictable scenarios Broad covers all real-world conditions
Ideal for Testing new APIs, performance benchmarking Monitoring ongoing API usage, troubleshooting

How Treblle Solves Monitoring Pain Points

Treblle makes it easier to monitor your APIs by focusing entirely on Real User Monitoring (RUM). This provides valuable insights into your API’s performance as experienced by real users, not simulations.

Here’s how Treblle makes it easier to keep track of your API performance:

  • Real-Time Monitoring with RUM: Track user interactions as they happen. 

Treblle gives you immediate feedback on API performance across different regions, devices, and networks.

Unlike other monitoring tools like Grafana and Firebase, Treblle doesn’t require complicated configurations. Once set up, you get real-time performance data without overhauling your infrastructure. 

  • Instant Alerts: You will get notified immediately if your API is slow, down, or encountering errors. 

It means you can address any issue as soon as it occurs to keep the user experience smooth.

  • Data Control with Sampling: Treblle lets you control the amount of data you gather. 

Using sampling, you can balance collecting meaningful insights without data overload.

You’ll get metrics on response times, errors, and uptime—everything you need to make informed decisions about improving your APIs.

Case Studies: Treblle’s Impact on API Performance

Example 1: Funxtion

Problem: Funxtion, a cloud-based platform, received complaints about slow API responses during peak traffic. While synthetic monitoring provided general performance data, it couldn't help them pinpoint the specific regional issues users were facing.

Solution: By integrating Treblle’s Real User Monitoring (RUM), Funxtion uncovered a performance bottleneck in certain regions, particularly during peak usage times. Treblle’s real-time data highlighted an issue with increased response times in Europe, which was missing in synthetic tests.

Action: Funxtion adjusted its infrastructure, implementing load balancing to optimize resources for high-traffic regions. This change reduced response times by 30%, improving the experience for users in the affected areas.

Outcome: As a result, Funxtion experienced:

  • Faster response times
  • Less downtime during traffic surges
  • A smoother overall application experience, especially for users in Europe
  • A more proactive approach to handling future traffic spikes

Read the case study in detail at Funxtion's customer story.

Example 2: Autopix

Problem: Autopix, a photo processing service, noticed inconsistent API performance across different devices and locations. Mobile users, especially in rural areas, faced high latency, but the team couldn't pinpoint the cause from the available data.

Solution: Autopix used Treblle’s Real User Monitoring (RUM) to gather detailed data about network speed, device type, and location. The RUM helped the team identify that mobile users in remote regions struggled due to unstable network conditions.

Action: After pinpointing the issue, Autopix optimized mobile API calls by:

  • Adjusting image compression settings to reduce data size.
  • Tweaking the API’s data transfer method to work better with lower bandwidth.

Outcome:

  • As a result, API performance improved by 50% for mobile users, particularly in rural areas, reducing latency and improving the overall mobile experience.
  • There are fewer complaints from users about performance issues, especially in regions with poor network connections.

Read the case study in detail at Autopix's customer story.

Getting Started with Treblle

Getting up and running with Treblle is straightforward. 

Follow these steps to start monitoring your APIs:

  1. Sign Up for Treblle: Create your account on Treblle and grab your API key.
  1. Integrate Treblle with Your API: Use the provided documentation to add Treblle’s monitoring code to your API endpoints. It’s a simple setup that doesn’t take much time.
  1. Track Your API’s Performance: Once set up, you’ll start seeing real-time data. Treblle will monitor your API’s health and notify you when something goes wrong.
  1. Review and Make Changes: After collecting some data, Treblle will show you where your API might need improvement. Take those insights and make your API better.

Conclusion

Real User Monitoring (RUM) is the best way to understand how users truly experience your service. While synthetic monitoring can provide valuable insights in controlled conditions, RUM accurately describes how your API performs in real-world scenarios—based on user interactions.

Whether you're building a small app or a large-scale platform, your APIs are the backbone of your system. Without proper monitoring, you can be exposed to risks like downtime, slow performance, and poor user experiences.

Treblle focuses on Real User Monitoring (RUM), offering real-time insights into your APIs' performance in the wild. By leveraging RUM, you gain a more transparent, more accurate understanding of your API’s performance, helping you make proactive decisions to address any issues before they affect users.

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Start optimizing your API performance today with Treblle. Experience the benefits of real-time monitoring, comprehensive logging, and actionable insights. See how Treblle can enhance your API observability and help you maintain robust and reliable APIs!

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