How does Synthetic Monitoring work?
At its core, synthetic monitoring is about simulating user interactions with an application to preemptively identify issues before they impact real users. Synthetic monitoring gives developers and operations engineers the confidence that they are one stay one step ahead, ensuring that potential problems are identified and resolved swiftly. In practice, synthetic monitoring works a lot like automated testing in production. Teams constantly run “tests” against a production environment from global locations. Using a Monitoring as Code workflow, its easy to even reuse real end-to-end tests as monitors, simply by deploying them to infrastructure such as Checkly. Synthetic monitors can measure uptime, transactions, status response performance and more - all from different regions of the globe set at a pre-configured frequency. This enables continuous confidence when making rapid changes to mission-critical services and applications by allowing you to notice issues before your customers do.Benefits of Synthetic Monitoring
Synthetic monitoring plays a pivotal role in understanding an application’s behavior under various scenarios. It allows teams to test how their application performs in different geographical locations, under various network conditions, and during peak load times. This insight is critical for applications that cater to a global audience, where performance can vary significantly based on a user’s location and the time of day. Here are some other benefits of synthetic monitoring:Proactive error detection
Considering your application’s essential features, how long would it be acceptable for these to be broken? The answer to this question is your ideal monitoring interval. You can only fix production issues you know about. If making a purchase is your core business, you probably don’t want to test this functionality only once a day after a production deployment. Nor do you want to rely on an observability platform reactive alerting you after a customer has encountered the broken checkout flow.Faster mean time to detection
Synthetic monitoring enables you to test your core functionality daily, every hour, or even every minute. The shorter your synthetic monitoring interval, the quicker your mean time to detect (MTTD) will be. A short MTTD will enable you to fix production issues before your customers reach out to your support channels!Accurate alerting & less noise
Betting on user experience testing with synthetic monitoring leads to more meaningful alerts. A failed transaction might be an issue, but your infrastructure could handle it gracefully. Alerts based on a broken user experience tell you the entire story and must be treated critically and acted on immediately.Performance benchmarking
Another benefit of running synthetic monitoring with headless browsers is that you can monitor performance implications while testing core functionality. Is your web app fast enough for customers in Australia? Does it provide a good Core Web Vitals experience? Do core flows like the customer login become slower over time? Many things can cause performance degradation, but synthetic monitoring will unveil a slower user experience with aggregated performance metrics. You can’t fix things you don’t know about!Controlled environments
Monitors are run from controlled environments with consistent browser properties and network connections to make root-cause analysis efficient and accurate.Synthetic monitoring vs Real User Monitoring (RUM)
Real user monitoring, also called RUM or passive monitoring, is another way to analyze and monitor your application. RUM monitoring offers insights into user interactions, performance statistics, and your users’ devices and locations in a way that differs greatly from synthetic monitoring. Unlike synthetic monitoring tools, RUM monitoring tools don’t simulate user interactions, but rather record real user interactions. There’s nothing for you to script or define. With RUM, an embedded JavaScript snippet records and reports the behavior of actual users back to you so that you can monitor and analyze your applications’ performance and health. Your users are the data source! This sounds great, but there are a few challenges with RUM.| Feature | Synthetic Monitoring | Real User Monitoring |
|---|---|---|
| Monitoring Approach | Simulates realistic scenarios and interactions | Observes and monitors real user traffic |
| Monitoring Type | Proactively monitors for errors or degraded performance | Reactively monitors metrics for abnormal data or performance |
| Trace Generation | Only produces traces when an error is encountered | Traces & stores vast amounts of user data (requires storage) |
| Data Privacy | Safe, secure data used during synthetic runs | May accidentally contain private user information or PII |
Types of Synthetic Monitoring
There are a number of terms used around synthetic monitoring; everything from “Synthetic User Monitoring” to “Heartbeat Monitors” can refer to the same test! However, in general, there are four types of monitoring that are most critical for monitoring your production services:Uptime or Availability Monitoring
Availability Monitoring is fundamental. Its primary objective is to verify whether a web service or application is accessible at any given time. This type of monitoring simulates user interactions to check the availability of websites, APIs, and servers. It’s not just about confirming that a server is up and returning “200 OK” status messages; it’s about ensuring that the application is operational and responding as expected.Transaction Monitoring
Transaction Monitoring takes a step further. To know that every part is really working as expected, Transaction Monitoring means simulating complex user transactions or workflows to verify that critical processes, like checkout or login, are working as intended. Scripts are designed to mimic the path a user would take through the application. This can be as simple as logging in or as complex as completing a multi-step transaction. The goal is to identify performance issues or bugs that might not be evident in other forms of testing. For example, this will reveal whether third-party services have failed, resulting in degraded performance on our own site.Performance Monitoring
Web Performance Monitoring is all about speed and efficiency. It evaluates how quickly and smoothly your web application loads and operates from the user’s perspective. This is a more analog measurement than the Availability or Transaction Monitoring, as exact loading times will vary and won’t give simple “up or down” feedback. Web Performance Monitoring can identify technical debt, as small changes to your experience can add up to degraded (or improved!) performance for your end users.Keyword Monitoring
Keyword monitoring entails monitoring for content that is expected to appear in an API response or within a UI. Keyword monitoring can be extremely helpful for commerce sites or other content-driven websites like news publishers and blogs.Synthetic Monitoring Best Practices
Implementing synthetic monitoring effectively ensures you maximize its value in identifying and resolving performance issues. Here are key best practices to follow:1. Define Key User Journeys
Before you implement synthetic monitoring, identify the most critical user interactions, such as login flows, checkout processes, or API endpoints that drive your business. These are the flows you want to be setting synthetic monitors for. Simulating these core pathways ensures that issues affecting customer satisfaction are detected early.2. Test From Multiple Locations
Set up monitors across geographically distributed data centers to simulate user access from various regions. This practice helps uncover location-specific latency or connectivity issues and ensures a consistent experience for global users.3. Use Realistic Scenarios
Craft test scripts that mimic real user behaviors, including complex interactions like multi-step forms or dynamic content loading. Ensure these scripts reflect typical device types, browsers, and network conditions to emulate authentic experiences.4. Monitor Continuously and Strategically
Schedule monitoring at frequent intervals to capture real-time performance data. Combine this with strategic off-peak monitoring to identify time-sensitive bottlenecks, such as overnight updates or backups affecting availability.5. Set Up Meaningful Alerts
Configure alerts to balance urgency and relevance. Alerts should only trigger for significant issues, avoiding noise from false positives or minor deviations, to ensure your team focuses on critical problems.6. Regularly Update Scripts
Keep monitoring scripts updated to align with application changes. Regular maintenance prevents outdated tests from providing inaccurate results or missing new vulnerabilities.7. Integrate Synthetic Monitoring with Your CI/CD Pipeline
Incorporate synthetic monitoring checks into your deployment workflows to catch issues before they reach production. Automated tests can act as gatekeepers for performance and functionality. By following these best practices, you can leverage synthetic monitoring to proactively enhance performance and deliver seamless user experiences.Synthetic Monitoring Use Cases
Here are key use cases where synthetic monitoring shines:- Website Performance Monitoring: Simulate user interactions to measure load times, responsiveness, and overall performance of web pages.
- API Monitoring: Ensure APIs are functional and responsive and deliver accurate data to dependent applications or services.
- Global Availability Testing: Verify the availability and performance of your applications from various geographical locations.
- End-to-End Testing: Test critical user workflows, such as account creation, login, or checkout processes, to ensure seamless experiences.
- Third-Party Service Validation: Monitor the performance of integrated third-party services, such as payment gateways or content delivery networks (CDNs).
- Mobile App Monitoring: Test app functionalities across different devices, platforms, and network conditions.
- Baseline and SLA Verification: Establish performance baselines and ensure compliance with service-level agreements (SLAs).