Over a million developers have joined DZone.

Synthetic Monitoring — Why and When to Use It

DZone's Guide to

Synthetic Monitoring — Why and When to Use It

Learn how synthetic monitoring works and how it helps to ensure your website's performance and availability more than typical monitoring.

· Performance Zone ·
Free Resource

Sensu is an open source monitoring event pipeline. Try it today.

A bad digital experience can be very costly. On an average, the cost to acquire an online visitor is around $5, and while only 3% of them actually convert, any performance issues can burn a big hole in your pocket. How can you set a benchmark for a quality digital experience?

According to industry experts, your website/application should be glitch-free, to begin with, and all web pages should load within 3 seconds. HubSpot claims that if the site brings in $100,000 per day in revenue, a 1-second page improvement will bring in an extra $7,000. That’s how much a second is worth; it can mean a 7% increase or decrease in your revenue.

Though upholding performance at a benchmark is difficult, monitoring it to take proactive actions can be easy. But performance monitoring yields results only if you choose the right tool. This is because most monitoring tools offer some basic features like pinging URLs to check availability and load time. Moreover, it is different from how a real user would behave on your website. So, why would you use a monitoring tool that doesn’t tell you anything about the user journey?

The only way you can analyze whether a user journey meets the customer expectations is by using a synthetic monitoring tool. It is used to monitor critical user journeys on a website and warn developers in case something doesn’t work or perform as expected. If you’re not familiar with synthetic monitoring, this article will help you learn about it in depth.

What Is Synthetic Monitoring?

Synthetic monitoring (also known as active monitoring or proactive monitoring) is web application monitoring that is done using a web browser emulation or scripted recordings of web transactions regardless of whether or not users are currently visiting your site. Synthetic monitoring tools are used to identify and resolve web application performance and availability issues from different geographical locations worldwide.

When and Why Is Synthetic Monitoring Needed?

  • Synthetic monitoring is used to check your site’s availability and end-to-end performance 24/7  from the end-user perspective. Synthetic monitoring predicts, to a fair degree of accuracy, how your application will perform in which geographies and isolate the root cause of any detected bottlenecks. Synthetic monitoring prevented or pre-empted 95 to 99 percent of previous performance issues for most of our customers.
  • To provide rich customer experiences, websites and applications increasingly depend on 3rd parties such as shopping carts, ads, customer reviews, web analytics, social networking, SEO, video, and more. In fact, retailers around the globe increased the number of 3rd parties by 21% in 2015, from an average of 25 to 30 3rd parties. These third parties help increase traffic, conversions and improve customer satisfaction, but any one of them could weaken your site’s overall performance or even take it down. While SLAs may let you point the finger, from the end-user point of view, you’re the one who’s accountable. Using synthetic monitoring, you can evaluate components via pre-production testing for proof of concept and load testing based upon what you expect during high-traffic periods.
  • To objectively measure your own service level agreements (SLAs) and also your third-party service provider’s. When your site is not functional, loading so slow and timing out that customers go elsewhere, then your site becomes unreliable. Imagine if this happens at a business-critical moment such as cyber Monday or during a major news event, this will impact your entire year negatively. Continuous testing and synthetic monitoring are the best possible ways to ensure your web applications are reliable. No application is immune from performance issues. Complex infrastructure and integrations that support web application delivery in today’s world make it even more vulnerable. You can get ahead of any problems and preserve your customer experience by taking a top-down approach and having visibility into how your application is performing and all of the factors that affect that performance.
  • To measure, baseline and analyze performance trends of your application across different geographies, browsers, and resolutions. If you don’t track and baseline your performance during normal operations, you won’t know how your applications are performing for your end-users during peak periods. Synthetic monitoring enables a consistent, reliable approach to measure performance throughout the days, weeks or months. With synthetic monitoring, baseline tests can mirror the way your end users access your applications. These simulated user tests can monitor key transactions across geographies, browsers, and devices. Armed with this data, you can assess whether you are meeting user requirements, identify areas to improve, and use the data for capacity planning. Established baseline metrics from synthetic monitoring will give you concrete data to support negotiations and to monitor going forward before entering an SLA. 
  • To track and benchmark your application performance versus the competitors. Benchmarking using synthetic monitoring provides valuable insight into how market leaders and the competition are performing. It also provides a context for shared goal-setting between IT and business stakeholders to improve business results, and as a tool for measuring performance over time.

What Synthetic Monitoring Will Not Do

  • Resolve end-user complaints. Synthetic monitoring would tell nothing about what the end user was actually doing or experiencing when a real user raises a support ticket.
  • Troubleshoot servers and network problems. Operation team may need visibility into servers and network related problems. Synthetic monitoring does not provide this visibility. 
  • Determine how server or network performance affects application performance. Under-resourced networks or servers impact application performance. Synthetic monitoring is not a good solution to identify root cause is such cases. 
  • Analyze the performance of every page in an application. Creating and maintaining scripts for synthetic testing is time-consuming, even for one application. It should be judiciously used for monitoring only critical flows of an application 
  • Validate the impact of change because of change in application or infrastructure. When IT team makes changes to applications or infrastructure, they must validate the impact of those changes on actual end-user experience to determine the impact. Comparing metrics from synthetic testing won’t provide the full picture.

How to Evaluate Synthetic Monitoring Tools

Creating Monitoring Scenarios

It should be as easy as navigating the website like real users. The best way to do that is to use a record and playback tool which captures user-like actions and starts monitoring them. Not all monitoring tools offer record and playback. A few website monitoring tools like CloudQA and Dynatrace have this capability while some of the popular tools like Pingdom requires you to code for synthetic monitoring. 

Due to ever increasing complexities of modern web applications, synthetic monitoring tools should be able to work on websites with technologies like single page applications. If the monitoring tool does not support working with complex web functionalities, the scope for catching performance issues is severely narrowed.

Once a scenario is created for monitoring, synthetic monitoring tools should provide an easy way to extend it. If such feature is not available then any incomplete scenarios can frustrate the tester working with the monitoring tool.

Management of Monitoring Scenarios

Agile methods bring frequent updates to the application. Hence, any synthetic monitoring tool should allow modification of scenarios that are as agile as the application development process.

Websites usually have many workflows; however, there are some common scenarios like login, logout, and payment. Synthetic monitoring tools should allow joining separate scenarios to create a new one; thereby, reducing a lot of effort in creating new scenarios. Hence, a monitoring tool should contain a library of scenarios which can be tested collectively and interchangeably.

Data-Driven Monitoring

No monitoring is complete without verifying all possible combinations of data inputs. For example, a website may have calendar settings/filter. In such cases, synthetic monitoring tools should be able to verify performance with alternating "Date" inputs. The same can be said about other variations like a "Filter and Sort" option on the website.

Minimize False Positives

False positives are one of the most annoying things about website monitoring. They, however, cannot be escaped. Issues arise from server maintenance, glitches, poor coding, and problems with the CDN. Synthetic monitoring tools should be capable of reducing false positives.

A well designed synthetic monitoring tool reduces overheads like retesting for any false alerts.

Only a handful of synthetic monitoring tools are resistant to unexpected behavior of an application. For example, web elements of apps developed using AngularJS are dynamic and load unpredictably. In such cases, an element loading slower than the speed of detection by a monitoring tool can misfire an alert.

Location-Based Monitoring

Latency could be higher from certain location(s) from where your customers access the website. Monitoring from different geographic locations is a way to see how the application performs with latency and load issues.

Alerts and Notification

Synthetic monitoring tools should offer an alerting mechanism for situations where the desired performance goes below an established threshold . You should check whether the alerting tool of your choice integrates easily with your technology stack. Bare minimum requirements for monitoring alerts are SMS and email. Integrations with popular tools like Slack and Pagerduty are also sought-after.


  • Baselining is an important feature for comparing current performance to a historical metric, or a baseline. The performance figures can be used as a comparative baseline for configuration changes.

  • Reports from a synthetic monitoring tool must include performance metrics for availability, uptime, fully-loaded time, network time, client time, server time, and resource timings.

  • Data retention is variable for monitoring tools. The retention offered is generally six months or one year.

Other Criteria

  • Synthetic monitoring is not readily available with most APM tools. An integration with APM tools is desirable in such cases. 

  • AI/ML can be an important feature to reduce false alerts, prioritize problems, and predict issues.

  • Few synthetic monitoring tools offer mobile browser support. This is important for businesses having sizeable web traffic through smartphones and tablets.

  • To see how the application behaves with different bandwidths, a bandwidth throttling support is essential.  

Sensu: workflow automation for monitoring. Learn more—download the whitepaper.

synthetic monitoring ,monitoring ,performance ,website performance

Published at DZone with permission of

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}