APM Spectrum: Frontend vs Backend Application Monitoring

This post was originally published on the Rigor Web Performance blog.

When having discussions with clients and prospective clients in the marketplace the inevitable question comes up: Where does Rigor sit on the application performance management (APM) spectrum?

There are many different ways that I can navigate to answer this question, but it can be difficult to explain unless I fully understand the technology background of the person asking the question.

When I first joined Rigor, I asked the same question and for a long time I was told that we were a “frontend monitoring solution.” Now that was all well and good, but I didn’t really understand what that meant or how our technology differentiated from other “APM” technologies that were designated as “backend.”

So in this blog, I will explain the difference between “frontend and backend APM technologies” for all the uninitiated out there who are unfamiliar with the myriad of buzzwords being thrown around the web performance industry today.

Backend Monitoring

Backend monitoring provides visibility into the performance of a client’s infrastructure. These include the HTTP server, middleware, database, third party API services, and more.  Components can have multiple instances, and components can exist in the same data center or be located in data centers across the globe. Some synonymous words for “backend monitoring” include: data center monitoring, infrastructure monitoring, application performance monitoring. 

Backend monitoring is helpful for resolving problems around the following:

  • Code Bugs
  • System Problems (Operating system issues, security issues)
  • Hardware Problems (CPU failure, disk failure, out of disk space)
  • Software Performance Problems

Frontend Monitoring

Front-end monitoring provides the finished view of the performance of your web application from the perspective of an end user and encompasses all third-party content. Frontend monitoring provides insight into what your user’s actually experience when they visit your website. This experience varies dramatically based on the device, network, location, and a host of other variables. Some synonymous words for “frontend monitoring” include: end user monitoring, user experience monitoring, web performance monitoring.

Unlike backend monitoring, there is more than one monitoring technique for measuring the frontend experience of end users, each with its relative strengths and weaknesses.

The first technique is called synthetic monitoring. Synthetic monitoring allows you to test and measure the experience of your web application by simulating traffic with set test variables (network, browser, location, device). Benefits of using synthetic monitoring can be found here.

The second technique is called Real User Monitoring or simply RUM. Rum is a javascript tag that site owners insert on their web page that tracks the users interactions with their site. Rum tags send back to administrators high level metrics such as response time, server time, and the location and device that a user is accessing from. Benefits of using RUM can be found here.

Frontend monitoring is helpful for resolving problems around the following:

  • Third Party Content
  • Web page structure, organization, and weight
  • Location, network, or browser-related performance problems
  • Troubleshooting the effectiveness of mobile websites or responsive-design

What to Use?

Both frontend and backend monitoring technologies offer valuable insight into the performance of your application. Ideally, you should be leveraging all of the technologies listed above. However, if your budget makes employing all of these technologies prohibitive, try to find a frontend technology to test only your mission critical web pages and scale your monitoring with your business. Frontend technologies tend to be the cheapest and simplest to implement and understanding/improving the experience of your end-user should be your goal from day one.

More of a visual learner? Check out this infographic!

Rigor vs APM

Published by

Chapman Lever

The Most Interesting Man in the World

Leave a Reply

Your email address will not be published. Required fields are marked *