Alerty Blog

Everything You Need To Know About Javascript Monitoring

Written by Jack Dwyer | Jul 17, 2024 1:34:03 PM

JavaScript monitoring can be a crucial, albeit challenging, task in Vercel logging. Developers must understand how NextJS logging can simplify this process and improve the performance of their applications. 

Exploring JavaScript monitoring solutions and NextJS logging can enhance your coding skills and create a more user-friendly application.

Table of Contents

What Is JavaScript Monitoring?

Javascript monitoring systematically observes and analyzes the performance, behavior, and errors associated with JavaScript code execution within web applications. Javascript is a key scripting language for creating dynamic and interactive website elements. Monitoring Javascript is crucial for:

  • Ensuring the smooth functioning of web applications
  • Optimizing performance
  • Enhancing the overall user experience

JavaScript has become a critical component of modern e-commerce websites, powering rich user experiences and complex functionality. The increased reliance on JavaScript also introduces new challenges in monitoring and maintaining website performance and stability.

Key Aspects of Javascript Monitoring

Performance Monitoring

Tracking and analyzing the execution time and efficiency of Javascript code to identify bottlenecks and optimize critical e-commerce paths.

Code Profiling

Assessing which Javascript functions consume the most resources to pinpoint areas for optimization.

Error Detection

Automating the detection and resolution of Javascript bugs that can negatively impact the user experience and revenue.

UX Monitoring

Evaluate how Javascript code performs across browsers, devices, and network conditions to assess the end-user experience.

Resource Usage Monitoring

Tracking how the Javascript code consumes system resources like memory and CPU to identify potential issues like memory leaks.

Synthetic Monitoring

Proactively testing various user scenarios to identify potential performance problems before they impact real users.

Third-Party App Monitoring

Monitoring the impact of third-party scripts and plugins on the website's performance and user experience.

Related Reading

Why You Need To Implement JavaScript Monitoring

Implementing JavaScript monitoring is essential for several reasons, each significantly enhancing the

  • Performance
  • Reliability
  • User experience of web applications

Let's break down why this is so important:

User Experience Optimization

JavaScript monitoring gives real-time insights into how your web application performs. You can ensure a smooth and efficient user experience by racking metrics like:

  • Page load times
  • Script execution speed
  • Responsiveness 

Real User Monitoring (RUM) takes this further by showing how users interact with your site, helping you identify and fix performance issues that could frustrate users.

Proactive Issue Detection

Monitoring tools help you detect and log errors in the client-side code. This early detection is crucial for maintaining your application's functionality and preventing issues from escalating.

It helps pinpoint performance bottlenecks, allowing you to address these areas before they impact your users.

Performance Optimization

Through detailed analysis of JavaScript code execution, developers can:

  • Find and fix inefficient code
  • Optimize critical paths
  • Reduce the overall footprint of the code

This leads to faster load times and better overall performance. Monitoring resource usage also helps manage memory and CPU usage, preventing potential memory leaks and ensuring efficient use of system resources.

Third-Party Dependency Management

Many web applications rely on third-party scripts and dependencies. Monitoring these external components ensures they do not negatively impact your application's performance. Keeping track of different third-party libraries and APIs versions helps you make informed decisions about upgrades or changes to improve overall performance.

SEO and Business Impact

Page load speed is a crucial factor for search engine rankings. JavaScript monitoring ensures your application meets performance standards, positively affecting your SEO. Improved performance also correlates with better business metrics, such as:

  • Lower bounce rates
  • Higher conversion rates
  • Increased user engagement. 

This supports data-driven decision-making, aligning development efforts with business goals.

Continuous Improvement

JavaScript monitoring provides the data and insights needed for data-driven development. By continuously analyzing performance, developers can:

  • Prioritize improvements 
  • Allocate resources effectively

This ongoing feedback loop is essential for maintaining and enhancing the overall quality of web applications.

Comprehensive Monitoring for Modern Development Stacks

Alerty is a cloud monitoring service tailored for developers and early-stage startups. It provides application performance monitoring, database monitoring, and incident management. Key features include:

  • Support for Next.js, React, Vue, and Node.js, helping developers identify and resolve issues.
  • Monitoring of databases such as Supabase, PostgreSQL, and RDS, tracking key metrics like CPU usage and memory consumption.
  • Quick incident management and Real User Monitoring (RUM) to optimize user experience.
  • Universal service monitoring for dependencies like the Stripe API, OpenAI, and Vercel.

Alerty leverages AI to streamline the setup process, offering a more affordable solution than its competitors. It's user-friendly, allows quick and easy setup, and seamlessly integrates with tools like Sentry. This makes it perfect for developers and small teams seeking efficient, cost-effective monitoring.

Use Alerty's NextJS logging tool to detect issues before they impact your users!

How To Set Up Javascript Monitoring

Setting up Javascript monitoring can provide valuable insights into your website's performance. By adding a tracking code to your website's HTML head tag and integrating it into monitoring software like Google Analytics or Alerty, you can monitor real-time performance data and identify areas that require attention. 

This process is crucial for ensuring your website runs optimally and quickly identifying problematic pages.

Proactive Approach

Javascript monitoring is not a one-time task; it requires regular monitoring to ensure your website functions optimally. You can set up alerts to notify you of any performance changes, allowing you to address any issues that may arise promptly. By staying on top of performance data, you can ensure your website runs smoothly and effectively.

Common JavaScript Errors And How To Track Them

JavaScript is a dynamic language used in web development. It is prone to errors that disrupt your application's functionality. Understanding and tracking these errors efficiently is critical for a smooth user experience.

Syntax Errors

Syntax errors occur when code violates JavaScript syntax rules, caused by:

  • Missing semicolons
  • Mismatched brackets
  • Typos

Runtime Errors

These occur during code execution and are caused by operations like referencing undefined variables or calling non-existent functions.

Logical Errors

Mistakes in code logic where the syntax is correct, but the code doesn't perform as expected.

Type Errors

When operations are performed on values of the wrong type, like trying to call a non-function variable.

Tracking JavaScript Errors Effectively

Effective tracking and logging of JavaScript errors save time debugging and ensure a smooth user experience. Here are some ways to do it:

Using Console Logging

Utilize console.log(), console.error(), and console.warn() to output messages directly to the browser console for real-time feedback.

Error Handling with Try...Catch

Wrap your code in try...catch blocks to gracefully catch exceptions, preventing application crashes and providing meaningful error messages.

Global Error Handlers

Utilize window.onerror and window.onunhandledrejection to catch errors not handled locally, which is useful for catching unexpected exceptions in your application.

Error Tracking Tools

Integrating error-tracking tools like Alerty can provide comprehensive error logging, insights, and 

help monitor application health, automatically capturing exceptions and sending detailed reports for efficient issue fixing.

6 Best Practices For JavaScript Monitoring

1. Reduce Noisy Errors

It is crucial to prioritize and address the most critical JavaScript errors that impact vital user journeys and revenue. By reducing noisy errors, developers can concentrate on resolving issues that significantly affect the application's:

  • Overall performance 
  • User experience

2. Configure Allowed Domains

To enhance the efficiency of JavaScript monitoring, it is essential to automatically ignore errors from debugging scripts or third-party scripts from other domains. By configuring allowed domains, developers can filter out irrelevant errors and focus on the most crucial issues affecting the application's performance.

3. Filter Out Browser Extensions

By identifying and excluding errors caused by browser extensions, developers can eliminate noise and improve the accuracy of JavaScript monitoring. This practice ensures that monitoring tools focus on errors directly related to the application's codebase rather than issues arising from external factors.

4. Correlate Errors to Conversion Rate

Understanding the impact of JavaScript errors on the website's conversion rate provides valuable insights for developers. By correlating errors to the conversion rate, developers can prioritize and address critical issues impacting the application's:

  • Revenue 
  • User experience

5. Proactive Error Detection

Logging client-side JavaScript errors and performance bottlenecks quickly enables faster issue resolution. By implementing proactive error detection, developers can identify and address problems before they escalate, ensuring:

  • A seamless user experience 
  • Optimal application performance

6. Leverage Monitoring Tools

Utilizing specialized JavaScript monitoring tools automates the monitoring process and provides deeper insights into the application's performance. By leveraging monitoring tools, developers can streamline the monitoring process, identify critical issues more efficiently, and make data-driven decisions to optimize the application's performance.

Versatile Compatibility

Alerty is a robust cloud monitoring service tailored for developers and early-stage startups looking to enhance their application performance and incident management. By supporting a vast array of technologies like:

  • NextJS
  • React
  • Vue
  • Node.js

Alerty positions itself as a versatile tool for a wide range of developers. Alerty is not limited to just application performance monitoring; it also includes database monitoring capabilities, supporting databases such as:

  • Supabase
  • PostgreSQL
  • RDS

This breadth of compatibility ensures that developers can effectively monitor key metrics like CPU usage and memory consumption, allowing for more informed decisions regarding performance optimization.

Optimizing Development Workflow

One of Alerty's standout features is its quick incident management system. This feature is handy for developers looking to swiftly and efficiently address any potential issues that may arise. Alerty also offers Real User Monitoring (RUM), a vital tool for developers aiming to optimize user experiences. 

By tracking user behavior and interactions, RUM allows developers to pinpoint areas for improvement, resulting in a more user-friendly application. Alerty's Universal Service Monitoring extends its reach to various dependencies such as:

  • Stripe API
  • OpenAI
  • Vercel

This broad coverage ensures that developers can monitor all aspects of their applications, providing a comprehensive view of their system's health.

AI-Powered Efficiency and Seamless Integration

One of Alerty's main strengths is its AI-driven setup process. Alerty offers developers a cost-effective monitoring solution compared to competitors by utilizing artificial intelligence to simplify the setup process. This approach makes Alerty attractive for developers and small teams looking for efficient and affordable monitoring options. 

Alerty integrates seamlessly with popular tools like Sentry, further streamlining the monitoring process for developers. Alerty's emphasis on ease of use and efficient setup makes it an invaluable resource for developers seeking a robust monitoring solution. With Alerty's NextJS logging tool, developers can catch issues before they impact user experience, ensuring a smoother application performance overall.

Challenges Associated With JavaScript Monitoring

Managing Alerts and Notifications

One key challenge of JavaScript monitoring is managing the number of alert notifications you receive. Too few notifications might cause you to miss an issue, and too many notifications may cause you to become overwhelmed by your dashboard. 

To ensure you receive the most helpful notifications, customize alert settings to prioritize serious issues, such as impacting the user experience or significantly slowing down page loading times. Tailoring these alerts helps you focus on what matters most without getting bogged down by less critical issues.

Monitoring Code Changes

In addition to customizing alert settings, it’s crucial to ensure that your monitoring system can detect and alert you to any changes in your code. This is especially important for frequently updated websites, as changes to the code can significantly impact website performance. 

By monitoring your code for changes, you can quickly identify and address any issues that may arise. This proactive approach ensures that updates or new features don't inadvertently degrade the user experience or introduce new bugs.

Performance Overhead

Integrating monitoring tools can introduce additional performance overhead. These tools must track various metrics and log detailed data, potentially slowing down the application, especially if not optimized properly. 

To mitigate this, choose lightweight monitoring tools and configure them to balance:

  • Capturing essential data 
  • Minimizing performance impact

Balancing Performance & Insights

Review and optimize the monitoring configurations to ensure they do not hamper the application's performance. Leveraging sampling techniques and reducing the granularity of collected data can also help manage the overhead effectively.

Data Privacy and Security

Monitoring tools collect vast amounts of data, some of which may be sensitive. Ensuring this data is handled securely to comply with privacy regulations (like GDPR) is crucial. There's a risk of exposing user data if the monitoring system is not adequately secured. 

Implement strict data governance policies to manage the collected data. Ensure that sensitive data is

  • Anonymized 
  • Encrypted

Security & Data Protection

Regularly audit the monitoring systems and access controls to protect against unauthorized access. Compliance with data protection regulations should be a priority, and monitoring tools should offer features that facilitate these compliance requirements.

False Positives and Data Noise

JavaScript monitoring can sometimes generate false positives or overwhelming data noise, making it difficult to identify genuine issues. This can lead to alert fatigue, where critical alerts may be overlooked. 

Smart Alerting

  • Implement intelligent alerting mechanisms that prioritize and filter out non-critical issues.
  • Utilize machine learning and anomaly detection to distinguish between normal variations and actual problems.
  • Regularly tune the alert thresholds and rules based on the application's evolving behavior to reduce noise and improve the accuracy of alerts. 

6 Troubleshooting Tips For Javascript Monitoring

1. Prioritize and Manage Alerts

Customize alert settings to prioritize the most critical issues that impact user experience or significantly slow down page loading. Avoid getting overwhelmed by too many alerts—focus on the ones most matter.

2. Stay on Top of Code Changes

Ensure your monitoring system can detect and alert you to any changes in your JavaScript code, especially for frequently updated websites. This allows you to identify and address issues introduced by code changes quickly.

3. Review Alerts Promptly

The most effective troubleshooting tip is to review notification alerts as soon as possible to identify and address issues before they escalate. Take screenshots of error codes or broken features to aid in debugging.

4. Keep Monitoring Tools Up-to-Date

Check for updates to your JavaScript monitoring software regularly and apply them to ensure you have the latest features and bug fixes.

5. Leverage Browser Developer Tools

Use the browser's developer tools, such as the console, network analyzer, and debugger, to:

  • Inspect variables
  • Track function calls
  • Analyze network requests,
  • Diagnose performance issues

6. Employ Debugging Techniques

Set breakpoints in your code to pause execution and examine variable values. Step through the code line-by-line and invoke the browser's debugger using the debugger statement. 

Utilize the console.trace() method to output a stack trace and understand the sequence of function calls leading to an issue.

Related Reading

7 Best Tools For Javascript Monitoring

1. Alerty

Alerty is a robust cloud monitoring service tailored for developers and early-stage startups looking to enhance their application performance and incident management. By supporting a vast array of technologies like:

  • NextJS
  • React
  • Vue
  • Node.js

Alerty positions itself as a versatile tool for a wide range of developers. Alerty is not limited to just application performance monitoring; it also includes database monitoring capabilities, supporting databases such as:

  • Supabase
  • PostgreSQL
  • RDS

This breadth of compatibility ensures that developers can effectively monitor key metrics like CPU usage and memory consumption, allowing for more informed decisions regarding performance optimization.

2. SigNoz

SigNoz is an MIT-licensed, open-source alternative to many APM tools. It's a full-stack observability tool that allows you to monitor metrics and traces, with Log management on the way. 

SigNoz supports OpenTelemetry for instrumentation and offers out-of-the-box charts and visualizations. It runs on either Kafka+Druid or the OLAP database ClickHouse for the backend. The Query service is built-in GO, and the front end is Typescript-powered.

3. LogRocket

LogRocket offers a complex front-end monitoring and product analysis platform. It allows you to:

  • Replay sessions
  • Evaluate front-end performance impact
  • Analyze end-user experience
  • Track errors
  • Evaluate metrics critical for conversions 

LogRocket analyses the impact of UX issues, allowing you to see user journeys and also allows for alerting and integration with third-party tools.

4. Sentry.io

Sentry offers APM for JavaScript applications and frameworks like:

  • React
  • Angular
  • Ember
  • Vue
  • Next.js
  • Electron

Performance Deep Dives

Sentry allows you to:

  • Monitor and identify application performance issues
  • Observe and obtain end-to-end tracing
  • See the root cause of performance issues

Sentry's APM allows for the collection of complete stack traces, or you can simulate the error environment.

5.  Dynatrace

Dynatrace's all-in-one monitoring solution also offers an APM tool for automated observability for cloud-native services. It provides:

  • Automated discovery and mapping
  • End-to-end observability
  • Multiplatform app monitoring
  • Root-cause and impact analysis

It's a feature-packed, enterprise-ready monitoring solution, often making it expensive and painful.

6. AppSignal

AppSignal is a tool that provides an overview of your frontend and backend performance, has host monitoring and error tracking, and allows you to collect metrics from your application. 

Use easy-to-customize dashboards to track: 

  • Load size
  • Database queries
  • Revenue

Limited Functionality

AppSignal has an anomaly analysis system with precautionary warnings that trigger when things are not working. The most significant disadvantage is that it needs fundamental logging and monitoring features.

7. Glitchtip

Glitchtip is an open-source bug reporting application that collects and organizes problem reports into a legible, fixable format. The solution appears to have been developed in response to Sentry's decision to abandon open-source, but it still works with Sentry's open SDK. 

Open-Source Benefits

You can host the solution locally because it is open-source, but the company also provides hosting choices. In addition, it outperforms other alternatives because it is open-source, which means it has a larger community of users than some other products. 

Glitchtip is still in its infancy but could be the ideal answer for tiny enterprises or low-budget projects requiring open-source.

Related Reading

Catch Issues Before They Affect Your Users with Alerty's NextJS Logging Tool

Alerty is a robust cloud monitoring service tailored for developers and early-stage startups looking to enhance their application performance and incident management. By supporting a vast array of technologies like:

  • NextJS
  • React
  • Vue
  • Node.js

Alerty positions itself as a versatile tool for a wide range of developers. Alerty is not limited to just application performance monitoring; it also includes database monitoring capabilities, supporting databases such as:

  • Supabase
  • PostgreSQL
  • RDS

This breadth of compatibility ensures that developers can effectively monitor key metrics like CPU usage and memory consumption, allowing for more informed decisions regarding performance optimization.

Optimizing Development Workflow

One of Alerty's standout features is its quick incident management system. This feature is handy for developers looking to swiftly and efficiently address any potential issues that may arise. Alerty also offers Real User Monitoring (RUM), a key tool for developers aiming to optimize user experiences. 

By tracking user behavior and interactions, RUM allows developers to pinpoint areas for improvement, resulting in a more user-friendly application. Alerty's Universal Service Monitoring extends its reach to various dependencies such as:

  • Stripe API
  • OpenAI
  • Vercel

This broad coverage ensures that developers can monitor all aspects of their applications, providing a comprehensive view of their system's health.

AI-Powered Efficiency and Seamless Integration

One of Alerty's main strengths is its AI-driven setup process. Alerty offers developers a cost-effective monitoring solution compared to competitors by utilizing artificial intelligence to simplify the setup process. This approach makes Alerty attractive for developers and small teams looking for efficient and affordable monitoring options. 

Alerty integrates seamlessly with popular tools like Sentry, further streamlining the monitoring process for developers. Alerty's emphasis on ease of use and efficient setup makes it an invaluable resource for developers seeking a robust monitoring solution. With Alerty's NextJS logging tool, developers can catch issues before they impact user experience, ensuring a smoother application performance overall.