Software Development Updates

It is essential to monitor the Node.js app to protect the effectiveness, reliability, and security of your Node.js applications. By monitoring the key metrics, you can find performance issues, security holes, and APIs with excessive slowness. In short, keeping a Node.js application stable, healthy, and user-friendly is what a Node.js development company always looks for, which is why performance monitoring is essential.

A wide variety of Node.js monitoring tools are available, each offers a unique combination of capabilities. Here, you will find tips and tricks for monitoring Nodejs applications along with some monitoring tools.

1. What is Node.js Monitoring?

Node.js performance monitoring refers to gathering performance data & real-time insights from applications running on Node.js and analyzing the results to ensure optimal service delivery. It includes monitoring the accessibility of applications, tracking log data and analytics, and reporting any potential threats. Additionally, it allows you to see the application stack graphically, which is great for finding problems and seeing where they came from. Therefore, it’s a great way to keep your program running smoothly and make the most of its features.

Factors that impact the performance of any program include high latency, recurring problems, memory leaks, server unavailability, and many more. As a result, Node.js performance monitoring enables you to observe how each component of your Node.js architecture and its supporting infrastructure behaves in detail.

2. Importance of Node.js Monitoring

When you deploy your Node.js application to the production environment, you’ll want to know the different pain points and bottlenecks that are impacting the performance of your application, so you can have a better idea of where it needs improvement. However, without a proper monitoring system, it can be difficult to get these details. Therefore, it’s important to integrate a robust monitoring system that can provide metrics to help improve the application’s performance.

You should be aware of the many performance issues and obstacles affecting your Node.js application before deploying it to the production server. This will help you identify areas that require improvement. Nevertheless, obtaining these details might be challenging in the absence of an adequate monitoring system. To enhance the application’s performance, it is crucial to have a strong monitoring system that can supply metrics.

Below are the reasons why is it important to have a proper monitoring system.

2.1 Eliminating Obstacles

The performance of your application is adversely affected by bottlenecks. They have the potential to slow down your application and annoy your end users. Running an inefficient function, like one that does database queries in a nested loop, or an inefficient query, like one that executes unnecessary joins, are both examples of bottlenecks.

Understanding elimination obstacles in detail by taking the example of an obstacle known as an “external API call”.

An external API call is a request to the server to get access to third-party resources. It can be problematic because a poorly optimized API call may consume more CPU time, memory space, network bandwidth, etc. increasing the load on the Node.js server. This can lead to difficult monitoring of error rates, API errors, and debugging. 

Example of an Inefficient Query

SELECT users.id, users.name, orders.id, orders.total_amount, products.name
FROM users
JOIN orders ON users.id = orders.user_id
JOIN products ON orders.product_id = products.id
WHERE users.city = 'New York';

Why Inefficient?

• The above query fetches more than the required columns to perform the Join operation leading to increased data size involved in transfer and processing. 
• The Join operation needs to find the matching rows between the given tables. To do this, it performs a full table scan identifying the matching rows and joining them. However, this is a very slow and inefficient process in the case of large tables. Therefore the related columns must be properly indexed to find the matching rows and join them easily.

Efficient Query Example

SELECT u.id, u.name, o.id AS order_id, o.total_amount, p.name AS product_name
FROM users u
JOIN orders o ON u.id = o.user_id
JOIN products p ON o.product_id = p.id
WHERE u.city = 'New York';

Explanation

Optimized version of the above inefficient query. Here, you can see that the select statement in this query only contains the necessary columns i.e.  u.id, u.name, o.id, o.total_amount, and p.name.

Efficient Query with Indexes to Reduce Search Time

CREATE INDEX idx_user_id ON users(id);
CREATE INDEX idx_order_user_id ON orders(user_id);
CREATE INDEX idx_order_product_id ON orders(product_id);
CREATE INDEX idx_users_city ON users(city);

Explanation

Here indexes are added to the column names, user.id, order.user_id, order.product_i, and users.city to easily retrieve the matching rows and perform the Join operation. These kinds of issues might reduce your app’s performance, particularly if they crop up in a heavily utilized section. By using a reliable monitoring technology, you may detect these obstacles in their early stages and resolve them before their disruptive potential.

2.2 Better User Experience

Poor user experience can drive users away from your application. Issues like slow API response times, app crashes, and server unavailability can significantly impact user satisfaction. These problems could go undetected until they’ve cost you clients if you don’t have a solid monitoring system.

As an example, it’s not always easy to manually identify which APIs are experiencing sluggish response times. However, with effective monitoring, you can measure the average response time for each API. In the event that one becomes stuck, you can quickly resolve the issue preventing people from abandoning your application.

2.3 Lower Expenses

Your Node.js application may have poorly optimized functions, which causes it to execute slowly. This can result in unexpected costs if you’re utilizing serverless computing. This kind of inefficient function can cause your computer resources to balloon out of control if you don’t have a reliable monitoring and warning system in place.

3. What to Monitor in Your Node.js Application?

In the context of monitoring Node.js performance, runtime efficiency-critical metrics are important. You should keep an eye on these important metrics in your Node.js app: 

3.1 Processing Time

A program’s responsiveness is an important factor in attracting users. If you want your application to respond quickly to user requests, you need to monitor the response time. Gaining an understanding of this statistic will enable you to prevent and manage latency, thereby enhancing your application’s performance. 

Establish a starting point for the program’s operations to monitor the latency of your apps. After that, the assessment is carried out to find how late your Node.js application is based on whether its efficiency is lower, constant, or over the baseline. Keep an eye on this to make sure your app’s service is running well for users. 

3.2 Monitoring Throughput

The event loop mechanism in Node.js enables it to handle multiple events asynchronously. Therefore throughput i.e. the number of actions processed simultaneously in a particular time interval becomes a crucial metric to monitor in your application. You can assess the performance of your application using this metric, figure out the delays, and work on them.

3.3 Error Rates

You can discover more about the error’s cause from its code, message, and stack trace. It is possible for your Node.js application to continuously throw the same error in certain situations. Possible causes include malfunctioning features, hostile attackers attempting to breach your application’s defenses using brute force, or an unauthorized user attempting to access a protected API.

You can avoid mistakes from badly impacting your application by implementing a solid monitoring system that alerts you when errors occur repeatedly. Something critical needs immediate attention if there is a surge in mistakes or if an error occurs regularly.

You can use the Sentry platform to track, manage, and resolve errors in your Node.js application. It is an open-source platform to detect and correct errors in real-time.

Use of sentry for stack traces and reporting to sentry dashboard.

try {
// Simulate fetching user data (might throw an error)
const user = await fetchDataFromUserDatabase();
if (!user) {
throw new Error('User not found');
}

res.json(user);
} catch (error) {
// Capture the exception with Sentry
Sentry.captureException(error);

res.status(500).send('Internal Server Error');
}

Explanation:

The above code snippet demonstrates Node.js error handling using the try-catch block. The given scenario is the retrieval of data from the database in an asynchronous operation. 

Try Block:

The try block contains the code where an error can occur. Therefore the function fetchDataFromUserDatabase() is included in the try block. The throw statement will throw the error if no user data is found in the database. 

Catch Block:

The catch block handles the error that occurred in the try block i.e. during the fetch operation. Here, it uses the Sentry platform to log the error and respond with HTTP status code 500 along with a generic, “Internal  Server Error” message. 

3.4 Downtime and System Health

Online sales will suffer if users are unable to access your application. Businesses relying on your APIs will also experience downtime if they are not available.

It may be expensive for an application to have frequent, unanticipated downtime. Integral to every reliable monitoring solution is the ability to observe and analyze system activity. Keeping your application up and running at all times by monitoring unauthorized access attempts should be your number one goal. 

Since they often gather service-level data, Node.js APMs may readily assist you in finding and avoiding downtimes. While this information can reveal how well your app processes requests, it may not be useful for determining the availability of your public sites or APIs. You may make the necessary modifications promptly to prevent any downtime.

3.5 Resource Usage

Your Node.js application’s resource consumption may be tracked using a reliable monitoring solution. Imperfect optimization of your application’s components leads to increased resource consumption, which in turn affects the application’s overall performance and increases associated expenses. Such technical debts might lead you to believe that additional hardware is necessary to manage the excessive resource use, which can be rather expensive. With the right monitoring system in place, you can identify areas that may need some optimization, leading to better performance and cost savings.

4. Node.js Monitoring Best Practices

There are best practices to consider to monitor Node.js performance efficiently. As best practices for monitoring Node.js performance, the following have been periodically used and shown to be effective: 

4.1 Establish the Criteria for Monitoring

The key to successful Node.js application monitoring is to understand what you need to monitor. The correct metrics can be traced and tracked, and data about your Node.js application’s performance can be collected in this way. 

Learning which logs to monitor is just as important as keeping an eye on latency, mistakes, productivity, and services. To do a successful monitoring exercise, you must first identify the essential occurrences.  

4.2 Configure Urgency-Based Alerts

Prioritize the configuration of notifications according to their significance. Each company has its system for determining which notifications are considered high priority and which are considered low priority. Not everyone on your team needs to respond immediately to high-priority notifications. Attention must be given promptly to high-priority notifications. Not configuring alerts according to priority means that less important warnings will get more attention than more critical ones. Your application may be badly impacted by this lack of assurance in reacting to notifications.

4.3 Ensure the Right Person Receives the Alerts

Although it would be more convenient to have all notifications sent to everyone, it is recommended to just send them to the person accountable for the occurrence. Not taking responsibility for it or expecting someone else to handle it becomes more likely when you notify everyone. If you want the people in charge of fixing the problem to feel empowered to do so, it’s best to send them notifications directly to their inbox.

5. Top 6 Node.js Monitoring Tools

Among the Node.js community, you may find a plethora of well-liked application monitoring tools. A selection of the most well-known ones is shown below.

5.1 PM2

Many Node.js developers rely on PM2 as their go-to application performance management tool. This tool collects metrics, like CPU and memory consumption of your program, how long it takes for HTTP requests to complete, how many errors it finds, and much more besides. You may see changes that can affect your program’s performance in real-time thanks to its online interface, which lets you monitor your application. When measurements exceed user-defined thresholds, PM2 may be set up to notify the user via email and Slack.

Installing PM2 Globally

npm install pm2 -g

Start Your App with PM2

pm2 start app.js

Monitor Logs and Stats

pm2 monit

Start the App with a Specific Name for Easy Monitoring

pm2 start app.js --name "my-app"

To View Your App Stats

pm2 status

To View the List of Processes

pm2 list

Actions on PM2

pm2 stop
pm2 restart
pm2 delete

5.2 Appmetrics

You can keep tabs on your app’s health with the help of App Metrics’s online web interface and tools like AppMetrics-dash. Since you can utilize it as middleware to construct a monitoring application, App Metrics is a proper monitoring tool for Node.js performance testing.

The App Metrics application dashboard shows the metrics for a Node.js application’s performance while it’s operating. You can utilize the module with ease. Its sole setup and placement requirements are an entry in the main Node.js file.

The open-source project App Metrics was created and is maintained by IBM. Providing a foundation for great application metrics applicable to many tasks is its principal objective. Among these responsibilities are monitoring the following: garbage collection, CPU profiling, database query performance, data transaction pace, and memory utilization.

Installing Appmetrics

npm install appmetrics --save

Initializing Appmetrics in Your App

const appmetrics = require('appmetrics');
const monitor = appmetrics.monitor();
// Log memory usage
monitor.on('memory', (data) => {
console.log('Memory Usage:', data);
});

// Log CPU usage
monitor.on('cpu', (data) => {
console.log('CPU Usage:', data);
});

// Log response times
monitor.on('http', (data) => {
console.log('HTTP Request:', data);
});

5.3 Prometheus

You can keep tabs on your Node.js app with Prometheus, an open-source monitoring tool. All the detailed performance data for all metrics is kept as a time series, which implies that statistics are collected at various times and saved with previous values for the same metric. As a result, you can see how measurements like CPU utilization vary over time with more clarity.

To help you keep an eye on your application and learn more about it, Prometheus includes a visualization tool. Another open-source Node.js monitoring tool for graphical representation, Grafana, can be integrated with Prometheus if you are dissatisfied with the default tools in Prometheus. With Grafana, you can make your unique dashboards to keep tabs on your app.

Installing Prometheus Client

npm install prom-client --save

Import the Prometheus Client

const client = require('prom-client');
const http = require('http');

// Create a counter for requests
const requestCounter = new client.Counter({
name: 'http_requests_total',
help: 'Total number of HTTP requests',
});

// Expose a /metrics endpoint
const server = http.createServer((req, res) => {
if (req.url === '/metrics') {
res.setHeader('Content-Type', client.register.contentType);
res.end(client.register.metrics());
} else {
requestCounter.inc();
res.end('Hello, World!');
}
});

server.listen(8080, () => {
console.log('Server is running at http://localhost:8080');
});

Code Explanation 

First, we import the client from the prom-client library. After that, we create a request counter to count HTTP requests. You can store the total number of HTTP requests in the http_requests_total metric. The metric is named http_requests_total and tracks the total number of HTTP requests, with labels for method (HTTP method) and route (endpoint path) to categorize metrics.

In the root endpoint /, you increment the counter using requestCounter.inc();, where you specify the HTTP method and the endpoint path.

5.4 Retrace

When it comes to maintaining and keeping tabs on application performance, Retrace is a popular cloud-based option. In conjunction with APM, it offers centralized logs, integration for errors and logs, and basic metrics for servers. Businesses of every kind use it to spot problems before they impact production and to jump into crisis mode when problems do emerge.

Using Retrace’s monitoring dashboard, the development team can monitor the code’s effectiveness almost in real-time. Shopping carts and login pages are just two examples of the kinds of websites that dashboards can monitor.

With the creation of Retrace, developers were able to gain a deeper understanding of how their code performed in both test and production environments. Using Retrace, developers may get centralized logging, code profiling, integrated logs, errors, and automated performance monitoring (APM) in a single location. The integrated errors and logs give developers detailed trace views, making it easy to identify the root cause of performance bottlenecks.

Installing the Stackify Logger Package Using npm

npm install stackify-logger

Importing the Logger

const stackify = require('stackify-logger');
// this should be executed only once in the app
stackify.start({apiKey: '***', appName: 'Node Application', env: 'Production'});
//Logging Examples
stackify.log('info', 'hey!');
stackify.debug('any message');
stackify.info('any message', {anything: 'this is metadata'});
stackify.warn('attention');
stackify.log('error', {error : new Error()});

5.5 Express Status Monitor

Express Status Monitor is essential for a JavaScript developer to have control over their server. Developers can gain complete control if a server issue or overload occurs with the aid of GitHub, an Express Status monitor module. It is a free and open-source tool that keeps tabs on Express.js, a widely used Node.js framework.

You can control the average overload, CPU use, response time, request frequency, and status code using Express Status Monitor.

Installation

npm install express-status-monitor

Importing Required Modules

const express = require('express');
const statusMonitor = require('express-status-monitor');
const app = express();
// Add Express Status Monitor middleware
app.use(statusMonitor());
// Your other middleware and routes
// ...
// Start the server
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(`Server is running on port ${PORT}`);
});

Explanation:

You need to install the Express Status Monitor from the npm into your application. Observe the /status part of the URL to access the monitoring dashboard in your web browser. E.g., http://localhost:3000/status denotes that your server is running locally on port 3000. You will see a dashboard showing the CPU utilization, memory consumed, response time, and so on. 

5.6 Sematext

Keeping tabs on and analyzing logs is easier using Sematext, which is a robust monitoring solution. It offers full-stack monitoring whether it’s in the cloud or on-premises. When you go full-stack, you can see how your apps are doing and how your infrastructure is managed.

Node.js can monitor several metrics, including request rate, server downtime, respiration, staff members, meetings, GC, and variations. You have the option to use a pre-made monitoring dashboard that looks great or create your own if you like. When anything goes wrong, you may get an alert via Slack, WebHooks, PageDuty, HipChat, or another application.

Install Sematext Agent

npm install @sematext/agent --save

Configure Sematext Monitoring in Your App

const sematext = require('@sematext/agent');
sematext.init({
apmToken: 'your-apm-token', // Replace with your Sematext APM token
logsToken: 'your-logs-token', // Replace with your Sematext logs token
appName: 'your-app-name',
});


// Example of custom metrics
sematext.apm.customMetrics('custom.metric', 1);

6. Conclusion

Though often overlooked, Node.js monitoring is a necessity. It ensures that your application does not have any security vulnerabilities or performance bottlenecks. Knowing them would certainly help deliver optimal user experience and avoid unnecessary costs down the road.

In this article, we explored some important metrics for you to keep an eye on, followed by a discussion on Node.js monitoring best practices and tools that can help you address the issues.   

Consider your project requirements and pick a suitable monitoring and alerting solution that fits the criteria. Using the right monitoring tool helps enhance the performance, reliability, and availability of your Node.js application.

FAQs:

How to monitor Node.js performance?

To monitor Node.js performance, follow these steps:

• Utilize pre-installed Node.js modules.
• Integrate a logging system to track essential errors
• Perform load testing 
• Utilize error-tracking tools 
• Track and analyze metrics at the system level 
• Utilize benchmarking tools for quantifying performance

How to check RAM usage in Node.js?

You can check RAM usage in Node.js using a memoryUsage() functionality that takes an object as input and returns data on the current process’s memory use.

How to check CPU utilization in Node.js?

To check CPU utilization, type npm install g node-inspector into your terminal to install the Node Inspector as an npm package and start using it. This will let you monitor your application’s performance metrics, including memory and CPU consumption.

How to monitor file changes in Node.js?

You can choose either the fs. watch() or fs. watchFile() feature option to monitor a file for any changes.