Leveraging OpenTelemetry in Next.js 14

Anton Ioffe - November 12th 2023 - 11 minutes read

In the ever-evolving landscape of modern web development, the quest for greater system transparency and operational intelligence has brought observability to the forefront. Next.js 14 ushers in a new realm of possibilities for building and monitoring robust web applications. This article delves into the integration and potent advantages of employing OpenTelemetry within your Next.js projects, promising to illuminate the path to superior observability. From a thorough walkthrough of integrating this powerful tool, to leveraging its tracing capabilities to pinpoint performance dilemmas and customizing telemetry to suit your unique needs, we shall navigate the intricacies of enhancing your application's insightfulness. Finally, we'll tackle strategies to scale and secure your telemetry practices as your application grows. Get ready to transform the way you understand and optimize your Next.js applications, embarking on a journey towards an observable, insight-rich future.

Embracing OpenTelemetry for Enhanced Observability in Next.js 14 Applications

In the realm of modern web development, observability serves as the cornerstone for deconstructing the intricate behaviors of complex systems like those built with Next.js 14. Precise observability facilitates not only monitoring system health but also informs strategies to enhance performance, ensuring systems are resilient and consistently offering excellent user experiences. Next.js 14 applications benefit from the inclusion of OpenTelemetry, which provides developers with the essential tools to monitor, understand, and optimize application flows effectively.

OpenTelemetry emerges as a pivotal component in this context, providing a suite of instrumentation capabilities for collecting a diverse set of telemetry data—including metrics, logs, and traces. Its strength lies in its platform-neutral design, endorsing a smooth transition between observability providers. For architects of Next.js 14 applications, OpenTelemetry fosters a flexible and future-ready approach to monitoring, capable of adapting to the application's lifecycle and the dynamic nature of observability services.

Next.js 14 comes with integrated support for OpenTelemetry, significantly streamlining the tracing process. By automatically instrumenting key functions such as getStaticProps with detailed span data, Next.js allows developers to glean insights into server-side execution with minimal manual effort. This automatic instrumentation captures critical operational metrics within serverless functions, overcoming manual instrumentation challenges.

To further the depth of insight, developers should consider extending the default instrumentation with custom spans for a tailored observability profile. This initiative equips developers with the precision required for pinpointing inefficiencies and formulating effective solutions to enhance application performance. Contemporary bindings in Next.js for OpenTelemetry are targeted at serverless functions, leaving scope for future enhancement to potentially include edge and client-side code instrumentation.

Adopting OpenTelemetry in a Next.js 14 project is a prudent move towards optimizing performance and maintaining system health. The structured data that OpenTelemetry yields elevates a developer's capacity to make informed optimization decisions. Developers might consider how the current observability strategy aligns with the evolving needs of the application or in what ways further developments to OpenTelemetry could strengthen its role within the development pipeline. Such considerations underscore the importance of a proactive approach to leveraging OpenTelemetry's robust capabilities within Next.js 14 applications.

Integrating OpenTelemetry with Next.js 14: Practical Walkthrough

To successfully integrate OpenTelemetry with your Next.js 14 project, begin by ensuring your application is set up to handle server-side processes, as Next.js openly supports OpenTelemetry for these operations. Navigate to your project's root and install the OpenTelemetry Node.js packages:

npm install @opentelemetry/sdk-node @opentelemetry/resources @opentelemetry/semantic-conventions @opentelemetry/sdk-trace-node @opentelemetry/exporter-trace-otlp-http

Once the necessary packages are installed, create an instrumentation.ts file at the root of your project. This file will serve as the entry point for initializing the OpenTelemetry NodeSDK. The setup should look something like this:

const { NodeSDK } = require('@opentelemetry/sdk-node');
const { Resource } = require('@opentelemetry/resources');
const { SemanticResourceAttributes } = require('@opentelemetry/semantic-conventions');
const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-http');

const sdk = new NodeSDK({
  resource: new Resource({
    [SemanticResourceAttributes.SERVICE_NAME]: 'your-service-name',
  traceExporter: new OTLPTraceExporter(),

// Initialize the SDK
  .then(() => console.log('Tracing initialized'))
  .catch((error) => console.error('Error initializing tracing', error));

module.exports = sdk;

For the initial setup, simply import the instrumentation.ts as the first module in your server-side application code, ensuring OpenTelemetry starts with your application. In Next.js 14, a typical place to do this would be at the top of your server.js or index.js file, depending on your starting point:


To check if the instrumentation works, set the environment variable NEXT_OTEL_VERBOSE=1. This will display additional spans and can be done by including it in your .env.local file or directly in the terminal before running your Next.js server.

NEXT_OTEL_VERBOSE=1 npm run dev

Finally, remember that you might need to self-host an OpenTelemetry Collector if you're deploying outside of platforms like Vercel. If so, follow the official OpenTelemetry Collector documentation to set up the collector and configure it to receive data from your Next.js application. The exports from the Node.js SDK will target this collector to provide you with the traces from your server-side code, giving you insights into the performance and potential bottlenecks in your application.

This practical walkthrough aims to give you a hands-on understanding of how to implement OpenTelemetry within a Next.js 14 project. By following these steps, you can capture essential trace data, allowing for a robust observability setup in your server-side Next.js environment. Remember, this is only an initial setup and further customization and configuration will be required to tailor OpenTelemetry to specific needs within your applications.

Harvesting and Analyzing Traces with OpenTelemetry in Next.js

Harvesting and analyzing trace data in Next.js applications enables developers to dissect serverless function executions and gain actionable insights. By diving into traces, hidden inefficiencies come to light, guiding developers toward specific optimizations. This analytical approach not only uncovers performance issues but also validates the impact of improvements, contributing to the fine-tuning of applications.

As part of this deep dive, one would scrutinize trace outputs to observe the orchestration of events – from database interactions to API calls. Monitoring the flow and latency of such operations through trace data is key to optimizing execution paths and resource consumption. Identifying patterns or bottlenecks becomes easier, leading to targeted changes that enhance response times.

It is paramount that each trace is accurately annotated with meaningful metadata and that parent-child span relationships are correctly maintained. In the absence of precise trace information, the root cause of issues can be masked, impeding effective analysis and optimization. High-fidelity trace data, rich with contextual information, propels developers toward thorough performance evaluations and swift remediation.

An exemplary strategy for analyzing trace data would hinge on correlating timing discrepancies with resource usage spikes. Developers might examine spans that encompass third-party API calls, seeking correlations between slow responses and overall request latency. Moreover, they would assess database query patterns within spans, identifying repeated queries that suggest the need for caching or query optimization.

In conclusion, effective leveraging of OpenTelemetry’s trace data is a strategic asset for developers working on Next.js serverless functions. The diligent collection and rigorous examination of trace data unearth areas for improvement, thus tightening the efficiency of the serverless execution model. This dedication to granular observability ensures that even elusive performance challenges are addressed, paving the way for a responsive and resilient application experience.

Performance Bottlenecks and Anomaly Detection

Within the power of OpenTelemetry's tracing capabilities lies a potent tool for identifying performance bottlenecks within an application. By examining trace data, developers can pinpoint slow-running segments of code, inefficient database queries, or API calls contributing to latency. Spans, representing discrete units of work, accumulate timing information that, when analyzed, reveal these bottlenecks. The recognition of anomalies within the span durations or the frequency of span errors may also signal underlying issues that warrant closer scrutiny.

Anomalies can manifest as a marked deviation from typical response time patterns or as unexpected spikes in error rates. Techniques like deploying service-level indicators (SLIs) and utilizing span attributes enable developers to define normal operation thresholds, against which performance can be continuously measured. When metrics exceed these thresholds, tracing data serves as a starting point for root cause analysis. Tracing not only highlights the problematic component but also shows its execution context, detailing intertwined service interactions.

Optimization entails not just identifying a bottleneck but understanding its cause. This is where tracing's granularity is essential. For instance, a particular service might exhibit increased latency, yet traces would allow developers to dissect the sequence of events within that service, isolating whether the delay is due to algorithmic inefficiency, resource contention, or a dependency waiting period. The wealth of span attributes, such as database table names or cache hit rates, can guide developers in tuning performance or redesigning aspects of the architecture for better scalability and resilience.

Tracing data can also aid in detecting anomalies post-optimization changes, ensuring that modifications have had the intended effect. By comparing traces before and after adjustments, developers can confirm the alleviation of bottlenecks or spot any unintended side-effects that may have been introduced elsewhere. This iterative process of performance tuning is crucial for maintaining an application’s health and user satisfaction.

Lastly, proactive monitoring using the tracing data gathered by OpenTelemetry can lead to the preemptive identification of potential issues. By analyzing patterns over time, developers can predict trends and plan capacity accordingly or adjust resource allocation strategies. This proactive stance positions teams to thwart bottlenecks before they escalate to user-impacting problems, thereby fostering a more robust and responsive application environment.

Extending OpenTelemetry for Custom Telemetry Needs

When working with Next.js applications, custom telemetry is often a necessity. By leveraging the OpenTelemetry API, developers can add custom spans and metrics tailored to their specific needs. Let's delve into how we can augment the default span collection with custom spans using OpenTelemetry, demonstrating this customization capability within Next.js.

import { trace } from '@opentelemetry/api';
export async function fetchGithubStars() {
    return await trace.getTracer('nextjs-custom')
        .startActiveSpan('fetchGithubStars', async (span) => {
            try {
                // Your fetch logic here
            } catch (error) {
                // Error handling
            } finally {

In the above code, the creation of a custom span named fetchGithubStars enables developers to monitor the time it takes to fetch GitHub stars. By attaching custom logic inside this span, we gather more granular and relevant data for our application.

The flexibility of custom spans means that developers can monitor specific areas of their code, such as database queries or external API calls. Through active spans like the one demonstrated, there is an opportunity to measure the performance and potential delays within specific operations that could impact overall application responsiveness.

function databaseQuery() {
    const span = tracer.startSpan('databaseQuery');
    // Database query logic
    // Be sure to record any exceptions

However, developers must take heed of potential pitfalls when implementing custom spans. Common mistakes include failing to end spans, which can lead to memory leaks, or mislabeling spans, making it harder to correlate data and identify issues. It is crucial to ensure proper closure of spans and use precise, descriptive names that adhere to semantic conventions.

A well-instrumented application using custom spans can help developers discover opportunities for performance optimization previously unseen. The question remains, how can we further enhance the quality of telemetry data? By refining the attributes attached to each span, you can achieve more detailed insights. Consider whether you're capturing all relevant data that defines the operation's context and outcome. If the operation interacts with particular entities, like users or products, those identifiers are likely worth tracking. Would adding such detail enhance your diagnostic capabilities?

Finally, integrating custom telemetry with adherence to the aforementioned best practices can be a deciding factor in your application's ability to scale while maintaining high performance and reliability. Discuss amongst your team which critical paths or operations in your application could benefit most from custom instrumentation. How can these focused insights guide your optimization efforts and contribute to a better understanding of your system's behavior under different load conditions?

Scaling and Securing OpenTelemetry in Production

OpenTelemetry has facilitated a revolutionary step forward in observability, fueling engineers with high-resolution insights into their Next.js applications. Nonetheless, when elevating your deployment from a trial phase to a full-scale production, meticulous attention to scalability and security measures is paramount. A core consideration lies in designing an architecture that can handle a growing volume of telemetry data without performance degradation. Efficient sampling strategies can alleviate data deluge by transmitting a representative subset of the total data, which can drastically reduce storage costs and network overhead while still preserving the critical diagnostic value of the traces. Likewise, adopting a microservices-based approach for your OpenTelemetry Collector deployment can lead to better load distribution and easier management under high-throughput conditions.

On the front of security, guaranteeing the integrity and confidentiality of trace data is non-negotiable. Trace information may inadvertently contain sensitive user data, so it's incumbent upon developers to establish secure transmission channels, generally via encryption-in-transit, and restrict data access rigorously using authentication and authorization mechanisms. Moreover, since telemetry data often resides in third-party observability platforms, ensuring that data is handled in compliance with data-protection regulations like GDPR and CCPA is essential. It may involve data masking techniques or filtering certain data points out before they leave the network boundary.

Performance tuning of your Next.js application should not be at the expense of system security. It involves a strategic balance between data granularity and operational secrecy, ensuring that finer-level details don't expose the system to potential vulnerabilities. It's of particular importance when enabling verbose tracing, as it's tempting to capture as much data as possible without considering the exposure of sensitive information. Therefore, defining strict data governance protocols that dictate which data points are safe to collect is vital. Ensuring a strong correlation between internal development teams and security operations will cultivate a culture of observability that respects and upholds stringent data security regulations.

Another angle to consider is resource allocation. As demand increases, the infrastructure hosting your OpenTelemetry services will need scaling. Whether it’s through auto-scaling groups or orchestrated containers, provisioning must sync with predictable load patterns, and be complemented by monitoring systems that alert to scaling needs in real-time. A common mistake is to under-provision resources, which can lead to lost data and potential service outages. Revisit your resource allocation frequently to ensure it scales alongside your application's growing user base and increased complexity.

Lastly, despite employing cutting-edge tools like OpenTelemetry, the human factor remains integral to the security of your setup. Regularly conducting code audits, security assessments, and training developers in best practices for observability code can mitigate many vulnerabilities from the outset. This preemptive stance combined with automated security scanning tools can significantly curtail the risk of exposing your production environment to potential breaches. Emphasizing security in the development lifecycle, especially when observability tools are involved, paves the way for resilient, secure instrumented applications.


The article explores the integration and benefits of using OpenTelemetry in Next.js 14 for enhanced observability in web applications. It covers how to integrate OpenTelemetry with Next.js 14, analyzing trace data and identifying performance bottlenecks, extending OpenTelemetry for custom telemetry needs, and scaling and securing OpenTelemetry in production. The key takeaways include the importance of observability in modern web development, the capabilities of OpenTelemetry for monitoring and optimizing applications, and the need for scalability and security when implementing OpenTelemetry. The challenging technical task for the reader is to implement custom spans using OpenTelemetry in their Next.js application to monitor specific areas of code or operations that could impact overall application responsiveness.