Debugging and Issue Resolution

Logging Strategy, Visualization, and API Performance Monitoring

Error Tracking and Alerting
Error Tracking and Alerting

Logging Strategy, Visualization, and API Performance Monitoring

  1. Debugging and Issue Resolution: Logging allows developers to track and record the execution flow and state of a backend application. It provides valuable insights into the application's behavior, allowing developers to identify and debug issues effectively. By examining log messages, developers can trace the sequence of events leading up to errors or unexpected behavior, helping them pinpoint the root cause and resolve issues efficiently.
  2. Error Tracking and Alerting: Backend applications often encounter errors and exceptions during their operation. Logging these errors helps in identifying and understanding the nature and frequency of the problems. With proper logging, developers can quickly detect and diagnose errors, enabling them to take corrective actions promptly. Additionally, automated alerting systems can be set up to notify the development team or system administrators when critical errors occur, allowing them to respond swiftly and minimize downtime.
  3. Performance Optimization: Performance monitoring provides insights into the runtime behavior and efficiency of a backend application. By tracking metrics such as response times, resource consumption (CPU, memory, disk I/O), and database query performance, developers can identify performance bottlenecks and areas for optimization. Monitoring helps to understand how the application performs under various loads, allowing developers to fine-tune and optimize the code, database queries, and infrastructure to ensure optimal performance and scalability.
  4. Capacity Planning and Scaling: Performance monitoring data can aid in capacity planning and scaling strategies. By analyzing historical performance metrics, developers can identify usage patterns, peak traffic periods, and resource requirements. This information is invaluable when determining when and how to scale the backend infrastructure to handle increasing loads. Performance monitoring helps ensure that the application's capacity is aligned with the user demand, preventing issues such as performance degradation, slow response times, or crashes due to insufficient resources.
  5. Security and Auditing: Logging plays a crucial role in security and auditing aspects of backend applications. By logging relevant security-related events and access attempts, developers can track and analyze potential security breaches or suspicious activities. In the event of a security incident, log data can provide essential forensic evidence for investigation and resolution. Additionally, logging can assist in meeting compliance and regulatory requirements by maintaining an audit trail of critical actions performed within the application.
In summary, logging and performance monitoring are vital for backend applications as they facilitate effective debugging, error tracking, performance optimization, capacity planning, scaling, security, and auditing. These practices help developers ensure the reliability, performance, and security of the application, leading to a better user experience and reduced downtime.

Logging Strategy

This section outlines the recommended logging strategy for a Node.js backend application. Logging is essential for monitoring and troubleshooting the application, providing valuable insights into its execution. A well-defined logging strategy helps in debugging issues, understanding application behavior, and identifying potential errors or warnings.

Recommended Approach

To implement the logging strategy, follow these guidelines:
  1. Choose a Logging Library: Select a logging library that best fits your application's requirements and integrates well with your existing stack. Consider factors such as ease of use, performance, flexibility, and community support.
  2. Configure Log Levels: Configure the logging library to use the four levels defined in this strategy (debug, info, warning, and error). This allows you to control the verbosity of logs based on your needs.
  3. Define Log Formats: Determine the format of log messages to ensure consistency and readability. Include relevant information such as timestamps, log levels, source code locations, and contextual details.
  4. Log Relevant Information: Log events, errors, and important information that can help in understanding the application's behavior and diagnosing issues. Avoid logging sensitive or unnecessary data to maintain security and performance.
  5. Handle Errors: Implement appropriate error handling mechanisms to catch and log errors. Ensure that detailed error messages are captured, including stack traces, when applicable. This helps in effective troubleshooting and root cause analysis.
  6. Log Output and Storage: Decide where the log output should be directed. It could be the console, log files, a centralized logging service, or a combination of these options. Consider log rotation and archiving to manage disk space effectively.
  7. Monitoring and Alerting: Implement monitoring and alerting mechanisms to notify relevant stakeholders about critical errors or warning events. This enables timely response and proactive maintenance.
  8. Review and Improve: Regularly review your logging strategy to ensure it aligns with your application's evolving requirements. Consider feedback from developers, operations personnel, and users to identify areas for improvement.
A well-defined logging strategy is crucial for Node.js backend applications to facilitate effective monitoring, troubleshooting, and maintenance. By following the recommended approach outlined in this document, you can establish consistent logging practices that aid in understanding application behavior, diagnosing issues, and maintaining a reliable system. Remember to select an appropriate logging library and configure it to capture the desired log levels and formats. Continuously review and refine your logging strategy to meet changing needs and evolving best practices.

Logging Libraries

There are several logging libraries available for Node.js that can be used to implement the logging strategy. Here are some popular options:


Pino is a long-established and very popular logging tool, with over 10.9K Github stars and millions of downloads on npm. Pino is a popular logging library for Node.js because it provides several key features that make it well-suited for use in Node.js applications:
  • Fast - Pino is designed to be fast and lightweight, with a focus on performance. It uses a binary format for log messages, which allows it to generate log output quickly and efficiently.
  • Structured logs - Pino logs messages in JSON format, which allows for easy parsing, filtering, and analysis of log data. This makes it easier to search, visualize, and analyze log data, and to integrate log data into other systems.
  • Easy to extend - Pino is designed to be highly extensible, and includes a number of built-in plugins that can be used to add additional functionality, such as writing log data to a file or sending log data to a remote server.
  • Low overhead - Pino is a highly efficient Node.js logging library due to its minimal resource utilization. The logging process with Pino gradually accumulates messages, leading to a throttling of the application and a decrease in the number of requests per second. Throttling is a technique where the function connected to an event is triggered to run only once within a specified time frame, even if the event is fired multiple times.
  • Transports - Pino offers a variety of options for sending logs, including writing to files, displaying in the console, and utilizing platforms such as Sentry, Azure Application Insights, and CouchDB.
To use Pino in a Node.js application, follow these steps:
Installing Pino
To install Pino, simply install it by running the following command in a new directory:
yarn add pino
Import - in your Node.js application, import Pino by adding the following line of code at the top of your file:
import pino from 'pino';
Using Pino
Initialization - initialize Pino by creating a logger instance, for example:
const logger = pino({
  level: 'info'
This script produces logs with a logging level of INFO and above on the console.
Log levels in Pino
The default log levels in Pino are (ordered by ascending severity) trace, debug, info, warn, error, and fatal, and each of these have a corresponding method on the logger:
import logger from './logger';

When you execute the code above, you will get the following output:
Notice how the severity level is represented by a number that increments in 10s according to the severity of the event. You'll also observe that no entry is emitted for the debug() and trace() methods due to the default minimum level on a Pino logger (info) which causes less severe events to be suppressed.
This code only creates a Pino logger instance with the log level set to INFO. No log messages are generated or displayed until you log something using the logger instance. For example:'This is an info message');
This would produce the following output on the console:
{"level":30,"time":1624825088703,"msg":"This is an info message","pid":1234,"hostname":"my-machine"}
The logged data displayed on the console includes the log level, the timestamp when it was recorded, the message being logged, an identifier for the log, and the hostname.
Logging - you can use the logger instance to log other messages in your application as well. For example:
logger.warn('This is a warning message');
logger.error('This is an error message');
Output - by default, Pino logs to the console. If we want to change the output, we can use any of the known transport methods from Pino to send the logs to either a file, or to a dashboard like Loki
As an example, below is how we can send over the logs to Loki:
npm install pino-loki
import pino from 'pino'
import type { LokiOptions } from 'pino-loki'

const transport = pino.transport({
  target: "pino-loki",
  options: {
    batching: true,
    interval: 5,

    host: 'https://my-loki-instance:3100',
    basicAuth: {
      username: "username",
      password: "password",

const logger = pino(transport);
logger.error({ foo: 'bar' })


With over 20K stars on GitHub, Winston is a very popular logging library for Node.js. Winston is a unique logging library in the Node.js ecosystem because of its comprehensive feature set and ease of use. Some of the reasons why Winston stands out are:
  • Flexible - Winston is highly customizable, and provides a variety of logging options and transport mechanisms that allow logs to be written to multiple outputs, such as the console, a file, or a remote server.
  • Queryable logs - Winston provides a query-able log archive, which makes it easier to search and analyze logs.
  • Easy to use - Winston has a simple, easy-to-use API that makes it easy to get started with logging in a Node.js application. It provides a minimal set of core functionality, while also allowing developers to extend and customize the logging functionality as needed.
  • Well-documented - Winston has a comprehensive documentation that provides detailed information about its API, and includes a number of examples and tutorials to help developers get started quickly and easily.
  • Community-driven - Winston is an open-source project with a large and active community of developers, which helps ensure that the library is well-maintained, bug-free, and updated to keep up with the latest trends and technologies.
Installing Winston
To install Winston in your Node.js project, you can use the yarn package manager by running the following command in your terminal:
yarn add winston
Using Winston
Once the installation is complete, you can import and use Winston in your Node.js code by including the following line:
import winston from'winston'
You can then use the Winston library to configure and create your logging instances, for example:
const logger = winston.createLogger({
level: 'info',
format: winston.format.json(),
transports: [
new winston.transports.Console()
This creates a logger instance with an info level and a console transport. We can configure winston to transport logs to the Loki dashboard by adding the transport as follows:
logger.add(new winston.transports.Http(options));
The Http transport is a generic way to log, query, and stream logs from an arbitrary Http endpoint. It takes options that are passed to the node.js http or https request:
  • host: (Default: localhost) Remote host of the HTTP logging endpoint
  • port: (Default: 80 or 443) Remote port of the HTTP logging endpoint
  • path: (Default: /) Remote URI of the HTTP logging endpoint
  • auth: (Default: None) An object representing the username and password for HTTP Basic Auth
  • ssl: (Default: false) Value indicating if we should use HTTPS
  • batch: (Default: false) Value indicating if batch mode should be used. A batch of logs to send through the HTTP request when one of the batch options is reached: number of elements, or timeout
  • batchInterval: (Default: 5000 ms) Value indicating the number of milliseconds to wait before sending the HTTP request
  • batchCount: (Default: 10) Value indicating the number of logs to cumulate before sending the HTTP request
You can use this logger instance to log messages in your application, for example:'Hello World');
This will log the message Hello World to the console with the info log level.
Logging levels in Winston
Winston is equipped with six default logging levels, arranged in accordance with the guidelines outlined in the RFC5424 document. The levels are assigned numerical priority, with the highest severity being assigned the lowest number. The six levels and their respective priority values are:
error: 0,
warn: 1,
info: 2,
http: 3,
verbose: 4,
debug: 5,
silly: 6
For each of the six log levels, there is a corresponding method on the logger object:
You can also pass a string representing the logging level to the log() method:
logger.log('error', 'error message');
logger.log('info', 'info message');
The level property on the logger dictates which log messages will be passed on to the transports you’ve configured. For instance, if the level property is set to info, only log entries with a severity of info or higher will be written and all others will be deprioritized. This means that in the current configuration, only log messages with levels of info, warn, and error will be outputted.


After comparing the two most popular logging libraries, I recommend using Winston. It has been actively maintained, with the latest commit to its codebase being just 2 weeks ago. In contrast, Pino's latest commit was made 1 year ago. Furthermore, considering the weekly downloads and GitHub stars, all indications point to Winston as the preferable choice for a logging library.

Visualization Tools

This section aims to compare two popular data visualization and analysis tools, Grafana and Kibana, specifically in the context of API log collection and visualization. Both Grafana and Kibana have extensive capabilities for log analysis, dashboard creation, and data visualization, making them suitable choices for monitoring and analyzing API logs. This comparison will help us understand the strengths and weaknesses of each tool and make an informed decision based on our specific requirements.


Grafana: Grafana is an open-source, feature-rich analytics and monitoring solution known for its highly customizable dashboards, diverse data source integration options, and extensive plugin ecosystem. It provides a user-friendly interface that allows users to create visually appealing and interactive dashboards to visualize and analyze data.
Kibana: Kibana is also an open-source analytics and visualization platform primarily designed for Elasticsearch. It provides a powerful interface for searching, analyzing, and visualizing large datasets. Kibana offers a broad range of capabilities for log analysis, including real-time monitoring, interactive visualizations, and data exploration.

Log Collection:

Grafana: Grafana doesn't have native log collection capabilities but serves as a frontend visualization layer for various data sources. It supports integration with numerous logging systems, such as Elasticsearch, InfluxDB, Prometheus, and more. Users can leverage Grafana to visualize API logs stored in these data sources effectively.
Kibana: Kibana seamlessly integrates with Elasticsearch, which is commonly used for log storage and analysis. It provides robust log collection features and offers several ingestion methods like Filebeat, Logstash, and Elasticsearch API. With Kibana, users can easily collect and index API logs for subsequent visualization and analysis.

Data Visualization:

Grafana: Grafana is widely recognized for its flexible and visually appealing dashboards. It offers a vast library of pre-built panels and plugins for creating interactive visualizations, including line charts, bar graphs, tables, heatmaps, and more. Grafana's intuitive UI allows users to customize dashboards with rich formatting options, annotations, and drill-down capabilities.
Kibana: Kibana provides a broad range of visualization options to explore and present log data effectively. It offers various chart types like line, bar, pie, and area charts, as well as geospatial and tag cloud visualizations. Kibana's Discover feature allows users to filter and search log data, while Visualize enables the creation of custom visualizations with aggregations and filters.

Alerting and Monitoring:

Grafana: Grafana excels in alerting and monitoring capabilities. It allows users to set up threshold-based alerts and send notifications through various channels. Grafana's alerting engine supports multiple data sources and provides flexible alerting rules. Additionally, it offers real-time monitoring and provides robust support for time-series data.
Kibana: Kibana provides basic alerting capabilities, but its focus lies more on log analysis and visualization. While it supports alerting based on query results, it may require additional configuration and integrations with external notification systems for sending alerts. However, Kibana is well-suited for real-time log monitoring and analysis.

Community and Ecosystem:

Grafana: Grafana benefits from a vibrant and active community. Its extensive plugin ecosystem offers a wide range of data source integrations and visualization options. Grafana has a large user base, contributing to its frequent updates, bug fixes, and feature enhancements. Community support is readily available through forums, documentation, and online resources.
Kibana: Kibana is part of the Elastic Stack ecosystem and enjoys strong community support. Being tightly integrated with Elasticsearch, it benefits from Elasticsearch's extensive features and ecosystem. Kibana's community provides valuable resources, tutorials, and plugins, enabling users to leverage Elasticsearch's scalability and search capabilities.


Grafana: Grafana offers both an open-source version and a commercial version called Grafana Enterprise. The open-source version is free to use and has no licensing costs. However, Grafana Enterprise requires a subscription, and pricing details can be obtained from the Grafana website.
Kibana: Kibana is open-source and free to use. However, if you require additional features and commercial support, you can opt for the Elastic Stack subscription, which includes additional functionality and support. Pricing details for the Elastic Stack subscription can be found on the Elastic website.


Both Grafana and Kibana offer powerful features for API log collection and visualization. Grafana's strengths lie in its customizable dashboards, extensive plugin ecosystem, and robust alerting capabilities. On the other hand, Kibana excels in log collection, real-time monitoring, and deep integration with Elasticsearch. Ultimately, the choice between the two depends on our specific requirements, preference for visualization styles, and existing technology stack.

API Performance Monitoring

API performance monitoring is a critical aspect of ensuring the reliability, efficiency, and optimal functioning of your API. By monitoring key performance metrics, you can identify bottlenecks, detect issues, and optimize the performance of your API to deliver a seamless experience for your users. This Confluence page provides an overview of API performance monitoring, including its importance, key metrics to monitor, and recommended practices.

Why API Performance Monitoring Matters

Monitoring the performance of your API offers several benefits:
  1. Identify Performance Issues: Performance monitoring enables you to detect and diagnose performance issues such as slow response times, high error rates, or resource bottlenecks. By monitoring metrics in real-time, you can proactively identify and address these issues before they impact your users.
  2. Optimize Response Times: Monitoring API response times allows you to understand how quickly your API is serving requests. By identifying areas of slow performance, you can optimize your code, database queries, or infrastructure to improve response times and enhance user satisfaction.
  3. Capacity Planning and Scaling: Performance monitoring data helps you analyze usage patterns, peak traffic periods, and resource requirements. This information is crucial for capacity planning and scaling strategies, ensuring that your API can handle increasing loads without performance degradation or downtime.
  4. Ensure SLA Compliance: If you have service-level agreements (SLAs) with your users or clients, monitoring performance metrics allows you to track and ensure compliance with the agreed-upon performance targets. It helps you meet service level objectives and maintain a high level of service quality.

Key Metrics to Monitor

When monitoring API performance, consider tracking the following key metrics:
  1. Response Time: Measure the time it takes for your API to respond to requests. Monitor average response time, percentiles (e.g., 90th or 95th percentile), and identify any outliers or spikes in response times.
  2. Throughput: Monitor the number of requests your API processes within a given time frame. This metric helps you understand the load on your API and identify periods of high traffic.
  3. Error Rates: Track the frequency of errors or failures in API responses. Monitor the overall error rate, specific error codes, and analyze error trends to identify and resolve potential issues.
  4. Latency: Measure the time taken for a request to reach your API server. Monitor latency to identify network-related bottlenecks and optimize network infrastructure if needed.
  5. Resource Utilization: Monitor resource consumption, such as CPU usage, memory usage, and disk I/O, to identify potential resource bottlenecks and optimize resource allocation.
  6. Availability: Monitor the uptime and availability of your API to ensure it meets your desired service level objectives. Track downtime incidents and their durations to identify patterns or areas for improvement.

Best Practices for API Performance Monitoring

To effectively monitor API performance, consider the following best practices:
  1. Establish Baselines: Establish baseline performance metrics for your API to serve as a reference point. Monitor these baselines over time to identify deviations or abnormal behavior.
  2. Real-Time Monitoring: Implement real-time monitoring to promptly detect performance issues as they occur. Utilize monitoring tools that offer real-time alerts and notifications to ensure timely response and issue resolution.
  3. Distributed Tracing: Implement distributed tracing to gain visibility into the complete journey of an API request across different services and components. This helps pinpoint performance bottlenecks and optimize inter-service communication.
  4. Log Analysis: Utilize logging frameworks to capture relevant information about API requests and responses. Analyze logs to identify patterns, errors, and performance anomalies. Consider integrating with log analysis tools for efficient log searching and analysis.
  5. Automated Testing and Synthetic Monitoring: Implement automated tests and synthetic monitoring to simulate API

Possible Approaches:

  1. Application Performance Monitoring (APM) Tools: APM tools are specifically designed to monitor the performance of applications, including APIs. They provide comprehensive insights into various metrics such as response time, throughput, error rates, and resource utilization. Some popular APM tools include New Relic, Datadog, and AppDynamics. These tools often offer features like distributed tracing, real-time alerting, and detailed performance analytics to help diagnose and optimize API performance.
  2. Logging and Log Analysis Tools: Logging frameworks like Elasticsearch, Logstash, and Kibana (ELK Stack) or Splunk can be used to collect API logs and analyze them for performance monitoring. By adding log statements at critical points in your API code, you can capture essential information such as request/response payloads, success/failure status, and execution times. Log analysis tools enable you to search, filter, and aggregate log data, allowing you to track API performance and identify any anomalies or issues.
  3. API Gateways: API gateways, such as Kong, Apigee, or AWS API Gateway, often include built-in monitoring capabilities. They can track API usage, response times, error rates, and other metrics. API gateways act as intermediaries between clients and your backend services, allowing you to collect performance data and manage API traffic effectively. They may also offer features like rate limiting, authentication, and request/response transformation, which further enhance the monitoring and control of API performance.
  4. Real User Monitoring (RUM): RUM tools monitor API performance from the perspective of end users. These tools inject JavaScript snippets into web applications or mobile apps to capture data about the actual user experience, including API calls. RUM tools, like Google Analytics, enable you to track metrics such as page load times, API response times, and user interactions. This approach provides insights into the performance perceived by real users and helps identify bottlenecks or issues that may impact user satisfaction.
It's worth noting that a combination of these options may be suitable for comprehensive API performance monitoring. The choice of tools depends on factors such as your application's technology stack, scalability requirements, budget, and specific monitoring needs. It's recommended to evaluate different options and select the tools or approaches that best align with your requirements and infrastructure.

Comparison between the most popular APM Tools

New Relic

New Relic is a comprehensive Application Performance Monitoring (APM) tool that offers robust features for monitoring API performance.
Key Features:
  1. Transaction Tracing: New Relic provides detailed transaction traces, allowing you to visualize the execution flow and identify performance bottlenecks within your API.
  2. Real-time Monitoring: Real-time monitoring enables you to track key performance metrics, such as response times, error rates, and throughput, as they happen.
  3. Alerting and Notifications: New Relic allows you to set up custom alerts and notifications based on specific performance thresholds or anomalies.
  4. Database Monitoring: It offers integrations with popular databases, enabling you to monitor database queries and their impact on API performance.
  5. Deep Dive Diagnostics: New Relic provides in-depth diagnostics to help troubleshoot and optimize API performance, including CPU usage, memory utilization, and database query analysis.
Pricing Plan


Datadog is a cloud monitoring and analytics platform that offers a wide range of monitoring capabilities, including API performance monitoring.
Key Features:
  1. Real User Monitoring (RUM): Datadog provides RUM capabilities, allowing you to monitor API performance from the perspective of end users, capturing metrics such as page load times and API response times.
  2. Distributed Tracing: Datadog supports distributed tracing, providing insights into the performance of requests across different services and components.
  3. Customizable Dashboards: Datadog offers customizable dashboards to visualize and track API performance metrics in real-time, facilitating easy monitoring and analysis.
  4. Integrations and Extensibility: Datadog integrates with various frameworks, databases, and cloud platforms, making it flexible and adaptable to different API environments.
  5. Machine Learning and Anomaly Detection: Datadog leverages machine learning algorithms to identify performance anomalies and alert you in real-time.
Pricing Plan


AppDynamics is an APM solution that provides comprehensive monitoring capabilities for API performance.
Key Features:
  1. Business Transaction Monitoring: AppDynamics allows you to monitor and trace business transactions across your API, helping you understand the impact on overall business processes.
  2. Code-level Diagnostics: AppDynamics provides detailed code-level diagnostics, enabling you to identify and resolve performance issues within your API code.
  3. Deep Dive Visualization: It offers visualizations and dashboards that provide deep insights into API performance metrics, including response times, error rates, and resource consumption.
  4. End-to-End Visibility: AppDynamics provides end-to-end visibility into your API ecosystem, including third-party integrations, external services, and databases.
  5. Automation and Remediation: AppDynamics supports automation and remediation capabilities, allowing you to set up automated actions based on performance thresholds or anomalies detected within your API.
Pricing Plan


Prometheus is an open-source monitoring and alerting toolkit that focuses on time-series data and is widely used for monitoring APIs. Let's explore its key features:
  • Metrics Collection: Prometheus collects and stores time-series data, allowing you to track and analyze API performance metrics over time.
  • Flexible Querying: Prometheus provides a powerful query language (PromQL) that enables flexible analysis and querying of API performance metrics.
  • Alerting and Notifications: Prometheus supports alerting based on predefined rules and allows you to configure notification channels for timely alerts.
  • Service Discovery: Prometheus provides built-in service discovery mechanisms, making it easy to discover and monitor APIs in dynamic environments.

Comparison Summary

Feature New Relic Datadog Prometheus AppDynamics
Real-time Monitoring Yes Yes No Yes
Distributed Tracing Yes Yes No Yes
Alerting and Notifications Yes Yes Yes Yes
Database Monitoring Yes No No Yes
Integration Extensive integrations with frameworks, libraries, and platforms Extensive integrations with various frameworks, services, and cloud platforms Supports integration with various data sources and services Supports integration with various frameworks, services, and databases
Machine Learning No Yes No No
Anomaly Detection No Yes No No
Service Discovery No No Built-in service discovery mechanisms No
Code-level Diagnostics No No No Yes
Automation and Remediation No No No Yes


We must assess the choice of application monitoring by taking into account the balance between pricing and offered features, as well as the ease of use.