NGINX is a powerful, high-performance web server, reverse proxy server, and load balancer that is widely used for hosting websites and applications. But as with any software, you may occasionally run into issues that require troubleshooting. In this blog post, we'll walk you through the process of troubleshooting NGINX using the New Relic observability platform, which offers a wealth of capabilities and insights to help you diagnose and resolve problems quickly.

Why New Relic?

New Relic is a leading observability platform that empowers developers and DevOps teams to measure, analyze, and optimize their applications and infrastructure. The platform provides real-time performance data, visualizations, and analytics that can help you quickly identify issues, discover root causes, and take informed action to resolve problems. Its comprehensive suite of capabilities makes it an ideal solution for monitoring and troubleshooting NGINX.

Getting started with New Relic and NGINX

Before we dive into troubleshooting, make sure you have a New Relic account and have installed the New Relic agent on your NGINX server. Follow the official documentation to configure and install the agent, and enable the NGINX integration by editing the configuration file (NGINX-config.yml).

Common NGINX issues and how to troubleshoot them with New Relic

High latency and slow response times

A slow-loading website or application can significantly impact user experience and satisfaction. High latency and slow response times could be caused by various factors, such as overloaded servers, slow database queries, or inefficient code.

To diagnose this issue, use New Relic's APM (application performance monitoring) capability to monitor your application's response times and throughput. This capability provides detailed performance breakdowns, showing where the bottlenecks are and helping you identify the root cause.

502 Bad Gateway errors

A 502 Bad Gateway error occurs when NGINX is unable to forward a client's request to the appropriate upstream server. This can be due to network issues, an unresponsive upstream server, or misconfiguration.

To troubleshoot this issue, use New Relic's infrastructure monitoring capability to analyze the logs and metrics of your NGINX server. Look for error messages, high error rates, or unusual spikes in request rates that could indicate the problem's origin. Additionally, check the NGINX error logs for any relevant information.

504 Gateway Timeout errors

A 504 Gateway Timeout error occurs when an upstream server fails to respond within the designated timeout period. This could be caused by slow processing times, high server load, or misconfiguration.

To diagnose this issue, use New Relic's APM capability to monitor the response times of your upstream servers, and identify any slow-performing components or services. You can also use New Relic’s infrastructure monitoring capability to analyze your NGINX server's performance, checking for high CPU or memory usage that could be causing the timeouts.

SSL/TLS configuration issues

Misconfigured Secure Sockets Layer/Transport Layer Security (SSL/TLS) settings can lead to security vulnerabilities and prevent users from accessing your site securely.

To troubleshoot SSL/TLS issues, use New Relic's synthetics capability to run automated tests on your website or application. These tests can help you identify any SSL/TLS configuration issues, such as expired certificates or incorrect cipher suites. Additionally, check your NGINX configuration file for any errors in your SSL/TLS settings.

Conclusion

Troubleshooting NGINX can be a complex process, but with the right tools and insights, it becomes much more manageable. By leveraging the New Relic observability platform, you'll be able to quickly identify issues, determine root causes, and take corrective action to ensure your NGINX server remains performant.