Postmortem Report: Load Balancer Outage
Published: 2024-06-20 11:04:57




![I mean, really?](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/dkceqqe6knv26g4pg4ye.jpg)

## Issue Summary:
On June 18th, 2024, from 10:00 AM to 11:00 AM SAT, our web application decided to entertain us with an unexpected performance — a load balancer decided to take a break, causing HTTP 500 Internal Server Errors. Approximately 40% of our users were affected, feeling as if they'd been given front-row tickets to a silent concert. The root cause? A communication breakdown between the load balancer and backend servers, reminiscent of a bad telephone game.

## Timeline: (SAT)

* **10:00 AM:** An engineer noticed increased error rates in the logs. (The logs were screaming, “Help!”)
* **10:02 AM:** The engineer notified the team via Discord. (The Discord channel went from calm to chaos in seconds.)
* **10:05 AM:** Initial investigation began, focusing on server logs and load balancer health checks. (Engineers put on their detective hats.)
* **10:15 AM:** Identified intermittent communication failures between the load balancer and backend servers. (The load balancer was having trust issues.)
* **10:20 AM:** The initial hypothesis was network connectivity or misconfigured load balancer settings. (Guesswork ensued, with fingers crossed for an easy fix.)
* **10:30 AM:** Engineers investigated potential connectivity issues but found none. (The network was as clean as a whistle.)
* **10:40 AM:** Load balancer configuration reviewed and identified a recent update causing the issue. (The culprit was found—an update with more drama than a daytime soap opera.)
* **10:45 AM:** Reverted load balancer settings to the previous stable configuration. (Back to the tried and tested settings.)
* **10:50 AM:** Verified that the web application was operational and error-free. (Everything was back on track, much to everyone’s relief.)
* **11:00 AM:** Full service restored and monitoring confirmed stability. (The show must go on!)

![Pimp my load balancer](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/sud5wxprvj3g9wmeje25.jpg)

## Root Cause and Resolution:
The outage was caused by a misconfiguration in the load balancer settings during a recent update, which led to communication failures with backend servers. The issue was resolved by reverting the load balancer configuration to its previous stable state. (Lesson learned: if it ain't broke, don't fix it.)

## Corrective and Preventive Measures:

### Improvement Areas:
1. Implement pre-deployment configuration validation. (Measure twice, cut once.)
2. Enhance monitoring to detect configuration issues promptly. (Keep an eye on the divas.)
3. Increase redundancy to mitigate single points of failure. (Never put all your eggs in one basket.)

### Specific Tasks:
1. **Deploy Configuration Validation Tools:** Integrate tools to validate load balancer configurations before deployment. (No more unscripted drama.)
2. **Training Sessions:** Conduct training for engineers on load balancer management best practices. (Make sure everyone knows their lines.)
3. **Enhanced Monitoring:** Implement more detailed health checks and alerts to quickly identify and resolve similar issues. (No more surprise performances.)

### Conclusion:
In the end, this incident taught us that even the most minor changes can cause major disruptions. But with quick thinking and teamwork, we turned a potential disaster into a learning experience. And now, our systems are ready to face the music without missing a beat. 🎶