What are the best practices for quickly recovering from distributed application failures?

1 Detect failures

The first step to recover from a failure is to detect it. You need to monitor your distributed application and its components, such as nodes, services, data, and messages, and collect metrics and logs that indicate their health and status. You can use tools and frameworks that provide distributed tracing, alerting, and logging capabilities, such as Zipkin, Prometheus, or ELK stack. You should also define clear and relevant failure scenarios and thresholds that trigger alerts and actions when they occur.

4 Recover data

The fourth step to recover from a failure is to recover data. You need to ensure that your data is consistent, accurate, and available after a failure. You can use techniques such as replication, backup, and checkpointing to protect your data from loss and corruption. Replication is the process of copying your data to multiple nodes or locations to increase availability and fault tolerance. Backup is the process of storing your data to a secondary storage device or service to enable restoration in case of a failure. Checkpointing is the process of saving the state of your application to a stable storage device or service to enable recovery in case of a failure.

5 Restore functionality

The fifth step to recover from a failure is to restore functionality. You need to ensure that your application can resume its normal operation and provide the expected service level to your users and clients. You can use techniques such as retries, fallbacks, and compensations to restore functionality after a failure. Retries are mechanisms that attempt to execute a failed request again until it succeeds or reaches a limit. Fallbacks are mechanisms that provide an alternative response or service to a failed request, such as a default value, a cached value, or a reduced functionality. Compensations are mechanisms that undo or correct the effects of a failed request, such as reversing a transaction, issuing a refund, or sending an apology.

6 Improve resilience

The sixth step to recover from a failure is to improve resilience. You need to enhance your application's ability to withstand and adapt to failures in the future. You can use techniques such as chaos engineering, load testing, and performance tuning to improve resilience. Chaos engineering is the practice of injecting failures into your application in a controlled manner to test its behavior and identify weaknesses. Load testing is the practice of simulating high volumes of requests or data to your application to measure its performance and scalability. Performance tuning is the practice of optimizing your application's code, configuration, and resources to improve its speed and efficiency.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?