How to Invalidate CloudFront Cache Quickly and Correctly

To invalidate CloudFront cache, create an invalidation request using the aws cloudfront create-invalidation command or AWS SDK by specifying the distribution ID and the paths to refresh. This forces CloudFront to fetch updated content from the origin instead of serving cached files.

Syntax

The basic syntax to invalidate CloudFront cache using AWS CLI is:

• aws cloudfront create-invalidation --distribution-id <distribution-id> --paths <path1> <path2> ...

Where:

• --distribution-id is the unique ID of your CloudFront distribution.
• --paths lists the file paths to invalidate, such as /index.html or /* for all files.

bash

aws cloudfront create-invalidation --distribution-id EXAMPLE123 --paths /index.html /images/*

Example

This example shows how to invalidate the cache for the homepage and all images in a CloudFront distribution using AWS CLI.

bash

aws cloudfront create-invalidation --distribution-id E1234567890ABC --paths /index.html /images/*

Output

{
  "Invalidation": {
    "Id": "ID1234567890EXAMPLE",
    "Status": "InProgress",
    "CreateTime": "2024-06-01T12:00:00Z",
    "InvalidationBatch": {
      "Paths": {
        "Quantity": 2,
        "Items": [
          "/index.html",
          "/images/*"
        ]
      },
      "CallerReference": "unique-string"
    }
  }
}

Common Pitfalls

Common mistakes when invalidating CloudFront cache include:

• Using incorrect distribution ID, which causes the invalidation to fail.
• Not specifying the correct paths; remember to use /* to invalidate all files.
• Expecting instant cache clearing; invalidations take a few minutes to complete.
• Exceeding free invalidation limits; AWS allows 1000 free invalidation paths per month.

bash

aws cloudfront create-invalidation --distribution-id WRONGID --paths /index.html

# Correct usage:
aws cloudfront create-invalidation --distribution-id CORRECTID --paths /index.html

Quick Reference

Tips for efficient CloudFront cache invalidation:

• Use specific paths instead of /* to reduce invalidation time and cost.
• Automate invalidations in deployment scripts for updated content.
• Monitor invalidation status via AWS Console or CLI.
• Remember invalidations are eventually consistent, so allow a few minutes for changes.

Key Takeaways

Use the AWS CLI or SDK to create invalidation requests with distribution ID and paths.

Specify exact file paths or use wildcards like /* to refresh multiple files.

Invalidations take a few minutes to complete; they are not instant.

Avoid unnecessary invalidations to stay within free limits and reduce costs.

Automate cache invalidation in your deployment process for smooth updates.