How to Handle Let's Encrypt Rate Limits

Let's Encrypt enforces rate limits to ensure fair usage. Understanding these limits is essential for avoiding issuance failures. This guide walks through the specific troubleshooting steps to diagnose and resolve rate limit issues.

Before You Begin

Before you begin, be sure to have the following in place:

• A Linux server with the relevant software installed
• Access to the command line interface
• Appropriate permissions (root or sudo)

Quick Fix

Wrong

certbot certonly -d example.com

Wrong: Hitting production rate limits during testing

Right

certbot certonly --staging -d example.com

Right: Using staging environment for unlimited testing

Output

Saving debug log to /var/log/letsencrypt/letsencrypt.log\nPlugins selected: Authenticator manual\nObtaining a new certificate\nSuccessfully received certificate.\n(Test certificate -- NOT valid for production)

Prevention

To avoid future issues, follow these best practices:

• Use --staging environment to avoid hitting production rate limits during testing
• Track your certificate count -- limit is 50 certificates per registered domain per week
• Use the same IP address for all renewal requests to stay within per-IP limits
• Consolidate multiple subdomains into a single SAN certificate
• Use certbot certificates to list active certs

DodaTech Tools

For further assistance with any of the above issues, consider using DodaTech consulting services or DodaTech tutorials for more in-depth guidance.

Common Mistakes with rate limit

1. Non-exhaustive pattern matches that compile with warnings then crash at runtime
2. Misunderstanding that String is [Char] with poor performance for large text operations
3. Using foldl instead of foldl' causing stack overflow on large lists

These mistakes appear frequently in real-world LETSENCRYPT code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ