Troubleshooting Mysql2::Error (Too many connections)

Introduction

This guide will show you how to resolve the Mysql2::Error (Too many connections) error in Easy8. This error happens when the MySQL server runs out of available connections, often on older or smaller virtual machines (VMs). By following these steps, you can increase the connection limit and prevent the error from recurring.

Target Audience

• Administrator

Prerequisites

• Access to the server running the MySQL database
• Permission to edit system files and restart MySQL service
• Basic knowledge of terminal commands

How to Fix the Too many connections Error

Step 1: Understand the Error

The error may look like this in the logs:

Mysql2::Error (Too many connections):

  mysql2 (0.3.20) lib/mysql2/client.rb:70:in `connect'
  activerecord (4.2.5) ... connection_pool.rb:448:in `checkout_new_connection'

This means that the current number of allowed MySQL connections has been reached, and new connections are blocked.

Step 2: Edit MySQL Configuration

a. Open the MySQL configuration file in an editor:

sudo vim /etc/my.cnf

or

sudo vim /etc/mysql/my.cnf

b. Find the [mysqld] section.
c. Add or update this line:

max_connections = 100

Tip: You can adjust the value depending on your server resources and usage needs.

Step 3: Restart MySQL

Apply the changes by restarting the MySQL service:

sudo service mysql restart

Step 4: Confirm the Setting

Optional: Check the new max connections limit with:

mysql -u root -p -e "SHOW VARIABLES LIKE 'max_connections';"

Conclusion

You have successfully resolved the Too many connections error by increasing the MySQL connection limit. This is a common issue on older VMs and should not occur again if the server has enough capacity and the configuration is updated correctly.

Related Topics and Further Reading

• Easy8 Documentation
• Easy Project Documentation