How to troubleshoot when the MySQL connection limit is …

When the MySQL connection count is maxed out, you can troubleshoot by following these steps:

1. Check the number of database connections: Verify if the current number of connections has reached the maximum limit set by MySQL by executing the following command.

SHOW VARIABLES LIKE 'max_connections';
SHOW GLOBAL STATUS LIKE 'Threads_connected';

1. Check the current number of connections: Execute the following command to view the current active connection count and their status.

SHOW PROCESSLIST;

This command will display all current connections and queries being executed. By examining the connection status and queries, one can identify if there are any abnormal connections or long-running queries causing the connection limit to be reached.

1. View error logs: Check the error log of MySQL, usually located in the data folder under the MySQL installation directory or at a location specified in the my.cnf configuration file. Look for any relevant error messages in the error log, such as connection timeouts or reaching the maximum connection limit.
2. Check the configuration of the connection pool: If a connection pool is being used, ensure that the configuration is reasonable, including parameters such as maximum number of connections, maximum number of idle connections, and connection timeout.
3. Check the utilization of database resources: Use MySQL monitoring tools or operation and maintenance tools to review the resource usage of the database, including CPU, memory, disk, etc., to identify any potential bottlenecks that may be causing the connection limit to be reached.
4. Optimize query statements: analyze and optimize frequently executed query statements to minimize the cost of queries and reduce the load on connections.

Based on the steps above, you can pinpoint the specific reason why the connections are maxed out and take appropriate measures to resolve the issue.