What are the problems with too many MariaDB connections?

Excessive MariaDB connections can lead to several significant problems:

1. Resource Exhaustion: Each connection consumes memory and CPU resources. Too many connections can deplete server resources, slowing down or crashing the database.

   • Example: If the max_connections limit is set to 1000 but 900 idle connections persist, active queries may struggle for resources, causing delays.

2. Performance Degradation: High connection counts increase contention for locks and threads, leading to slower query execution.

   • Example: A web application with connection pooling misconfigured might open 500 connections instead of reusing 50, drastically reducing throughput.

3. Connection Timeouts: New connections may fail if the server reaches its limit, returning errors like "Too many connections."

   • Example: A spike in traffic overwhelms the database, causing legitimate user requests to time out.

4. Increased Latency: The database spends more time managing connections (authentication, thread allocation) instead of executing queries.

Mitigation Strategies:

• Optimize Connection Pooling: Use tools like ProxySQL or application-level pooling (e.g., HikariCP) to limit idle connections.
• Adjust max_connections: Set a realistic limit based on server resources (e.g., 200–500 for a moderate setup).
• Monitor with MariaDB Tools: Use SHOW STATUS LIKE 'Threads_connected' to track active connections.
• Scale with Tencent Cloud: Deploy MariaDB on Tencent Cloud Database TDSQL for MariaDB, which offers auto-scaling, connection management, and performance optimization. Its built-in monitoring helps identify connection spikes early.

For high-traffic scenarios, Tencent Cloud’s Elastic Load Balancing and Auto Scaling can distribute workloads efficiently, reducing connection pressure on the database.