This page describes what Managed Connection Pooling (MCP) is and how to use it with your Cloud SQL instances.
Managed Connection Pooling (MCP) lets you scale your workloads by optimizing resource utilization and connection latency for your Cloud SQL for MySQL instances using pooling. MCP creates a pool of threads to handle incoming requests. This delivers significant performance improvements, especially for scaled connections, by absorbing sudden connection spikes without overloading the server with a growth in the number of threads.
While you can use MCP for any transactional workloads, MCP provides the most throughput and latency benefit with applications that contain short-lived connections, or applications that result in a connection surge.
For long-lived connections, the connection performance using MCP can be slightly lower than when using a direct connection. In this case, MCP provides connection scaling when the number of connections is very high. However, for applications that typically establish long-lived connections, you might use direct connections to your instance instead.
For more information on how to enable MCP, see Configure Managed Connection Pooling.
Requirements
To use MCP, your instance must meet the following requirements:
- Your instance must be a Cloud SQL Enterprise Plus edition instance.
- MCP requires a minimum maintenance
version number of
MYSQL_$version.R20250304.00_01. For more information, see Self-service maintenance.
Available configuration options
You can customize MCP by using the following configuration parameters:MAX_POOL_SIZE: the amount of concurrency for MCP. The default value is number of cores in your database.
Limitations
Consider the following limitations when using MCP with your Cloud SQL Enterprise Plus edition instances:
- Enabling MCP on an existing instance results in a database restart.
- When you use the Cloud SQL API to enable, disable, or configure
MCP, the
instance.updateAPI can't contain any other instance configuration updates.