Re: How can I implement MySQL connection pooling in a Python Flask or Django application?

[ck kumar]

Implementing MySQL connection pooling in Python web frameworks like Flask or Django helps reuse database connections instead of opening a new one for every request. This improves performance, scalability, and resource usage—especially for high-traffic apps.

Below are practical ways to implement connection pooling.

1. MySQL Connection Pooling in Flask

In Flask, connection pooling is usually handled using SQLAlchemy.

Install Required Libraries
pip install flask flask-sqlalchemy pymysql
Example Configuration
from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql+pymysql://user:password@localhost/dbname'

# Connection Pool Settings
app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
"pool_size": 10, # number of permanent connections
"max_overflow": 20, # additional temporary connections
"pool_timeout": 30, # wait time before timeout
"pool_recycle": 1800 # recycle connection after 30 minutes
}

db = SQLAlchemy(app)
Example Query
@app.route("/")
def home():
result = db.engine.execute("SELECT * FROM users")
return str(result.fetchall())

How it works

pool_size → maximum number of open connections in pool

max_overflow → extra connections allowed during peak load