Analyzing the Cost of Establishing MySQL Database Connections in Java Applications

The article investigates the details of establishing a database connection in web applications, using MySQL as an example and Java as the programming language, and quantifies the time cost of the connection process.

Sample Java code used for the test is shown below:

Class.forName("com.mysql.jdbc.Driver");
String name = "shine_user";
String password = "123";
String url = "jdbc:mysql://172.16.100.131:3306/clever_mg_test";
Connection conn = DriverManager.getConnection(url, name, password);
// program ends, connection is forcibly closed

Wireshark captures reveal the MySQL protocol (built on TCP) and the three main steps of establishing a connection: (1) TCP three‑way handshake, (2) server sends handshake packet and client responds, (3) client sends authentication packet, server validates and returns OK.

Timing measurements from the capture show that the minimal connection setup takes 10.416042 - 10.190799 = 0.225243s = 225.243ms , i.e., about 225 ms.

When the connection is properly closed with conn.close(); , the total time from handshake to termination (excluding the final RST packet) is measured as 747.284311 - 747.100954 = 0.183357s = 183.357ms , roughly 183 ms.

Extrapolating to a site with 100 000 daily requests (assuming 150 ms per connection) yields 15 000 seconds, or about 4.17 hours spent solely on establishing connections, underscoring the necessity of a connection pool.

The article concludes that database connections are costly; frequent creation should be avoided, and techniques such as connection pooling, caching, prepared statements, and load balancing are recommended to improve performance.