go-check is a lightweight CLI tool built in Go to test and benchmark concurrent MySQL connections. It allows you to specify the number of threads (goroutines) that connect to a MySQL server and either hold the connections open for a specified duration or execute a given SQL query concurrently. This is useful for testing the performance, stability, and connection handling capacity of MySQL instances.

• Connects to a MySQL server using multiple concurrent connections (threads).
• Supports two modes: hold connections alive or execute SQL queries.
• Allows you to configure the number of threads and the duration for which connections should be kept alive.
• Supports reading MySQL credentials from the ~/.my.cnf file, simplifying authentication.
• Logs connection lifecycle, indicating when connections are established and closed.
• Built with standard Go project structure.

• Stress Testing: Evaluate the MySQL server's ability to handle concurrent connections under different loads.
• Performance Benchmarking: Identify connection bottlenecks and timeouts when multiple clients are connected.
• Testing Connection Limits: Experiment with thread counts to discover the maximum number of connections your MySQL instance can handle reliably.
• Query Load Testing: Run concurrent SELECT queries to simulate read-heavy workloads, e.g., during database upgrades.

First, clone the repository and navigate to the project directory:

git clone https://github.com/ChaosHour/go-check.git
cd go-check

Build the binary:

make build

Using Credentials from ~/.my.cnf If you have your MySQL credentials stored in a ~/.my.cnf file, go-check can automatically read them. Your ~/.my.cnf file should look something like this:

[client]
user = your_mysql_user
password = your_mysql_password
host = 127.0.0.1

./bin/go-check -host=192.x.x.x -database=sbtest -threads=10 -duration=60

# Execute query once
./bin/go-check -host=192.x.x.x -database=sbtest -threads=10 -query="SELECT COUNT(*) FROM users"

# Execute query every 30 seconds for 5 minutes (300 seconds)
./bin/go-check -host=192.x.x.x -database=sbtest -threads=10 -query="SELECT COUNT(*) FROM users" -interval=30 -duration=300

Goroutine 2: Connected to MySQL.
Goroutine 8: Connected to MySQL.
Goroutine 6: Connected to MySQL.
Goroutine 9: Connected to MySQL.
Goroutine 0: Connected to MySQL.
Goroutine 4: Connected to MySQL.
Goroutine 3: Connected to MySQL.
Goroutine 1: Connected to MySQL.
Goroutine 5: Connected to MySQL.
Goroutine 7: Connected to MySQL.
Goroutine 2: Query executed in 12.5ms
Goroutine 9: Query executed in 15.2ms
...
Goroutine 2: Closing connection.
Goroutine 9: Closing connection.
...
All 10 connections closed.

• -host: MySQL server host (overrides ~/.my.cnf if set)
• -port: MySQL server port (default: 3306)
• -user: MySQL username (overrides ~/.my.cnf if set)
• -password: MySQL password (overrides ~/.my.cnf if set)
• -database: MySQL database name (default: test)
• -threads: Number of concurrent connections (default: 10)
• -duration: Duration to keep connections alive in seconds (default: 10)
• -query: Optional SQL query to execute on each connection
• -interval: Interval to re-execute query in seconds (default: 0 = execute once, requires -query)

This project follows the standard Go project layout:

go-check/
├── cmd/check/          # Main application entry point
│   └── main.go
├── pkg/checker/        # Core business logic
│   ├── checker.go
│   └── checker_test.go
├── Makefile            # Build and test automation
├── go.mod
├── go.sum
└── README.md

make build

make test

make clean

make fmt

make vet

Contributions are welcome! Please feel free to submit a Pull Request.