How to handle database connection failures and retries in Go?

In Go, you can handle database connection failures and retries by using the database/sql package along with the retry package.

Here's a step-by-step guide on how to handle database connection failures and retries in Go:

Import the required packages:

import (
	"database/sql"
	"fmt"
	"time"

	_ "github.com/go-sql-driver/mysql"
	"github.com/avast/retry-go"
)

Define a function to establish a database connection:

func getDBConnection() (*sql.DB, error) {
	db, err := sql.Open("mysql", "username:password@tcp(localhost:3306)/dbname")
	if err != nil {
		return nil, err
	}

	err = db.Ping()
	if err != nil {
		return nil, err
	}

	return db, nil
}

Define a retry function to handle connection errors and retry the connection:

func retryDBConnection() (*sql.DB, error) {
	var db *sql.DB
	err := retry.Do(
		func() error {
			var err error
			db, err = getDBConnection()
			if err != nil {
				fmt.Println("Failed to connect to the database:", err)
			}
			return err
		},
		retry.Attempts(3),         // Number of retry attempts
		retry.Delay(time.Second), // Delay between retries
	)

	return db, err
}

Use the retry function to establish the database connection in your main function:

func main() {
	db, err := retryDBConnection()
	if err != nil {
		fmt.Println("Failed to connect to the database after multiple attempts:", err)
		return
	}

	// Perform database operations using db connection
}

This implementation retries the database connection three times with a delay of one second between each attempt. Adjust the number of attempts and the delay as per your requirement.

Note: Replace the mysql driver with the appropriate database driver (postgres, sqlite, etc.) if you are using a different database. Also, replace the connection string with the actual details of your database connection.

By following these steps, you can handle database connection failures and retries effectively in Go.