How does MyBatis determine if the database has crashed?

MyBatis is a persistence framework that is not responsible for running and monitoring databases. There are several ways to determine if a database is crashing.

1. Database connection exception: When unable to connect to the database, a database connection exception will be thrown. This exception can be caught, and based on the exception information, determine if the database is crashing.
2. Database error code: Each database has specific error codes, which can be obtained by capturing database exceptions, and then determining if the database is crashing based on the error code.
3. Monitoring tool: Database monitoring tools can be used to regularly check the running status of the database. These tools can provide performance metrics, connection numbers, error logs, and other information about the database. By monitoring these metrics, it is possible to determine if the database is crashing.
4. Heartbeat mechanism: A heartbeat mechanism can be established between the application and the database, regularly sending a simple SQL query to the database. If no response is received within a certain amount of time, it can be determined that the database has crashed.

It is important to note that determining a database crash is just a simple way of judgment. The true judgment requires a comprehensive evaluation based on the actual situation and database monitoring tools.