How to release Oracle Database connection when Node.js exits

Question

I am using oracle database for my nodejs application.

When altering any table, i am getting error resource already in used.

This error getting because when terminating or when exiting the nodejs application the database connection is not getting released or closed.

I know how to release database connection

function doRelease() {
    db.close(
        function (err) {
            if (err)
                console.error(err.message);
        });
}

But i dont know, how to call the above function on nodejs exit or node terminate??

So i want simple help

how to release db connection when exiting or terminating nodejs application

Any help will be appreciated

Answer 1

Similar Question on nodejs exit is in link

       function doRelease() {
            db.close(
                function (err) {
                    if (err)
                        console.error(err.message);
                });
            console.log(`db released successfully`)
        }
        function killProcess() {
            if (process.exitTimeoutId) {
                return;
            }
            process.exitTimeoutId = setTimeout(process.exit, doRelease());
        }
        process.on('SIGTERM', killProcess);
        process.on('SIGINT', killProcess);
        process.on('uncaughtException', function (e) {
            console.log('[uncaughtException] app will be terminated: ', e.stack);
            killProcess();
        });
        console.log('Try to press CTRL+C or SIGNAL the process with PID: ', process.pid);
        process.stdin.resume();

The above code have worked for me

Answer 2

The simple solution is to create a database module with methods like initialize and close. Then you need to call those methods at the right time. I like to tie them into various events in the main module.

Have a look at parts 1 and 2 in my series on Creating a REST API with Node.js and Oracle Database for ideas.