How to keep node app running?

1. First, you should focus on what is killing your node server. Forever isn't going to "fix" the problem. Every time node exits/restarts it will cause problems and your users can loose data. upstart or forever are just band-aids. (In fact, Upstart will restart your server, but it will give up if your server doesn't stay running.)

   The only long-term solution to find/fix each source of errors and write a regression test suite to verify that each previous problems has been fixed.

2. start on startup will not work

3. Your forever install broke because of permissions. Try sudo npm install -g forever Advanced: Your entire server setup should be scripted. That way you can set up a test/staging server that mirrors production. one simple way to do this is Vagrant. You can develop "locally" on the same OS that's on your server. And you can test things like "does node come up when I reboot?" or "if the server gets wiped out, can I re-create my server from the base OS?"

After a painful few hours of re configuring everything, I think I have finally solved my problem! It looks like I may have had 2 versions of node or something! For future reference: If you are new to Node, be sure to install nvm to make managing node versions easier and you won't experience this problem :)

I think forever doesn't exits your nodejs app unexpectedly, It might be because of the mysql 'wait_timeout' parameter which is set to 28800 second (i.e 8 hours) by default. If the nodejs app does not interact with mysql database for 8 hour, then the connection gets closed. You have to set the wait_timeout value to 'MAX value'(i.e 365 days) or any other value as you required in the mysql db settings.

Link for the wait_timeout settings:

http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_wait_timeout

or

Add the following code in your code. This code will ping the mysql db once in an hour and your connection will not break.

// MYSQL ping code starts

function keepalive() 
{
     conn.query('select 1', [], function(err, result) 
     {
         if(err) 
         return console.log(err);
         // Successul keepalive
         console.log("keepalive: "+ result);
     });
}

setInterval(keepalive, 1000*60*60);

// MYSQL ping code ends

You can also use the handledisconnect() code and handle the particular connection error in the code as given in the example below.

///Code starts

function handledisconnect() {

  log.info("handledisconnect()");
    // Reading config.json file for database connection
    var db_config = JSON.parse(fs.readFileSync(appRoot + "/conf.json"));

    conn = mysql.createConnection(db_config);

    conn.connect(function(err) {

        if (err) {

            log.error('error when connecting to db : ',err);
            // We introduce a delay before attempting to reconnect
            setTimeout(handledisconnect, 200);
        } else {
            log.info("database connected");
        }
    });

    conn.on('error', function(err) {

        log.error('db error : ',err);

        // handling the reconnection for 'PROTOCOL_CONNECTION_LOST' error
        if (err.code === 'PROTOCOL_CONNECTION_LOST') {

            log.error(err);
            setTimeout(handledisconnect, 200);
            handledisconnect();

        } else {
            log.error(err);
        }
        // handling the reconnection for 'EADDRINUSE' error
        if (err.code === 'EADDRINUSE') {

            setTimeout(handledisconnect, 200);
            handledisconnect();

        } else {

            log.error(err);
        }
        // handling the reconnection for 'ECONNREFUSED' error
        if (err.code === 'ECONNREFUSED') {

            log.error(err);
            setTimeout(handledisconnect, 200);
            handledisconnect();

        } else {
            log.error(err);
        }

    });

///**** ADD YOUR CODE HERE****////

}
handledisconnect();
/// Code ends

Use keymetrics.io, it will restart your node application automatically if any issue occurs.

https://keymetrics.io

http://unix.stackexchange.com/questions/479/keep-ssh-sessions-running-after-disconnection

do this:

screen // then press enter node server.js

From the logs what actually seems to be the problem in your case is your mysql connection. Whenever the mysql server closes the connection the node server would die. You can use a keealive or use connection pooling.