[SOLVED] pm2 does not restart worker when express error occur

pm2 does not restart worker when express error occur

I'm using pm2 to manage process in my nodejs express application (running in cluster mode).

We had 2 kind of error handler

FIRST: 'uncaughtException' will be handled with

process.on('uncaughtException', function(err){});

Actually, I do not declare an handler like this cause of letting pm2 detect died worker in this case so restart the died worker automatically.

SECOND: express error handler, I mean the error will be forwarded to express error handler, not uncaughtException handler, the error handler like below
```
app.use(function(err, req, res, next) {})
```

I also do not declare this error handler for same purpose as uncaughtException. But pm2 does not restart node in this case.

Any idea about this problem? Many thanks

Solution

When catching errors with express error handler or even "uncaughtException" event, the process is still running, so pm2 won`t restart it. If you want pm2 to restart after each exception, I would suggest something like this:

    process.on('uncaughtException', function(e) {
      console.log('An error has occured. error is: %s and stack trace is: %s', e, e.stack);
      console.log("Process will restart now.");
      process.exit(1);
    })

Same goes for the express error handler. When we execute process.exit method, the process will terminate and pm2 will restart it.