rethrowing of exception is good or bad

If you can't handle it (completely) or recover from it, you should rethrow it and give higher levels the chance to handle it.

No, it's better to handle it in the place where it makes sense to handle it. If you can't handle the errors, you pass it upwards or catch it, log a message and rethrow it.There's no One True Rule about it. It's up to the smart developer to know what to do.