Should you send DB errors to the user?

Question

In my NodeJS/MongoDB server I'm writing, I have a lot of API calls to store users and whatnot in the database. Mongoose has calls for MongoDB which, after doing a query, will return a callback function with an error (if there is one) and a document (if there is one to return).

I'm wondering if I should send the error to the user, throw it (stopping the whole server), or just send a 500 error.

Example:

  accountDocument.save(function (err, account) {
    if (err){
      res.status(500).json(err); // Option 1 - sends DB error to user
      res.status(500).end(); // Option 2 - just notifies there was a problem
      throw err; // Option 3 - stops the server completely
    }
    else
      res.status(200).json(account);
  });

Which should I choose to do?

Possible duplicate of [REST API error return good practices](https://stackoverflow.com/questions/942951/rest-api-error-return-good-practices) which is closed for being Primarily Opinion Based, much as this question essentially is. — Neil Lunn, Jun 24 '17 at 04:34
@NeilLunn yes and no...that talks a lot about WHICH code to return, and I already know I'm going to return 500. The question is whether or not I should send the error as well, or just stop the server. — Computor, Jun 24 '17 at 04:41
Why would you stop the server? That would mean it'd stop working for every other user — Maria Ines Parnisari, Jun 24 '17 at 04:46
@MariaInesParnisari not sure, didn't know if that was good practice or not, sounds like it's not though. So, now it's down to sending a 500 with the error or not. Ideas? — Computor, Jun 24 '17 at 04:47

score 1 · Accepted Answer · answered Jun 24 '17 at 04:53

First off, you have to determine if something catastrophic is wrong with your server or database. If so, then you probably need at least some admin attention, maybe even a server restart and you should make sure you've coded something to recognize that situation and notify whoever needs to know or take some definitive action. That's all internal to your ops team responsible for your site - nothing to do with the end user.

For example, if your code goes to open a connection to the database before doing a query and you can't even get a connection to it, then there's something seriously wrong and other than delaying a bit and retrying, there's nothing else your code can do, but to make sure somebody is notified who can try to figure out why there's no connection to the database any more.

Then, the best practice I've seen is to communicate back to the end user in a professional manner the following:

The fact that an unexpected error occurred on the server.
What the end-user can do about it (if there is anything). For example if this is an API query, then maybe you can offer advice on a safer query that might not cause this problem.
Some sort of code that uniquely corresponds to this particular error situation. While this isn't very user-friendly and should never be the main error feedback, having such a code makes it a TON easier for a report of the specific error to get all the way back to the developer without getting mangled and to give the developer enough info that they might be able to see what code path caused this error. For example "ErrorCode: 901". If there's only one place in your code that could generate error 901, then the developer can immediately know where in their code to go looking or testing to see what's causing this.
Whether or not this issue needs to be reported. If your internal system has already logged and reported the issue and will likely bring it to someone's attention automatically, then you can tell the user that this has already been done and they do not need to call in or email in to report it. If not, then you may even ask them to report it so you can hear about it and know that something isn't working.

Should you send DB errors to the user?

1 Answers1