CODEWITHSUNDEEP
node.jsmongodbmongoose
Ronak Vora
Ronak Vora

Reputation: 310

Writing to MongoDB without waiting for response

I'm trying to figure out how to write to a MongoDB using Mongoose and Node.js without waiting for the response. The typical way to write to MongoDB is either to use the callback syntax or use the await/async pattern. Both of these patterns don't execute the query unless you specify a call back or await the response.

Is there a way to write to MongoDB in a 'best-effort' fashion? I.e. just make the call, don't wait for the response, and if it succeeds great, and if not, no problem.

EDIT:

Code:

Async/await pattern: 

const doc = await Product.findByIdAndUpdate('prod1', {$inc: {viewed: 1}});
console.log(doc);

Callback pattern 

Product.findByIdAndUpdate('prod1', {$inc: {viewed: 1}, func(err, doc) {
    console.log(doc)
});

Both of these wait for the response.

Upvotes: 2

Views: 1699

Answers (1)

kevinadi
kevinadi

Reputation: 13775

You can do the write using w:0 write concern setting. This will instruct MongoDB to do the write, but not waiting for feedback. For example:

  conn.db('test').collection('test').insertOne({'a': 1}, {'w': 0}, function(err, res) {
    assert.equal(null, err);
    console.log(res);
  })

The default write concern is w:1 (wait for confirmation from the node you're connecting to). If you check the res output of the code above using w:1, it will show:

  ...
  insertedCount: 1,
  ...

In contrast, using w:0 will show:

  ...
  insertedCount: undefined,
  ...

Note: although writes will return quickly with best-effort using this setting, this is essentially UDP for your writes. Use at your own risk.

Upvotes: 4

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