Time to live in mongodb, mongoose dont work. Documents doesnt get deleted

Question

Im using this scheme for a session in my node.js app

var mongoose     = require(\'mongoose\');
var Schema       = mongoose.Schema;
// define the schema for o         


        

Answer 1

var UserSessionSchema   = new Schema({
    sessionActivity:    { type: Date, expires: '15s', default: Date.now }, // Expire after 15 s
    user_token:         { type: String, required: true }
});

A TTL index deletes a document 'x' seconds after its value (which should be a Date or an array of Dates) has passed. The TTL is checked every minute, so it may live a little longer than your given 15 seconds.

To give the date a default value, you can use the default option in Mongoose. It accepts a function. In this case, Date() returns the current timestamp. This will set the date to the current time once.

You could also go this route:

UserSessionSchema.pre("save", function(next) { 
    this.sessionActivity = new Date(); 
    next(); 
});

This will update the value every time you call .save() (but not .update()).