Node.js, MongoDB, and AngularJS Web Development

Understanding the Write Concern

Before connecting to and updating data on a MongoDB server, you need to decide what level of write concern you want to implement on your connection. A write concern is the guarantee that the MongoDB connection provides when reporting on the success of a write operation. The strength of a write concern determines the level of guarantee.

The basic idea is that stronger write concerns tell MongoDB to wait until a write has successfully been written to disk before responding. On the other hand, a weaker write concern may only wait until MongoDB has successfully scheduled a change to be written before responding. The downside of stronger write concerns is that the stronger they are, the longer MongoDB waits to respond ...