MongoError: pool is draining, new operations prohibited – How to fix? You might face this error while doing some operations on a Mongo database.

mongoose.connect(url, {bufferMaxEntries: 0, reconnectTries: 5000, useNewUrlParser: true,useUnifiedTopology: true});

This error basically means that the connection that you established with the mongodb has already expired. To elaborate, you haven’t used connection pool with your mongo connection.

This error (pool is draining, new operations prohibited) might occur if you are using the official mongodb library for node js or mongoose. Please check if you are specifying pool size while establishing mongodb connection.

mongoose.connect(url, {poolSize: 10, bufferMaxEntries: 0, reconnectTries: 5000, useNewUrlParser: true,useUnifiedTopology: true});

Specifying pool size while connecting to mongo database, eliminates this error.