Problem description
Egg project uses mongoose mongoose to report an error failed to connect to server.

PRIMARY：hostA, primary node
SECONDARY：hostB、hostC; Slave node
One master and two slaves, ports 27017

Copy set：rs0

The URL I wrote:’ MongoDB://Account: Password @ Hosta: 27017, Hostb: 27017, Hostc: 27017/Database? replicaSet=rs0′
Options: {} Empty No Configuration

The connection is not working, please ask the great gods to specify it.