Question:

Implementation db.auth (‘username ‘,’ password ‘),
monodb authentication failed,
error: authentication failed.  appears

environment

Root, admin, and business database user authentication failed

Solution

1. stop mongodb and open it without authentication,

##Go to the bin directory
cd 
##stop
mongod --shutdown --dbpath=/soft/mongo/mgserver/data/
##start
./mongod --dbpath=/soft/mongo/mgserver/data/ --logpath=/soft/mongo/mgserver/logs/mongod.log --logappend --port=27017 --fork

verify

mongo
show dbs

use  ${your db}
show users

use admin
show users

Modify password
3.1 modify root password:

#
mongo
#
db.changeUserPassword('root','${new  password}')
#
exit

#closed
mongod --shutdown --dbpath=/soft/mongo/mgserver/data/
#Certification Launch
./mongod --dbpath=/soft/mongo/mgserver/data/ --logpath=/soft/mongo/mgserver/logs/mongod.log --auth --logappend --port=27017 --fork

#
mongo
#
use admin
#user, pwd
db.auth('','')

Similarly, change the password of other users

3.2 new users

#
mongo
#
use ${your db}
#
db.createUser({
	user: "",
	pwd:"",
	roles:[{role:"readWrite",db:""}]
})