Connection Failure Message: exception: login failed and U_STRINGPREP_PROHIBITED_ERROR

Symptom

An error is reported when you run the following command to connect to a DDS instance:

./mongo "mongodb://rwuser:xxxxxx@192.168.0.45:8635,192.168.0.96:8635/test?authSource=admin&replicaSet=replica"

Error message:

MongoDB shell version v4.0.3
connecting to: mongodb://192.168.0.45:8635,192.168.0.96:8635/test?authSource=admin&replicaSet=replica
2021-11-05T05:52:53.717+0000 I NETWORK  [js] Starting new replica set monitor for replica/192.168.0.45:8635,192.168.0.96:8635
2021-11-05T05:52:53.718+0000 I NETWORK  [ReplicaSetMonitor-TaskExecutor] Successfully connected to 192.168.0.45:8635 (1 connections now open to 192.168.0.45:8635 with a 5 second timeout)
2021-11-05T05:52:53.718+0000 I NETWORK  [js] Successfully connected to 192.168.0.96:8635 (1 connections now open to 192.168.0.96:8635 with a 5 second timeout)
Implicit session: session { "id" : UUID("5945d2a5-8275-4e3c-b06f-632f062a2ead") }
MongoDB server version: 4.0.3
2021-11-05T05:52:53.722+0000 I NETWORK  [js] Marking host 192.168.0.96:8635 as failed :: caused by :: Location50692: can't authenticate against replica set node 192.168.0.96:8635 :: caused by :: Error preflighting normalization: U_STRINGPREP_PROHIBITED_ERROR
2021-11-05T05:52:53.722+0000 I NETWORK  [js] Successfully connected to 192.168.0.45:8635 (1 connections now open to 192.168.0.45:8635 with a 0 second timeout)
2021-11-05T05:52:53.723+0000 I NETWORK  [js] Marking host 192.168.0.45:8635 as failed :: caused by :: Location50692: can't authenticate against replica set node 192.168.0.45:8635 :: caused by :: Error preflighting normalization: U_STRINGPREP_PROHIBITED_ERROR
2021-11-05T05:52:53.724+0000 I NETWORK  [js] Marking host 192.168.0.96:8635 as failed :: caused by :: Location50692: can't authenticate against replica set node 192.168.0.96:8635 :: caused by :: Error preflighting normalization: U_STRINGPREP_PROHIBITED_ERROR
2021-11-05T05:52:53.725+0000 I NETWORK  [js] Marking host 192.168.0.45:8635 as failed :: caused by :: Location50692: can't authenticate against replica set node 192.168.0.45:8635 :: caused by :: Error preflighting normalization: U_STRINGPREP_PROHIBITED_ERROR
2021-11-05T05:52:53.725+0000 E QUERY    [js] Error: can't authenticate against replica set node 192.168.0.45:8635 :: caused by :: Error preflighting normalization: U_STRINGPREP_PROHIBITED_ERROR :
DB.prototype._authOrThrow@src/mongo/shell/db.js:1685:20
@(auth):6:1
@(auth):1:2
exception: login failed

Possible Cause

The instance password is incorrect.

Fault Locating

• Check whether the DDS instance password contains the at sign (@), percent sign ( %), and exclamation mark (!). If yes, escape them.
• DDS instances support the following special characters that require escaping ~!@#$ %^ *-_=+?. %@

Solution

Method 1: Change the password of the DDS instance. The new password cannot contain the at sign (@), percent sign ( %), and exclamation mark (!).

Method 2: When connecting to a DDS instance, escape the at sign (@), percent sign ( %), and exclamation mark (!) and replace them with hexadecimal URL codes (ASCII codes) %40, %25, and %21.

For example, if the password is ****@ %***!, the corresponding URL code is **** %40%25*** %21.

Background Information

The at sign (@), percent sign ( %), and exclamation mark (!) are processed as special characters when you connect to a DDS instance. If these characters are used, they must be escaped when you use the HA connection address to connect to the DDS instance, otherwise, the password cannot be parsed.