In the cluster of KingbaseES V8R3 cluster The error message “ERROR: md5 authentication failed; DETAIL: password does not match” often appears in the log. This case shows the cause of this error.

Applicable version:KingbaseES V8R3

Problem phenomenon:
cluster.log:

Analysis: 1, when the system user connects to port 9999 to execute “show pool_nodes”, you need to access the cluster kingbasecluster service and verify the user’s identity by cluster_password.

As shown below: cluster.log information

2. The password of the system user needs to be verified by the database sys_hba.conf (the password is encrypted by md5).

As shown below: cluster.log information

3. And port 9999 corresponds to the kingbasecluster service, which also needs to be verified by the md5 password in the cluster_password file.

4. If the database password and the password in cluster_password do not match, you cannot log in.

5. This error message does not affect the health detection of the background database by kingbasecluster.

Problem-solving:

When changing the database user system password in the cluster.
        1、Modify the password of the system user in the database.
        2, also need to modify the password of system user in cluster_password by sys_md5 tool. 
        3, you need to modify the password of system in the recovery.done and recovery.conf configuration files.