503 Service Unavailable The connection pool named: |default|lo|, encountered and error: mismatch with the server cert DN:IO Error

503 Service Unavailable
The connection pool named: |default|lo|, encountered and error: mismatch with the server cert DN:IO Error

Hope you have gone through my previous post of ORDS : 404 not found.

http://tanwanichandan.blogspot.com/2023/03/ords-404-not-found-request-could-not-be.html

Once I resolved above ORDS issue, I was getting error - 503 Service Unavailable

The connection pool named: |default|l0|, encountered and error: mismatch with the server cert DN:IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=N6Ys81zJRmyqf8zuk6YrOg==)

This is really frustrating when you solve one error and immediately get another error and are stuck with no clue why it happened.

Below is the screenshot for the reference.

Also If you see the weblogic log file, you will see the below error.

<Mar 16, 2023, 11:53:01,891 AM India Standard Time> <Error> <oracle.dbtools.rest> <BEA-000000> <<5077f343-f438-4659-a682-f867ee715c88-0000001c> GET 10.132.141.180 /ords/ 503 The connection pool named: |default|lo|, encountered an error: mismatch with the server cert DN: IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=N6Ys81zJRmyqf8zuk6YrOg==)

ServiceUnavailableException [statusCode=503, logLevel=SEVERE, reasons=[The connection pool named: |default|lo|, encountered an error: mismatch with the server cert DN: IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=N6Ys81zJRmyqf8zuk6YrOg==)]]

        at oracle.dbtools.http.errors.ServletResponseExceptionMapper.mapError(ServletResponseExceptionMapper.java:45)

        at oracle.dbtools.http.errors.ErrorLogger.log(ErrorLogger.java:27)

        at oracle.dbtools.http.errors.ErrorPageFilter.doFilter(ErrorPageFilter.java:106)

        at oracle.dbtools.http.filters.HttpFilter.doFilter(H

To resolve the the issue, I have followed below steps,

Step 1 - Check the TNS Entries on DB Server

Step 2 - Check listener is up and running. It serves your PDB database.

Step 3 - Check if TNS Ping working for your PDB

In my case all the above steps were working fine. There was no issue. If you have any issue in the above steps, first rectify the same.

Now, after cross checking all my installation documents and other things, I then found that user APEX_220200 was locked.

You can run the below command in your PDB/CDB and check if any of %APEX% users are locked or what. In my case APEX_220200 was locked.

select username, account_status from dba_users where username like '%APEX%';

Refer below screenshot

Unlock user and reset password with following command

sql> alter user apex_220200 identified by Manager#123 account unlock;

Also check any ORDS user is locked or what by running below query in database. 

select username, account_status from dba_users where username like '%ORDS%';

If the ORDSYS user is locked then no issue. No need to unlock it.

Finally, I was able to get the APEX login page after unlocking apex_220200 user.

Lesson learned, must check all the prerequisites and follow the Oracle documentation steps.

Thanks & Regards,

Chandan Tanwani