Reset password in weblogic portal

Error message

Caused By: javax.security.auth.login.FailedLoginException: [Security:090302]
Authentication Failed: User canopiadmin denied
       at weblogic.security.providers.authentication.shared.DBMSAtnLoginModuleImpl.login(DBMSAtnLoginModuleImpl.java:285)
       at com.bea.common.security.internal.service.LoginModuleWrapper$1.run(LoginModuleWrapper.java:110)
       at java.security.AccessController.doPrivileged(Native Method)
       at com.bea.common.security.internal.service.LoginModuleWrapper.login(LoginModuleWrapper.java:106)
       at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       Truncated. see log file for complete stacktrace
 
In weblogic portal the authentication happens via DB, since it uses SQL based authentication.
1. We need to enter the original username password in database
2. enable plain text password in config.xml if its not already so, since the above entered credentials are in plaintext and table will have encrypted values.

to enable plaintext in config.xml as

<wls:plaintext-passwords-enabled>true</wls:plaintext-passwords-enabled>

so it would look like below in config.xml

<realm>
     <sec:authentication-provider xsi:type="wls:sql-authenticatorType">
       <sec:control-flag>SUFFICIENT</sec:control-flag>
       <wls:data-source-name>p**nDataSource</wls:data-source-name>
       <wls:plaintext-passwords-enabled>true</wls:plaintext-passwords-enabled> 

3. restart the servers.

plaintext password is reachable via console as
console - security realm - myrealm - providers - authentication - select the respective sql authenticator - config - provider specific - Plaintext Passwords Enabled

You may disable plain text after successful login,  

To disable WLDF diagnostics

Access the Administration Console for you domain.
Click Lock & Edit to start a new configuration session.
Select the Diagnostics->Diagnostic Modules node in the left pane of the console.
disable or stop or delete the respective module and carry out a restart.
Also please check if any of the options are enabled under console - data source - configuration - diagnostics  

Else

1. Shut down WebLogic Server.
2. Clear the <SERVER>/data/store/diagnostics directories
3. Apply the below 3 parameters at JAVA_OPTIONS of your setdomainenv  file

-D_Offline_FileDataArchive=true
To control diagnostics data collected from the server instance and the applications running on them. If true, WLDF archives the data collected (default: false).

-Dcom.bea.wlw.netui.disableInstrumentation=true
To control Workshop page flow event reporting. Set to false by default in Workshop 10.1 and earlier). Set to true by default (in Workshop 10.2 and later).

-Dweblogic.connector.ConnectionPoolProfilingEnabled=false
JDBC Connection Pool profiling data (default: false).

4. Restart WebLogic Server.
 

 Else

Take a backup of config.xml and delete the lines from and to <server-diagnostic-config>
restart

Else
 
You can adopt a retirement policy by rotating the .dat file
console -  diagnostics - archives - select the respective server - create NEW 'Data Retirement Policies' followed by a restart.