The config.xml file cannot be modified at runtime. It can only be modified when the server is not up. If you modify it the server may overwrite the file when shut down.
By the way we have a forum specific for weblogic queries in the Products section. Please post your queries specific to Weblogic in that forum.
Thanks
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Mahindrakar
IBM/Websphere Forum Moderator Consultant -
Zensar Technologies ,Pune India.
SCJP2, SCJD2 & SCJEA (Part I)