Running yum update gives message "No Packages marked for Update" on Red Hat Enterprise Linux Server

Issue

• No updates available for the client system.
• Running yum update gives message "No Packages marked for Update" on Red Hat Enterprise Linux Server.
• While running yum update receives the following message:

    [root@localhost]# yum update 
    Setting up Update Process 
    No Packages marked for Update

• While running rhn_check -vvv receives the following message:

    [root@localhost]# rhn_check -vvv 
    D: opening  db environment /var/lib/rpm/Packages joinenv 
    D: opening  db index       /var/lib/rpm/Packages rdonly mode=0x0 
    D: locked   db index       /var/lib/rpm/Packages 
    D: opening  db index       /var/lib/rpm/Providename rdonly mode=0x0 
    D: do_call packages.checkNeedUpdate ('rhnsd=1',) 
    D: Attempt to call an unsupported action packages.checkNeedUpdate ('rhnsd=1',) 
    D: local action status:  (6, 'Invalid function call attempted', {}) 
    D: closed   db index       /var/lib/rpm/Providename 
    D: closed   db index       /var/lib/rpm/Packages 
    D: closed   db environment /var/lib/rpm/Packages 
    D: May free Score board((nil))