ORA-12521: TNS:listener does not currently know of instance requested in connect descriptor

Cause : The listener received a request to establish a connection to a database or other service. The connect descriptor received by the listener specified in addition to the service name an instance name for an instance (usually a database instance) that either has not yet dynamically registered with the listener or has not been statically configured for the listener. This may be a temporary condition such as after the listener has started, but before the database instance has registered with the listener.

Action - How to fix it : DBA Scripts :: www.high-oracle.com/scripts

- Wait a moment and try to connect a second time. - Check which instances are currently known by the listener by executing: lsnrctl services - Check that the INSTANCE_NAME parameter in the connect descriptor specifies an instance name known by the listener. - Check for an event in the listener.log file.

update : 21-08-2017
ORA-12521

ORA-12521 - TNS:listener does not currently know of instance requested in connect descriptor
ORA-12521 - TNS:listener does not currently know of instance requested in connect descriptor

  • ora-31205 : DBMS_LDAP: PL/SQL - Invalid LDAP Auth method.
  • ora-09888 : osnTXtt: txipc channel creation failed
  • ora-07845 : sllfcl: LIB$FREE_VM failue
  • ora-25334 : Buffered propagation must restart as the destination queue was recreated/moved
  • ora-06318 : IPA: Local maximum number of connections exceeded
  • ora-39951 : incomplete values specified for PL/SQL warning settings
  • ora-13110 : cannot drop topology with associated topo_geometry tables
  • ora-29858 : error occurred in the execution of ODCIINDEXALTER routine
  • ora-07820 : sspscn: SYS$CRELNM failure
  • ora-31210 : DBMS_LDAP: PL/SQL - LDAP get_dn error.
  • ora-33297 : (DBERR22) Analytic workspace string cannot be opened because it was last modified by an incompatible version of string.
  • ora-00162 : external dbid length string is greater than maximum (string)
  • ora-19648 : datafile string: incremental-start SCN equals checkpoint SCN
  • ora-16644 : apply instance not available
  • ora-13207 : incorrect use of the [string] operator
  • ora-24183 : invalid transformation
  • ora-16759 : resource guard unable to start SQL Apply with initial SCN
  • ora-25453 : invalid iterator: string
  • ora-02702 : osnoraenv: error translating orapop image name
  • ora-28591 : agent control utility: unable to access parameter file
  • ora-12410 : internal policy error for policy: string Error: string
  • ora-02713 : osnprd: message receive failure
  • ora-29817 : non-supported option with disassociate statement
  • ora-08196 : Flashback Table operation is not allowed on AQ tables
  • ora-25466 : data not specified for variable name: string
  • ora-24072 : cannot execute MIGRATE_QUEUE_TABLE procedure; must own queue table
  • ora-01493 : invalid SAMPLE size specified
  • ora-16723 : setting AlternateLocation property conflicts with the redo transport setting
  • ora-01666 : control file is for a standby database
  • ora-12323 : unable to open database (link name string)
  • Oracle Database Error Messages



    Oracle Database High Availability Any organization evaluating a database solution for enterprise data must also evaluate the High Availability (HA) capabilities of the database. Data is one of the most critical business assets of an organization. If this data is not available and/or not protected, companies may stand to lose millions of dollars in business downtime as well as negative publicity. Building a highly available data infrastructure is critical to the success of all organizations in today's fast moving economy.

    Well, the reason for above error is that i have taken the above script from a 11g database and running it on 10g database. 11g has bring some changes in password management. Below code is executed on 11g and user created successfully, which is expected result.