Resolve TNS Listener Cannot Hand Off Connection

Error:

ORA-12518:TNS:listener could not hand off client connection.

One Solution:

We created a manual entry to register the PDB service in listener.ora file. By mistake I missed the parameter GLOBAL_NAME in the file.

(SID_DESC =
   (SID_NAME = PDB1)
   (ORACLE_HOME = C:\Oracle19c)
)

Solution:

After adding the global_name in the listener.ora file, we were able to fix the issue.

(SID_DESC =
       (GLOBAL_NAME=PDB1)
       (SID_NAME = PDB1)
       (ORACLE_HOME = C:\Oracle19c)
)

Complete listener.ora file as :

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:\Oracle\dbhomeXE)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:C:\Oracle\dbhomeXE\bin\oraclr18.dll")
    )
	(SID_DESC =
	(GLOBAL_DBNAME = PDB1)
	(ORACLE_HOME = C:\Oracle\dbhomeXE)
	(SID_NAME = PDB1)
	)
     )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )

Solution 2: If max process is reached in alert log and producing the same error: TNS-12518: TNS:listener could not hand off client connection

Check the Post: https://smarttechways.com/2021/11/22/ora-12518-tns-listener-could-not-hand-off-client-connection-on-my-database/