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Linux: ORA-12518: TNS:listener Could Not Hand Off Client Connection (Doc ID 2298954.1)

Last updated on APRIL 05, 2018

Applies to:

Oracle Net Services - Version and later
Information in this document applies to any platform.


On : version, Clusterware

When attempting to connect to database via listener,
the following error occurs.


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

15-AUG-2017 01:40:01 * (CONNECT_DATA=(CID=(PROGRAM=myapp)(HOST=__jdbc__)(USER=admin))(SERVER=DEDICATED)(SERVICE_NAME=oracle)) * (ADDRESS=(PROTOCOL=tcp)(HOST= * establish * oracle * 12518
TNS-12518: TNS:listener could not hand off client connection
 TNS-12536: TNS:operation would block
  TNS-12560: TNS:protocol adapter error
  TNS-00506: Operation would block
  Linux Error: 11: Resource temporarily unavailable

The issue can be reproduced at will with the following steps:
1. sqlplus user/password@


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