ORA-27101 & ORA-1034 Error Attempting to Connect to the Database Via the Listener (Doc ID 256263.1)

Last updated on OCTOBER 27, 2016

Applies to:

Oracle Net Services - Version 9.2.0.8 to 12.1.0.2 [Release 9.2 to 12.1]
Information in this document applies to any platform.
***Checked for relevance on 30-JUN-2015***


Symptoms

The following errors are being returned to clients when they attempt a remote connection to the database.  The database is running and local  connections are successful.


ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist

Lsnrctl services shows that the listener is running and it has a static or UNKNOWN service handler for the instance to which connections are failing:

Service "bpstst09" has 1 instance(s).
Instance "BPS", status UNKNOWN, has 1 handler(s) for this service...

Clients may be able to connect after a short time if the instance registers dynamically with the listener.

A dynamically registered instance would appear in the lsnrctl services output as READY:

Service "bpstst09" has 2 instance(s).
Instance "BPS", status UNKNOWN, has 1 handler(s) for this service...
Instance "BPS", status READY, has 1 handler(s) for this service...

Cause

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