Question: I am getting this
ORA-12516 error:
ORA-12516, TNS: listener could not
find available handler with matching protocol stack' When
Running the RunETL Process
Can you explain a solution to the ORA-12516 error?
I have two application servers (Web Logic) and I am getting
the ORA-12516 from only one of the application servers.
Answer: The oerr utility shows this
for the ORA-12516 error:
ORA-12516: TNS: listener
could not find available handler with matching protocol
stack.
Cause: None of the
known and available service handlers for the given
SERVICE_NAME support the client's protocol stack: transport,
session, and presentation protocols.
Action:
Check to make sure that the service handlers (e.g.
dispatchers) for the given SERVICE_NAME are registered with
the listener, are accepting connections, and that they are
properly configured to support the desired protocols.
You have to check why the listener was rejecting the
connection and do nslookup for the saecopq20(DNS name),and
see what and all IP address are mapped to the DNS, and check
to see those IP address are listening.
Please refer to MOSC Note
1100982.1 and
MOSC note 240710.1, notes that talk about the TNS-12516
occurring intermittently in the clients.
This is because the listener, which relies on Automatic
Instance Registration (or AIR) for configuring the services
the listener should listen for, gets a lot of client
requests and thus runs out of handles to open with the
database server and hence this error.
Possible fixes
for the ORA-12516:
1.) As a Fix, increase the value
for PROCESSES in the init.ora file of the instance.
2.) You can have static registration for this instance
by having a SID_LIST in the listener.ora file in addition to
the automatic instance registration.
Also note bug
Bug 8232287 - PMON stops registering its services
(ORA-12516 errors) [ID 8232287.8]
