Cause:
Inbound connection was timed out
by the server because user
authentication was not completed
within the given time specified
by
SQLNET.INBOUND_CONNECT_TIMEOUT
or its default value
Action:
1) Check SQL*NET
and RDBMS log for trace of
suspicious connections.
2)
Configure SQL*NET with a proper
inbound connect timeout value if
necessary.
Troubleshooting ORA-03136 can be pretty tricky, but
Oracle MOSC offers information on ORA-03136 in Oracle Net Services,
version 10.2.
There can be three main reasons for the ORA-03136 error
1) The server gets a connection request from a malicious
client which is not allowed to connect to Oracle, in which case the ORA-03136
error is the correct behavior. You can get the client address for which the
error was thrown via sqlnet log file.
2) The server receives a valid
client connection request but the client takes a long time to authenticate the
request, more than the default 60 seconds.
3) The server is heavily
loaded or more of RAM usage due to which it cannot finish the client logon
within the timeout specified.
ORA-03136 means that an authentication was not able to be
completed, and can appear without a timeout error with in the sqlnet.log file.
It is important to that from 10.2 on, the parameter has a default of 60 seconds,
and when the client attempts to authenticate it will often throw ORA-03136.
To figure out which issue is causing your ORA-03136, try these checks,
especially considering that in many conditions, the default setting offers
enough resources for authenticating client connections:
1. Check whether local connection on the database server is successful
& quick.
2. If local connections are quick ,then check for underlying network delay
with the help of your network administrator.
3. Check whether your Database performance has degraded by anyway.
4. Check alert log for any critical errors for eg, ORA-600 or ORA-7445 and
get them resolved first.
Also, on
Oracle Forums, there is information regarding ORA-03136 and issues with
INBOUND_CONNECTION_TIMEOUT. If the listener does not receive the
command correctly, it will shutdown and throw errors such as ORA-03136.
For more information regarding
INBOUND_CONNECTION_TIMEOUT to help resolve ORA-03136, try
this article.
And you may want to also review these notes on
ORA-12170
