Issue caused by Fast Application Notification (FAN) for OCI client.
FAN uses Oracle Notification Services (ONS) to publish and subscribe
service for communicating information about all Fast Application Notification (FAN) events.
ONS uses port 6200 by default. If there is a firewall between the
client and the server and port 6200 port is closed then this behavior
is expected
You can use OCI to access Oracle TimesTen In-Memory Database and Oracle TimesTen Application-Tier Database Cache. OCI is an API that provides functions you can use to access the database and control SQL execution. OCI supports the data types, calling conventions, syntax, and semantics of the C and C++ programming languages.
TimesTen and TimesTen Cache support the Oracle Call Interface (OCI) for C or C++ programs.
Starting with Oracle Database Release 12c Release 1 (12.1), Oracle provides an oraaccess.xml file, a client-side configuration file. You can use the oraaccess.xml file to configure selected OCI parameters (some of which are accepted programatically in various OCI API calls), thereby allowing OCI behavior to be changed during deployment without modifying the source code that calls OCI.
Updates to the oraaccess.xml file will not affect already running clients. In order to pick up any updates to the oraaccess.xml file, already running clients need to be restarted.
The oraaccess.xml file is read from the directory specified by the TNS_ADMIN environment variable in regular and instant client installations.
This is the $ORACLE_HOME/network/admin directory on UNIX operating systems and the %ORACLE_HOME%\NETWORK\ADMIN directory on Microsoft Windows operating systems, if TNS_ADMIN is not set in regular client installations.
The oraaccess.xml file has a top-level node with the three elements. One of them is . the tag allows specifying default values for various OCI parameters. Some parameters can only be specified once and hence apply to all connections. These global parameters are described using by some tags. One of them is <events> tag.
Ref .
If you already have an oraaccess.xml file, then convert the part
<events>true</events> to <events>false</events>.
Otherwise create an oraaccess.xml file with the following information in the default_parameters section:
<?xml version="1.0" encoding="ASCII" ?>
<oraaccess xmlns="http://xmlns.oracle.com/oci/oraaccess"
xmlns:oci="http://xmlns.oracle.com/oci/oraaccess"
schemaLocation="http://xmlns.oracle.com/oci/oraaccess
http://xmlns.oracle.com/oci/oraaccess.xsd">
<default_parameters>
<events>false</events>
</default_parameters>
</oraaccess>
put this file under TNS_ADMIN directory, and then restart the SQL*Plus Client.
