EBS 12.2 -- Configuring Application connections manually ( including jdbc connections) - on RAC / on Exadata

In some cases, we may want to configure application connections manually.. As you may already know, EBS 12.2 configures its Forms&Reports, Concurrent processing and web (HTTP Server) connections through the tnsnames.ora file which resides in the Application nodes.. ( tnsnames.ora file located in the directory pointed by $TNS_ADMIN  -- in application nodes)

These TNS configurations are all autoconfig-managed and they are tide to the autoconfig variables named s_tools_twotask, s_cp_twotask and s_weboh_twotask..

In addition to that, the configuration for all the JDBC connections of EBS 's Apps Tier is also automatic managed and it is configured through the s_apps_jdbc_connect_descriptor.

Normally, when we run autoconfig, or when we install the apps with an Oracle RAC database configuration, then we will end up with a connection configuration which is based on scan listeners.. This configuration supports both load balance and fail over..  

This seems good as it leverages the RAC and SCAN-based architecture.. It provides load balancing and failover for databases connections.

However; as I mentioned in the beginning, we may want to change that.. Especially when we have an unbalanced environment where we have a node which is more crowded and loaded than the others.. (this may be caused by several reasons, like manual tns configuration for Discoverer clients or 3rd party applications that are configured to connect to only one of the db nodes..)

So in such a case, we may want to configure all the EBS apps tier connections and make the application tier services connect only a single node (least crowded one). 

In order to make such a configuration, we update the application tier context file and set twotask autoconfig variables to the failover TNS entries (TNS entries which have _FO suffix in our case) present in tnsnames.ora file of the Application node/or nodes

We also set the s_apps_jdbc_connect_descriptor according to our needs. Ofcourse we don't forget to set s_jdbc_connect_descriptor_generation to FALSE, as well.. 

Note that, s_jdbc_connect_descriptor_generation setting is very important.. I mean, if we set it or leave it as is (I mean if it is set to TRUE), then the apps tier autoconfig will overwrite the jdbc url with the scan-based & load balanced one... So if it iset to true, autoconfig will revert the change that we do for the  jdbc url.. Note that, jdbc url is used by all the jdbc connections in EBS + dbc file is also created with that url..

Following are the twotask and jdbc url related settings that I made in environment where customer wanted me to make all the services (including Concurrent Processing, Forms and Weblogic) connect to a RAC Node.. (Exadata Node 1 in this case). As the TNS Entries and jdbc url settings are based on failover mode (not the load balance mode), the services will always connect that RAC Node (Exadata Node 1), unless that RAC Node is down. So this supports failover a well.

Note that, this is tested in an EBS 12.2.9 environment with an Oracle 19C Database ( running on Exadata Cloud at Customer)

<TWO_TASK oa_var="s_tools_twotask" osd="unix">PROD_FO</TWO_TASK>

<CP_TWOTASK oa_var="s_cp_twotask">PROD_FO</CP_TWOTASK>

<TWO_TASK oa_var="s_weboh_twotask" osd="unix">PROD_FO</TWO_TASK>

<jdbc_url oa_var="s_apps_jdbc_connect_descriptor">jdbc:oracle:thin:@(DESCRIPTION=(LOAD_BALANCE=no)(FAILOVER=yes)(ADDRESS=(PROTOCOL=TCP)(HOST=exadata01-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=ebs_PROD))(ADDRESS=(PROTOCOL=TCP)(HOST=exadata02-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=ebs_PROD)))</jdbc_url>

<jdbc_url_generation_check oa_var="s_jdbc_connect_descriptor_generation">false</jdbc_url_generation_check>

After those settings, we run autoconfig on apps Tier and that's it! (ofcourse, we need to shutdown the apps tier before running autoconfig)

One more thing, you can check your jdbc url and ensure its correct before writing it to the s_apps_jdbc_connect_descriptor.. I know, there are many ways to do that.. But! You can also use SQLPLUS to do this job... Easy and clean :)

Here is an example for the syntax:

sqlplus 'apps/apps_password@(DESCRIPTION=(LOAD_BALANCE=no)(FAILOVER=yes)(ADDRESS=(PROTOCOL=TCP)(HOST=exadata01-vip)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=ebs_PROD))(ADDRESS=(PROTOCOL=TCP)(HOST=exadata02)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=ebs_PROD)))'

I hope it was useful. Take care of yourselves :)