.dbc and .cfg file

What is a .dbc and a .cfg file?

The .dbc file is mostly used to define database parameters,stands for database connect descriptor file, used to connectto database, it authenticate users against database in FND_USER table.

How it work's

The .dbc file is actually the database connector descriptor file used to connect to database and this file is by-default located in $FND_TOP/secure directory, this file is quite important as whenever any program likes to connect to database like forms it uses dbc file where there you find the Guest_user_pwd ,when the guest user connect it does not allow it to directly connect to the database but it first connect goes via this file and cross verify the password of the guest which is kept in this file.

DBC file is quite important as whenever Java or any other program like forms want to connect to database it uses dbc file.

Typical entry in dbc file are:
GUEST_USER_PWDAPPS_JDBC_URLDB_HOST


The dbc file is used to set up the connectivity for a given database. Each vendor requires different values to determine the server name, database name, user and password, plus any native options including special instructions for the vendor's client API or utility loader.When you drag an Output Table/Input Table etc. onto the canvas, the DBC file lets the component know where to direct the activity. The DBC file is also the mechanism through which a given table can be accessed and its column definition pulled automatically into the given component's DML definition.

There will be lot of dbc file under $FND_SECURE, how we determine which dbc file to use from $FND_SECURE ?

This value is determined from profile option "Applications Database ID"
Authenication:-

In order to authenticate your user against database in FND_USER table this request is passed from core Apache Module to mod_pls ( plsql) and it uses few files like wdbsvr.app in Apache/modplsql/conf $CONTEXT_NAME.dbc , tnsnames.ora in 806/network/admin/$CONTEXT_NAME , GUEST user & few other file so focus on these files & directories & see what changed recently.

.dbc file in R12 -->the dbc file in R12 is in the new $INSTANCE_TOP

$INST_TOP/appl/fnd/12.0.0/secure or $INSTANCE_TOP/apps//appl/fnd/12.0.o/secure.

Last but not the least .cfg is a unix-level file that is fed into a Korn Shell script as an auto-parameter feeder for a parameter-driven shell script. Cfg files are unix-defined where dbc files are AbI-defined.

A Database Connection (DBC) file holds information used by application servers to identify and authenticate with an application database. DBC files must be created on all tiers if it is a multi-tier system.

To recreate DBC file Login to your system as the APPLMGR, ensure that your environment is set correctly by running /.env.
Run common_top/admin/install/adgendbc.sh (UNIX)
This will create the DBC file for the current environment instance. Verify log file to check environment, which should be pointing to 806.Location of file is in /admin/install/adgendbc.txt.

DBC file Parameters

Verify dbc file exists and is in the right location. $FND_TOP/secure//_.dbc. Verify db_host using %uname -aVerify db_sid from v$instance or echo $ORACLE_SID.

Parameters:
APPL_SERVER_ID APPS_JDBC_DRIVER_TYPE=THIN DB_PORT <> DB_HOST GWYUID FNDNAM <> TWO_TASK GUEST_USER_PWD. this is application account and should exists in applications with out any responsibility.
Note:Make sure environment value specified for DB_HOST is db host not application host.
Optional parameters:

FND_MAX_JDBC_CONNECTIONS
Maximum number of open connections in the JDBC connection cache. This number is dependent on the amount of memory available, the number of processes specified in the init.ora file of the database.

FND_IN_USE_CONNECTION_TIMEOUT
Maximum number of seconds a connection can be in use. In order to avoid connections being locked up for too long, the connection cache uses this parameter to forcibly close connections that have been locked for over this time. If this parameter is unspecified,connections in use will not be cleaned up. This should be set to a number larger than the time taken to complete the largest transaction.It is difficult to estimate and recommendation is not to use this.

FND_UNUSED_CONNECTION_TIMEOUT
Maximum number of seconds an unused connection can remain in the cache. The connection cache will close and remove from the cache any connection that has been idle for longer than this specified limit.
Checking DBC file entries: Check Encrypted String for APPL_SERVER_ID parameter in the DBC file with entry in db using following sql stmt.These should be same.
Log in as apps/
Select server_id,server_address from FND_APPLICATION_SERVERS;

The output server_id should match APPL_SERVER_ID and server_address should match IPADDRESS of db host.

%nslookup Address: xxx.xx.xxx.xx Name: Address:
verify hostname above with db_host parameter in dbc file.

Checking db connectivity using DBC file :


syntax:

jre -v oracle.apps.fnd.security.AdminAppServer apps/ STATUS dbc=

Output :
Database Server
---------------
DATABASE_ID: *********
AUTHENTICATION: OFF

Application Server
------------------
APPL_SERVER_STATUS: VALID
APPL_SERVER_ID: 2CF3A427AB3AE01EE0439C143428E01E24739190873060609592242102215611


Status return's APPL_SERVER_ID and other db related info. This verifies DBC setup.

No comments:

ORA-01552: cannot use system rollback segment for non-system tablespace 'TEMP'

 ORA-01552: cannot use system rollback segment for non-system tablespace "string" Cause: Used the system rollback segment for non...