Addressing OLTP Solutions with CICS: The Transaction Server ... - Ibm

emote DRDA database. Information about the attributes must be gathered as
part of the planning process for DDCS customization. See the DDCS User′s
Guide, S20H-4793, for more details.
There are security considerations with this type of connection. In the CICS for
AIX region, the security policy should be based on CICS security facilities such
as transaction security and resource access security for the reasons we discuss
in “Security Implications” on page 100.
Security is implemented through the use of authentication and DB2 internal
security. Authentication can take place in one or both machines, depending on
the configuration of the RDBMSs and the network products. The internal security
of the DB2 products then determines what the user can do with regard to DB2
resources.
With DDCS for AIX, it is possible to specify where the user name and password
are to be validated when a user tries to connect to a particular database. With
your own security requirements in mind, you must plan ahead and decide the
location of authentication for each database. The authentication type is specified
when you catalog the database in the DB2 system database directory at the local
machine. The possible authentication types are:
• AUTHENTICATION = CLIENT
The user name and password are validated locally. The user is expected to
be authenticated at the location where he or she first signs on. Passwords
do not flow across the network.
• AUTHENTICATION = SERVER
The user name and password are validated at the DDCS workstation on
which DDCS is installed. Passwords flow to the DDCS workstation over the
network.
• AUTHENTICATION = DCS
The user name and password are validated at the mainframe.
Authentication takes place at the host for the user accessing a host
database.
The specified authentication type along with the SECURITY parameter value
(either SAME or PROGRAM) defined for the APPC node that represents the
DRDA connection determine the flow and where validation takes place. This is a
complex area. We recommend reading Distributed Relational Database Cross
Platform Connectivity and Application, SG24-4311.
7.4.4 Accessing a DB2 for MVS/ESA Database through CICS/ESA
104 CICS for AIX as the Transaction Server
Another way for a CICS for AIX application to access a DB2 for MVS/ESA
database is to use the CICS intersystem communication (ISC) facilities as the
transport mechanism and then access the DB2 for MVS/ESA database from an
application running within the CICS/ESA region. Either CICS DPL or DTP can be
used to facilitate the communication between the pair of user application
programs involved. For simplicity we assume CICS DPL is used.
In the local RISC System/6000 machine, the user application program running in
a CICS for AIX region writes the required SQL access information into a
COMMAREA and then issues the DPL request (EXEC CICS LINK call). The
access information might consist of an SQL select statement along with the
associated qualifiers and predicates, for example. The request travels though