International Technical Support Organization Database Systems ...

tools conversation. It could also be used instead of the NETBIOS protocol to
connect OS/2 Database Manager clients to the database server.
• OS/2 Database Manager
OS/2 Database Manager provides you with a relational database interface
that is used to access either local or remote databases. You will need to
customize the different OS/2 Database Manager directories to enable the
different connections. Two protocols are used in a DataHub environment:
− DRDA for interconnection between the MVS, VM, and AS/400 hosts. The
DRDA protocol is also used to connect OS/2 Database Manager servers
to these three hosts.
− RDS is used to interconnect OS/2 Database Manager clients and servers.
Note: OS/2 Database Manager is not the name of a product. When we use
the term OS/2 Database Manager, we are really talking about the database
manager component of Extended Services for OS/2 or the DB2/2 product.
Because the directory tool interface has not changed, the examples we
provide are applicable to both products.
• Distributed Database Connection Services/2
DDCS/2 enables the DRDA architecture on the OS/2 Database Manager
platform. It is not required if you do not have any MVS, VM, or AS/400 hosts
in your organization. This product enables an additional directory, the DCS
Directory, which is customized through the OS/2 Database Manager
Directory Tool.
3.7.2 Relationship between OS/2 Components
As you will have noticed when reading the previous section, many components
are used on the OS/2 platform. Many of the values used to customize one
component are used by other components. Figure 46 on page 71 will help you
understand the relationships between the different values used. Problem
determination will become very easy if you understand those relationships.
The diagram on Figure 46 on page 71 shows the flow of three different OS/2
Database Manager requests:
• Local connect request
70 DataHub Implementation and Connectivity
• Inbound connect request, as it would be received by an OS/2 Database
Manager server workstation or a DDCS/2 gateway
• Outbound connect request, as it would be sent by an OS/2 Database
Manager client to a server or a DDCS/2 gateway or from a DDCS/2 gateway
to a DRDA server.
Figure 46 on page 71 does not show the flow for a NETBIOS type of connection
used between an OS/2 Database Manager client and an OS/2 Database Manager
server or between servers. We do not show this flow because the NETBIOS flow
does not involve OS/2 Communications Manager. It involves only the OS/2
Database Manager component.