Ways to access data sharing groups

A requester is a client that manages connections and data access for client applications. Requesters can access data sharing groups in TCP/IP and SNA networks. Any product that supports the application requester protocols that are defined by DRDA can be a requester.

In this topic, the focus is on the following requesters:
  • IBM® Data Server Driver for JDBC and SQLJ.
  • IBM Data Server Driver for ODBC and CLI.
  • Db2 for z/OS® requester support with built-in workload balancing support.
  • Db2 Connect Server with connection concentrator and workload balancing support.

In a connection request, a client application specifies the Db2 location name of the data sharing group to which it wants to connect. The requester then maps this Db2 location name to an actual network element that identifies the member to which to connect. In the case of TCP/IP, this network element is either a domain name or an IP address. In the case of SNA, this network element is an LU name.

Recommendation: For TCP/IP access, use the group dynamic virtual IP address (DVIPA) and the common port to access the Db2 group from remote clients. For more information, see Supported methods for specifying DVIPAs

Mixed TCP/IP and SNA networks

The members of a data sharing group support both TCP/IP and SNA network protocols. However, when acting as requesters, members must be configured to communicate with other data sharing groups by using either TCP/IP or SNA. The DDF uses the group's communication database (CDB) to map each remote Db2 location name to either an IP address (for TCP/IP) or an LU name (for SNA). You can configure a Db2 location name for either TCP/IP or SNA, but not both. If you configure the same remote Db2 location name for both TCP/IP and SNA, only TCP/IP is used to communicate with the remote location.