Member-specific TCP/IP access

A Db2 location name represents all members of a data sharing group. In contrast, member-specific access uses location aliases that map to the domain names or IP addresses of only a subset of the members of the data sharing group.

A requester can use location aliases to bypass default TCP/IP workload balancing and to establish connections with one or more members. Workload is balanced among members at the discretion of the requester.

With member-specific access, a requester uses a location alias to make an initial connection to one of the members that is represented by the alias. The member that receives the connection request works in conjunction with Workload Manager (WLM) to return a list of members that are currently active and able to perform work. The list includes member IP addresses and ports, and a weight for each active member that indicates the current capacity of the member. The IP addresses are the member-specific alias IP addresses, if they exist, or the member-specific IP addresses. The requester uses this information to connect to the member or members with the most capacity that are also associated with the location alias.

To enable RACF® PassTickets you must define either a generic LU name for the data sharing group, an IPNAME for the data sharing group, or both. If all members of the data sharing group are to be configured to enable TCP/IP communications only, then all members of the data sharing group must share the same IPNAME value. If you use RACF PassTickets, then all LOCATION aliases must eventually refer to a single common IPNAMES row whose LINKNAME value must match the remote group's generic LU name or IPNAME value. The IPADDR value in the IPNAMES row must eventually refer to the group distributing DVIPA of the data sharing group.

If some of the members of the data sharing group are to be configured to enable TCP/IP communications only and the others are to enable both, then the IPNAME value of the TCP/IP only members must match the generic LU name of the members that enable both TCP/IP and SNA/APPC communications. The generic LU name or IPNAME value is used as the RACF application name when validating a RACF PassTicket at any member of the data sharing group.