Member-routing SNA access

To access any member of a remote data sharing group with member routing, the location name of the data sharing group is associated with a list of LUNAMEs of the group members.

A subset of the member LUNAMEs can comprise the list to limit which members of the group can be accessed by the requester.

Requesters can use an LULIST to bypass VTAM® workload balancing by establishing sessions with one or more members. Workload is balanced among members at the requester's discretion.

With member-routing access, a requester uses an LULIST to make an initial connection to one of the members that is represented by the alias. The Db2 Sysplex transaction program (Db2 STP) works in conjunction with the z/OS® Workload Manager (WLM) to return a list of members that are currently active and can perform work. It also returns a weight for each active member that indicates the member's current capacity. The requester uses this information to connect to the member or members with the most capacity. If the LULIST contains a subset of the members, only the members of that subset can be accessed.

Two-phase commit resynchronization

If two-phase commit resynchronization is necessary, due to previous communication or system failure, the resynchronization request is sent to the member that is involved in the failure. Db2 performs resynchronization asynchronously, so that requesters are not prevented from establishing new sessions with other members.

RACF PassTicket limitation

If you use RACF® PassTickets, you can define only one location alias. The generic LU name is used to generate a valid PassTicket for the data sharing group. Generation of a valid PassTicket for individual members or sets of members in a group is not possible.