Member-specific location aliases

Member-specific location aliases represent one, a subset, or all members of a data sharing group.

Location aliases are useful in several ways.

  • Member-specific access requires that you identify to the server (remote data sharing group) each location alias that is defined by a requester. Doing so enables a server to recognize itself as the intended recipient of connection requests that specify location aliases instead of the server's location name.
  • After adding a new member to a data sharing group, you can create an alias for the member's old (subsystem) Db2 location name that maps to its new (group) Db2 location name. Doing so enables applications that are coded to connect to the member's old Db2 location name to continue to work.
  • Location aliases enable you to define subsets of data sharing group members. Subsetting gives you the ability to limit the members to which DRDA requesters can connect.

Clients can connect to a location alias using any port that Db2 is listening on. Therefore, location aliases can be defined without an alias-port or alias-secport value. Clients that use a location alias without an alias-port or alias-secport value receive information only about the member that processes the connection request in the list of servers. To distribute work requests across the group or a subset of a group, clients must be configured to use the Db2 group location name or location alias name that is defined for a subset of members.

Dynamic location aliases

You can use the MODIFY DDF command with the ALIAS option to define and manage as many as 40 location aliases dynamically. You can start, stop, cancel, change, and delete dynamic location aliases without stopping either DDF or Db2. You can use the DISPLAY DDF command to find information about existing location aliases.

Static location aliases

You can use DSNJU003 (change log inventory) utility to define and modify as many as 8 static location aliases per member. Changes to these aliases require you to stop both DDF and Db2. The MODIFY DDF command cannot be used to manage this type of alias. Any alias of this type that has the same name as an alias that was previously defined by the MODIFY DDF command is not used. In that case, the dynamically defined alias takes precedence, and is used instead.