Configure tier 2 distributed DVIPAs for each CPC containing target servers used by a group of DataPower appliances

Code VIPADEFINE, VIPABACKUP, and VIPADISTRIBUTE statements within the VIPADYNAMIC block of the TCP/IP profile, using the following parameters to define the characteristics of the tier 2 DVIPAs that are to receive connections from DataPower® appliances:

Parameter: Description
CPCSCOPE: Appears on the VIPADEFINE or VIPABACKUP statement, and indicates that distribution targets must be on the same CPC as the distributor.
TIER2: Appears on the VIPADEFINE or VIPABACKUP statement, and the VIPADISTRIBUTE statement, and indicates that this dynamic VIPA is used to distribute incoming requests from a TIER1 target to a named group of server instances.
groupname: Appears on the VIPADISTRIBUTE statement, and specifies the name of a cluster of equivalent server applications in the sysplex. The group name correlates VIPADISTRIBUTE TIER2 statements with a corresponding VIPADISTRIBUTE TIER1 statement.

In the following example, the DataPower appliances in site 2 are configured to send requests to IP address 10.81.2.2 and port 9001:

VIPADEFINE TIER2 CPCSCOPE 255.255.255.0 10.81.2.2
VIPADISTRIBUTE DEFINE
    DISTMETHOD SERVERWLM
    TIER2 GROUP1
    10.81.2.2 Port 9001
    DESTIP ALL

The TIER2 parameter, in conjunction with the group name (GROUP1), indicates that the tier 2 sysplex distributor gathers information about availability and capacity of the target servers of that group. This information is forwarded to the corresponding tier 1 distributor for that group as a combined CPC weight for use in making the tier 1 load-balancing decision.

The tier 2 weight information cannot be used until the next step in the configuration process (configure a CPCSCOPE DVIPA for each CPC for use by a group of DataPower target appliances) is completed and the tier 1 distributor is able to determine which CPC is used by a DataPower appliance.

Similar to the tier 2 configuration for site 2, the DataPower appliances using site 1 send requests to IP address 10.81.1.1 and port 9001:

VIPADEFINE TIER2 CPCSCOPE 255.255.255.0 10.81.1.1
VIPADISTRIBUTE DEFINE
    DISTMETHOD SERVERWLM
    TIER2 GROUP1
    10.81.1.1 Port 9001
    DESTIP ALL