To define the characteristics of tier 1 DVIPAs for use with target DataPower® appliances,
code the VIPADEFINE, VIPABACKUP, and VIPADISTRIBUTE statements with
the following parameters in the VIPADYNAMIC block of the TCP/IP profile:
- Parameter
- Description
- TIER1
- Appears on the VIPADEFINE or VIPABACKUP statement, and on the
VIPADISTRIBUTE statement, and indicates that the DVIPA specified as
an IP address on this statement is to be used in a multi-tiered distribution
configuration.
- groupname
- Appears on the VIPADISTRIBUTE statement, and specifies the name
of a cluster of equivalent server applications in the sysplex. This
name is a required value on the TIER1 parameter of the VIPADISTRIBUTE
statement; however, the name is used only when there is a corresponding
VIPADISTRIBUTE statement with the TIER2 parameter. The name correlates
a VIPADISTRIBUTE TIER1 statement with the corresponding VIPADISTRIBUTE
TIER2 statements with the same name.
- GRE
- Appears on the VIPADISTRIBUTE statement. GRE indicates that the
tier 1 target is a non-z/OS target (a DataPower target), and that GRE is used
in distributing requests to the DataPower appliances. GRE is the only routing
type supported for DataPower load balancing.
- CONTROLPORT port_number
- Optionally appears on the VIPADISTRIBUTE statement, and enables
configuration of a control port other than the default for the DataPower sysplex
distributor agent. The control port must be the same on all VIPADISTRIBUTE
TIER1 statements. If a control port is not specified, the default
control port is 1702.
- DISTMETHOD TARGCONTROLLED
- Appears on the VIPADISTRIBUTE statement. TARGCONTROLLED indicates
that connection requests are distributed using weights provided by
the DataPower sysplex
distributor agent, and by availability and capacity of the z/OS® server applications in the
application group.
- DESTIP target_IP_list
- Appears on the VIPADISTRIBUTE statement; the target IP address
list includes the IP addresses of the DataPower appliances.
For more information about these statements and parameters, see z/OS Communications Server: IP Configuration
Reference.
In the following example, clients in the network send requests
to IP address 10.91.1.1, port 8080, and the DESTIP list consists of
the IP addresses of the DataPower appliances:
VIPADEFINE TIER1 255.255.255.0 10.91.1.1
VIPADISTRIBUTE DEFINE
GRE DISTM TARGCONTROLLED
TIER1 GROUP1
CONTROLPORT 5601
10.91.1.1 Port 8080
DESTIP 201.81.10.1 201.81.10.2
201.81.10.3 201.81.10.4
The DataPower appliances
have been configured with control port 5601. If the CONTROLPORT parameter
is not specified on the VIPADISTRIBUTE statement, then the control
port is 1702 by default.
DISTMETHOD TARGCONTROLLED indicates that sysplex distributor and
the DataPower appliances
exchange information about the availability and capacity of the DataPower appliances,
and sysplex distributor uses this information to make load-balancing
decisions.
These VIPADEFINE and VIPADISTRIBUTE statements are placed in the
TCP/IP profile of one sysplex stack, and another sysplex stack on
any LPAR in the sysplex might have the following VIPABACKUP statement
to enable nondisruptive VIPA takeover:
VIPABACKUP 10 TIER1 10.91.1.1