When operating in a sysplex subplexing environment, this step requires
additional actions. For information about the changes to this step,
see Customizing TCP/IP profiles in a subplexing environment.
There are several things to do to customize the TCP/IP profile
to accommodate the Advisor and Agents.
- In the appropriate TCP/IP profiles that they will use, including
the TCP/IP stacks that they could potentially move to, reserve the
ports that the Advisor and Agents will use. All ports for the Advisor
and Agent use the TCP protocol, and thus should be reserved for TCP.
The Advisor has at least two ports, and potentially three ports, to
reserve, including the ports specified on the following statements:
- lb_connection_v4
- lb_connection_v6
- agent_connection_port
For CINET considerations regarding the lb_connection_v4 and
lb_connection_v6 statements, see Customizing TCP/IP profiles in a CINET environment.
- If you use dynamic VIPAs for the Advisor as recommended, you need
to configure the appropriate TCP/IP profiles in the sysplex for the
DVIPA definition and usage. The preferred definitions would include
VIPADEFINE with MOVEABLE IMMEDIATE, or VIPARANGE with MOVEABLE NONDISRUPTIVE.
For more specific information, see Using dynamic VIPAs.
Restriction: Do
not mix sysplex distributor functions with these DVIPAs.
- If you are currently using the SHAREPORT or SHAREPORTWLM parameters
on the TCP/IP profile PORT statement to enable multiple TCP applications
to share the same port, some additional considerations might apply
to your configuration. For example, if the TCP applications sharing
the same port are also members of groups that are being reported to
external load balancers with SASP, it is important to ensure that
consistent criteria are used by the various load balancing components.
When
using the z/OS® Load Balancing
Advisor, all instances of a TCP application sharing the same port
on a target system are reported to external load balancers using a
single member entry, and therefore, a single recommendation. This
recommendation reflects the average net weight calculated for all
the servers sharing the same port on a target system, and is based
on the type of WLM recommendation configured on the Advisor. When
the TCP connection requests reach a target TCP/IP stack and multiple
applications are sharing the same port, the connections are then load
balanced by TCP/IP across the multiple application server instances.
How this load balancing is performed depends on whether the SHAREPORT
or SHAREPORTWLM parameter is specified on the PORT statement. For
more details on the PORT statement, see z/OS Communications Server: IP Configuration
Reference.
Guideline: If
server-specific WLM recommendations are configured within the Advisor
for a given group that contains servers that share the same port on
a given system or TCP/IP stack, the SHAREPORTWLM parameter should
also be specified on the PORT statement in the TCP/IP profile for
these servers. This enables both the external load balancers and the
internal TCP/IP load balancer to operate with the same type of recommendations
when load balancing work requests to these servers. Similarly, if
WLM system weight recommendations were configured in the Advisor for
a group, the SHAREPORT parameter would probably be more appropriate.