There are two aspects of Advisor configuration, the Advisor configuration file itself, and the underlying PROFILE.TCPIP changes that go along with the remainder of the z/OS® Load Balancing Advisor system configuration.
The following example is the Advisor configuration file:
debug_level 7 # Error, Warning, Events-- the default
update_interval 60 # Agents update every minute-- the default
wlm serverwlm # Request server-specific WLM weights
port_list
{
21 wlm basewlm # Use system WLM weights for FTP
}
lb_connection_v4 10.1.5.1..3860 # DVIPA load balancer connects to
lb_id_list
{
10.1.10.11 # Load balancer's SASP client interface
}
agent_connection_port 8100 # Port Agents connect to
agent_id_list
{
10.1.1.1..8000 # This system's Agent source
10.1.5.22..8000 # SYSA's Agent source
}In this example Advisor configuration file, the debug level is set to 7 in the optional debug_level statement. The value of 7 is the default value, so this statement is redundant but is shown for completeness. At the default level of 7, messages are written to the log if they are at error, warning, or event level. Messages at other debug levels, such as info or debug, are not written to the log file.
The optional update_interval statement is set to 60 seconds, which is also the default. This means that each Agent updates the Advisor with new information every minute. For some load balancer implementations, depending upon load balancer configuration, it might also determine how often the load balancer is updated with new information from the Advisor.
The wlm statement specifies the default WLM recommendation type to be used for all groups when calculating the net weights. The value of severwlm indicates that server-specific WLM recommendations will be requested of each Agent, unless overridden by the port_list statement (see next paragraph). Although server-specific WLM is the WLM recommendation type to be used for all groups except FTP in this example, there is still a possibility that WLM system weights might have to be used for some or all groups. For further details on the serverwlm value on the wlm statement, see z/OS Communications Server: IP Configuration Reference.
The port_list statement contains one port number, 21. The wlm keyword indicates that the WLM recommendation type will be overridden for all members using port 21 (FTP), to use WLM system weights rather than server-specific WLM weights when calculating the net weight. Multiple port numbers can appear in the port_list statement on separate lines, if you want to use WLM system weights for other groups of members.
The lb_connection_v4 statement includes DVIPA 10.1.5.1 and port 3860 (the default) as the address and port that load balancers use to connect to the Advisor. The load balancer specifies this address and port when defining the location of the Advisor.
The lb_id_list statement contains the address 10.1.10.11, which is the source IP address of the load balancer when the load balancer connects to the Advisor as a SASP client. If more than one load balancer is used to distribute workload requests to the sysplex, each load balancer needs to be represented in this statement list.
The agent_connection_port statement specifies that port 8100 is used to listen for connections from Agents in the sysplex. This same port appears on each Agent's advisor_id statement. This port is reserved on the TCP/IP stack that the Advisor runs on, and on any TCP/IP stacks that the Advisor could be moved to in the event of failure. Using this port, the Advisor opens a listening socket on the IPv4 or IPv6 unspecified address (0.0.0.0 or ::, respectively), depending upon the TCP/IP stack's IPv6 capability.
The agent_id_list statement contains the source IP address and port of each Agent in the sysplex. The 10.1.1.1 address and the associated port of 8000 represent the source IP address and port that the Agent on SYSB uses to communicate with the Advisor. This same address and port combination appears on the agent_connection statement in the Agent's configuration file on SYSB. The 10.1.5.22 address and the associated port of 8000 represent the source IP address and port that the Agent on SYSA uses to communicate with the Advisor. This same address and port combination appears on the agent_connection statement in the Agent's configuration file on SYSA.