Sun Microsystems SunLink SNA 9.1 PU2.1, Configuration Manual

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E-4 SunLink SNA 9.1 PU2.1 Server Configuration Guide—August 1997
E
2. SunGMAN looks for the user record with the name
foo
and if it finds
one, considers the first (preferred) default resource in the list of default
resources (
POOL-1
). If
POOL-1
is distributed across multiple systems and
more than one system has an available active LU, SunGMAN selects the
system with the lowest system load average and the highest bandwidth.
If an active LU is not available in
POOL-1
, SunGMAN considers the next
(alternate) default resource in the list (
PUBLIC
). If
PUBLIC
is distributed
across multiple systems and more than one system has an available active
LU, SunGMAN selects the system with the lowest system load average and
the highest bandwidth.
If no active LUs are found in either
POOL-1
or
PUBLIC
, SunGMAN returns to
POOL-1
and searches both
POOL-1
and
PUBLIC
again, this time allowing
inactive LUs to satisfy the request.
If the second pass is unsuccessful, SunGMAN selects the “least recently
used” system for the preferred resource.
3. SunGMAN returns the IP address of the system with the best LU for the
connection to DNS.
4. DNS returns the IP address of the system to the requesting client.
5. The client connects to the TCP port of the SunSMAN process on the
system with the IP address returned by SunGMAN.
6. The SunSMAN looks for a user record with the user name
foo
to
determine which LU to connect the client to. If multiple Sun PU2.1 server
processes (
sunPU21
) are available, the SunSMAN performs load
balancing based on the number of connections on each PU2.1 server and
the bandwidths of the connections. The SunSMAN process then passes
this connection to the PU2.1 server that has the selected LU configured.
7. The client is now connected to the IBM host using the selected LU.
E.3 Geographical Load Balancing
The following sections provide a description of geographical load balancing
and a geographical load balancing example.