Using APA to Build a Screaming Fast Network Server Connection for HP-UX 11i v2 and v3

-- Page 6 -- Hewlett Packard
CPU-based Load Balancing
The CPU-based algorithm is the ideal way to connect two collaborating HP 9000
multiple-CPU servers with APA. This is because it offers the highest level of
performance for back-to-back server configurations hosting CPU-intensive applications
such as ERP, workflow, data warehouses, data migration, and data backup.
This algorithm relies on a CPU ID generated by the system to balance the threads coming
from two or more CPUs to two or more Ethernet ports. The relationship between CPUs
and Ethernet ports should be two or more CPUs to two or more ports in the link
aggregate.
• The purpose of a scheduler is to balance server-processing demands
across one or more CPUs.
• The purpose of the CPU-based APA algorithm is to balance the output
threads from those same CPUs across two or more Ethernet ports.
To ensure predictable performance results, HP highly recommends that the CPU-based
algorithm only be used with processor affinity, which allows an application to be tied
directly to a CPU for the lifetime of the application. This will ensure that each link in the
Link Aggregate has the optimum load.
NOTE: While this algorithm will work with single CPU servers, it is not recommended.
Link Aggregate
Port 0
Port 1
Port 2
Port 3
APA Software
Scheduler
Thread
s
CPU 2
CPU 1
CPU 3
CPU 0