Expand Configuration and Management Manual (H06.21+, J06.10+)

Subsystem Description
Expand Configuration and Management Manual — 529522-013
17 - 72
Multi-CPU Feature
Multi-CPU Feature
The Expand multi-CPU feature enables you to spread the communications load over
multiple processors by connecting multiple Expand line-handler process, each in a
separate processor, between two adjacent nodes. The Expand multi-CPU feature
significantly increases the maximum throughput of an Expand path, especially for
Expand-over-IP connections, because an Expand-over-IP line-handler process and its
associated NonStop TCP/IP process must be configured in the same processor pair.
This subsection describes briefly how the Expand multi-CPU feature works so that you
can effectively configure and use this feature in your network. It includes:
•
Multi-CPU Paths on page 17-72
•
Multi-CPU Configuration on page 17-72
•
Multi-CPU Considerations on page 17-73
Multi-CPU Paths
The multi-CPU path is the fundamental component of the Expand multi-CPU feature. A
multi-CPU path can consist of up to 16 individual Expand paths, including multi-line
paths. Each Expand line-handler process (or multi-line path) that is a member of a
multi-CPU path can be configured in a different processor.
One Expand line-handler process at each source node and one Expand line-handler
process at each destination node are paired to guarantee message order; all
messages between that source and destination node are sent through this Expand
line-handler pair.
Multi-CPU Configuration
You configure an Expand line-handler process (or a path logical device, in the case of
a multi-line path) as member of a multi-CPU path using the SUPERPATH_ON modifier.
The SUPERPATH_OFF modifier indicates that the path is not part of a the multi-CPU
path. The default is SUPERPATH_OFF.
When a path comes up and any number of other paths to the same destination node
are already up, the action of $NCP is determined by the configuration of the new path.
If it is configured with the SUPERPATH_OFF modifier, then the new path becomes a
redundant normal path to the node. If it is configured with the SUPERPATH_ON
Note. For more information on the Expand-over-IP line-handler processes, see Expand-to-IP
Interface on page 17-53.
Note. For more information on the formation about Expand line-handler pairs, see
Multi-CPU
Paths on page 17-31.
Note. The SUPERPATH_ON and SUPERPATH_OFF modifiers are described in detail in
Section
16, Expand Modifiers.