BladeCluster Solution Manual

Expand and Message-System Traffic
In a BladeCluster, message-system traffic flows directly between processors by way of the message
system but under the control of Expand. The Expand product has an option called
Expand-over-ServerNet. This option provides high performance inter-application communication
with minimal processor cost. The illustration below diagrams this message-system traffic.
Secure message-system traffic between processes on different ServerNet nodes travels through the
Expand-over-ServerNet line handlers, and through the local message system between the
communicating processes and the line handlers. Nonsecure message-system traffic flows directly
between processors through the intersystem message-system ServerNet connections as directed by
the Network Routing Table (NRT) under the control of Expand. The intersystem ServerNet
message-system connections are not used if the appropriate settings are not made in the NRT.
Software Overview 21