ServerNet Cluster Manual

ServerNet Cluster Description
ServerNet Cluster Manual—520575-003
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Expand
Expand and Message-System Traffic
In a ServerNet cluster, message-system traffic flows directly between processors by
way of the message system but under the control of Expand. Figure 1-21 diagrams the
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 inter-
system 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.
For more details on the Expand subsystem, see the Expand Configuration and
Management Manual.
Figure 1-21. Message Passing Over ServerNet
LH
Process Process
Processor A
\ALPHA
Processor C
\BETA
File
System
Message
System
File
System
Message
System
Ordinary
Messages
File
System
Message
System
File
System
Message
System
Security-
Checked
Messages
Processor B
\ALPHA
Processor D
\BETA
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