Expand Configuration and Management Manual (H06.03+)

Planning for ServerNet Clusters
Expand Configuration and Management Manual—529522-002
4-5
Examples of ServerNet Clusters Coexisting With
ATM or IP
ServerNet Clusters Connected By ATM or IP Lines
All the systems in Figure 4-1 are Integrity NonStop NS-series systems.
Groups of systems at separate locations can use clustering technology to increase
performance within each location and connect to each other by using ATM or IP lines.
When systems on different ServerNet clusters need to communicate with each other,
the Expand line handlers are invoked at every node along the path between the source
and the destination node (including the source and destination nodes). Thus,
processor use is higher when networked applications transfer information between
systems located on separate ServerNet clusters. To avoid this situation, you can
provide the ATM or IP connectivity within the ServerNet cluster so that communications
between the ServerNet clusters travels over IT or ATM without invoking line handlers
to change technologies. Figure 4-1 shows two ATM-connected or IP-connected
ServerNet clusters in a configuration that incurs line hops. To modify this configuration
for inter-ServerNet cluster communications without line hops, add ATM or IP
connections within the ServerNet cluster as well.
In Figure 4-1, note that the multiple inter-ServerNet cluster of ATM connections or IP
connections produces a fault-tolerant design.
Figure 4-1. ServerNet Clusters Connected by ATM or IP Lines
\BBB #2
Cluster
Switch
\AAA #1
\GGG #9\CCC #3
Cluster
Switch
\DDD #7
\EEE #5\FFF #4
\HHH #6
\JJJ #8
5-Node ServerNet Cluster 4-Node ServerNet Cluster
ATM or IP
ATM
or IP
ATM or IP
ATM or IP
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