Expand Configuration and Management Manual (G06.24+)

Planning for ServerNet Clusters
Expand Configuration and Management Manual—523347-008
4-7
Considerations for ServerNet Clusters Coexisting
With ATM or IP
Considerations for ServerNet Clusters Coexisting With ATM
or IP
•
Traffic can be distributed in a balanced fashion over the ATM or IP lines by
appropriately configuring the time factors (TFs). For information about configuring
time factors, refer to Routing and Time Factors on page 18-22.
•
Be careful when mixing these technologies to ensure a fault-tolerant topology and
to prevent bottlenecks at the inter-technology connection points.
•
If you want to expand your ServerNet cluster by adding nodes, HP recommends
that you use the guided procedure. To add a node by using TSM, go to the system
console of the system you are adding, select Start>program>Compaq
TSM>Guided Configuration Tools>Configure ServerNet Node. Online help is
available to assist you in performing the procedure. To add a node by using the
OSM Service Connection, log onto the system being added, select the Configure
a ServerNet Node action for the System object, and perform the action. A guided
procedure is launched, with online help available to assist you in performing the
procedure.
Examples of ServerNet Clusters Coexisting With ATM or IP
The following examples are provided in this subsection:
•
ServerNet Clusters Connected By ATM or IP Lines on page 4-7
•
ServerNet Clusters Connected By a Single ATM or IP Line (Not Recommended) on
page 4-8
•
ServerNet Clusters Using Layered Topology With Connections to Nodes Outside
the Cluster on page 4-9
ServerNet Clusters Connected By ATM or IP Lines
All the systems in Figure 4-3 are NonStop S-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 4-3 shows two ATM-connected or IP-connected
ServerNet clusters in a configuration that incurs line hops. To modify this configuration
Note. For the layered topology, you must use OSM.