Availability Guide for Application Design

Overview of Server and Network Fault Tolerance

Availability Guide for Application Design—525637-004

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ServerNet Clustering for Availability and

Performance

ServerNet Clustering for Availability and

Performance

Dual ServerNet fabrics provide a fast, efficient, and reliable way for the processors to

exchange messages.

ServerNet technology can also be used to connect servers in groups called ServerNet

clusters. ServerNet clusters extend the ServerNet X and Y fabrics outside the system

boundary and allow ServerNet to be used for messaging between systems. A

ServerNet cluster consists of individual servers, each containing internal X and Y

fabrics, connected through fiber-optic cables and NonStop cluster switches to other

servers. The fiber-optic cables and NonStop cluster switches constitute external

ServerNet X and Y fabrics. Figure 2-10, 4-Node ServerNet Cluster shows how a

ServerNet cluster extends the X and Y fabrics to multiple systems.

ServerNet clusters allow multiple multiprocessor systems to work together and appear

to client applications as one large processing entity. Up to 24 servers can be joined in a

cluster.

Figure 2-10. 4-Node ServerNet Cluster

Node 1

Node 2

Node 4

ServerNet

interface

Node 3

External ServerNet Y fabric

External ServerNet X fabric

ServerNet

interface

ServerNet

interface

ServerNet

interface

Cluster switch