COMPUTER ORGANIZATION AND ARCHITECTURE DESIGNING FOR PERFORMANCE NINTH EDITION
In the literature, clusters are classified in a number of different ways. Perhaps the
simplest classification is based on whether the computers in a cluster share access to
the same disks. Figure 17.9a shows a two-node cluster in which the only interconnec-
tion is by means of a high-speed link that can be used for message exchange to coor-
dinate cluster activity. The link can be a LAN that is shared with other computers
that are not part of the cluster or the link can be a dedicated interconnection facility.
In the latter case, one or more of the computers in the cluster will have a link to a
LAN or WAN so that there is a connection between the server cluster and remote
client systems. Note that in the figure, each computer is depicted as being a multi-
processor. This is not necessary but does enhance both performance and availability.