SMA for SCI Clusters

Scalable Coherent Interface (SCI) is a memory-based high-speed interconnect that enables sharing of memory among cluster nodes. The SCI private interconnect consists of Transmission Control Protocol/Internet Protocol (TCP/IP) network interfaces based on SCI.

Clusters of all sizes may be connected through a switch or hub. However, only two-node clusters may be connected point-to-point. The Switch Management Agent (SMA) software component manages sessions for the SCI links and switches.

There are three basic SCI topologies supported in Sun Cluster (Figure 1-1 and Figure 1-2):

• Three- or four-node cluster that requires two SCI switches

• Two-node cluster connected point-to-point

• Two-node switched cluster (downgraded case of the four-node cluster that allows for future expansion of cluster nodes, with minimal interruption)

Figure 1-1 SCI Cluster Topology for Four Nodes

Figure 1-2 SCI Cluster Topologies for Two Nodes