Sun Cluster Overview for Solaris OS

Cluster Interconnect

All nodes must be connected by the cluster interconnect through at least two redundant physically independent networks, or paths, to avoid a single point of failure. While two interconnects are required for redundancy, up to six can be used to spread traffic to avoid bottlenecks and improve redundancy and scalability. The Sun Cluster interconnect uses Fast Ethernet, Gigabit-Ethernet, Sun Fire Link, or the Scalable Coherent Interface (SCI, IEEE 1596-1992), enabling high-performance cluster-private communications.

In clustered environments, high-speed, low-latency interconnects and protocols for internode communications are essential. The SCI interconnect in Sun Cluster systems offers improved performance over typical network interface cards (NICs). Sun Cluster uses the Remote Shared Memory (RSMTM) interface for internode communication across a Sun Fire Link network. RSM is a Sun messaging interface that is highly efficient for remote memory operations.

The RSM Reliable Datagram Transport (RSMRDT) driver consists of a driver that is built on top of the RSM API and a library that exports the RSMRDT-API interface. The driver provides enhanced Oracle Parallel Server/Real Application Clusters performance. The driver also enhances load-balancing and high-availability (HA) functions by providing them directly inside the driver, making them available to the clients transparently.

The cluster interconnect consists of the following hardware components:

Figure 3–4 shows how the three components are connected.

Figure 3–4 Cluster Interconnect

Illustration: Two nodes connected by a transport adapter, cables,
and a transport junction.