Sun Cluster Concepts Guide

This section discusses errors and omissions from the Sun Cluster Concepts Guide for Solaris OS.

In chapter 3, the section on “Using the Cluster Interconnect for Data Service Traffic“ should read as follows:

A cluster must have multiple network connections between nodes, forming the cluster interconnect. The clustering software uses multiple interconnects both for high availability and to improve performance. For both internal and external traffic (for example, file system data or scalable services data), messages are striped across all available interconnects.

The cluster interconnect is also available to applications, for highly available communication between nodes. For example, a distributed application might have components running on different nodes that need to communicate. By using the cluster interconnect rather than the public transport, these connections can withstand the failure of an individual link.

To use the cluster interconnect for communication between nodes, an application must use the private hostnames configured when the cluster was installed. For example, if the private hostname for node 1 is clusternode1-priv, use that name to communicate over the cluster interconnect to node 1. TCP sockets opened using this name are routed over the cluster interconnect and can be transparently re-routed in the event of network failure. Application communication between any two nodes is striped over all interconnects. The traffic for a given TCP connection flows on one interconnect at any point. Different TCP connections are striped across all interconnects. Additionally, UDP traffic is always striped across all interconnects.

Note that because the private hostnames can be configured during installation, the cluster interconnect can use any name chosen at that time. The actual name can be obtained from scha_cluster_get(3HA) with thescha_privatelink_hostname_node argument.