Oracle API Gateway can be configured as a cluster on Solaris SPARC. The documentation explains how to install API Gateway on two nodes and configure them as a cluster. Key steps include modifying the /etc/host files on each node to include both, extracting and running the installation files on each node as the Oracle user, and registering the second node while specifying the first node as the Admin Node Manager. The process generates certificates and adds the nodes to the topology. Starting the Node Manager on each node completes the basic cluster configuration.