3 - Designing and Planning a Cluster

Abstract

A cluster can have many benefits over an otherwise non-clustered solution, but there are many configuration options in designing a TruCluster Server. Cluster solution has a direct impact on how beneficial it will be over a stand-alone system. This chapter discusses configuration choices beginning with basic high-level options and working toward more detailed levels. Configuration supported by HP for TruCluster Server is regarded as best. To illustrate the trade-offs and decision process, a common example will be used and revisited as each major concept is presented. The example is a hypothetical Biotech Company planning a new TruCluster Server cluster. The first task is to determine the member systems and their configuration as computing resources. This is based on the performance needs of the applications. The starting point of designing a TruCluster Server cluster-based solution is to specify the applications and then determine the basic platform or platforms and their resources required to run the applications at the desired performance levels. Just like a stand-alone platform, a cluster can host multiple applications. Parallel applications run as separate instances on multiple cluster members. One-to-one mapping of applications to servers in a cluster can simplify tuning, support, and computing resource management for the members. The TruCluster Server software supports homogeneous or heterogeneous cluster configurations. With a cluster, the computing power can be grown in two dimensions—the size of the members and the number of members. The TruCluster Server Connection Manager (CNX) component is responsible for maintaining a list of which cluster members are actively participating members at any moment in time. Quorum Disk is required for two node clusters. TruCluster Server supports two types of cluster interconnects: Memory Channel and LAN-based. Cluster Interconnect should be Dual Redundant.