An Introduction to the New IBM eServer pSeries High Performance Switch

74 An Introduction to the New IBM Eserver pSeries High Performance Switch

3.1 RSCT Resource Monitoring and Control

RSCT (Reliable Scalable Cluster Technology) is a standard component of AIX that provides

the clustering infrastructure for the IBM Eserver Cluster 1600 suite of products. The RSCT

infrastructure contains the basic tools and architecture to build reliable and secure clustered

applications.

RSCT provides the foundation for the following applications:

 IBM Virtual Shared Disk (VSD)

 IBM General Parallel File System (GPFS)

 IBM High Availability Cluster Multi-Processing (HACMP)

 IBM LoadLeveler (LL)

 IBM Eserver IBM Eserver pSeries High Performance Switch (HPS) network table

functions

3.1.1 What is RSCT?

RSCT is a set of software components that work together to provide a comprehensive

clustering environment for AIX and Linux. RSCT is a component of AIX 5L derived from the

PSSP high-availability infrastructure.

The new IBM High Performance Computing (HPC) clusters provide a different approach from

the previous version (PSSP) in the sense that there is no more control workstation (CWS) nor

System Data Repository (SDR). Because of this, applications relying on the RSCT clustering

infrastructure must take a different approach for storing and managing their configuration

data.

RSCT is the infrastructure used by a variety of IBM products to provide clusters with improved

system availability, scalability, and ease of use. RSCT is well proven to provide clustering

infrastructure for CSM, Distributed Resource Managers, HACMP, GPFS, and VSD, etc.

This chapter provides an overview of the RSCT components. It describes:

 Resource Management and Control (RMC) subsystem

This is the scalable, reliable backbone of RSCT. It runs on a single machine or on each

node (operating system image) of a cluster and provides a common abstraction for the

resources of the individual system or the cluster of nodes. You can use RMC for single

system monitoring or for monitoring nodes in a cluster. RMC provides global access to

subsystems and resources throughout the cluster, thus providing a single monitoring and

management infrastructure for clusters.

 RSCT core resource managers

A resource manager is a software layer between a resource (a hardware or software entity

that provides services to some other component) and RMC. A resource manager maps

programmatic abstractions in RMC into the actual calls and commands of a resource.

 RSCT cluster security services

Provides the security infrastructure that enables RSCT components to authenticate the

identity of other parties.

 Topology Services subsystem

The Topology Services subsystem is used within an RSCT peer domain to provide other

RSCT applications and subsystems with network adapter status, node connectivity

information, and a reliable messaging service. The Topology Services subsystem runs as

a separate daemon process on each machine (node) in the peer domain.