ExpressCluster X 3.1 for Linux Getting Started Guide - Nec

Table of ContentsPreface.................................................................................................................................................... ixWho Should Use This Guide............................................................................................................................................... ixHow This Guide is Organized............................................................................................................................................. ixExpressCluster X Documentation Set ................................................................................................................................. xConventions ........................................................................................................................................................................ xiContacting NEC.................................................................................................................................................................. xiiSection I Introducing ExpressCluster........................................................................... 13Chapter 1 What is a cluster system? ............................................................................... 15Overview of the cluster system............................................................................................................................ 16High Availability (HA) cluster ............................................................................................................................ 16Shared disk type.................................................................................................................................................................. 17Data mirror type.................................................................................................................................................................. 19Error detection mechanism .................................................................................................................................. 20Problems with shared disk type........................................................................................................................................... 20Network partition (split-brain-syndrome) ........................................................................................................................... 21Taking over cluster resources .............................................................................................................................. 22Taking over the data............................................................................................................................................................ 22Taking over the applications ............................................................................................................................................... 23Summary of failover ........................................................................................................................................................... 23Eliminating single point of failure ....................................................................................................................... 24Shared disk.......................................................................................................................................................................... 24Access path to the shared disk............................................................................................................................................. 25LAN .................................................................................................................................................................................... 26Operation for availability..................................................................................................................................... 27Failure monitoring............................................................................................................................................................... 27Chapter 2 Using ExpressCluster ..................................................................................... 29What is ExpressCluster? ...................................................................................................................................... 30ExpressCluster modules....................................................................................................................................... 30Software configuration of ExpressCluster ........................................................................................................... 31How an error is detected in ExpressCluster ........................................................................................................................ 31What is server monitoring? ................................................................................................................................................. 32What is application monitoring? ......................................................................................................................................... 33What is internal monitoring?............................................................................................................................................... 33Monitorable and non-monitorable errors............................................................................................................................. 33Detectable and non-detectable errors by server monitoring ................................................................................................ 33Detectable and non-detectable errors by application monitoring ........................................................................................ 34Network partition resolution................................................................................................................................ 35Failover mechanism............................................................................................................................................. 36Failover resources ............................................................................................................................................................... 37System configuration of the failover type cluster................................................................................................................ 37Hardware configuration of the shared disk type cluster ...................................................................................................... 40Hardware configuration of the mirror disk type cluster ...................................................................................................... 41Hardware configuration of the hybrid disk type cluster ...................................................................................................... 42What is cluster object? ........................................................................................................................................................ 43What is a resource?.............................................................................................................................................. 44Heartbeat resources............................................................................................................................................................. 44Network partition resolution resources ............................................................................................................................... 44Group resources .................................................................................................................................................................. 44Monitor resources ............................................................................................................................................................... 45VM monitor resource (vmw) .............................................................................................................................................. 46Getting started with ExpressCluster..................................................................................................................... 48Latest information............................................................................................................................................................... 48Designing a cluster system.................................................................................................................................................. 48Configuring a cluster system............................................................................................................................................... 48Troubleshooting the problem .............................................................................................................................................. 48v