What’s cluster

A cluster is a group of servers, consists of 2 or more servers, running and sharing resource one another to working as a single system and provide high avaiability of service for clients. The advantages of clustering are:

  • High Availability (HA)
    When a failure occurs on applications, services and hardware device on one server, the cluster service will switch all the workload on that server to other server in the cluster so it can reduces downtime on applications or services that client is requesting.
  • Scalability
    Adding new server to the existing cluster is easily. If applications or services support clustering, they can be distributed workload on servers in the cluster to improve the system efficiency.
  • Management
    Administrator can move applications or services from one server to another server easily in case of disaster or maintenance the system.

The series are divided into 6 parts:

Microsoft Cluster Service

Microsoft Cluster Service (MSCS) is a software on Windows 2003 server which manage servers to work together as a server cluster. With MSCS, applications and services on the server can be switch their workloads to another server in case of failure. In order to enable this feature, you need to have a shared storage connect to each server called quorum disk in the network. The quorum must be either SCSI, fiber channel or iSCSI interface. If you don’t have the quorum, you can only create a cluster as a Single Node Cluster type which purpose is for developer to test an application in clustering environment only. This type, you can’t switch applications and services to other nodes. Secode type is an Single Quorum Device Multiple Nodes Cluster. In this type, there is a shared storage (quorum disk) between nodes therefore you can switch applications and services to other nodes.
Note: There is another type of cluster which is Majority Node Set Cluster which is for enterprise solution so I would mention in this tutorial.

Setup environment

In this tutorial, I’ll demonstate how to setup a file cluster server and MS SQL cluster server which type is Single Quorum Device Multiple Nodes Cluster so that the services can be swtiched over between nodes. The network diagram is as the figure below:
Sample Cluster Diagram

Server

There are 3 servers in this environment. The first server is an active directory. The others are cluster nodes.

  1. BKKPDC010, Windows Server 2003 Enterprise x64 running active directory domain ‘virtual.com’. IP Address is 192.168.1.2
    A Domain controller
  2. BKKSQL010, Windows Server 2003 Enterprise x64. The server has two network interface cards:
    • One is for LAN – client communication (192.168.1.21).
    • The other for heartbeat (10.0.0.1).

      • First cluster server

  3. BKKSQL020, Windows Server 2003 Enterprise x64. The server has two network interface cards:
    • One is for LAN – client communication (192.168.1.22).
    • The other for heartbeat (10.0.0.2).

      • Second cluster server

Note: The servers which will be configured as a cluster should have the same hardware configuration to avoid any conflicts. These servers have the same hardware configurations.

Quorum disk

  1. iSCSI 2 drives on 192.168.1.9:
    • 512 MB for quorum
    • 8 GB for keep data

In the next part, I’ll show how to setup iSCSI disks on the servers using Microsoft iSCSI Initiator.

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