Section 6.1:A Basic LVS Configuration
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6
Linux Virtual Server Overview
As mentioned in the introduction, Red Hat Enterprise Linux AS LVS clustering uses a Linux machine
called the active router to send requests from the Internet to a pool of servers. To accomplish this, LVS
clusters consist of two basic machine classifications — the LVS routers (one active and one backup)
and a pool of real servers which provide the critical services.
The active router serves two roles in the cluster:
•
To balance the load on the real servers.
•
To check the integrity of the services on each of the real servers.
The backup router’s job is to monitor the active router and assume its role in the event of failure.
To explain how LVS clusters perform these functions, let us look at a basic configuration.
6.1 A Basic LVS Configuration
Figure 6–1, A Basic LVS Configuration shows a simple LVS cluster consisting of two layers. On
the first layer are two LVS routers — one active and one backup. Each of the LVS routers have two
network interfaces per machine, one interface on the Internet and one on the private network, enabling
them to regulate traffic between the two networks. For this example the active router is using Network
Address Translation or NAT to direct traffic from the Internet to a variable number of real servers
on the second layer, which in turn provide the necessary services. Therefore, the real servers in this
example are connected to a dedicated private network segment and pass all public traffic back and
forth through the active LVS router. To the outside world, the server farm appears as one entity.
Summary of Contents for ENTERPRISE LINUX AS 2.1 -
Page 1: ...Red Hat Enterprise Linux AS 2 1 The Official Red Hat Enterprise Linux AS Installation Guide ...
Page 8: ...viii ...
Page 14: ...xiv Introduction ...
Page 15: ...Part I Installing Red Hat Enterprise Linux AS ...
Page 16: ......
Page 26: ...26 Chapter 1 Steps to Get You Started ...
Page 30: ...30 Chapter 2 System Requirements Table ...
Page 80: ...80 Chapter 3 Installing Red Hat Enterprise Linux AS ...
Page 94: ...94 Chapter 4 Installing Red Hat Enterprise Linux AS via Text Mode ...
Page 95: ...Part II Configuring Red Hat Enterprise Linux AS ...
Page 96: ......
Page 100: ...100 Chapter 5 Introduction ...
Page 114: ...114 Chapter 6 Linux Virtual Server Overview ...
Page 153: ...Part III Appendixes ...
Page 154: ......
Page 156: ...156 Appendix A Additional Resources for LVS Clustering ...
Page 160: ...160 Appendix B A Sample etc sysconfig ha lvs cf File ...
Page 162: ...162 Appendix C Removing Red Hat Linux ...
Page 168: ...168 Appendix D Getting Technical Support ...
Page 178: ...178 Appendix E Troubleshooting Your Installation of Red Hat Enterprise Linux AS ...
