Unix tài khoản người dùng và tài khoản WUI. Unix tài khoản người sử dụng chỉ được cấu hình mặc định là root, có tư cách siêu người dùng. Unix tài khoản chỉ áp dụng cho CLI. Nhiều tài khoản WUI có thể được tạo ra hoặc truy cập chỉ đọc hoặc siêu người dùng. Họ chỉ áp dụng cho các WUI. | C Sample Configurations The purpose of this appendix is to provide a quick reference guide to the multitude of possible load-balancing configurations and implementations available. All diagrams are vendor-neutral and a specific product may require slight changes. Not all vendors will support all configurations so be sure to check the manual or the vendor if you are not sure. Virtually all load balancing can be classified by using this simple matrix in Figure C-l Figure C-l. An SLB implementation matrix Each configuration falls under one of each of the three columns. Not all combinations work but this matrix should greatly simplify how load-balancing implementations are classified and represented no matter what product is used. All of the figures presented here involve redundancy so that any unit in the configuration could fail without an interruption of service. Redundancy in a given scenario can often depend on the other equipment in a configuration so keep in mind that these figures do not represent the only way to achieve full redundancy. 157 158 Appendix C Sample Configurations Flat-Based Topologies Flat-based scenarios involve IPs of the VIPs and real servers on the same subnet. They are so named because of the flat-type subnet topology they use. Figure C-2 shows the possible scenarios available with the flat-based topology in white with variations that don t work in gray. Figure C-2. Aflat-based matrix There are two primary methods for implementing flat-based SLB bridge-path and route-path. Flat-Based Bridge-Path Two-Armed The configuration shown in Figure C-3 is common with the switch-based load balancers. It involves the load balancer in the Layer 2 path of the return traffic. This type of configuration utilizes flat-based SLB exclusively not allowing for any type of NAT-based configuration. Redundancy is an issue because there cannot be more than one Layer 2 path in the configuration. One load balancer must be inactive and must not forward Layer 2 traffic.
