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Siebel Deployment Planning Guide > Siebel Infrastructure Planning >
Choosing a Load Balancing Method
This task is a step in Process of Infrastructure Planning. Siebel Business Applications support two methods of load balancing requests from a Web server to multiple Siebel Servers: Siebel native load balancing and third-party HTTP load balancers. For a description of these two methods, see About Siebel Server Load Balancing. Siebel native load balancing and third-party HTTP load balancers provide similar features. Table 4 compares key characteristics of these load balancing options. In the table, SISNAPI is the Siebel protocol used to communicate with Siebel Servers.
Table 4. Load Balancing Method Comparison
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Siebel Native Load Balancing |
Third-Party HTTP Load Balancer |
Product form |
Part of the Siebel Web Server Extension software. |
Can be a dedicated device or part of an intelligent network switch. If it is software-based, then it is usually installed on an available server. Considered part of customer's networking infrastructure environment. |
Installation |
Part of the Siebel installation process. |
Varies by vendor. Hardware-based load balancers must be physically installed on the network. Might have network topology restrictions. |
Configuration |
Supports SISNAPI protocol. |
Must define server rules to support routing of SISNAPI connections. Hardware-based load balancers are typically administered using a Web browser. Software-based load balancers provide administration software. |
Load balancing scheme |
Round-robin only. |
Response-time-based, resources-based, or round-robin. |
Scalability |
No application-imposed hard limit. |
Varies by vendor. Typical limiting factors are network traffic throughput and number of servers for each load balancing pool. |
Server health checks |
Connection success or failure is monitored through the SWSE stat page. No active checks. |
Supports ICMP, TCP, and HTTP health-checks. HTTP health-checks are recommended. |
Security and network access |
The Web server must directly connect to the Siebel Server. |
Generally supports NAT, VIPs, VPorts. Also supports packet inspection and filtering. |
Administration and configuration |
Configured using text file. Administered through Siebel Server administration methods. |
Generally configured and administered through Web interface and command line tools. |
Deployment limitations |
All of the load-balanced servers must have the same configuration and equal load capacity. |
No limitations on load balancer except network topology requirements. |
Load Balancing Guidelines
Third-party HTTP load balancers are a good choice when any of the following is true:
- Hardware load balancers are already in use or are preferred.
- Hardware load balancer provide security features that you require.
- A more sophisticated load-balancing scheme is desired.
- The site requires centralized monitoring and management of system hardware and network infrastructure.
Siebel native load balancing distributes user login requests in a round-robin fashion, which works best if all of the servers are configured equally and have similar capacities. Other considerations include the following:
- Configure all of the load-balanced Siebel Servers with the same Maximum Tasks setting for an application.
- Allocate all of the load-balanced Siebel Servers with an equal amount of server resources, such as CPU and memory configuration. For example, assume you run Siebel Call Center on two Siebel Server computers. One of these computers also runs some other Siebel Server component or some other software. On this server, Siebel Call Center must compete for resources with the other software. Allocating unequal loads on your Siebel Servers is not recommended.
- Once you have selected a load balancing method, it is important not to set the maximum number of tasks for an Application Object Manager on a server or other load-balanced component higher than the server can reasonably handle. For information about planning and managing server task loads, see Siebel Performance Tuning Guide.
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