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Setting Up Third-Party HTTP Load Balancers

This topic is part of Configuring Load Balancing for Siebel Applications.

Third-party load balancers receive SISNAPI messages from the Web server. The load balancer routes these messages based on the URL that they contain. To configure an HTTP load balancer, you must write connection rules that route these messages to the correct Siebel Servers.

Siebel applications include a command that generates these rules: generate lbconfig. The command reviews the configuration of the Siebel Servers, then generates a file that pairs connection strings included in SISNAPI messages with paths to the correct Siebel Servers. The rules are stored in the load balancing configuration file (lbconfig.txt). Use this file to help configure the load balancer.

The file provides three types of connection rules: component rules, server rules, and round-robin rules. These rule types are mandatory. You must include all three types when you configure the load balancer.

• Not configuring round-robin rules can cause login failures.
• Not configuring server rules can cause unexpected session termination.

Most load balancers allow you to associate a virtual IP (VIP) address and port number with a group of load balancing rules. They also allow you to define servers as resources and to create groups for them. The procedure below outlines general steps for setting up load balancers for Siebel Servers.

Prerequisites

Observe the following requirements for setting up a third-party HTTP load balancer:

• The third-party HTTP load balancer must be validated for use with Siebel Business Applications. For more information, see 477835.1 (Article ID) on My Oracle Support. This document was previously published as Siebel Technical Note 540.
• If you use a noncertified load balancer, it must have the following characteristics:
  • Must be an HTTP load balancer capable of level 7 HTTP routing. Must be able to parse URLs in HTTP headers.
  • Must allow end-points to manage TCP connections. Specifically, must allow one-to-one mapping between client and server TCP sessions. Also, must not do back-end connection pooling, such as reverse proxy server pooling.
• Verify that all the Siebel Servers for which you want to provide load balancing are running.
• On each Siebel Server, verify that the Application Object Managers (AOMs) you want to load balance are enabled. Disable any AOMs that will not be used.
• Prior to configuring the Siebel Web Server Extension, select an unallocated, static VIP address and port number for the load balancer.
• Generate the load-balancing configuration file (lbconfig.txt). Review the HTTP load balancer rule types: component rules, server rules, and round-robin rules.
• Install the Siebel Web Server Extension on the desired Web servers. The SWSE Configuration Wizard will ask you to choose Siebel load balancing or third-party load balancing. Choose third-party load balancing and enter the VIP address and port number for the load balancer. For more information, see Configuring the SWSE.
• At least one Siebel Server must be installed and running.

To set up a third-party HTTP load balancer

1. Install and complete initial configuration of the third-party HTTP load balancer.

   Refer to the vendor documentation for details.

2. Verify that the load balancer can work with the machines that will host the Siebel Servers.

   Refer to the vendor documentation for networking requirements.

3. Add the desired Siebel Servers to the load balancer as pools of resources.

   Typically, each resource is defined as a combination of hostname or IP address, and TCP Port. Use the hostname or IP address of the Siebel Server, and the SCBroker port (by default, this is port 2321).

4. Create load balancing rules or content rules in the load balancer.

   Load balancing rules are mappings between URLs and pools of resources. For each line in the lbconfig.txt file, create one such mapping or rule in the load balancer.

   For more information, see 477835.1 (Article ID) on My Oracle Support. This document was previously published as Siebel Technical Note 540.

   NOTE:  You must configure the HTTP load balancer to handle all three types of rules: component, server, and round-robin.

5. For each group of load balancing rules, define the desired load balancing scheme.

   For component rules, use any preferred load balancing scheme.

   For server and round-robin rules, a round-robin load balancing scheme is recommended.

6. Define a VIP address and virtual port for all the load balancing rules.

   The VIP and virtual port must match the VIP and virtual port specified in the object manager connect strings of the Siebel Web Server Extension configuration file (eapps.cfg).

   This file is located in SWSE_ROOT\bin, where SWSE_ROOT is the Siebel Web Server Extension installation directory.

7. If the load balancer has a configurable TCP connection time-out, adjust the time-out so that it is greater than the value of the parameter SISNAPI Connection Maximum Idle Time (alias ConnIdleTime). Doing so prevents the load balancer from disconnecting active SISNAPI sessions.

   For more information on setting ConnIdleTime, see Setting the Load Balancer Connection Time-Out. See also Siebel System Administration Guide.