Siebel Installation Guide for UNIX: Servers, Mobile Web Clients, Tools > Preparing for Installation > General Considerations in Planning Your Siebel Deployment >

Planning Topologies

You should consider running specialized components on dedicated machines. Whether you should do so depends on considerations that include available resources, overall load, and performance.

NOTE:  All Siebel products used within a given Siebel Enterprise must share the same release level. For additional information about Siebel releases, see About Installing Siebel Releases. Third-party products must use supported release levels as documented in System Requirements and Supported Platforms on Siebel SupportWeb.

• Installing Multiple Instances of Siebel Business Applications
• Siebel Server and Enterprise Server Naming Conventions
• File and Directory Naming Conventions
• Creating the Siebel File System

Record the machine names and installation directory names you decide on in your copy of the worksheet in Deployment Planning Worksheet.

For more information about planning your topologies, see the Deployment Planning Guide. See also the Performance Tuning Guide.

Planning Web Server Topology

Before you install the Siebel Web Server Extension (SWSE), as described in Installing the Siebel Web Server Extension you must decide how you will distribute the Web servers and other components.

• Single-node. Installation of Siebel Enterprise Server components and your Web server and SWSE on a single machine or node. (If you do this, use separate installation directories to avoid file permission problems at installation time.)
• Distributed. Distribution of the preceding components, where multiple Web servers connect to multiple Siebel Servers in the Siebel Enterprise. These Web servers can be dynamically balanced across Application Object Manager components on different Siebel Server machines.

Each deployment choice involves trade-off. However, in enterprise-sized deployments, it is strongly recommended that you use a distributed node deployment, for the following reasons:

• Less resource contention. Distributing the Web server and the Siebel Server (with Application Object Manager) on different machines eliminates contention for CPU and other server resources. However, to take advantage of the performance improvement, you must have a high-speed network connection between the two machines.
• Higher fault tolerance. Operating multiple instances of components on multiple machines reduces downtime and the impact of failure on any one machine.
• Greater flexibility with firewalls. Putting the Web components of the Siebel Business Applications on a different machine from the Siebel Server with Application Object Managers lets you deploy your Web server in the DMZ while keeping the Enterprise Server behind a secure firewall.
• High availability. A multinode configuration is required for deployments that support large numbers of concurrent users or where high availability is an operating requirement.

For more information, see the Deployment Planning Guide. See also the Security Guide for Siebel Business Applications.