An ArcGIS Server system can consist of one or more computers, depending on the needs of your organization. It’s therefore advisable to plan your ArcGIS Server system configuration before installing ArcGIS Server. This section includes an overview and some common system configuration scenarios to help get you started on planning your ArcGIS Server system.
Overview
ArcGIS Server is fundamentally an object server that manages a set of ArcObjects running on a server. ArcObjects being served are called GIS server objects. ArcGIS Server's server objects are software objects that serve a GIS resource like a map, locator, and so on. Applications created by developers make use of server objects. ArcObjects is a collection of software objects that make up the foundation for the family of ArcGIS products (ArcGIS Desktop (ArcInfo, ArcEditor, ArcView), ArcReader, ArcGIS Engine and ArcGIS Server).
ArcGIS Server is a distributed system consisting of one or more computers where the GIS server (the Server Object Manager (SOM) and Server Object Containers (SOC)), and Application Developer Framework (ADF) Runtimes (and optionally Software Developer Kit (SDK)) reside. The SOM manages the set of server objects that are distributed across one or more SOC machines. The SOC machine or machines host the server objects that are managed by the SOM. Each SOC machine is capable of hosting multiple SOC processes. A SOC process is a process in which one or more server objects are running. The ADFs provide the framework, Web controls and convenience classes to build and deploy Web applications and Web services that make use of ArcObjects running in the GIS server. The ADFs require a Web server, and, in the case of the Java ADF, a servlet engine. For more information on the ADF system requirements, see the install guides for the .NET ADF and Java ADF located on the .NET Application Developer Framework and Java Application Developer Framework CDs.
ArcGIS Desktop (ArcInfo, ArcEditor, ArcView) products are the applications that provide the tools to create maps, address locators and so on, as well as administer the various aspects of the GIS server. Specifically, the ArcMap application creates map documents (mxd), and with the optional ArcGIS Publisher extension, can create Published Map Documents (pmf) which can then be served as GIS Server server objects. ArcCatalog both creates address locators for use in GeocodeServer server objects, and provides the tools for administrating the GIS server itself.
There are many possible ArcGIS Server system configurations. It’s possible to run all components of ArcGIS Server on a single computer, or to distribute the various components across multiple computers. Configurations will vary depending on the needs of an organization, the available computing resources, and the intended use of the ArcGIS Server system. For the Server Object Containers, processing speed and the ability to handle load are important. Some questions to consider are, will the Server Object Containers perform process-intensive functions, will the nature of those functions and the applications that perform them allow for the use of pooled server objects, or will they require non-pooled server objects? How many server objects will the system need to run at one time, and how many users will the applications that use those server object need to support? Will the Web server computer, where any ArcGIS Server Web applications or Web services are running be dedicated to supporting these applications, or will it also be used for other purposes? Answers to these types of questions will assist in planning your ArcGIS Server system.
Configure your ArcGIS Server system based on its intended usage and number of simultaneous users. If you are a developer and intend to use your ArcGIS Server system to build and prototype applications, then you may want to install all the components on a single computer (your development computer). If the anticipated number of simultaneous users of your GIS server is low, satisfying on the order of 100 to 1000 requests per day, then you may be able to run the entire system on one computer. As you get into higher-volume usage of the GIS server and its associated Web applications, your system should be distributed across multiple computers.
When planning your ArcGIS Server system configuration, there are some common installation recommendations to follow:
The ADF Runtimes must be installed on your Web server computer or computers. If you are installing the ADF on a development Web server for the purposes of developing Web applications or Web services, the ADF Software Developer Kit (SDK) should also be installed on the development Web server computer. If you create desktop applications using the ADF, the ADF Runtime must be installed on any machine on which your application runs.
The ArcGIS Desktop applications (ArcMap and ArcCatalog) used for creating data and managing the GIS server, can be installed on any Windows machine that can connect to the GIS server over a local area network (LAN).
The Server Object Manager (SOM) should only be installed on a single machine in your ArcGIS Server system. Each SOM manages its own collection of Server Object Container (SOC) machines.
Server Object Containers (SOCs) can be installed on one machine or many machines. Each machine on which a SOC is installed needs to be added to the list of machines managed by a SOM. Use ArcCatalog to connect to a machine running the SOM and add the SOC machines that it will manage. One SOC cannot support multiple SOMs, but one SOM can manage multiple SOCs. If you expand your ArcGIS Server system with additional machines, those machines will be SOCs.
Each SOC machine requires an ArcGIS authorization file.
Common site configuration scenarios
This section presents a series of common configuration scenarios that illustrate how to distribute various installation components across various computer platforms.
ArcGIS Server on a single machine
Multiple Server Object Containers
ArcGIS Server on a single machine
This installation scenario consists of the GIS server (Server Object Manager, Server Object Container), and Application Developer Framework on the Web server machine. Additionally, ArcGIS Desktop can also be installed on this machine if another machine is not available to install and run the applications necessary to administer the GIS server.
In order to install all components of ArcGIS Server on a single machine, that machine must satisfy the installation requirements for both the GIS Server and the ADF of choice (.NET or Java).
This type of configuration is useful for those sites with limited computing resources, light server loads, or for developers who want to install ArcGIS Server for the purpose of developing applications.
The configuration in the diagram above illustrates the Web server, Application Developer Framework, and GIS Server (Server Object Container and Server Object Manager) on one machine. ArcGIS Desktop is shown connected to the Server Object Manager over a LAN. However, ArcGIS Desktop does not have to be on another machine, it could also be installed on this machine.
Mutiple Server Object Containers
Additional Server Object Containers (SOCs) can be added to the ArcGIS Server system configuration as the load on the GIS Server increases or to optimize performance. There is no one formula for determining the number of SOCs necessary for a particular system. The number of SOCs will vary depending on the number of server objects, the number of users of those server objects the system needs to support, and the nature of the applications using those server objects, specifically whether they require pooled or non-pooled server objects.
You can add new SOC machines, or additional CPUs to SOC machines already on the system. It’s important to note that the GIS server assumes that all SOC machines have the same configuration (number and speed of CPUs and amount of RAM) when it balances the load across the system. The Server Object Manager (SOM) also assumes the same licensing exists across all SOCs, meaning if your system makes use of functionality provided by one of the ArcGIS Server options (Spatial, 3D or StreetMap), then it’s assumed that all SOC machines are licensed for that functionality.
The SOM can also be on a dedicated machine. There is no requirement that the SOM and a SOC be installed on the same machine.
The configuration in the diagram above illustrates the Web server, Application Developer Framework, and GIS Server (Server Object Container and Server Object Manager) on one machine. An additional Server Object Container has been installed on another machine. The load is equally balanced between the two Server Object Containers. ArcGIS Desktop is shown connected to the Server Object Manager over a LAN. However, ArcGIS Desktop does not have to be on another machine, it could also be installed on one of these machines.
Dedicated Web server machine
Your organization may require your Web server to be on one machine while the ArcGIS Server components reside on a different machine. In this configuration, the Application Developer Framework Runtime for Java or .NET (depending on which your organization uses) must be installed on your Web server machine.
The configuration in the diagram above illustrates the Web server and Application Developer Framework on one machine. The GIS Server (Server Object Container and Server Object Manager) is on another machine. ArcGIS Desktop is shown connected to the Server Object Manager over a LAN. However, ArcGIS Desktop does not have to be on another machine, it could also be installed on one of these machines.