Local (DCOM) connections are only supported for ArcGIS Server versions prior to 10.1.
About licensing ArcGIS for Server
In an ArcGIS for Server installation, only the machine on which the server object container (SOC) is installed must be authorized using a Server (.ecp) license. Other components must be licensed—such as the server object manager (SOM) and the Web Application Developer Framework (ADF) runtime—but do not require authorization. The SOC includes a local installation of ArcObjects that contains the same components as those packaged with ArcGIS Engine for Windows. The ArcGIS for Server for .NET installation also includes the Component Object Model (COM) proxies, the .NET primary interop assemblies, and the .NET connection libraries to support using ArcObjects in a .NET development environment. The SOC uses the Server license to authorize its use of ArcObjects locally.
Working with ArcObjects locally means creating and using ArcObjects in the same application process, such as in an ArcGIS Engine or ArcGIS for Desktop application. Working with ArcObjects remotely means creating and using ArcObjects in the context of a client-server application. The client application process creates ArcObjects in a server process and maintains references to the (remote) ArcObjects instances. This scenario includes a client application that works with ArcObjects via ArcGIS for Server (that is, ArcObjects are created in the SOC process [ArcSOC.exe]).
Working with ArcObjects locally requires a local installation of ArcObjects—at a minimum ArcGIS Engine for Windows, which includes the ArcObjects COM proxies. Working with ArcObjects remotely requires, at a minimum, the ArcObjects COM proxies on the client. The ArcObjects COM proxies are used to broker communication between ArcObjects references and instances, both within and across processes. In a .NET environment, primary interop assemblies (PIAs) are used to provide type information and manage interoperability with local and remote ArcObjects via the COM proxies. The PIAs, COM proxies, and connection libraries (ESRI.ArcGIS.ADF.dll, ESRI.ArcGIS.ADF.Connection.dll, ESRI.ArcGIS.ADF.Connection.Local.dll) are included with the installation of ArcGIS for Server for .NET (Web ADF runtime and SOC), ArcGIS Engine for Windows (via the .NET Support option), and the ArcObjects Software Development Kit (SDK) for the Microsoft .NET Framework.
Explicit use of the ArcGIS for Server license
In general, the Server license can only be used on a machine where the ArcGIS Server SOC component has been installed and licensed. With this in mind, the scenarios in which the Server license can be used (checked out) to work with ArcObjects locally in an application are as follows:
- Developing a single use desktop client or console application to be deployed on the same machine as a SOC. The deployed application checks out the Server license and runs in a separate process from the SOC. If this application is moved to another machine, it might only require an Engine license depending on the ArcObjects capabilities required by the application.
- Developing a multiuser Web application or service, or a Windows service, to be deployed on the same machine as a SOC. The deployed application checks out the Server license and runs in a separate process from the SOC. Any machine on which the application or service is deployed must be licensed for server use. ArcGIS Engine and ArcGIS for Desktop licenses alone (for example, Engine or Engine geodatabase) cannot be used when deploying this type of application.
- Developing a COM utility or custom server object extension (SOE) to use with ArcGIS Server. Because COM utilities and SOEs work in-process with the SOC, they work with ArcObjects locally. During development, the Server license can be checked out to execute the COM utility and SOE code. For deployment, remove the code to check out the Server license, since the SOC process already performs this step.
This scenario also applies to Python scripts used in a geoprocessing service. Scripts that run in a server context should reference the ArcGIS for Server product license for development and deployment.