DCOM (Distributed Component Object Model) is a Microsoft technology that enables software components to communicate with each other over a network. DCOM is built on top of the Component Object Model (COM) and provides a mechanism for components to interact with each other in a distributed environment.
DCOM allows components to be distributed across multiple machines, and for those components to interact with each other as if they were on the same machine. DCOM provides a layer of abstraction between components, so that components can be written in different languages and run on different operating systems.
DCOM is used by a number of Microsoft products, including COM+, ActiveX, and OLE Automation.
How does DCOM work?
COM is a technology for software componentry introduced by Microsoft in 1993. COM is the foundation technology for Microsoft's OLE (Object Linking and Embedding), and ActiveX technologies. OLE allows an object created in one application to be embedded in another. ActiveX is a set of technologies that enables software components to be reused in a networked environment. COM provides a language-neutral way for applications to access objects created in other programming languages.
DCOM is an extension of COM that enables COM components to be used across a network. DCOM provides a mechanism for COM components to interact with one another in a distributed environment. DCOM components can be located on different machines on a network. DCOM allows COM components to be invoked remotely by clients. DCOM also provides a security model that allows for secure communication between COM components on different machines.
COM+ is a set of services that build on COM and DCOM to provide a more robust and scalable component model for distributed component-based applications. COM+ services include object pools, just-in-time activation, and event handling. COM+ also provides a security model that is more fine-grained than the security model provided by DCOM.
What is object model in distributed system?
In distributed systems, the object model refers to the way in which objects are represented and accessed over a network. There are two main approaches to this: the distributed object model and the distributed component model.
In the distributed object model, objects are represented as remote objects that can be accessed by any system on the network. This approach is typically used in CORBA-based systems.
In the distributed component model, objects are represented as local objects that are accessed through a component interface. This approach is typically used in DCOM-based systems. Which applications use DCOM? DCOM is a Microsoft technology that allows components to communicate with each other over a network. It is used by many applications, including Microsoft Office, Visual Studio, and Exchange Server.
Why is DCOM necessary?
DCOM is a Microsoft technology that enables software components to communicate with each other over a network in a transparent, location-independent manner. DCOM is an evolution of Microsoft's earlier COM technology, which allows components to communicate with each other on the same computer.
DCOM is necessary in order to provide the following benefits:
- Interoperability: DCOM components can communicate with each other regardless of their location or operating system.
- Platform independence: DCOM components can be written in any programming language and run on any operating system that supports DCOM.
- Language independence: DCOM components can be written in any programming language and can be called from any other language that supports DCOM.
- Location transparency: DCOM components can be located on any computer in the network, and they can be invoked from any other computer in the network.
- Security: DCOM components can be securely invoked from any other computer in the network, using Microsoft's security model. What ports does DCOM use? DCOM uses a range of ports to communicate, depending on the configuration. By default, DCOM uses ports 135 and a dynamic port in the range 1024-65535.