Internet Inter-ORB Protocol

K2 is implemented as a multithreaded server that can handle multiple client connections. Clients communicate with the server using either Remote Method Invocation, Internet Inter-Orb Protocol, or an ad hoc socket protocol. In addition to a set of client libraries that simplify accessing K2 from any Web application that uses Java servlets, a chent that provides interactive command line access to the system has been implemented. 

DCOM distributed component object model EDI electronic data interchange HTTP hypertext transfer protocol HOP internet inter-orb protocol JVM java virtual machine ORB object request broker SET secure electronic transaction TCP/IP transmission control protocol/in-ternet protocol... 

CORBA objects are accessed by applications, for example by Java applets or CGI (common gateway interface) scripts for Web services though the HOP (Internet Inter-ORB Protocol). HOP is a general protocol for communication between objects and applications. Once an application talks HOP, for example, by loading an ORB Java class, all CORBA services can be accessed. One of the weaknesses of CORBA, especially in the computational chemistry context, is that it is rather geared towards synchronous communication. An immediate response is not always a reasonable prerequisite for this type of application. 

Here there is a difference between DCOM and CORBA, Microsoft uses MIDL, while CORBA uses CORBA IDL. Objects talk to each other across the network, using ORB (for CORBA) and Microsoft uses different DCOM products. Multiple CORBA ORBs communicate via a standard communications protocol known as Internet Inter-ORB Protocol (HOP) as shown in figure A2-4, while Microsoft uses DCOM protocol as shown in figure A2-5. EJB uses its own standard communication for Java-to-Java communication called Remote Method Invocation (RMI). The term BOA is used for Basic Object Adapter and RPC is used for Remote Procedure Call . 

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