---
title: "Short note: CORBA components for RMI"
subject: "Distributed System"
chapter: 4
key: "semester_7/distributed_system:corba-rmi-component-note"
source: https://www.bctengineer.com/q/semester_7/distributed_system/corba-rmi-component-note
site: BCT Engineering
---

# Short note: CORBA components for RMI

Distributed System · Chapter 4: Distributed Heterogeneous Applications and CORBA

- Asked in: 2076 Chaitra, 3 marks
- Video: [CORBA Architecture | Part-1/2 | Distributed Systems | Lec-45 | Bhanu Priya](https://www.youtube.com/watch?v=aEOfsRKTlv0) — Education 4u
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/distributed_system/corba-rmi-component-note
- Whole chapter: https://www.bctengineer.com/md/semester_7/distributed_system/chapter-4

## Question

Write a short note on CORBA component for RMI.

## Short answer

CORBA RMI relies on: IDL definitions compiled into client stubs and server skeletons; the ORB (Object Request Broker) that routes requests using GIOP/IIOP; an Object Adapter (POA) that manages servants and dispatching; the actual servant implementing the operation; and services like Naming for locating objects via IOR. Dynamic invocation uses DII/DSI and the Interface Repository.

## Answer

For CORBA remote method invocation the following components cooperate:
- **IDL and IDL compiler**: define the interface and generate stub and skeleton code.
- **Client stub (proxy)**: a local representative of the remote object; marshals arguments and sends the request.
- **ORB (Object Request Broker)**: finds the object, transports requests and replies between client and server using GIOP/IIOP.
- **Object Adapter (POA)**: registers servants, creates object references and dispatches requests.
- **Server skeleton**: unmarshals the request and calls the right method of the servant.
- **Servant (object implementation)**: the actual code that does the work.
- **Interface Repository** and **DII/DSI**: for dynamic invocation.
- **Implementation Repository**: locates and starts servers.
- **Naming service / IOR**: gives the object reference the client needs.

Together they provide location- and language-transparent method calls.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the main job of the ORB in CORBA RMI?
   A. Generate stub and skeleton code
   B. Execute the actual business logic of the method
   C. Store the interface definitions for dynamic use
   D. Locate the object and transport requests and replies between client and server using GIOP/IIOP
   Answer: D. The ORB finds objects and carries requests/replies between client and server. (Key point: Role of the ORB)

2. Which component unmarshals the request on the server side and calls the right method of the servant?
   A. Server skeleton
   B. Client stub
   C. Implementation repository
   D. Interface repository
   Answer: A. The skeleton unmarshals the request and invokes the servant's method; the servant holds the real code. (Key point: Skeleton vs servant)

3. What does the Object Adapter (POA) do?
   A. Marshals arguments on the client
   B. Registers servants, creates object references and dispatches requests
   C. Starts server processes that are not running
   D. Translates IDL into code
   Answer: B. The POA manages servants and dispatches incoming calls to them. (Key point: Object adapter)

4. Which component locates and starts servers when they are needed?
   A. Interface Repository
   B. Naming service
   C. Implementation Repository
   D. Client stub
   Answer: C. The Implementation Repository finds and activates servers; the Interface Repository supports dynamic invocation. (Key point: Implementation repository)

## Related in Distributed System

- [IDL and CORBA RMI with services](https://www.bctengineer.com/question.md?key=semester_7%2Fdistributed_system%3Aidl-corba-rmi) — Distributed System, chapter 4
- [Components of CORBA architecture](https://www.bctengineer.com/question.md?key=semester_7%2Fdistributed_system%3Acorba-components) — Distributed System, chapter 4, asked 2×

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