L3 - Evolution of SI, Messaging Flashcards
What are the two goals of the lecture on message-oriented integration?
Describe message-oriented integration.
Explain the pattern-based solutions for message integration.
How does message-oriented integration (MoSI) differ from IoSI?
MoSI is a solution, while IoSI is one of the three approaches (IoSI, SoSI, and PoSI).
What are the three types of messages in MoSI?
Command messages – a call to a function.
Document messages – e.g., order messages with details.
Event messages – e.g., checking availability before sending a message.
What type of integration does messaging support?
Messaging supports both functional and data integration.
What is one major difference between RPC and CORBA?
RPC is language-dependent.
CORBA is both language and platform-independent.
What is the primary architectural limitation of RPC?
It follows a fixed client-server model where the client can only access services provided by the server.
How do DOs solve the fixed client-server architecture issue in RPC?
DOs allow applications to communicate in a peer-to-peer manner.
What is a major downside of RPC and DOs in terms of communication reliability?
Neither provides guaranteed message delivery.
How does synchronous processing in RPC and DOs affect client applications?
The client is blocked until the server completes execution and returns control.
How does messaging improve upon RPC and DOs in terms of scalability?
Messaging supports asynchronous communication, allowing high transaction volumes and loose coupling
What are the six steps in the messaging process?
- Both applications register to the same queue in the MOM.
- The sender application creates a message and populates it with data.
- The message is sent to a queue in MOM.
- MOM stores and tries to deliver the message.
- The receiver application retrieves the message from the queue.
- The receiver processes the message.
What is the role of Message-Oriented Middleware (MOM)?
It manages the sending, receiving, and reliable delivery of messages between applications.
What is the purpose of patterns in system integration?
To provide reusable solutions to common integration problems.
What are the standard elements in a pattern description?
Name
Problem
Motivation
Solution
Related Patterns
Additional information (e.g., Consequences, Code)
What are the three core integration pattern groups for messaging?
Message Routing Patterns – Direct messages to the correct receiver.
Message Transformation Patterns – Modify message content for compatibility.
Message
Management Patterns – Handle errors and performance issues.
What problem does a Content-Based Router solve?
It directs messages to the correct recipient based on the message’s content.
Give an example of the Content-Based Router pattern in use.
A company with separate inventory systems for widgets and gadgets uses a Content-Based Router to send orders to the correct system.
What problem does a Content Enricher solve?
It adds missing information to messages when the sender does not have all required data.
Give an example of the Content Enricher pattern in use.
A hospital scheduling system sends messages missing necessary billing data. A Content Enricher retrieves the required data from a customer care system before forwarding it to the accounting system.
What problem does the Message History pattern solve?
It allows tracking of messages through a system by attaching a history log.
How does the Message History pattern work?
Every system that processes a message adds an entry to the message history, allowing easy debugging.
What are three key benefits of messaging?
Reliability – MOM ensures message delivery by persisting messages.
Loose Coupling – Applications can run independently and asynchronously.
Scalability – Messaging allows high transaction volume without overloading receivers
What are three limitations of messaging?
MOMs require learning and understanding.
Messaging is not suitable for synchronous communication needs.
Middleware reduces overall reliability.
