L2 - Evolution of System Integration Flashcards
Goal of System Integration Evolution
Explain system integration solutions from a historical perspective.
Explain essential concepts related to system integration.
What is System Integration Evolution About?
Enabling applications’ connection and communication in a distributed system.
Facilitating loose coupling between systems/applications.
What is Loose Coupling?
Reducing assumptions that two systems/applications make about each other.
Message in System Integration
A message is used to communicate between networked applications.
A message contains meta-data (protocols, timestamps, error codes, authentication, etc.) and data (actual content).
Protocol in System Integration
A formal description of message formatting that applications must follow.
Defines how message parts are arranged and exchanged.
Network in System Integration
Infrastructure linking computers, servers, and mobile devices.
Can include middleware components like routers and integration middleware.
Application Layer in Networking
Used by software programs requiring network communication.
Examples: HTTP, FTP, Telnet, SMTP.
Transport Layer in Networking
Manages end-to-end message transfer.
Handles flow control, error control, and retransmission.
Example: TCP protocol.
Network/Internet Layer in Networking
Solves packet routing and addressing.
Uses the IP protocol for networking.
Works with TCP to form TCP/IP protocol.
What Happens with High Coupling?
More efficiency but less flexibility for changes.
Requires applications to match in:
Time: Must be available simultaneously.
Application protocol: Must match (e.g., HTTP).
Data format: Data types must match (syntax, semantics).
Why is Loose Coupling Important?
Enables independent execution of tasks.
Facilitates integration with multiple systems.
Allows internal changes without impacting other systems.
What is an API?
Stands for Application Programming Interface.
Provides functions for application communication.
Examples: ODBC API, RPC API, RMI API, RESTful API.
Example: Spotify RESTful API allows client apps to fetch artist and album data.
What is Data Sharing?
Different methods for sharing data between applications.
Applications first shared data before sharing functionalities.
3 Evolutionary Data Sharing Methods
- File-based data sharing (non-real-time).
- Common database (non-real-time).
- Sockets (real-time).
Real-time vs. Non-real-time Integration
Real-time Integration:
Processes data immediately upon receipt.
Non-real-time Integration:
Processes data later (batch processing).
Advantages:
Real-time = Up-to-date data.
Non-real-time = Cost-effective.
File-based Data Sharing
Uses files to transfer data between applications.
Example: Application A writes to a file → Application B reads it later.
Common formats: CSV, XML, JSON, Flat files.
Modern File-based Data Sharing
Recommended protocols: SFTP, FTPS.
Cloud solutions: Google Drive, OneDrive, Dropbox API.
Modern data formats: JSON, XML, Avro, Parquet, YAML.
Advantages of File-based Data Sharing
Simple and supported by all programming languages.
Disadvantages of File-based Data Sharing
Not real-time.
Requires format agreement between applications.
Point-to-point integration makes it hard to scale.
Common Database Integration
Applications share a database and access data via SQL.
Multipoint integration (multiple applications can connect).
Advantages of Common Database Integration
Uses relational databases (SQL-based).
Suitable when applications lack API compatibility but support SQL.
Disadvantages of Common Database Integration
Not real-time.
Requires a unified database schema.
Database locks can cause bottlenecks.
Not suitable for long-distance networks due to performance issues.
What are Sockets?
Real-time integration method.
A socket is an IP address + port number.
Standard for TCP/IP communication.
How Sockets Work?
Client Process:
1. Create a socket
2. Connect to server
3. Exchange data
Server Process:
1. Create a socket
2. Bind to a port
3. Accept client connection
4. Exchange data
Advantages of Sockets
Real-time communication.
Fast due to low metadata overhead.
Still used in modern applications.
Disadvantages of Sockets
Only data is shared, not functionality.
Low-level programming required.
Point-to-point connection leads to high coupling.
What is Remote Procedure Call (RPC)?
Allows function calls between applications.
Works in a client-server architecture.
Example: Application A calls a function on Application B over a network.
Disadvantages of RPC
Language-dependent (both sides must use the same language).
Synchronous calls (blocking).
Not scalable for large distributed systems.
What are Distributed Objects (DO)?
Evolution of RPC, decouples client-server connection.
Uses middleware (Object Request Broker - ORB).
Examples: CORBA, DCOM, Java EJB.
Advantages of Distributed Objects (DO)
anguage-independent.
Platform-independent.
Multipoint integration instead of point-to-point.
Integration Middleware - ORB
ORB = Object Request Broker.
Manages communication between client and server applications.
Handles requests, dispatches results, and manages exceptions.
Distributed Object Process
Step 1: Client finds the server object using ORB.
Step 2: ORB marshals/unmarshals data between client and server.
Step 3: Server processes request and sends response via ORB.
Additional ORB Services
Naming Services: Help clients find objects.
Security Services: Control access and encryption.
Transaction Services: Ensure atomic transactions.
