【Database Architecture】

Describe some common deployment topologies.
Recognize the advantages of deploying databases in cloud.

Intro

• deployment topology involves organizing hardware, software, and network components
• a single-tier architecture deploys all components of an application on a single server or machine
• in a two-tier database setup, the database server and application operate in separate tiers
• in a three-tier database architecture, the application presentation layer and business logic layer exitst in different tiers
• users with an internet connection can access cloud-based databases from anywhere

Common deployment topologies

single-tier architecture

• Deploys all components on a single server
• Operates within the same environment

client-server architecture or two-tier database architecture

• Divides the application into two distinct layers
  • client layer: responsible for user interface
  • server layer: manages the application logic
• The remote server hosts the database
• User access it from client systems
• server and application operate in separate tiers
• application connects using language-dependent interface
• interface communicates with the server through API
• DBMS layers
  • Data Access layer
  • Database Engine layer
  • Database Storage layer
• Communication in database interface
  • Database Interface
    • communicates via Database client or api
  • Data Access Layer
    • Server includes various client interfaces
    • examples: JDBC, ODBC, CLP, vendor-specific interfaces
  • Database Server Engine:
    • Compiles queries
    • Retrieves, processes data, returns result set

three-tier architecture

• introduce middle tier between client and server
• three-tier architecture emergence
  • security concern:
    • prevent unauthorized data access or modification
  • performance
    • avoid overloading the server with unnecessary traffic
  • maintainability
    • avoid making changes to data except for administrators
• three-tier database architecture
  • application and business layer in separate tiers
  • presentation layer:
    • serves as UI
    • accessible through various platforms
  • application server:
    • client connects over the network
    • encapsulates the application and business logic
    • communicates the database server through API/driver
• three-tier database example
  • Internet banking app scenario
    • mobile connects to a banking application server
    • server communicates with teh bank’s database

cloud-based

• cloud deployment
  • Involves residing the database within a cloud
  • Offers many advantages inferent to cloud-based services
  • eliminates the need to download database software locally
• cloud deployment overview
  • are easily accessible to users with internets
  • involves communication within the cloud environment
  • suitable for:
    • development
    • testing
    • full-scale production environments