Multi-Tier Architecture and Load Balancing Quiz

Multi-User DBMS Architectures Overview

• CORBA is a standard by OMG that enables software components across languages and computers to work together.
• Orbix by Progress Software is a commercial ORB middleware product.
• SQL-oriented data access middleware connects applications with databases and translates SQL requests.
• Database-oriented middleware like ODBC and JDBC provide a single interface for accessing various databases.
• Transaction Processing Monitors (TP Monitors) provide a consistent environment for online transaction processing.
• TP Monitors manage distributed transactions and provide load balancing and funneling.
• They control transactions using the X/Open Distributed Transaction Processing (DTP) standard.
• TP Monitors act as transaction managers and maintain database consistency, offloading processes from the DBMS server.
• Prominent examples of TP Monitors include CICS and Tuxedo from Oracle Corporation.
• The Java Transaction API (JTA) enables distributed transactions in a Java environment.
• Web services support interoperable machine-to-machine interaction over a network.
• Unlike other Web-based applications, Web services have no user interface and share business logic, data, and processes programmatically across a network.

Web Services, REST, and Service-Oriented Architectures

• Web services examples include Microsoft Bing Maps, Google Maps, Amazon Simple Storage Service (Amazon S3), Geonames, DOTS Web services, and Xignite
• Amazon S3 charges are based on a "pay-as-you-go" policy, currently $0.125 per GB for the first 50TB/month of storage used
• Key technologies and standards in Web services include XML, SOAP (Simple Object Access Protocol), WSDL (Web Services Description Language), and UDDI (Universal Discovery, Description, and Integration)
• RESTful Web services emphasize moving away from SOAP-based services towards Representational State Transfer (REST) based communications
• REST services do not require XML, SOAP, WSDL, or UDDI definitions, and are based on an architectural style that specifies constraints for desirable properties
• REST architecture style adopts a client-server architecture, uses a stateless communication protocol, and exchanges representations of resources using a standardized interface and protocol
• Service-Oriented Architectures (SOA) is a business-centric software architecture for building applications that implement business processes as sets of services published at a granularity relevant to the service consumer
• SOA emphasizes flexibility and reusability as key requirements for businesses in a rapidly changing technological landscape
• SOA architecture typically involves three processes: Service Scheduling, Order Processing, and Account Management, each accessing a number of databases
• SOA aims to design loosely coupled and autonomous services that can be combined to provide flexible composite business processes and applications
• Common SOA principles include loose coupling, reusability, and adherence to a communications contract defining information exchange and service description information
• SOA design approach focuses on building Web services for SOA with an emphasis on loose coupling, reusability, and adherence to communication contracts.

Test your knowledge on multi-tier architecture, application servers, and load balancing in high throughput environments. Learn about the roles of web servers and application servers in a multi-user DBMS architecture.