System Models For Distributed And Cloud Computing.
Distributed and cloud computing systems are built over a large number of autonomous computer nodes. These node machines are interconnected by SANs, LANs, or WANs in a hierarchical manner.
With today’s networking technology, a few LAN switches can easily connect hundreds of machines as a working cluster. A WAN can connect many local clusters to form a very large cluster of clusters. Massive systems are considered highly scalable, and can reach web-scale connectivity, either physically or logically.
Massive systems are classified into four groups:
- Clusters : A distributed systems cluster is a group of machines that are virtually or geographically separated and that work together to provide the same service or application to clients. It is possible that many of the services you run in your network today are part of a distributed systems Cluster Distributed Services:
- Domain Naming System
- Windows Internet Naming Service
- Active Directory
2. P2P Networks : In a P2P system, every node acts as both a client and a server, providing part of the system resources. Peer machines are simply client computers connected to the Internet. All client machines act autonomously to join or leave the system freely. This implies that no master-slave relationship exists among the peers. No central coordination or central database is needed. The system is self-organizing with distributed control.
3. Computing Grids :This is the use of widely distributed computer resources to reach a common goal. A computing grid can be thought of as a distributed system with non-interactive workloads that involve many files. Grid computing is distinguished from conventional high-performance computing systems such as cluster computing in that grid computers have each node set to perform a different task/application. Grid computers also tend to be more heterogeneous and geographically dispersed than cluster computers.
4. Internet clouds :The idea is to move desktop computing to a service-oriented platform using server clusters and huge databases at data centers. Cloud computing leverages its low cost and simplicity to benefit both users and providers. Machine virtualization has enabled such cost-effectiveness. Cloud computing intends to satisfy many user Virtualized resources from data centers to form an Internet cloud, provisioned with hardware, software, storage, network, and services for paid users to run their applications.
