Cluster System

Cluster System

AU:May19

• Clustered system is a group of computer system connected with a high speed communication link. Each computer system has its own memory and peripheral devices. Clustering provides high availability.

• Clustering systems are integrated with hardware cluster and software cluster. Hardware cluster support sharing of high performance disks. Software cluster is in the form of unified control of the computer system in a cluster.

• Cluster node contains layer of cluster software and it run on the node. Each node monitors the network whether the cluster is working properly or not. If the monitored computer fails, then the monitoring computer takes the control and ownership of its storage and other resources. It restarts the application of failed computer. The users and other clients will get the resources. The failed computer  can remain down until it repair.

• Clustered systems are divided into two groups:

1. Asymmetric clustering 2. Symmetric clustering.

• Asymmetric clustering: In this type of clustering, one machine is always in the hot standby mode and other machines are running its applications. The hot standby machine only monitors the active server. When active server fails, then hot standby machine takes the control and becomes the active server.

• Symmetric clustering:more than one host runs the applications. It uses all of the available hardware for operation. Host monitors working of other host for smooth operation of the cluster.

• Fig. 1.5.1 shows structure of cluster system.

• Clustered system and symmetric multiprocessor provide a support for high demand applications.

• Clustered system is different than parallel system.

• Other type of clustered system is parallel clusters. It uses shared storage of data. Parallel cluster requires some special purpose software and special type of applications. Example of parallel cluster is Oracle Parallel Server.

• Cluster technology changes rapidly. New developments are added to this cluster technology. Now a day, global cluster concept is used for large organizations.

Pros:

1. Increased resource availability.

2. Cluster computing is manageable and easy to implement.

3. Clustered systems are quite fault-tolerance and the loss of a single node does not result in the system's failure.

4. There is a high availability of resources meaning that if one node fails, another node takes over.

Cons:

1. Extra hardware is needed to maintain system.

2.Difficult to manage and organize a large number of computers.

University Question

1. Discuss the pros and cons of single processor system, multi core system and clustered system. AU:MAY-19,MARKS 8