1. Concept
A computer system is a cluster, which is tightly connected height collaboratively through a set of calculations loosely integrated computer software and (or) hardware. In a sense, they can be seen as a single computer with a cluster system commonly referred to as a node, usually via a LAN connection, but there are other possible connections.
Cluster computers typically used to improve the calculation speed of the computer and (or) reliability, in general, a computer cluster than a single computer, such as a workstation or a supercomputer performance and low cost is much higher.
2. Cluster Features
1) Scalability: The performance of the cluster service is not limited to a single entity, the new service entity can be dynamically added to the cluster, thereby enhancing the performance of the cluster
2) availability: When a system wherein a cluster node fails, the applications running above this node will be automatically taken over on another node, remove single point of failure for the enhanced data availability, accessibility and reliability sex is very important.
3. The ability of the two clusters
Two clusters must have the following capabilities:
3.1 Load Balancing
Load balancing the relatively even distribution of tasks to computing and network resources under a cluster environment, to increase data throughput, which is a cluster of two main characteristics of high availability.
3.2 Error Recovery
If one of the servers in the cluster due to failure or maintenance need not be used, resources, and applications will be transferred to the available cluster nodes, this can not work due to the resources of a node, and the other resources available nodes transparently take over and to continue the process to complete the task, called the error recovery.
note:
Load balancing and error recovery requirements of each service resource perform the same task entity exists, but also for each resource in the same tasks, the information required to perform the task view must be the same.
4. clusters and distributed difference
4.1 similarities
And are distributed cluster server nodes need to have a lot to complete the overall mission objectives through the network to work together
4.2 difference
Distributed means business systems split, ie each node is distributed for different functions, and each node in the cluster to do the same thing. That is, each person has a different division of labor, with the collaboration do one thing, called distributed.
See the figure, each paddle people do live are the same, called clusters
Each node of the distributed clusters can also be made, as shown above, the overall opinion belongs distributed, comprising two drums and paddle distributed nodes, the node is rowing form clusters.
