The Cluster Based On Linux And The Heartbeat Design

With the development of computer architecture, cluster gains lots of appreciates because it is cheap, easy to expand. It becomes an important research field now. And it is widely used by enterprises and governments to fulfill the need for high-availability. As the system grows larger, the possibility of unexpected system faults grows larger, nature disasters or others reasons will easily crush the system. At the same time, it has to be avoided because people are so depended on this system. To solve the problem, HA(high availability) becomes more and more important. In layers of cluster software, heartbeat is used to keep network safe, manage low level cluster membership, and monitor the node in the cluster and so on. Heartbeat contributes a lot to high availability of the cluster. In this article, the cluster we talk about use Linux as its operating system. Linux has improved a lot in recently years, in many parts it is as good as commercial operating system, in some it is better. It is open source software, users can download it from network and use it at will, such low cost gives Linux advantages.This article will introduce several clusters, such as TurboCluster, EDDIE, LVS(Linux virtual server). It is described and analyzed that the architecture of cluster, the performance and the way to test the performance of clusters. The author has joined cluster software development, will work on several technical problems in this article which happened during his development. In ha clusters, the state of processes will be monitored frequently. The most common tools for this is ps and mon, but they could not run fast enough for high frequency as 60 times per minute. In this article, we will find why ps are slow, and then give a tool which will fulfill the need to monitor frequently. The tool works well because we cut some unnecessary functions and use some trick to make it faster.As the number of cluster nodes increases, the heartbeat messages become a heavy burden for cluster network. We will study the most recently success in multicast technology, and find a way to solve that problem. We will develop a new multicast heartbeat which is base on multicast technology, can efficiently...