Campus Network Center scheme based on Linux cluster technology

With the development of network technology and the further deepening of network application, the campus network undertakes more and more applications from teaching, scientific research and management. The Campus Network Center, as the data storage release, traffic management control, user management and internal and external network Transfer Control center, must solve a series of problems caused by the increase of traffic. The Traditional Network Center scheme, when the traffic increases, generally is to upgrade a single server system, which often leads to excessive input and maintenance costs, greatly reducing the performance price ratio. The design of Campus Network Center based on Linux cluster technology can solve this problem effectively.

Campus Network Center System structure

The architecture of Campus Network Center based on Linux cluster technology is based on Linux core layer cluster technology and security technology, which is a highly scalable, high availability and high security operating platform. The structure is shown in Figure 1.

Figure 1

Under this architecture, the configuration of Network Center can be divided into three levels of load Balancer, service node pool and storage System.

1. Load Balancer

This is the only portal to the cluster, and the campus network is connected to the Internet through the device. From the campus of a single client, the cluster through this layer of service as a single system image (SSI) based on IP address, the entire campus network share this virtual address, through which the client can see the whole cluster as a separate host system with a legitimate IP address, All access to the client is addressed to this virtual IP address, which can effectively address the shortage of school IP addresses.

If there is only one load balancer, it is easy to create a single point of failure of the load balancer, making it the weakest link in the cluster. Therefore, it is necessary to provide fault-tolerant mechanism, which can be automatically detected and smoothed when the load balancer is invalidated. In this scheme, a backup load balancer is provided, which can monitor the running state of load balancer in real time and make alarm, takeover and recovery response according to the detected state.

2. Service Node Pool

The service node pool in the scenario refers to the server farm that provides the actual service. After the service request from the client is processed by the equalizer, it is forwarded to the service node pool by the specific server responding to the request and returning the data. In the campus network generally provide WWW, FTP, mail and courseware on demand and other services, using a single server system can not cope with peak time data access, through multiple servers to share the load is more economical and feasible.

Server nodes are also likely to have a temporary failure, especially when a node provides a variety of services, the system's random failure or the external environment of the mutation may cause a service temporarily unavailable. This needs to be recognized by the fault-tolerant mechanism of load balancing and processed in time, when the error is eliminated, the cluster can automatically recognize the recovery event and put the good nodes back into the cluster to continue running.