Linux Server Load balancer cluster system solution-Linux Enterprise Application-Linux server application information. For details, refer to the following section.
1. Introduction to Linux virtual servers
Linux Virtual Server (LVS) is a high-availability Server Load balancer cluster system. The system can provide Load Capacity proportional to the number and performance of server nodes, effectively improving service throughput, reliability, redundancy, adaptability, and high performance and price ratio. At the same time, LVS is also an effective way to achieve high-end server performance using low-end devices.
Linux Virtual Server (LVS) is built on a cluster composed of a director server and several real-Server instances. Real-server is responsible for providing services. The master server controls the real-server Based on the specified scheduling algorithm. The cluster structure is transparent to users. The client only communicates with a single IP address (virtual IP address of the cluster system). That is to say, from the client perspective, only one server exists here.
Real-server provides many services, such as ftp, http, dns, telnet, nntp, and smtp. The master Server controls the Real-Server. When a client sends a service request to LVS, Director uses a specific scheduling algorithm to specify a Real-Server to respond to the request. The client only responds to the Load Balancer IP address (virtual IP address, VIP.
Ii. Advantages
* Increase throughput: to achieve higher throughput, the overhead of adding real-servers in LVS only increases linearly. If we choose to replace a higher-performance server to achieve a considerable throughput, the overhead is much larger, and the replaced old server will cause a waste of resources.
* Redundancy: if a real-server in LVS stops the service due to upgrade or other reasons, the termination and restoration of the service will not interrupt the service of the entire LVS client.
* Adaptability: whether the throughput needs to change gradually (due to changes in daily transactions) or quickly (due to sudden changes in transactions), the increase or decrease in the number of servers is transparent to the client.
Iii. Structure Diagram
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The traditional "Client/Server" relationship is still applicable in LVS because:
* The IP addresses of all servers are mapped to one IP address (VIP). The client can only see this IP address.
* All servers regard it as directly related to the client.
Basic settings of an LVS
