How to implement server load balancing

Load balancing is divided into hardware load and software.

In terms of hardware, F5 can be used as a load, and dozens of algorithms are built-in.

In terms of software, you can use reverse servers, such as apache, nginx and other highly available reverse servers.

With the intelligent DNSPod function, you can implement load balancing for multiple machines.

First of all, you use a high-configuration machine as the database server. Then copy the front-end page of ** into multiple copies and put them on several other machines. Then use dnspod to do intelligent resolution, and point the domain name resolution to the IPs of multiple servers, and DNSPOD has the function of intelligent diversion by default, that is, when the resources of one machine are insufficient, it will automatically guide users to access other machines.

This is a relatively simple way to implement load balancing.

With the increase in the number of applications accessed, one server can no longer meet the needs of the application, and multiple server clusters are needed, so load balancing will be used.

Its benefits: Load balancing optimizes the distribution of access requests among server groups and eliminates load imbalance between servers, thereby improving the response speed and overall performance of the system.

Load balancing can monitor the operation status of the server, find the abnormal operation of the server in time, and move the access request bucket to other service socks that can work normally, so as to improve the reliability of the server group.

Does it depend on whether the backend service of ** is a stateless service?

If there is no state, you don't need to use session persistence, you can use a polling strategy.

If there is state, i.e., session persistence is required, and a hashing algorithm based on the source IP address needs to be used, that is, requests from the same IP address will be distributed to the same backend service vertical wheel.

Load balancing has hardware devices and open-source software, except for the IDC computer room and Dazao, the company can afford expensive physical devices like F5, and physical devices also need two machines to implement HA.

Open source Yanxian Bird software nginxhaproxylvs and other works with keepalived are also a good choice.

You can select an appropriate scheduling strategy based on the device or software you use and the business.

Server Clusters:

A server cluster is a collection of servers that work together to provide the same service, as if there was only one server for the client. Clusters can use multiple computers for parallel computing to achieve high computing speeds, and can also use multiple computers for backup, so that the whole system can still run normally if any machine is broken.

Server Load Balancing:

Load balancing. （load

balancing）

Building on the existing network structure, it provides a cheap, effective, and transparent way to expand the bandwidth of network devices and servers, increase throughput, enhance network data processing capabilities, and improve network flexibility and availability.

Distributed Servers:

The so-called distributed resource sharing server refers to a form of theoretical computing model server in which data and programs can be distributed to multiple servers instead of being located on one server, and the distributed geographic information data on the network and the database operations affected by it are the research objects. Distributed is conducive to the distribution and optimization of tasks on the entire computer system, which overcomes the shortcomings of the traditional centralized system that will lead to the shortage of central host resources and response bottlenecks, and solves the problem of network GIS

The problems of data heterogeneity, data sharing, and complex operation are a major progress in GIS technology.

These three architectures are common server architectures, and the cluster is mainly done by IT companies, which can ensure the security of important data; Load balancing is mainly used to share the amount of access and avoid temporary network congestion, which is mainly used for e-commerce type. Distributed servers are mainly used to solve the problem of cross-regional, multiple single nodes to achieve high-speed access, and generally use distributed servers for the purpose of CDN.

Pure hand-typed, I hope it can help you!

There are three deployment modes for load balancing: route mode, bridging mode, and direct service return mode.

1. Route mode (recommended).

In the deployment mode of route mode, the gateway of the server must be set to the LAN port address of the load balancer, and all returned traffic must also pass through the load balancer. This approach requires minimal network changes and balances any downstream traffic.

2. Bridging mode.

The bridging mode is simple to configure and does not change the existing network. The WAN port and LAN port of Server Load Balancer connect to the uplink device and the downlink server, respectively. All servers and load balancers are on the same logical network.

3. Service direct return mode.

For the client, the IP address that responds to him is not the virtual IP (VIP) of the load balancer, but the IP address of the server itself. This means that the returned traffic is not load-balanced. Therefore, this method is suitable for services with large traffic and high bandwidth requirements.