Three methods of load balancing: 1. Routing mode; the gateway of the server must be set to the LAN port address of the load balancing machine, and be deployed in a different logical network from the WAN port. 2. Bridge mode; WAN port and LAN port are connected to the uplink device and downlink server respectively. 3. Service direct return mode; the WAN port and the server are in the same network. Internet clients access the virtual IP (VIP) of the load balancer. The virtual IP corresponds to the WAN port of the load balancer. The load balancer distributes traffic to the server according to the policy. , the server directly responds to the client's request.
The operating environment of this tutorial: Windows 10 system, Dell G3 computer.
Load balancing is built on the existing network structure. It provides a cheap, effective and transparent method to expand the bandwidth of network devices and servers, increase throughput, strengthen network data processing capabilities, and improve network flexibility. and availability.
Load Balance (Load Balance) means to allocate execution to multiple operating units, such as Web servers, FTP servers, enterprise key application servers and other mission-critical servers, etc., so as to complete work tasks together.
Three ways of load balancing
There are three deployment methods of load balancing: routing mode, bridge mode, and service direct return mode. Routing mode is flexible to deploy, and about 60% of users deploy it this way; bridge mode does not change the existing network architecture; direct service return (DSR) is more suitable for network applications with high throughput, especially content distribution. About 30% of users adopt this mode.
1. Routing mode (recommended)
In the deployment method of routing mode, the gateway of the server must be set to the LAN port address of the load balancing machine and be deployed separately from the WAN port. Different logical networks. Therefore all returning traffic is also load balanced. This method requires minimal changes to the network and can balance any downstream traffic.
2. Bridge mode
Bridge mode configuration is simple and does not change the existing network. The load-balanced WAN port and LAN port are connected to the upstream device and the downstream server respectively. The LAN port does not need to be configured with an IP (the WAN port and the LAN port are bridged), and all servers and load balancing are in the same logical network.
Because this installation method has poor fault tolerance, the network architecture lacks flexibility, and is sensitive to errors associated with broadcast storms and other spanning tree protocol cycles, this installation architecture is generally not recommended.
3. Service direct return mode
The load-balanced LAN port of this installation method is not used. The WAN port and the server are in the same network. The Internet client Access the load balancing virtual IP (VIP). The virtual IP corresponds to the WAN port of the load balancing machine. The load balancing distributes traffic to the server according to the policy, and the server directly responds to the client's request. Therefore, for the client, the IP that responds to him is not the virtual IP (VIP) of the load balancing machine, but the IP address of the server itself. In other words, the returned traffic is not load balanced. Therefore, this method is suitable for services with large traffic and high bandwidth requirements.
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