CN107846365A - A kind of load balancing based on SDN realizes system and method - Google Patents

Abstract

The technical solution of the present invention includes a system and method for realizing load balancing based on SDN. The system includes a terminal, a controller, a switch and a plurality of back-end servers, and is used to realize: The message to the back-end server, the message includes the terminal IP and virtual IP address, and also includes the data packet for business processing; generate a flow table that the switch can identify, and send the flow table to the switch; preset according to the flow table Modify the virtual IP address according to the rules, and receive the data packet sent by the back-end server and restore the IP address; receive the data packet sent by the switch, and perform the corresponding business operation and generate the corresponding data packet, where the data packet includes the message . The beneficial effects of the invention are: realizing link-level load balancing, compared with traditional agent-level load balancing; greatly improving the forwarding performance of load balancing; dynamically modifying flow table rules, and realizing flexible customization of the network.

Description

A system and method for realizing load balancing based on SDN

technical field

The invention relates to an SDN-based load balancing realization system and method, belonging to the field of computer data processing.

Background technique

Load Balance (LB for short) is a clustering technology of servers or network devices. Load balancing distributes specific services (network services, network traffic, etc.) to multiple servers or network devices, thereby improving service processing capabilities and ensuring high availability of services.

For example: A certain system has 70 million transactions per day, and a single server can only handle 50 million transactions at full load, and a single server cannot handle such a large transaction volume at all. At this point, you can add another server with the same processing capacity, distribute all the business to these two servers, and let them handle part of it separately. The load balancing technology just solves how to distribute the business to two or more servers.

At present, the way to achieve load balancing is mainly realized through the full proxy. To achieve load balancing through the full proxy, the client needs to establish a connection with the full proxy, and the proxy establishes a connection with the back-end server. Two connections need to be established, which greatly reduces the performance of load balancing.

The load balancing implementation process of the full proxy as shown in Figure 1 is as follows: first, the client establishes a TCP connection with the full proxy (full load balancing proxy), sends the HTTP request to the full proxy, and the full proxy parses the HTTP request and performs Session management, access control and other operations, and then allocate a back-end server for the HTTP request according to the load balancing algorithm, and forward the processed HTTP request to the back-end server. After the server completes the processing, it sends the HTTP response message to The full proxy returns the response message to the client via the full proxy. Such a request requires two connections to be established.

SDN: Software Defined Networking;

OpenFlow: SDN control plane and forwarding plane communication protocol;

OpenFlow switch: A software switch that supports the OpenFlow protocol.

Contents of the invention

The technical solution of the present invention provides a system and method for implementing load balancing based on SDN. The load balancing based on SDN technology realizes link-level load balancing. Only one connection needs to be established for one request, which solves the shortcomings of the prior art.

The technical solution of the present invention includes a load balancing implementation system based on SDN, the system includes a terminal, a controller, a switch, and a plurality of back-end servers, wherein: the terminal is used to generate and distribute the service of the terminal when load balancing is achieved; The message to the back-end server, the message includes the terminal IP and virtual IP address, and also includes data packets for business processing; the controller is used to generate a flow table that can be recognized by the switch, and send the flow table to the A switch; a switch, configured to receive the request instruction sent by the terminal and the flow table sent by the controller, modify the virtual IP address according to the preset rules of the flow table, and send the modified data packet, and receive The data packet sent by the back-end server is restored to the IP address; the back-end server is used to receive the data packet sent by the switch, perform corresponding business operations and generate a corresponding data packet, wherein the data packet includes a message.

According to the SDN-based load balancing implementation system, it is characterized in that: the terminal is further a server for executing business processing, and the back-end server is used to share a database for business load scheduling.

According to the SDN-based load balancing implementation system, wherein the controller further includes: a flow table rule customization module for customizing the flow table rules, and sending the flow table rules to the switch and the server, the flow table rules It is used to limit the IP conversion of the controller.

According to the described SDN-based load balancing implementation system, wherein the switch is used to perform the following steps: record the conversion rules when performing IP conversion on any data packet, and record the conversion identification in the data packet and the controller at the same time; when the flow table When the rule changes dynamically, check whether there is a historical conversion identifier in the data packet passing through the controller. If it exists, call the historical conversion rule to perform restoration conversion on the data packet. If there is no historical conversion identification, use the new conversion to execute on the data packet. convert.

According to the SDN-based load balancing implementation system, the switch further includes: when it is recognized that the passing data packet does not exist in the terminal, sending the data packet to the controller for storage or deletion.

The technical solution of the present invention also includes an SDN-based load balancing implementation method, which is characterized in that the method includes: when load balancing is achieved, generating a message for distributing the business of the terminal to the back-end server, and the message includes the terminal IP and virtual IP address, as well as data packets used for business processing; generate a flow table recognizable by the switch, and send the flow table to the switch; receive the request instruction sent by the terminal and the flow table sent by the controller, according to the flow table The preset rules modify the virtual IP address, send the modified data packet, and receive the data packet sent by the back-end server and restore the IP address; receive the data packet sent by the switch, and execute the corresponding business operation and A corresponding data packet is generated, wherein the data packet includes a message.

The invention has the beneficial effects of: realizing link-level load balancing, compared with traditional agent-level load balancing; greatly improving the forwarding performance of load balancing; dynamically modifying flow table rules, and realizing flexible customization of the network.

Description of drawings

Fig. 1 shows that according to the flow chart of the load balancing implementation of the full proxy of the present technology;

Fig. 2 shows the overall structural block diagram according to the embodiment of the present invention;

Fig. 3 shows an interaction diagram according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The SDN-based load balancing realization system and method of the present invention are applicable to the realization of server load balancing.

Fig. 2 is a general structural block diagram according to an embodiment of the present invention. These include terminals, switches, controllers, and multiple servers, among which the switch is OpenFlow

Different from traditional load balancing, the forwarding of OpenFlow-based load balancing is finally realized through the flow table.

First, the controller generates a flow table that can be recognized by the OpenFlow switch according to the load balancing rules, and distributes the flow table to the OpenFlow switch.

When the OpenFlow switch receives the data packet sent to the virtual IP, it modifies the destination IP in the data packet to the IP of the backend server according to the rules set in the flow table, and then forwards it. When it cannot be found in the local flow table, the data packet is handed over to the controller for processing or discarded.

When the response message from the backend server passes through the OpenFlow switch, the switch restores the source address of the message to the VSIP of the virtual service according to the flow table, and then returns it to the client to complete the entire load scheduling process.

Fig. 3 shows an interaction diagram according to an embodiment of the present invention.

It includes the following processes:

(1) The terminal user requests the transmission of the data packet, that is, the service request, at this time, the destination IP=virtual IP address, and the source IP=terminal IP address;

(2) switch is processed data packet according to flow table, and this moment purpose IP=(back end) server IP address, source IP=terminal IP address;

(3) server is to the response of switch, according to flow table processing data packet purpose IP=terminal IP, source IP=server IP address;

(4) The switch responds to the terminal, where destination IP=terminal IP, source IP=virtual IP address.

It can be seen from the above process that when the client request reaches the load balancer, the connection is not established but the destination address in the IP packet is modified, and then the IP packet is directly forwarded to the corresponding server, thus realizing link-level load balancing , a request only establishes a connection, which greatly improves the forwarding performance of load balancing.

The above descriptions are only preferred embodiments of the present invention, and the present invention is not limited to the above-mentioned embodiments, as long as they achieve the technical effects of the present invention by the same means, they should all belong to the protection scope of the present invention. Various modifications and changes may be made to the technical solutions and/or implementations within the protection scope of the present invention.

Claims (6)

1. A load balancing realization system based on SDN, the system includes a terminal, a controller, a switch and a plurality of back-end servers, wherein: The terminal is used to generate a message for distributing the business of the terminal to the back-end server when load balancing is achieved, and the message includes the terminal IP and virtual IP address, and also includes data packets for business processing; a controller, configured to generate a flow table recognizable by the switch, and send the flow table to the switch; The switch is configured to receive the request instruction sent by the terminal and the flow table sent by the controller, modify the virtual IP address according to the preset rules of the flow table, and send the modified data packet, and receive the The data packet sent by the backend server and restore the IP address; The backend server is configured to receive the data packet sent by the switch, execute corresponding business operations and generate a corresponding data packet, wherein the data packet includes a message. 2. The load balancing realization system based on SDN according to claim 1, characterized in that: The terminal is further a server for performing business processing, and the backend server is used for sharing a database for business load scheduling. 3. The load balancing realization system based on SDN according to claim 1, wherein said controller also includes: The flow table rule customization module is used to customize the flow table rules and send the flow table rules to the switch, and the flow table rules are used to limit the IP conversion of the controller. 4. The load balancing realization system based on SDN according to claim 1, wherein the switch is used to perform the following steps: Record the conversion rules when performing IP conversion on any data packet, and record the conversion identification in the data packet and the controller at the same time; When the flow table rule changes dynamically, check whether there is a historical conversion identifier in the data packet passing through the controller. If it exists, call the historical conversion rule to perform restoration conversion on the data packet. If there is no historical conversion identifier, use the new conversion pair Packets perform transformations. 5. The load balancing realization system based on SDN according to claim 1, wherein said switch further comprises: When it is recognized that the passed data packet does not exist in the terminal, the data packet is sent to the controller for storage or deletion. 6. A load balancing implementation method based on SDN, characterized in that the method comprises: When the load balance is achieved, generate a message that distributes the terminal's business to the back-end server. The message includes the terminal IP and virtual IP address, and also includes data packets for business processing; Generate a flow table recognizable by the switch, and send the flow table to the switch; Receive the request command sent by the terminal and the flow table sent by the controller, modify the virtual IP address according to the preset rules of the flow table, and send the modified data packet, and receive the data packet sent by the back-end server and perform IP Restoration of addresses; Receive the data packet sent by the switch, execute the corresponding business operation and generate the corresponding data packet, wherein the data packet includes the message.