WO2017219813A1

WO2017219813A1 - Traffic processing method and transparent buffer system

Info

Publication number: WO2017219813A1
Application number: PCT/CN2017/085382
Authority: WO
Inventors: 黄凌云
Original assignee: 华为技术有限公司
Priority date: 2016-06-23
Filing date: 2017-05-22
Publication date: 2017-12-28
Also published as: CN105959228B; CN105959228A

Abstract

The embodiments of the present invention relate to a traffic processing method and a transparent buffer system, the method comprising: when a transparent buffer system receives from a client a synchronous sequence number (SYN) message for establishing a first transfer control protocol (TCP) connection between the client and a service server, performing Internet protocol (IP) layer forwarding of the SYN message; if the transparent buffer system does not receive an SYN + acknowledgment (ACK) response message for the SYN message, when the transparent buffer system receives a data message of a TCP stream transmitted by means of the first TCP connection, performing IP layer forwarding of the data message. As can be seen from the above, in the embodiments of the present invention, a client can achieve normal access to a Web server using asymmetric routing.

Description

Traffic processing method and transparent cache system

This application claims the priority of the Chinese Patent Application entitled "Flow Processing Method and Transparent Cache System" by the Chinese Patent Office on June 23, 2016, the application number is 201610464005.9, the entire contents of which are incorporated herein by reference. In the application.

Technical field

The present invention relates to the field of computers, and in particular, to a traffic processing method and a transparent cache system.

Background technique

With the rapid development of the Internet, the rapid growth of network traffic has brought enormous challenges to network operators. The network infrastructure expansion investment is huge, and it is difficult to match the growth rate of user traffic. About 80% of the current network traffic comes from Hyper Text Transfer Protocol (HTTP). For example, video, file download, web browsing, etc. use HTTP. Because HTTP is based on client/server mode, users access resources. You need to get the same data from the source station. The more people access the unified resources, the more duplicate data traffic is generated. Providing a cache service through an Internet Cache (Web Cache) system is an effective way to solve this problem.

Based on the idea of storing bandwidth and traffic localization, Web Cache caches hot resources to the local area and directly provides services to clients from the local network. This greatly reduces the traffic to the upper-level network. The basic workflow of the Web Cache is: the Web Cache system performs real-time analysis and statistics according to the client's uplink request, and selects the most popular resources for local caching; when the Web Cache system subsequently receives the client's uplink request, it determines that the target resource is local. Whether it has been cached; if it is, the Web Cache system reads the resource data locally and returns it to the client, avoiding the client getting the resource to the original website.

Transparent caching is a type of Web Cache. It is usually configured by routing policies on the router to direct upstream and downstream traffic to the transparent cache system. The transparent caching system interacts with the client or web server using the web server address or client address, so that the client and the web server are not aware of the transparent caching system.

However, there are cases of asymmetric routing in some networks of the existing network, that is, round-trip data packets between the client and the server are transmitted through different routing paths. Generally, the Web Cache system is deployed on one of the paths, and only some of the packets of the Transmission Control Protocol (TCP) flow, such as the uplink packet or the downlink packet, are obtained. As a result, some packets cannot be processed normally. Processing of the business layer.

In the prior art, the Web Cache system detects the traffic of the asymmetric routing through trial and error, and records the network protocol (IP) address corresponding to the asymmetric routing traffic to the local asymmetric routing address record table. The Web Cache system The traffic of these addresses is directly forwarded by the IP layer and is not sent to the service layer for processing.

However, in this mode, when the IP address of the client is recognized as an asymmetric routing IP address by the Web Cache system, the Web Cache system will interrupt the current connection of the client, causing the access failure.

Summary of the invention

The embodiment of the invention provides a traffic processing method and a transparent cache system, which can implement normal access of the client to the web server during asymmetric routing.

In one aspect, a method for traffic processing for a transparent cache system is provided, the method comprising: when the transparent cache system receives from a client, establishing a first TCP connection between the client and a service server. When the Synchronize Sequence Numbers (SYN) message is sent, the SYN message is subjected to IP layer forwarding processing; if the transparent buffer system does not receive the SYN+Acknowledgement (ACK) response for the SYN message And a message, when the transparent cache system receives the data packet of the TCP stream transmitted by using the first TCP connection, performing IP layer forwarding processing on the data packet.

It can be seen that, in the embodiment of the present invention, after receiving the SYN packet for establishing the first TCP connection between the client and the service server, the transparent cache system does not immediately establish a TCP connection with the client. The IP layer forwarding process is performed on the SYN packet, and if the SYN+ACK response packet for the SYN packet is not received, when the data packet of the TCP stream transmitted through the first TCP connection is received, Performing IP layer forwarding processing on the data packet, so that the client can access the service server normally during asymmetric routing.

In a possible design, the method further includes: if the transparent cache system receives the SYN+ACK response message for the SYN message, the transparent cache system is established by using the TCP protocol stack to simulate a second TCP connection of the client, and a third TCP connection between the transparent cache system and the service server by using a TCP protocol stack; and receiving, by the transparent cache system, a TCP flow transmitted through the first TCP connection The data packet is buffered by the second TCP connection and the third TCP connection.

It can be seen that, in the embodiment of the present invention, when the transparent cache system receives the SYN packet sent by the client to the service server, the second TCP connection between the transparent cache system and the client is not established immediately, and the transparent cache system and the service server are established. The third TCP connection, but the IP layer forwarding process is performed on the SYN packet, and when the SYN+ACK response message for the SYN packet sent by the service server to the client is received, the transparent cache system and the client are established. a second TCP connection and a third TCP connection between the transparent cache system and the service server. When the transparent cache system receives the data packet of the TCP stream transmitted through the first TCP connection, the second TCP connection and the third TCP connection pair are used. The data packet is processed by the cache service. In the above manner, on the one hand, it is possible to normally provide a cache acceleration service for a symmetrically routed TCP stream, and on the other hand, it is established immediately when receiving a SYN message sent by the client to the service server according to the commonly used transparent cache system. The embodiment of the present invention can prevent the TCP stream transmitted through the first TCP connection from being asymmetrically routed, causing communication when the second TCP connection between the transparent cache system and the client and the third TCP connection of the transparent cache system and the service server are established. The problem of interruption.

In a possible design, the transparent cache system simulates establishing a second TCP connection between the transparent cache system and the client through a TCP protocol stack, and simulates establishing the transparent cache system by using a TCP protocol stack. The third TCP connection of the service server includes: the transparent cache system simulates a three-way handshake between the transparent cache system and the client in the TCP protocol stack according to the SYN packet and the SYN+ACK response packet Establishing a connection, establishing a second TCP connection between the transparent cache system and the client; and the transparent cache system simulating the TCP protocol stack according to the SYN packet and the SYN+ACK response packet The transparent cache system is connected to the three-way handshake of the service server, and a third TCP connection between the transparent cache system and the service server is established.

It can be seen that, in the embodiment of the present invention, after receiving the SYN+ACK response message sent by the service server to the client, the transparent cache system can be simulated by the TCP protocol stack according to the SYN message and the SYN+ACK response message. The second TCP connection between the transparent cache system and the client, and the third TCP connection between the transparent cache system and the service server is simulated by the TCP protocol stack, without waiting for the ACK message sent by the client to the service server, and then according to The SYN packet, the SYN+ACK response packet, and the ACK packet are simulated by the TCP protocol stack to establish a second TCP connection between the transparent cache system and the client, and the third TCP of the transparent cache system and the service server is simulated by the TCP protocol stack. Connection, flexible processing.

In a possible design, the TCP protocol stack simulates establishing a second TCP connection between the transparent cache system and the client, and simulates establishing the transparent cache system and the service server by using a TCP protocol stack. Before the third TCP connection, the method further includes: the transparent cache system forwarding the SYN+ACK by means of IP layer forwarding The response packet is sent to the client; the transparent cache system receives an ACK message sent by the client to the service server for the SYN+ACK response message; the transparent cache system forwards through the IP layer The method sends the ACK message to the service server.

In a possible design, the transparent cache system simulates establishing a second TCP connection between the transparent cache system and the client through a TCP protocol stack, and simulates establishing the transparent cache system by using a TCP protocol stack. The third TCP connection of the service server includes: the transparent cache system emulating the transparent cache system in the TCP protocol stack according to the SYN message, the SYN+ACK response message, and the ACK message Establishing a third handshake of the client, establishing a second TCP connection between the transparent cache system and the client; and, the transparent cache system, according to the SYN packet, the SYN+ACK response packet, An ACK packet is simulated in the TCP protocol stack to establish a third handshake connection between the transparent cache system and the service server, and a third TCP connection between the transparent cache system and the service server is established.

It can be seen that, in the embodiment of the present invention, the transparent cache system can receive the ACK message sent by the client to the service server, and then pass the TCP protocol stack according to the SYN message, the SYN+ACK response message, and the ACK message. The simulation establishes a second TCP connection between the transparent cache system and the client, and simulates establishing a third TCP connection between the transparent cache system and the service server through the TCP protocol stack, and the processing manner is flexible.

On the other hand, an embodiment of the present invention provides a transparent cache system, which can implement the functions performed by the transparent cache system in the foregoing method example, and the functions can be implemented by hardware or by executing corresponding software through hardware. achieve. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the transparent cache system includes a processor and a transceiver configured to support the transparent cache system to perform the corresponding functions in the above methods. The transceiver is used to support communication between the transparent cache system and other network elements. The transparent cache system can also include a memory for coupling with the processor that holds the program instructions and data necessary for the transparent cache system.

In still another aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions for use in the transparent cache system, including a program designed to perform the above aspects.

Compared with the prior art, in the embodiment of the present invention, it is identified whether each TCP stream is an asymmetric route. If the TCP stream is a symmetric route, the system normally provides the cache acceleration service. If the TCP flow is an asymmetric route, the system performs the bypass, which does not affect the normal access of the client to the service server. This mechanism does not add additional performance overhead based on the normal business process flow.

DRAWINGS

FIG. 1 is a schematic diagram of an application scenario of a traffic processing method for a transparent cache system according to an embodiment of the present disclosure;

2 is a schematic structural diagram of a transparent cache system according to an embodiment of the present invention;

FIG. 3 is a flowchart of a method for processing traffic of a transparent cache system according to an embodiment of the present invention;

FIG. 3 is a flowchart of another method for processing traffic of a transparent cache system according to an embodiment of the present invention;

4 is a signal flow diagram of a traffic processing method for a transparent cache system according to an embodiment of the present invention;

FIG. 5 is a signal flow diagram of another traffic processing method for a transparent cache system according to an embodiment of the present invention;

FIG. 6 is a structural diagram of another transparent cache system according to an embodiment of the present invention;

FIG. 7 is a structural diagram of another transparent cache system according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings in the embodiments of the present invention.

First, the terms involved in the embodiments of the present invention will be briefly described.

TCP, a connection-oriented, reliable, IP-based transport layer protocol in the Open System Interconnection (OSI) reference model, by the Internet Engineering Task Force (IETF) RFC 793 instructions. The protocol number of TCP in IP packets is 6.

HTTP is the most widely used network protocol on the Internet. HTTP provides a way to publish and receive HyperText Markup Language (HTML) pages. RFC 2616 describes HTTP 1.1.

Web Cache is a device deployed between a client and a service server. The service server can also be called a web server. The Web Cache monitors the client's uplink request and saves the response of the service server to the local, including the HTML web page. Images and file downloads, etc. Subsequent to receiving a request to access the same resource, the saved response copy is returned to the client instead of the original web server request.

The transparent cache system is a kind of Web Cache that uses a web server address or a client address to interact with a client or a web server, so that the client and the web server have no perception of the transparent cache system.

Symmetric routing is a routing method in which round-trip packets are transmitted through the same routing path.

Asymmetric routing is a routing method in which round-trip packets are transmitted through different routing paths.

FIG. 1 is a schematic diagram of an application scenario of a method for processing a traffic of a transparent cache system according to an embodiment of the present invention. Referring to FIG. 1 , the scenario mainly involves a client 101, a server 102, and a transparent cache system. Cache) 103, wherein the location of the transparent cache system 103 is between the client 101 and the service server 102, and the transmission path of the TCP stream between the client 101 and the service server 102 may be a symmetric route or an asymmetric route. Only the case of asymmetric routing is shown in 1, and round-trip packets are transmitted through different routing paths. Generally, the transparent cache system is deployed on one of the paths and can only obtain some packets (uplinks or downlinks) of these TCP flows. The service layer cannot be processed normally. For traffic with asymmetric routes, the transparent cache system needs to be able to be identified and released.

The embodiment of the present invention provides a traffic processing method for a transparent cache system. When the transparent cache system 103 receives a SYN packet for establishing a first TCP connection between the client 101 and the service server 102, Establishing a TCP connection between the client 101 and the transparent cache system 103 and a TCP connection between the service server 102 and the transparent cache system 103, but first determining whether the SYN+ACK response message for the SYN message is received according to whether a TCP connection is received between the service server 102 and the transparent cache system 103. Whether the TCP stream belongs to a symmetric route, if it belongs to an asymmetric route, performs IP layer forwarding processing on the data packet, and if it belongs to a symmetric route, establishes a TCP connection between the client 101 and the transparent cache system 103, and the service server 102 and the transparent The TCP connection between the cache systems 103 performs a cache service processing on the data packets, thereby achieving precise control of traffic.

2 is a schematic structural diagram of a transparent cache system according to an embodiment of the present invention. The transparent cache system may be specifically referred to as a Web Cache Server, and the Web Cache Server includes a Linux kernel (Kernel), a socket (Socket) management module, and a service. The processing module, wherein the Linux Kernel includes a TCP protocol stack, an IP protocol stack, and a Web Cache Kernel module, and the Web Cache Kernel module specifically includes a TCP flow table management submodule. When the Web Cache Server receives the SYN packet sent by the client to the Web server, the Web Cache Server does not establish a TCP connection with the client. Instead, it forwards the IP layer through the IP protocol stack. The packets forwarded by the IP layer do not enter the TCP. The protocol stack; when the SYN+ACK response of the web server is received, the Web Cache Server determines that the upstream and downstream packets of the TCP stream pass through the Web Cache Server and belong to the symmetric route, and then the Web Cache Server reuses the saved SYN. The SYN+ACK packet recovers the TCP connection with the client or the web server in the TCP protocol stack, so that the Web Cache Server can communicate with the client or the web server separately. Therefore, for asymmetrically routed TCP flows, the Web Cache Server can be released without affecting client-to-web server access; for symmetrically routed TCP flows, Web Cache can provide cache acceleration services by the service processing module through the TCP protocol stack, for example. , HTTP protocol parsing, target resource unique identifier calculation, resource access heat accumulation, target resource index query, and the like.

FIG. 3 is a flowchart of a method for processing traffic of a transparent cache system according to an embodiment of the present disclosure, where the method includes:

Step 301: Perform an IP layer forwarding process on the SYN packet when the transparent cache system receives the SYN packet from the client for establishing the first TCP connection between the client and the service server.

Step 302: If the transparent cache system does not receive the SYN+ACK response packet for the SYN packet, when the transparent cache system receives the data packet of the TCP stream transmitted through the first TCP connection, the data packet is IP-enabled. Layer forwarding processing.

FIG. 3 is a flowchart of another method for processing a traffic of a transparent cache system according to an embodiment of the present invention. The method includes: in addition to the foregoing

steps

301 and 302, the method includes:

Step 303: If the transparent cache system receives the SYN+ACK response message for the SYN message, the second TCP connection between the transparent cache system and the client is simulated through the TCP protocol stack, and the transparent cache system is established through the TCP protocol stack simulation. A third TCP connection to the business server.

In an example, the transparent cache system may simulate the three-way handshake establishment of the transparent cache system and the client in the TCP protocol stack according to the SYN message and the SYN+ACK response message. The transparent cache system is connected to the second TCP connection of the client; and the transparent cache system simulates the transparent cache system in the TCP protocol stack according to the SYN packet and the SYN+ACK response packet. Establishing a third handshake with the service server to establish a third TCP connection between the transparent cache system and the service server.

In another example, the transparent cache system sends the SYN+ACK response message to the client by means of IP layer forwarding; the transparent cache system receives the client sends the message to the service server. The ACK message is sent to the service server in the manner of the IP layer forwarding manner. The transparent cache system simulates the three-way handshake establishment of the transparent cache system and the client in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet, and establishes The transparent cache system is connected to the second TCP connection of the client; and the transparent cache system simulates in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet. A transparent connection between the transparent cache system and the service server is established, and a third TCP connection between the transparent cache system and the service server is established.

Step 304: When the transparent cache system receives the data packet of the TCP stream transmitted through the first TCP connection, the second TCP connection and the third TCP connection are used to perform the buffer service processing on the data packet.

It can be seen that, in the embodiment of the present invention, when the transparent cache system receives the SYN packet sent by the client to the service server, the second TCP connection between the transparent cache system and the client is not established immediately, and the transparent cache system and the service server are established. The third TCP connection, but the IP layer forwarding process is performed on the SYN packet, and when the SYN+ACK response message for the SYN packet sent by the service server to the client is received, the transparent cache system and the client are established. Two TCP Connecting and establishing a third TCP connection between the transparent cache system and the service server, and subsequently, when the transparent cache system receives the data packet of the TCP stream transmitted through the first TCP connection, using the second TCP connection and the third TCP connection to the datagram The text is cached for business processing. In the above manner, on the one hand, it is possible to normally provide a cache acceleration service for a symmetrically routed TCP stream, and on the other hand, it is established immediately when receiving a SYN message sent by the client to the service server according to the commonly used transparent cache system. The embodiment of the present invention can prevent the TCP stream transmitted through the first TCP connection from being asymmetrically routed, causing communication when the second TCP connection between the transparent cache system and the client and the third TCP connection of the transparent cache system and the service server are established. The problem of interruption.

In the current network traffic, there are symmetrically routed TCP flows and asymmetrically routed TCP flows. The following describes the traffic processing methods used for the transparent cache system for symmetrically routed TCP flows and asymmetric routes. The processing flow of the TCP stream.

4 is a signal flow diagram of a traffic processing method for a transparent cache system according to an embodiment of the present invention. The embodiment is directed to processing a symmetrically routed TCP flow, and the Web Cache is configured to establish a client or web after receiving a response from the web server. The server's TCP connection, the method includes:

In step 401, the client sends a SYN packet to the web server, and the web cache receives the packet.

Step 402: The Web Cache performs IP layer forwarding, and forwards the SYN packet of the client to the web server. The Web Cache generates a corresponding flow table in the TCP flow table management module and saves the SYN packet.

Step 403: The Web Cache receives the SYN+ACK response packet sent by the web server to the client, and determines that the uplink and downlink packets of the TCP stream pass through the Web Cache, and therefore belong to a symmetric route.

Step 404: The Web Cache updates the flow table status in the TCP flow table management module, identifies the current TCP flow as a symmetric route, and saves the SYN+ACK message.

In step 405, the Web Cache sends a SYN+ACK response to the client.

Step 406: The Web Cache receives an ACK message sent by the client to the web server.

Step 407: The Web Cache uses the SYN packet, the SYN+ACK packet, and the ACK packet information (source/destination IP address, port number, and TCP sequence number) in

steps

402, 404, and 406 in the TCP protocol stack. The three-way handshake is simulated and the TCP connection between the Web Cache and the client is restored.

Among them, the above simulation is a relatively normal TCP connection establishment process. Since the TCP connection is actually established between the client and the Web server, the Cache translates into two TCP connections in the local TCP protocol stack based on the information of the TCP connection. Unlike the usual calling system API to create a socket, this technology uses the message information to create a socket structure and directly into the kernel TCP connection table.

Step 408: The Web Cache uses the SYN packet, the SYN+ACK packet, and the ACK packet information (source/destination IP address, port, and TCP sequence number) in

steps

402, 404, and 406 to simulate three times in the TCP protocol stack. The handshake is built and the TCP connection between the Web Cache and the Web server is restored.

Different from the usual calling system API to establish a socket, the technology uses the message information to create a socket structure and directly into the kernel TCP connection table.

In step 409, the Web Cache sends an ACK packet to the web server.

At this point, the Web Cache successfully establishes a TCP connection with the client and the web server, and the subsequent received packets are not forwarded by the IP layer, but are sent to the TCP protocol stack for processing.

In the embodiment of the present invention, step 404 is optional. The alternative is: after the Web Cache receives the SYN+ACK response packet of the web server, the simulated operating system protocol stack restores the TCP connection with the client or the web server. That is, starting from the

above step

403, 407 and 408 in the above steps are sequentially performed, and then 405, 406, and 409 in the above steps are sequentially executed.

Because the serial number between the TCP packets is continuous, the Web Cache can calculate the serial number of the ACK packet according to the SYN+ACK packet after receiving the SYN packet and the SYN+ACK response packet. In addition, the ACK The source/destination IP address and port number carried in the packet are also available in the SYN packet and the SYN+ACK packet. Therefore, the three-way handshake connection can be simulated in the TCP protocol stack when the ACK packet is not obtained. Restore the TCP connection between the Web Cache and the client, and restore the TCP connection between the Web Cache and the Web server.

The execution sequence of the

steps

407 and 408 is not specifically limited. For example, the step 407 may be performed before the step 408 is performed, or the step 408 may be performed first, and then the step 407 and the step 408 may be performed simultaneously.

The following gives an example of the processing flow of a symmetrically routed TCP stream:

Web Cache (IP:20.1.1.2) receives the SYN packet sent by the client (IP: 10.1.1.10) to the web server (IP: 30.1.1.2).

The Web Cache (IP: 20.1.1.2) performs IP layer forwarding and forwards the SYN packet of the client (IP: 10.1.1.10) to the Web server (IP: 30.1.1.2). The Web Cache generates a corresponding flow table in the TCP flow table management module and saves the SYN packet.

The Web Cache (IP: 20.1.1.2) receives the SYN+ACK response packet sent by the Web server (IP: 30.1.1.2) to the client (IP: 10.1.1.10), and determines that both the upstream and downstream packets of the TCP stream are received. After Web Cache, it is a symmetric route.

Web Cache (IP:20.1.1.2) updates the flow table status in the TCP flow table management module, identifies the current TCP flow as a symmetric route, and saves the SYN+ACK message.

Web Cache (IP:20.1.1.2) sends a SYN+ACK response to the client (IP: 10.1.1.10).

Web Cache (IP:20.1.1.2) receives an ACK message from the client (IP: 10.1.1.10) to the web server (IP: 30.1.1.2).

The Web Cache (IP:20.1.1.2) uses the SYN packet, the SYN+ACK packet, and the ACK packet information to simulate the three-way handshake connection and restore the Web Cache (IP:20.1.1.2) and the client in the TCP protocol stack. (IP: 10.1.1.10) TCP connection. Since the Web Cache performs IP address translation, the TCP connection object seen by the client (IP: 10.1.1.10) is the Web server (IP: 30.1.1.2).

Web Cache (IP:20.1.1.2) uses SYN packets, SYN+ACK packets, and ACK packets to simulate three-way handshake establishment and restore Web Cache (IP:20.1.1.2) and Web server in the TCP protocol stack. TCP connection (IP: 30.1.1.2). Since the Web Cache performs IP address translation, the TCP connection object seen by the Web server (IP: 30.1.1.2) is the client (IP: 10.1.1.10).

Web Cache (IP: 20.1.1.2) sends an ACK message to the web server (IP: 30.1.1.2).

FIG. 5 is a signal flow diagram of another traffic processing method for a transparent cache system according to an embodiment of the present invention. The embodiment is directed to processing a TCP flow of an asymmetric route, and the Web Cache does not receive a response from the web server, and the TCP The stream is bypassed, and the method includes:

In step 501, the client sends a SYN packet to the web server, and the web cache receives the packet.

Step 502: The Web Cache performs IP layer forwarding, and forwards the SYN packet of the client to the web server. The Web Cache generates a corresponding flow table in the TCP flow table management module and saves the SYN packet.

In step 503, the SYN+ACK response packet of the web server is returned to the client through other routing paths (without passing through the Web Cache).

Step 504: The client sends an ACK packet to the web server, and the web cache receives the packet.

In the embodiment of the present invention, the default TCP connection belongs to an asymmetric routing state, and the Web Cache receives the report of the TCP connection. The text will be forwarded. Since the Web Cache does not receive the SYN+ACK response packet from the web server, the current TCP stream is still in the IP layer forwarding state on the Web Cache (that is, the Web Cache considers the TCP stream to belong to an asymmetric route), and the Web Cache performs the IP layer. Forward, forward the ACK message of the client to the web server.

During the whole process, the Web Cache forwards the connection between the client and the Web server, that is, the TCP connection handshake packet is forwarded by the IP layer. The Web Cache itself does not establish a TCP connection with the client or the Web server. For the HTTP interaction packets between the client and the web server, the Web Cache forwards the IP layer.

The following gives an example of the processing flow of asymmetrically routed TCP flows:

Web Cache (IP:20.1.1.2) receives the SYN packet sent by the client (IP: 10.1.1.20) to the web server (IP: 30.1.1.2).

The Web Cache (IP: 20.1.1.2) performs IP layer forwarding and forwards the SYN packet of the client (IP: 10.1.1.20) to the Web server (IP: 30.1.1.2).

The SYN+ACK response of the web server (IP: 30.1.1.2) is returned to the client via other routing paths (IP: 10.1.1.20).

Web Cache (IP:20.1.1.2) receives an ACK message from the client (IP: 10.1.1.20) to the web server (IP: 30.1.1.2).

The Web Cache (IP: 20.1.1.2) performs IP layer forwarding and forwards the ACK message of the client (IP: 10.1.1.20) to the Web server (IP: 30.1.1.2).

FIG. 6 is a structural diagram of another transparent cache system according to an embodiment of the present invention. The transparent cache system is configured to execute a traffic processing method for a transparent cache system provided by the foregoing embodiment of the present invention, where the system includes: a receiving unit 601. , processing unit 602 and transmitting unit 603;

The receiving unit 601 is configured to receive a packet from the client or the service server, where the packet is a SYN packet or a data packet.

The processing unit 602 is configured to: when the receiving unit 601 receives a SYN packet for establishing a first transmission control protocol TCP connection between the client and the service server, the sending unit 603 The SYN packet performs an IP layer forwarding process; and, if the receiving unit 601 does not receive the SYN+ACK response message for the SYN packet, when the receiving unit 601 receives the first When the TCP connection transmits the data packet of the TCP stream, the transmitting unit 603 performs IP layer forwarding processing on the data packet.

Optionally, the processing unit 602 is further configured to: if the receiving unit 601 receives the SYN+ACK response packet for the SYN packet, simulate establishing the transparent cache system and the client by using a TCP protocol stack. a second TCP connection, and establishing, by the TCP protocol stack, a third TCP connection between the transparent cache system and the service server; when the receiving unit 601 receives the data of the TCP stream transmitted through the first TCP connection And performing a cache service processing on the data packet by using the second TCP connection and the third TCP connection.

Optionally, the processing unit 602 is specifically configured to simulate the transparent cache system and the TCP protocol stack according to the SYN packet and the SYN+ACK response packet received by the receiving unit 601. The third handshake of the client is established, and the second TCP connection between the transparent cache system and the client is established; and the SYN packet and the SYN+ACK response packet are received according to the receiving unit 601. And simulating a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack, and establishing a third TCP connection between the transparent cache system and the service server.

Optionally, the sending unit 603 is further configured to: at the processing unit 602, simulate, establish, by using a TCP protocol stack, a second TCP connection between the transparent cache system and the client, and simulate establishing the transparent cache by using a TCP protocol stack. Sending the SYN+ACK response packet by means of IP layer forwarding before the third TCP connection between the system and the service server Sent to the client;

The receiving unit 601 is further configured to receive an ACK message sent by the client to the service server for the SYN+ACK response message;

The sending unit 603 is further configured to send, by using an IP layer, the ACK message received by the receiving unit 601 to the service server.

Optionally, the processing unit 602 is configured to simulate, according to the SYN packet, the SYN+ACK response packet, and the ACK packet, the transparent cache system and the Establishing a three-way handshake of the client, establishing a second TCP connection between the transparent cache system and the client; and, in the TCP protocol, according to the SYN packet, the SYN+ACK response packet, and the ACK packet A three-way handshake connection between the transparent cache system and the service server is simulated in the stack, and a third TCP connection between the transparent cache system and the service server is established.

FIG. 7 is a structural diagram of another transparent cache system according to an embodiment of the present invention. The transparent cache system is configured to execute a traffic processing method for a transparent cache system provided by the foregoing embodiment of the present invention, where the system includes:

Memory 701, processor 702 and communication interface 703;

The memory 701 is configured to store program instructions.

The processor 702 is configured to perform the following operations according to the program instructions stored in the memory 701:

When receiving, by the communication interface 703, a SYN packet for establishing a first TCP connection between the client and the service server, performing an IP layer forwarding process on the SYN packet;

If the SYN+ACK response message for the SYN message is not received by the communication interface 703, when the data message of the TCP stream transmitted through the first TCP connection is received through the communication interface 703, And performing IP layer forwarding processing on the data packet.

Optionally, the processor 702 is further configured to perform the following operations according to the program instructions stored in the memory 701:

If the SYN+ACK response message for the SYN message is received through the communication interface 703, the second TCP connection between the transparent cache system and the client is simulated by using the TCP protocol stack, and the TCP protocol is used. The stack simulation establishes a third TCP connection between the transparent cache system and the service server;

When receiving the data packet of the TCP stream transmitted through the first TCP connection through the communication interface 703, performing buffer processing processing on the data packet by using the second TCP connection and the third TCP connection .

Optionally, the processor 702 performs the second TCP connection between the transparent cache system and the client by using a TCP protocol stack, and simulates establishing the transparent cache system and the service by using a TCP protocol stack. The operation of the server's third TCP connection, including:

And simulating a three-way handshake connection between the transparent cache system and the client in the TCP protocol stack according to the SYN packet and the SYN+ACK response packet, and establishing the transparent cache system and the client Two TCP connections; and,

And simulating a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack, and establishing the transparent cache system and the service server according to the SYN packet and the SYN+ACK response packet. The third TCP connection.

Establishing a second TCP connection between the transparent cache system and the client by using the TCP protocol stack, and performing a third TCP connection between the transparent cache system and the service server by using a TCP protocol stack to simulate Sending, by the IP layer, the SYN+ACK response packet to the client through the communication interface 703;

Receiving, by the communication interface 703, the SYN+ACK sent by the client to the service server ACK message of the message;

The ACK message is sent to the service server through the communication interface 703 by means of IP layer forwarding.

And simulating a three-way handshake connection between the transparent cache system and the client in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet, and establishing the transparent cache system. a second TCP connection with the client; and,

And simulating a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet, and establishing the transparent cache A third TCP connection of the system to the service server.

A person skilled in the art should further appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, in order to clearly illustrate hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

It will be understood by those skilled in the art that all or part of the steps of implementing the above embodiments may be performed by a program, and the program may be stored in a computer readable storage medium, which is non-transitory ( Non-transitory medium, such as random access memory, read only memory, flash memory, hard disk, solid state disk, magnetic tape, floppy disk, optical disc, and any combination thereof.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A method for processing a traffic of a transparent cache system, the method comprising:

When the transparent cache system receives a synchronization sequence number SYN packet for establishing a first transmission control protocol TCP connection between the client and the service server, the network protocol IP is performed on the SYN packet. Layer forwarding processing;

If the transparent cache system does not receive the SYN+ acknowledgment ACK response message for the SYN packet, when the transparent cache system receives the data packet of the TCP stream transmitted through the first TCP connection, The data packet is subjected to IP layer forwarding processing.
The method of claim 1 wherein the method further comprises:

If the transparent cache system receives the SYN+ACK response message for the SYN packet, the TCP protocol stack is used to simulate establishing a second TCP connection between the transparent cache system and the client, and the TCP protocol stack is established. Simulating establishing a third TCP connection between the transparent cache system and the service server;

And when the transparent cache system receives the data packet of the TCP stream transmitted by using the first TCP connection, performing the cache service processing on the data packet by using the second TCP connection and the third TCP connection.
The method according to claim 2, wherein the transparent cache system simulates establishing a second TCP connection between the transparent cache system and the client through a TCP protocol stack, and establishing the transparent through a TCP protocol stack simulation. a third TCP connection between the cache system and the service server, including:

The transparent cache system simulates the three-way handshake connection between the transparent cache system and the client in the TCP protocol stack according to the SYN packet and the SYN+ACK response packet, and establishes the transparent cache system and a second TCP connection of the client; and,

The transparent cache system simulates a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack according to the SYN packet and the SYN+ACK response packet, and establishes the transparent cache system. A third TCP connection with the service server.
The method of claim 2, wherein the establishing, by the TCP protocol stack, the second TCP connection between the transparent cache system and the client is established, and the transparent cache system is simulated by using a TCP protocol stack. Before the third TCP connection of the service server, the method further includes:

Sending, by the IP layer, the SYN+ACK response packet to the client by using the IP layer forwarding manner;

The transparent cache system receives an ACK message sent by the client to the service server for the SYN+ACK response message;

The transparent cache system sends the ACK packet to the service server by means of IP layer forwarding.
The method according to claim 4, wherein the transparent cache system simulates establishing a second TCP connection between the transparent cache system and the client through a TCP protocol stack, and establishing the transparent through a TCP protocol stack simulation. a third TCP connection between the cache system and the service server, including:

The transparent cache system simulates the three-way handshake establishment of the transparent cache system and the client in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet, and establishes The transparent cache system is connected to the second TCP of the client; and

The transparent cache system simulates a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet. Establishing a third TCP connection between the transparent cache system and the service server.
A transparent cache system, the system comprising: a receiving unit, a processing unit, and a sending unit;

The receiving unit is configured to receive a message from a client or a service server, where the message is a synchronization sequence number SYN message or a data message;

The processing unit is configured to: when the receiving unit receives, from the client, a SYN packet for establishing a first transmission control protocol TCP connection between the client and the service server, by the sending unit Performing network protocol IP layer forwarding processing on the SYN packet; and, if the receiving unit does not receive the SYN+ acknowledgment ACK response message for the SYN packet, when the receiving unit receives the When a TCP connection transmits a data packet of a TCP stream, the transmitting unit performs an IP layer forwarding process on the data packet.
The system of claim 6 wherein:

The processing unit is further configured to: if the receiving unit receives the SYN+ACK response message for the SYN message, simulate establishing a second TCP connection between the transparent cache system and the client by using a TCP protocol stack. And establishing, by the TCP protocol stack, a third TCP connection between the transparent cache system and the service server; and when the receiving unit receives the data packet of the TCP stream transmitted by using the first TCP connection, using The second TCP connection and the third TCP connection perform a cache service processing on the data packet.
The system according to claim 7, wherein the processing unit is configured to simulate in the TCP protocol stack according to the SYN message and the SYN+ACK response message received by the receiving unit. The transparent cache system is connected to the three-way handshake of the client to establish a second TCP connection between the transparent cache system and the client; and, according to the SYN packet received by the receiving unit, The SYN+ACK response message simulates a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack, and establishes a third TCP connection between the transparent cache system and the service server.
The system of claim 7 wherein:

The sending unit is further configured to: at the processing unit, simulate, establish, by using a TCP protocol stack, a second TCP connection between the transparent cache system and the client, and simulate establishing the transparent cache system by using a TCP protocol stack. Sending the SYN+ACK response packet to the client by means of IP layer forwarding before the third TCP connection of the service server;

The receiving unit is further configured to receive an ACK message sent by the client to the service server for the SYN+ACK response message;

The sending unit is further configured to send, by using an IP layer, the ACK message received by the receiving unit to the service server.
The system according to claim 9, wherein the processing unit is configured to simulate in the TCP protocol stack according to the SYN packet, the SYN+ACK response packet, and the ACK packet. The transparent cache system is connected to the three-way handshake of the client, and establishes a second TCP connection between the transparent cache system and the client; and, according to the SYN packet, the SYN+ACK response packet, and the The ACK message is configured to simulate a three-way handshake connection between the transparent cache system and the service server in the TCP protocol stack, and establish a third TCP connection between the transparent cache system and the service server.