WO2012072045A1 - Method, network node and system for data transmission in cdn network - Google Patents

Abstract

The embodiments of the present invention relate to a method, a network node and a system for data transmission in a CDN network. The method for data transmission in the CDN network includes: receiving a plurality of Hyper Text Transfer Protocol (HTTP) request messages; acquiring data requested by the plurality of HTTP request messages; sending the data requested by the plurality of HTTP request messages via a response message, wherein the order in which the data requested by the plurality of HTTP request messages is sent corresponds to the order in which the data requested by the plurality of HTTP request messages is acquired. The order in which the data requested by the plurality of HTTP request messages is sent corresponds to the order in which the data requested by the plurality of HTTP request messages is acquired, with the result that the data requested by the HTTP request that are acquired first are transmitted with priority and this improves the data transmission efficiency.

Description

 Data transmission method, network node and system in CDN network, the application claims the data transmission method, network node and system in the CDN network, which is filed on December 3, 2010, with the application number of 201010579563. The priority of the Chinese application, the entire contents of which is incorporated herein by reference.

Technical field

 The present invention relates to the field of communication technologies, and in particular, to a CDN (Content Delivery

Data transmission method, network node and system in Network, content distribution network). Background technique

 CDN is to add the new network architecture to the existing IP transmission network to publish the content of the website to the "edge" of the network closest to the user, so that users can obtain the required content and solve the network congestion. Improve the responsiveness of users to the network.

 In the CDN, when the user clicks on the connection of a certain content on the website, the corresponding HTTP (Hyper Text Transfer Protocol) request is routed to the edge server; when the edge server checks that it does not cache the content requested by the terminal, Querying, to the CDN routing device, the address information of the regional node or the central node that saves the requested content; the CDN routing device returns the address information of the regional node or the central node that holds the requested content; the edge server saves the content through the HTTP protocol The regional node or central node of the requested content requests content; the regional node or central node returns the requested content to the edge server.

In the prior art, when multiple HTTP requests are initiated, the sending request and the receiving response need to be performed in strict order. If the data of the previous HTTP request is not responded, the subsequent HTTP request will not receive the response, so it is not conducive to Full use of data transmission and bandwidth. Summary of the invention Embodiments of the present invention provide a data transmission method, a network node, and a system in a CDN network, which improve data transmission efficiency.

 In one aspect, an embodiment of the present invention provides a data transmission method in a CDN network, including:

 Receiving multiple HTTP hypertext transfer protocol request messages;

 Obtaining data requested by a plurality of the HTTP request messages;

 Transmitting, by the response message, the data requested by the plurality of the HTTP request messages, wherein a sequence of data requested by the plurality of the HTTP request messages is sent to a sequence of data acquired by the plurality of the HTTP request messages In order, the plurality is at least two.

 Correspondingly, an embodiment of the present invention provides a network node, including:

 a request receiving unit, configured to receive multiple HTTP hypertext transfer protocol request messages;

 An obtaining unit, configured to acquire data requested by multiple of the HTTP request messages;

 The transmitting unit sends the data requested by the HTTP request message by using a response message, where a sequence of data requested by the plurality of the HTTP request messages is sent to obtain data requested by the plurality of HTTP request messages. In the order, the plurality is at least two.

 In another aspect, an embodiment of the present invention provides a data transmission system including a first network node and a second network node:

 The first network node is configured to receive multiple HTTP request messages, obtain data requested by the HTTP request message, and send data requested by the HTTP request message by using a response message, where multiple HTTP requests are sent. The order of the data requested by the message corresponds to the sequence of obtaining the data requested by the plurality of the HTTP request messages;

 The second network node is configured to send the multiple HTTP request messages to the first network node, and receive data requested by the HTTP request message sent by the first network node, where the multiple At least two.

As can be seen from the technical solution provided by the above embodiments of the present invention, by sending multiple HTTPs The order of the data requested by the request message corresponds to the sequence of obtaining the data requested by the multiple HTTP request messages, and the data of the HTTP request obtained first is preferentially transmitted, which can improve the data transmission efficiency. DRAWINGS

 In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be described in detail below. It is obvious that the drawings in the following description are only some embodiments of the present invention. It will be apparent to those skilled in the art that other drawings may be obtained from these drawings without the inventive labor.

 1 is a schematic flowchart of a data transmission method in a CDN network according to an embodiment of the present invention; FIG. 2 is a schematic structural diagram 1 of a network node according to an embodiment of the present invention;

 3 is a schematic diagram 2 of a network node according to an embodiment of the present invention;

 4 is a schematic flowchart of a data transmission method in a CDN network according to another embodiment of the present invention; FIG. 5 is a schematic structural diagram 1 of an edge node according to an embodiment of the present invention;

 6 is a schematic structural diagram 2 of an edge node according to an embodiment of the present invention;

 7 is a schematic structural diagram of a data transmission system according to an embodiment of the present invention;

 FIG. 8 is a schematic diagram of an application scenario of a data transmission method in a C D N network according to another embodiment of the present invention; FIG. 9 is a schematic diagram of an application scenario of a data transmission method in a C D N network according to another embodiment of the present invention;

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, those of ordinary skill in the art are not doing All other embodiments obtained under the premise of creative labor are within the scope of the invention. As shown in FIG. 1, an embodiment of the present invention provides a data transmission method in a CDN network, including:

 Step 1 1. Receive multiple HTTP request messages.

 Step 12: Acquire data requested by multiple HTTP request messages.

 Step 13: Send the data requested by the multiple HTTP request messages by using the response message, where the sequence of data requested by sending the multiple HTTP request messages corresponds to the sequence of obtaining the data requested by the multiple HTTP request messages.

 The executor of the data transmission method in the CDN network may be a network node in the CDN network, and the network node may include: a regional node or a central node. The regional node and the central node are used to store network data. The central node acts as the upper node of the regional node, and one central node can connect multiple regional nodes. Optionally, there may be multiple levels of regional nodes between the edge node (which may be an edge server) and the central node to meet the business needs.

 In the embodiment of the present invention, if multiple HTTP request messages are received, when the data requested by the multiple HTTP request messages is sent in step 13, the data of multiple HTTP request messages may be obtained, or Get some of the data (here can be one, or several of them) that are requested by the HTTP request message. Then, when the acquired data is sent, the data requested by the other HTTP request message is acquired at the same time. For example: After receiving 5 HTTP request messages, you can send data after obtaining the data requested by 5 HTTP request messages, or you can get 1 in it (this can also be 2, 3 or 4) The data is sent after the HTTP request message is requested.

 The following describes the data transmission method in the CDN network according to the embodiment of the present invention:

When the end user clicks on the connection of a certain content on the website, the corresponding HTTP request is routed to the edge server, and the edge server checks the content requested by the edge server to save the requested data to the CDN routing device. Address information of a node or a central node, The CDN routing device returns the address information of the regional node or the central node that holds the requested data, such as an IP address or a domain name. The address information of the regional node or the central node includes a domain name or an IP address. When the address information is a domain name, the edge server obtains the corresponding IP address through the DNS (Domain Name System) resolution, and details are not described herein.

 After that, the edge server requests data from the area node or the central node that saves the requested content through the HTTP request, so as to enter the step 1 1 the regional node or the central node receives the multiple HTTP request messages sent by the edge server, and then proceeds to the step 12 area. The node or the central node acquires the data requested by the plurality of HTTP request messages, and then proceeds to step 13 where the regional node or the central node sends the data requested by the HTTP request message through the response message.

 According to the technical solution provided by the foregoing embodiment of the present invention, the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, and the first step is obtained. The data of the HTTP request is preferentially transmitted, which can improve the data transmission efficiency.

 Embodiments of the Invention The data transmission method in a CDN network is also applicable to data transmission between an area node and a central node, data transmission between an edge server and other edge servers, and data transmission between a regional node and other regional nodes.

 The data transmission method in the CDN network of the embodiment of the present invention will be described below by taking only the edge server and the network node as an example.

 In the data transmission method in the CDN network of the embodiment of the present invention, in step 1 1 and step 13, the network node may receive an HTTP request message sent by the edge server through a TCP (Transmission Control Protocol) connection, and send a response message to Edge server.

 Specifically, the network node may respond to one or more TCP connection requests of the edge server, and establish one or more TCP connections with the edge server. Among them, multiple TCP connections can be understood as at least two TCP connections, and multiple HTTP request messages can be understood as at least two HTTP request messages.

Exemplarily, the CDN routing device returns a network that saves the requested data to the edge server. After the address information of the network node, the edge server checks whether there is already a TCP connection to the address information of the corresponding network node. If not, the edge server can request to establish multiple TCP connections with the network node. In this way, the network node responds to multiple TCP connection requests of the edge server, and establishes multiple TCP connections with the edge server.

 The number of TCP connections between the network node and the edge server can be determined as needed.

 When the TCP connection between the edge server and the network node is one, the HTTP request message carries the flow index indicating X-Flow-lndex, and the response message corresponding to the HTTP request message carries the flow index indication X-Flow-lndex, where, the flow The index indicates that X-Flow-lndex is used to identify the requested content of the HTTP request message.

 It can be seen that the flow index in the response message of the network node indicates the value of the X-Flow-lndex, and the corresponding stream index in the HTTP request message of the edge server indicates that the value of the X-Flow-lndex is consistent, and the HTTP request message and the response message are not Need to be strictly ordered. Moreover, after receiving the response message of the network node, the edge server indicates that the X-Flow-lndex can be associated with the HTTP request message according to the flow index, thereby being associated with the end user, and finally the edge server delivers the data returned from the network node to the terminal user. .

 When there are multiple TCP connections between the edge server and the network node, the HTTP request message carries the flow index indicating that X-Flow-lndex and the connection index indicate X-Connection-lndex, and the response message corresponding to the HTTP request message carries the flow index. Instructing X-Flow-lndex and the connection index to indicate X-Connection-lndex, wherein the flow index indicates that X-Flow-lndex is used to identify the request content of the HTTP request message, and the connection index indicates that X-Connection-lndex is used to identify the HTTP request message. The TCP connection used.

It can be seen that each HTTP request initiated on the same TCP connection is consistent in the value of the connection index indicating X-Connection-lndex. Therefore, the HTTP request message and the response message do not need strict order preservation, and the HTTP request message and the response message may not be on the same TCP connection. Parallel data transmission, making full use of TCP bandwidth.

 It should be noted that, in step 12, the time delay for the network node to obtain data corresponding to each HTTP request is different. For example, the HTTP request received by the network node may be acquired later than the HTTP request received later. .

 Therefore, when the number of TCP connections between the edge server and the network node is multiple, the data transmission method in the CDN network may further include:

 The network node selects the data requested by the HTTP request message by selecting the TCP connection with the smallest transmission delay according to the current transmission delay of the plurality of TCP connections.

 The manner in which the network node determines the transmission delay of the TCP connection may include:

 The transmission delay refers to the waiting delay of waiting for the TCP connection to idle to send data. The network node can determine the transmission delay of the TCP connection according to the amount of data to be transmitted and the TCP connection bandwidth of the TCP connection. Specifically, the specific manner of determining the transmission delay of the TCP connection can be understood by referring to the existing common technologies, and details are not described herein.

 It can be seen that, based on the existence of multiple TCP connections between the edge server and the network node, the network node responds to the HTTP request according to the order of obtaining the data corresponding to each HTTP request, and selects the TCP connection with the smallest transmission delay to transmit the HTTP request message. The requested data, and the HTTP request message and the response message both extend the stream index indication X-Flow-lndex and the connection index indicates X-Connection-Index, the HTTP request message and the response message do not need strict order, HTTP request message and The response message may not be on the same TCP connection. For example, if two end users request content from the same edge server at the same time, the edge server can follow the Pipeline mode without waiting for the response data of the network node, and the edge server continuously initiates the request directly on multiple TCP connections, and then Asynchronous receiving response data on multiple TCPs can realize parallel data transmission and make full use of TCP bandwidth.

 The data transmission method in the CDN network may further include:

When there are multiple TCP connections, if there is a minimum transmission delay in the current transmission delay of multiple TCP connections If the delay is greater than the establishment of a new TCP connection, the network node establishes a new TCP connection;

 Or, when the TCP connection is one, if the current transmission delay of the TCP connection is greater than the delay of establishing a new TCP connection, the network node establishes a new TCP connection.

 Specifically, the network node can detect the bandwidth of each TCP connection in real time. If the data corresponding to an HTTP request has been obtained, but the network node needs to wait for the previously established TCP connection to idle to send data, the network node according to the current transmission bandwidth. And transmitting data to predict the transmission delay of each TCP, determining the TCP connection with the minimum transmission delay, and predicting the delay of newly establishing the TCP connection according to the RTT (Round-Trip Time) to the edge server:

 If the minimum transmission delay is less than the delay of the newly established TCP connection, the number of current TCP connections is maintained stable, and the TCP connection established before is still used to transmit data.

 If the minimum transmission delay is greater than the delay of the newly established TCP connection, the network node actively establishes a TCP connection to the edge server.

 Therefore, the network node can actively establish a TCP connection to the edge server, which improves the response speed of the CDN to the end user request, and improves the QoE (Quality of Experience).

 The network node can actively establish a TCP connection to the edge server by responding to the HTTP request response message, or actively establish a TCP connection to the edge server through HTTP POST. Moreover, the POST message carries the X-Flow-Index and X-Connection-Index header fields for association with the previous HTTP request message.

 Among them, you can set the maximum number of TCP connections that the network node can dynamically establish to each edge server, thus limiting the number of TCP connections that each network node and edge server needs to maintain.

 The data transmission method in the CDN network may further include:

 When the current transmission delays of the multiple TCP connections are the same, according to the sequence of the TCP connection establishment, the data requested by the HTTP connection message is sent by the first established TCP connection.

Therefore, the network node preferentially selects the data of the first established TCP connection transmission request, and then newly creates The TCP connection can be gradually reclaimed, which reduces the number of TCP connections that need to be maintained, and reduces the overhead of the edge server and network nodes needing to maintain a large number of TCP connections at the same time.

 The data transmission method in the CDN network may further include:

 The number of response messages sent by multiple TCP connections is monitored. When the number of sent response messages is less than a predetermined threshold or no response message is sent, the corresponding TC P connection is deleted.

 It can be seen that the network node can monitor the number of response messages on each TCP connection according to the actual use of the TCP connection. If the number of response messages on a TCP connection is less than the specified threshold, or the number of response messages on a TCP connection is smaller than the specified threshold on other TCP connections, the TCP connection passes. The network path is not in good condition. The network node can dynamically delete the TCP connection and re-establish a new TCP connection.

 In addition, the edge server may no longer have traffic between a certain zone node that has previously established a connection, so the network node can monitor the traffic on each TCP connection that has been established. If there is no traffic on each TCP connection to an IP address for a specified period of time, the edge server deletes all connections to the IP address, reducing the number of TCP connections that need to be maintained.

 It should be noted that, in the data transmission method in the CDN network of the embodiment of the present invention, for the network node, if the content to be requested has been stored in a storage medium such as a memory or a hard disk, the network node can directly obtain the local network, otherwise The network node can obtain the requested content from the upper-layer network node in a similar manner to the content obtained by the edge server, and details are not described herein. As shown in FIG. 2, corresponding to the data transmission method in the CDN network of the foregoing embodiment, the embodiment of the present invention provides a network node, including:

 The request receiving unit 21 is configured to receive a plurality of HTTP hypertext transfer protocol request messages.

 The obtaining unit 22 is configured to acquire data requested by multiple HTTP request messages.

The transmitting unit 23 is configured to: obtain the data requested by the HTTP request message, and send the data requested by the HTTP request message by using the response message, where the sending of the multiple HTTP request message is requested The order of the data corresponds to the order in which the data requested by the plurality of HTTP request messages is obtained.

 Among them, multiple TCP connections can be understood as at least two TCP connections, and multiple HTTP request messages can be understood as at least two HTTP request messages.

 The above network node may include: a regional node or a central node. The regional node and the central node are used to store network data. Optionally, there may be multiple levels of regional nodes between the edge server and the central node to meet the business needs.

 According to the technical solution provided by the foregoing embodiment of the present invention, the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, and the first step is obtained. The data of the HTTP request is preferentially transmitted, which can improve the data transmission efficiency.

 As shown in FIG. 3, the network node in this embodiment of the present invention may further include:

 The identifier unit 31 is configured to: when the TCP connection is sent by the TCP transmission control protocol connection, when the TCP connection is one, the HTTP request message carries the flow index indication X-Flow-lndex, and the response message corresponding to the HTTP request message The carrying flow index indicates an X-Flow-Index, where the flow index indicates that the X-Flow-lndex is used to identify the request valley of the HTTP request message.

 When the TCP connection is multiple, the HTTP request message carries the flow index indicating that the X-Flow-lndex and the connection index indicate the X-Connection-Index, and the response message corresponding to the HTTP request message carries the flow index indicating the X-Flow-lndex and the connection. The index indicates X-Connection-lndex, where the stream index indicates that X-Flow-lndex is used to identify the request content of the HTTP request message, and the connection index indicates that the X-Connection-lndex is used to identify the TCP connection used by the HTTP request message.

Therefore, each HTTP request initiated on the same TCP connection is consistent in the value of the connection index indicating X-Connection-lndex. After receiving the response message from the network node, the edge server indicates that the X-Flow-lndex and the connection index indicate the X-Connection-Index according to the flow index. Associated with the HTTP request message to associate with the end user, the final edge server will deliver the data returned from the network node to the end user.

 The network node of the embodiment of the present invention may further include:

 The first selecting unit 32 is configured to: when the TCP connection is multiple, select, according to the current transmission delay of the multiple TCP connections, the TCP connection with the smallest transmission delay to send the data requested by the HTTP request message.

 In summary, since both the HTTP request message and the response message extend the stream index indication X-Flow-lndex and the connection index indication X-Connection-Index, the HTTP request message and the response message do not need to be strictly preserved. For example, if two end users request content from the same edge server at the same time, the edge server can wait for the response data of the network node according to the Pipeline mode without waiting for the response data of the network node, and the edge server continuously initiates on multiple TCP connections. Requests, and then asynchronously receive response data from multiple TCPs, can achieve parallel data transmission, making full use of TCP bandwidth.

 The network node of the embodiment of the present invention may further include:

 The first establishing unit 33 is configured to establish a new TCP connection when the TCP connection is multiple, the minimum transmission delay in the current transmission delay of the multiple TCP connections is greater than the delay of establishing a new TCP connection; or, when TCP When the connection is one, the current transmission delay of the TCP connection is greater than the delay of establishing a new TCP connection, and a new TCP connection is established.

 Therefore, the network node can actively establish a TCP connection to the edge server to improve the data transmission speed. The network node can actively establish a TCP connection to the edge server by responding to the HTTP request response message, or actively establish a TCP connection to the edge server through HTTP POST. Moreover, the POST message carries the X-Flow-Index and X-Connection-Index header fields for association with the previous HTTP request message.

Moreover, you can set the maximum number of TCP connections that a network node can dynamically establish to each edge server, thereby limiting the number of TCP connections that each network node and edge server needs to maintain. The network node of the embodiment of the present invention may further include:

 The second selecting unit 34 is configured to: when the current transmission delays of the multiple TCP connections are the same, select the data requested by the first established TCP connection to send the HTTP request message according to the sequence of establishing the TCP connection.

 Therefore, if the network node preferentially selects the data of the first established TCP connection transmission request, the TCP connection of the first establishing unit can be gradually recovered, thereby reducing the number of TCP connections that need to be maintained.

 The network node of the embodiment of the present invention may further include:

 The monitoring unit 35 is configured to monitor the number of sending response messages of multiple TCP connections. When the number of sent response messages is less than a predetermined threshold or no response message is sent, the corresponding TCP connection is deleted.

 It can be seen that there is no more traffic between the edge server and a certain regional node that has already established a connection. Therefore, the network node can monitor the traffic on each TCP connection that has been established. If there is no traffic on each TCP connection to an IP address for a specified period of time, the edge server deletes all connections to the IP address, reducing the number of TCP connections that need to be maintained.

 It can be seen from the technical solution provided by the foregoing embodiment of the present invention that a plurality of TCP connections are maintained between the edge server and the network node, and the network node obtains an HTTP request after receiving multiple HTTP request messages sent by the edge server. The data is first transmitted on the TCP connection with the least delay, the data of the HTTP request is transmitted, the parallel data is transmitted, and the TCP bandwidth is fully utilized. As shown in FIG. 4, an embodiment of the present invention provides a data transmission method in a CDN network, including:

 Step 41: Determine whether a TCP connection is established with the network node.

 Step 42: Determine that a TCP connection is not established with the network node, establish multiple TCP connections with the network node, and send multiple HTTP request messages through multiple TCP connections.

Step 43: Receive a response message sent by the network node by using multiple TCP connections, and obtain response data of the HTTP request message. The execution body of the data transmission method in the CDN network of the embodiment of the present invention may be an edge node, and the edge node may be an edge server, and multiple TCP connections may be understood as at least two TCP connections, and multiple HTTP request messages may be understood as at least Two HTTP request messages.

 The above network node may include: a regional node or a central node. The regional node and the central node are used to store network data. Optionally, there may be multiple levels of regional nodes between the edge node and the central node to meet the business needs.

 It can be seen that the foregoing technical solution provided by the embodiment of the present invention maintains multiple TCP connections between the edge node and the network node, and the network node implements parallel data transmission after receiving multiple HTTP request messages sent by the edge node. Make full use of TCP bandwidth.

 Specifically, the data transmission method in the CDN network in the embodiment of the present invention:

 After the CDN routing device returns the address information of the regional node or the central node storing the requested data to the edge node (the address information may include the domain name or the IP address), the process proceeds to step 41.

 Specifically, step 41 may include:

 The edge node checks if a TCP connection to the corresponding IP address already exists.

 If there is already a TCP connection with the corresponding IP address, the edge node directly sends an HTTP request message through the TCP connection.

 If there is no TCP connection with the corresponding IP address, go to step 42.

 Specifically, step 42 may include:

 If there is no TCP connection between the edge node and the corresponding IP address, the edge node establishes the corresponding number of TCP connections according to the configuration requirements. For example, if the default configuration needs to establish two TCP connections, the edge node actively establishes two TC P connections to the corresponding IP address.

The edge node may poll a TCP connection on which to submit an HTTP request message to the regional node layer or the central node. At the same time, the HTTP request message carries a stream index indicating X-Flow-lndex and a connection index indicating X-Connection-lndex. The stream index indicates X-Flow-lndex, The request content used to identify the HTTP request message, and the connection index indicates X-Connection-lndex, which is used to identify the TCP connection used by the HTTP request message.

 Thus, the network node can select to transmit the data requested by the HTTP request message through multiple TCPs. Proceeding to step 43, the edge node receives the response message sent by the network node through multiple TCP connections, and obtains response data of the HTTP request message. At the same time, the response message carries the stream index indication X-Flow-lndex and the connection index indication X-Connection-lndex.

 If the network node selects the TCP connection with the smallest transmission delay to transmit the data requested by the HTTP request message, in step 43, the edge node receives the response message sent by the network node through the TCP connection with the smallest transmission delay among the multiple TCP connections, and obtains The response data of the HTTP request message.

 Finally, the edge node receives the response message sent by the network node, and indicates that the X-Flow-lndex and the connection index indicate that the X-Connection-lndex can be associated with the HTTP request message according to the flow index of the response message, thereby finally associating to the end user, and The data returned by the network node is delivered to the end user.

 Since both the HTTP request message and the response message extend the stream index indication X-Flow-lndex and the connection index indication X-Connection-Index, the HTTP request message and the response message do not need to be strictly protected. For example, if two terminal users request content from the same regional node at the same time, the edge node can wait for the response data of the regional node according to the Pipeline mode without waiting for the response data of the network node, and the edge node continuously initiates directly on multiple TCP connections. Requests, and then asynchronously receive response data from multiple TCPs, can achieve parallel data transmission, making full use of TCP bandwidth.

 Optionally, the edge node may further determine, according to the heat replacement algorithm, whether to cache the data delivered to the end user locally, so that the edge node serves the same service request of other subsequent end users. Heat replacement algorithms, such as LRU (Least Recently Used) algorithms, and so on.

 The data transmission method in the CDN network of the embodiment of the present invention may further include:

Monitor the number of response messages received by multiple TCP connections, when the TCP connection responds to the message When the number of times is less than the predetermined threshold, the corresponding TC P connection is deleted.

 Or, monitor multiple TCP connections. When there is no traffic on the TCP connection, delete the corresponding TCP connection.

 Specifically, the edge node monitors the number of response messages received from the various TCP connections based on the actual use of the TCP connection. If the number of response messages received on a TCP connection is less than the specified threshold, or the number of response messages received on a TCP connection is less than the specified threshold, the number of response messages received on other TCP connections is less than the specified threshold. The network path through which the TCP connection passes is not well transmitted. The edge node can dynamically delete the TCP connection and re-establish a new TCP connection.

 Moreover, after the routing policy is adjusted by the CDN routing server, there is no more traffic between the edge node and a certain regional node that has already established a connection. Therefore, the edge node needs to monitor the traffic on each TCP connection that has been established. If there is no traffic on each TCP connection to an IP address for a specified period of time, the edge node deletes all connections to the IP address, reducing the number of TCP connections that need to be maintained. As shown in FIG. 5, in accordance with the data transmission method in the CDN network of the foregoing embodiment, an embodiment of the present invention provides an edge node, including:

 The determining unit 51 is configured to determine whether a TCP connection is established with the network node.

 a second establishing unit 52, configured to determine that a TCP connection is not established with the network node, establish multiple TCP connections with the network node, and send multiple HTTP request cancellation response receiving units 53 through multiple TCP connections, Receiving a response message sent by the network node through multiple TCP connections, and obtaining response data of the HTTP request message.

 In the embodiment of the present invention, the edge node may be an edge server, and multiple TCP connections may be understood as at least two TCP connections, and multiple HTTP request messages may be understood as at least two HTTP request messages.

The above network node may include: a regional node or a central node. Regional node, central node Used to store network data. Optionally, there may be multiple levels of regional nodes between the edge node and the central node to meet the business needs.

 It can be seen from the technical solution provided by the foregoing embodiments of the present invention that multiple TCP connections are maintained between the edge node and the network node, parallel data transmission is realized, and TCP bandwidth is fully utilized.

 Specifically, the response receiving unit 53 is further configured to receive, by using a TCP connection with a minimum transmission delay among the plurality of TCP connections, a response message sent by the network node, to obtain response data of the HTTP request message.

 The HTTP request message sent by the second establishing unit 52 carries the stream index indication X-Flow-lndex and the connection index indication X-Connection-lndex.

 The response message received by the response receiving unit 53 carries the stream index indication X-Flow-lndex and the connection index indication X-Connection-lndex.

 The flow index indicates an X-Flow-lndex, which is used to identify a request content of an HTTP request message, and the connection index indicates an X-Connection-lndex, which is used to identify a TCP connection used by the HTTP request message.

 Since both the HTTP request message and the response message extend the stream index indication X-Flow-lndex and the connection index indication X-Connection-Index, the HTTP request message and the response message do not need to be strictly protected. For example, if two terminal users request content from the same regional node at the same time, the edge node can wait for the response data of the regional node according to the Pipeline mode without waiting for the response data of the network node, and the edge node continuously initiates directly on multiple TCP connections. Requests, and then asynchronously receive response data from multiple TCPs, can achieve parallel data transmission, making full use of TCP bandwidth.

 As shown in FIG. 6, the edge node of the embodiment of the present invention may further include:

 The first monitoring unit 61 is configured to monitor the number of response messages received by the multiple TCP connections. When the number of response messages of the TCP connection is less than a predetermined threshold, the corresponding TCP connection is deleted.

It can be seen that the network path through which the TCP connection passes is not well transmitted, and the edge node can dynamically delete the TCP connection and re-establish a new TCP connection. Alternatively, the edge node of the embodiment of the present invention may further include:

 The second monitoring unit 62 is configured to monitor multiple TCP connections. When there is no traffic on the TCP connection, the corresponding TCP connection is deleted.

 It can be seen that the edge node deletes all connections to the IP address, reducing the number of TCP connections that need to be maintained. As shown in FIG. 7, an embodiment of the present invention provides a data transmission system including a first network node 71 and a second network node 72:

 The first network node 71 is configured to receive multiple HTTP request messages, obtain data requested by the HTTP request message, and send data requested by the HTTP request message by using a response message, where the data requested by the multiple HTTP request messages is sent. The order corresponds to the order in which the data requested by the plurality of HTTP request messages is obtained;

 The second network node 72 is configured to send a plurality of HTTP request messages to the first network node 71, and receive data requested by the HTTP request message sent by the first network node 71.

 Embodiments of the Invention In the CDN system, the first network node 71 can be understood by referring to the network node of the above embodiment. The second network node 72, such as an edge server, can be understood with reference to the edge server of the above embodiment. Multiple TCP connections can be understood as at least two TCP connections, and multiple HTTP request messages can be understood as at least two HTTP request messages.

According to the technical solution provided by the foregoing embodiment of the present invention, the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, and the first step is obtained. The data of the HTTP request is preferentially transmitted, which can improve the data transmission efficiency. As shown in FIG. 8, the edge server 81 serves as a media delivery node, and is responsible for media delivery tasks of the plurality of terminals 82. The edge server 81 and the area node 83 maintain a plurality of TCP connections. And in the district There may also be multi-level regional nodes in addition to the domain node 83 to meet the business needs.

 As shown in Figure 9, the edge server and the area node are taken as an example to describe the data transmission method in the CDN network, including:

 91. When the end user clicks on the connection of a certain content on the website, the corresponding HTTP request is routed to the edge server.

 92. The edge server according to the URI requested by the end user (Uniform Resource

The Identifier, the universal resource identifier, confirms that the requested content is not cached locally, and the edge server queries the CDN routing device for the address information of the regional node or the central node that holds the requested content.

 93. The CDN routing server returns to the edge server location information of the area node that holds the requested content, including the domain name or the IP address. If the domain name is returned, the edge server can also obtain the corresponding IP address through DNS resolution.

 94. The edge server checks whether there is a TCP connection to the corresponding IP address. If it does not exist, the corresponding multiple TCP connections are established according to the configuration requirements. If the configuration requires a TCP connection with the corresponding IP address. The number does not require a new TCP connection to be established.

 95. The edge server selects a TCP connection, submits an HTTP request to the regional node on the TCP connection, the HTTP request message indicates the URI information of the content to be requested, and expands an X-Flow-I ndex header in the HTTP request message header. The fields are as follows:

 X-Flow-lndex = "X-Flow-lndex" ":" "DIGIT

 The X-Connection-Index header field is also extended in the HTTP request header as follows:

 X-Connection-lndex = "X-Connection-lndex" ":" 1 *DIGIT

 Exemplarily, the HTTP request message between the edge server and the zone node is as follows:

 GET / HTTP/1 .1

 Accept: */*

Accept-Language: zh-cn Accept-Encoding: gzip, deflate

 User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) Host: www.ABC.com

 X-Flow-lndex = 1234

 X-Connection-lndex = 1

 96. After receiving the HTTP request message of the edge server, the area node locates the content to be requested according to the URI in the HTTP request message. After the zone node obtains the content required by the edge server HTTP request, it selects the TCP connection that needs to be used to send the response data to the edge server.

 The area node checks the transmission bandwidth of each TCP connection to the edge server and the amount of data that needs to be transmitted on each TCP connection. The transmission delay of the TCP connection can be calculated according to the amount of data to be transmitted and the transmission bandwidth. Waiting for the TCP connection to be idle to send data, the regional node selects the TCP connection with the smallest transmission delay to transmit the response data.

 The area node first transmits the corresponding data according to which HTTP request data is first acquired, and which transmission delay on the TCP connection is small, and then transmits on the TCP connection, thereby realizing flexible and efficient transmission of data, reflecting data priority and delay. priority.

 The area i or the node also carries the X-Flow-Index and X-Connection-Index header fields in the response message. The values of the two header fields are the same as those in the HTTP request message.

 Exemplarily, the response message is as follows:

 HTTP/1 .1 200 OK

 Date: Mon, 19 Jul 2010 07:10:06 GMT

 Expires: -1

 Cache-Control: private, max-age=0

 Content-Type: text/html; charset=UTF-8

 Content-Encoding: gzip

 Server: gws

 X-Flow-lndex = 1234

X-Connection-lndex = 1 Content-Length: 4125

Message Body

 In addition, if the content to be requested has been previously stored in the storage medium such as the area node memory or the hard disk, the area node can be directly obtained from the local, otherwise the area node can acquire the upper area node in a manner similar to the content acquired by the edge server. The requested content.

 97. After receiving the response message of the regional node, the edge server may associate the HTTP request message according to the X-Flow-lndex and X-Connection-Index header fields, and finally associate with the terminal user request. The final edge server delivers the content returned from the zone node to the end user.

 Optionally, in the foregoing step 96, the area node checks the transmission bandwidth of each TCP connection to the edge server and the amount of data currently needed to be transmitted on each TCP connection, and the network node calculates according to the amount of data to be transmitted and the transmission bandwidth. The transmission delay of each TCP connection, the TCP connection with the minimum transmission delay is determined, and the delay of newly establishing the TCP connection is predicted according to the RTT to the edge server:

 If the minimum transmission delay is less than the delay of the newly established TCP connection, the number of current TCP connections is maintained stable, and the TCP connection established before is still used to transmit data.

 If the minimum transmission delay is greater than the delay of the newly established TCP connection, the network node actively establishes a TCP connection to the edge server.

 The regional node can transmit data through the HTTP POST method, and the X-Flow-Index and X-Connection-Index header fields are carried in the POST message, and are used to associate with the previous HTTP request message. The POST message example is as follows:

 POST / HTTP/1 .1

 Accept: */*

 Accept-Language: zh-cn

 Accept-Encoding: gzip, deflate

User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1) Host: www.ABC.com X-Flow-lndex = 1234

 X-Connection-lndex = 1

 Content-Length: 4125

Message Body

 According to the technical solution provided by the embodiment of the present invention, the principle of transmitting the corresponding data and the transmission delay on the TCP connection is transmitted on the TCP connection according to the data of which service request is first acquired. To achieve flexible and efficient data transmission, which reflects data priority and delay priority, reduces the overhead of dynamically deleting TCP connections, avoids the impact of TCP slow start on transmission rate, reduces the number of TCP connections that need to be maintained, and improves each TCP connection. Reuse, concurrency efficiency. It should be noted that, for the foregoing method embodiments, they are all described as a series of action combinations for the description of the device, but those skilled in the art should understand that the present invention is not limited by the described action sequence. Because certain steps may be performed in other orders or concurrently in accordance with the present invention. In addition, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

 In the above embodiments, the descriptions of the various embodiments are different, and the parts that are not detailed in a certain embodiment can be referred to the related descriptions of other embodiments.

 A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. In execution, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, or a read-only storage memory.

(Read-Only Memory, ROM) or random access random access memory (RAM). 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 may be within the technical scope disclosed by the present invention. Changes or substitutions that are easily conceived 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

Claim  A data transmission method in a CDN content distribution network, comprising: receiving a plurality of HTTP hypertext transfer protocol request messages;  Obtaining data requested by a plurality of the HTTP request messages;  Transmitting, by the response message, the data requested by the plurality of the HTTP request messages, wherein a sequence of data requested by the plurality of the HTTP request messages is sent to a sequence of data acquired by the plurality of the HTTP request messages In order, the plurality is at least two.  2. The method according to claim 1, wherein the HTTP request message is received by the TCP transmission control protocol, and the response message is sent, the TCP connection being one or at least two;  When the TC P is connected to one, the H TT P request message carries a flow index indication X - Flow-Index, and the response message corresponding to the HTTP request message carries the flow index indication X-Flow-lndex, The flow index indicates that the X-Flow-lndex is used to identify the content of the request of the HTTP request message.  When the TCP connection is at least two, the HTTP request message carries a flow index indication X-Flow-lndex and a connection index indication X-Connection-lndex, and the response message corresponding to the HTTP request message carries the flow The index indication X-Flow-lndex and the connection index indicate X-Connection-lndex, wherein the flow index indicates that X-Flow-lndex is used to identify a request content of an HTTP request message, and the connection index indicates X-Connection- Lndex is used to identify the TCP connection used by the HTTP request message.  The method according to claim 2, wherein when the TCP connection is at least two, the method further includes:  Select the TCP connection with the smallest transmission delay to send the data requested by the HTTP request message. The method according to claim 2, wherein the method further comprises: when the TCP connection is at least two, if at least two of the TCP connections are currently transmitted If the minimum transmission delay of the extension is greater than the delay of establishing a new TCP connection, a new TCP connection is established; or, when the TCP connection is one, if the current transmission delay of the TCP connection is greater than when a new TCP connection is established After the delay, a new TCP connection is established.  The method according to claim 2 or 4, wherein the method further comprises: when the current transmission delays of the at least two TCP connections are the same, selecting the first established TCP according to the sequence of establishing the TCP connection. Connects the data requested by the HTTP request message.  The method according to claim 2 or 4, wherein the method further comprises: monitoring the number of the TCP connection sending response message, when the number of sending the response message is less than a predetermined threshold or not sending a response message , delete the corresponding TC P connection.  7. A network node, comprising:  a request receiving unit, configured to receive multiple HTTP hypertext transfer protocol request messages;  An obtaining unit, configured to acquire data requested by multiple of the HTTP request messages;  a transmitting unit, configured to send, by using a response message, data requested by the plurality of HTTP request messages, where a sequence of data requested by the plurality of the HTTP request messages is sent in response to obtaining a plurality of the HTTP request messages The order of the data, the plurality of which are at least two.  The network node according to claim 7, wherein the network node further comprises:  An identifier unit, configured to receive the HTTP request message by using a TCP transmission control protocol connection, and when the response message is sent, when the TCP connection is one, the HTTP request message carries a stream index indicating X-Flow-lndex, The response message corresponding to the HTTP request message carries the flow index indication X-Flow-lndex, where the flow index indicates that the X-Flow-lndex is used to identify the content of the request of the HTTP request message; When the TCP connection is at least two, the HTTP request message carries a flow index indication X-Flow-lndex and a connection index indication X-Connection-lndex, and the response message corresponding to the HTTP request message carries the flow The index indicates X-Flow-lndex and the connection index indicates X- Connection-Index, where the flow index indicates that X-Flow-lndex is used to identify the request content of the HTTP request message, and the connection index indicates that the X-Connection-lndex is used to identify the TCP connection used by the HTTP request message.  The network node according to claim 8, wherein the network node further comprises:  And a first selecting unit, configured to: when the TCP connection is at least two, select, according to a current transmission delay of at least two of the TCP connections, a TCP connection with a minimum transmission delay to send data requested by the HTTP request message.  The network node according to claim 9, wherein the network node further comprises:  a first establishing unit, configured to: when the TCP connection is at least two, if a minimum transmission delay in a current transmission delay of at least two of the TCP connections is greater than a delay in establishing a new TCP connection, establishing a new TCP Connection  Alternatively, when the TCP connection is one, if the current transmission delay of the TCP connection is greater than the delay of establishing a new TCP connection, a new TCP connection is established.  The network node according to claim 8 or 10, wherein the network node further comprises:  And a second selecting unit, configured to: when the current transmission delays of the at least two of the TCP connections are the same, select the data requested by the first established TCP connection to send the HTTP request message according to the sequence of establishing the TCP connection.  The network node according to claim 8 or 10, wherein the network node further comprises:  The monitoring unit is configured to monitor the number of the TCP connection sending response messages, and when the number of the sent response messages is less than a predetermined threshold or no response message is sent, the corresponding TCP connection is deleted. 13. A data transmission system, comprising: a first network node and a second network node Point:  The first network node is configured to receive a plurality of HTTP request messages, obtain data requested by the HTTP request message, and send data requested by the plurality of the HTTP request messages by using a response message, where The order of the data requested by the HTTP request message corresponds to the sequence of obtaining the data requested by the plurality of HTTP request messages;  The second network node is configured to send the multiple HTTP request messages to the first network node, and receive data requested by the HTTP request message sent by the first network node, where the multiple At least two.  14. The system of claim 13, wherein the first network node comprises a network node as claimed in any of claims 7-12.