CN102158518B - Data transmission method in content distribution network (CDN), network node and system - Google Patents

Abstract

The embodiment of the present invention relates to a data transmission method, a network node, and a system in a CDN network, wherein, the data transmission method in the CDN network includes: receiving multiple HTTP hypertext transfer protocol request messages; obtaining multiple HTTP requests The data requested by the message; sending the data requested by multiple HTTP request messages through a response message, wherein the order of sending the data requested by multiple HTTP request messages corresponds to obtaining multiple HTTP request messages The sequence of the requested data. The sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages obtained, so that the data of the HTTP request obtained earlier is transmitted first, and the data transmission efficiency can be improved.

Description

Data transmission method, network node and system in a CDN network

technical field

The present invention relates to the field of communication technology, in particular to a data transmission method, network node and system in a CDN (Content Delivery Network, content distribution network).

Background technique

CDN is to add a new layer of network architecture to the existing IP transmission network, and publish the content of the website to the "edge" of the network closest to the user, so that the user can obtain the required content nearby and solve the network congestion situation. Improve the response speed of users accessing the network.

In the CDN, when a user clicks a link to a certain content on the website, the corresponding HTTP (HyperText Transfer Protocol, Hypertext 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, it sends The CDN routing device queries the address information of the regional node or central node that stores the requested content; the CDN routing device returns the address information of the regional node or central node that stores the requested content; the edge server sends the request to the storage through the HTTP protocol The regional nodes or central nodes of the content request content; the regional nodes or central nodes return the requested content to the edge server.

In the prior art, when multiple HTTP requests are initiated, the sending of the request and the receiving of the response must be performed in strict order. If the data of the previous HTTP request does not respond, the subsequent HTTP request will not receive a response. Therefore, it is not conducive to Data transmission and full utilization of bandwidth.

Contents of the invention

Embodiments of the present invention provide a data transmission method, network node and system in a CDN network, which improve data transmission efficiency.

On the one hand, the embodiments of the present invention provide a data transmission method in a CDN network, including:

receiving multiple HTTP hypertext transfer protocol request messages;

Obtain data requested by multiple HTTP request messages;

Sending the data requested by multiple HTTP request messages through a response message, wherein the order of sending the data requested by the multiple HTTP request messages corresponds to the order of obtaining the data requested by the multiple HTTP request messages Sequentially, 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 acquisition unit, configured to acquire data requested by multiple HTTP request messages;

The transmission unit sends the data requested by the HTTP request message through a response message, wherein the order of sending the data requested by the multiple HTTP request messages corresponds to the sequence of obtaining the data requested by the multiple HTTP request messages In sequence, the plurality is at least two.

On the other hand, 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 messages, and send the data requested by the HTTP request messages through a response message, wherein multiple HTTP requests are sent The sequence of data requested by the message corresponds to the sequence of data requested by multiple 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 messages sent by the first network node, the multiple being at least two.

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, so that the sequence of data requested by multiple HTTP request messages can be obtained first. The data of the HTTP request is transmitted first, which can improve the efficiency of data transmission.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without any creative effort.

1 is a schematic flow diagram of a data transmission method in a CDN network according to an embodiment of the present invention;

FIG. 2 is a first schematic diagram of the composition of a network node according to an embodiment of the present invention;

FIG. 3 is a second schematic diagram of the composition of a network node according to an embodiment of the present invention;

4 is a schematic flow diagram of a data transmission method in a CDN network according to another embodiment of the present invention;

FIG. 5 is a first schematic diagram of the composition of an edge node according to an embodiment of the present invention;

FIG. 6 is a second schematic diagram of the composition of an edge node according to an embodiment of the present invention;

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

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

FIG. 9 is a second schematic diagram of an application scenario of a data transmission method in a CDN network according to another embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, an embodiment of the present invention provides a data transmission method in a CDN network, including:

Step 11, receiving multiple HTTP request messages.

Step 12, acquiring data requested by multiple HTTP request messages.

Step 13: Send the data requested by the multiple HTTP request messages through the response message, wherein the sequence of the data requested by sending the multiple HTTP request messages corresponds to the sequence of the data requested by the multiple HTTP request messages obtained.

The execution subject of the data transmission method in the CDN network in the embodiment of the present invention may be a network node in the CDN network, and the network node may include: a regional node or a central node. Regional nodes and central nodes are used to store network data. The central node is the upper layer node of the regional nodes, and one central node can connect multiple regional nodes. Optionally, there may be multi-level regional nodes between the edge node (which may be an edge server) and the central node, so as to meet the business needs.

Wherein, in the embodiment of the present invention, if multiple HTTP request messages are received, when the data requested by multiple HTTP request messages is sent in step 13, it may be that the data of multiple HTTP request messages has been obtained, or it may be The data requested by several of them (here may be one or several of them) HTTP request messages have been obtained. Then, when the obtained data is sent, the data requested by other HTTP request messages is obtained at the same time. For example: a total of 5 HTTP request messages have been received, then the data can be sent after obtaining the data requested by the 5 HTTP request messages, or it can be obtained in 1 (here can also be 2, 3 or 4) ) The data is sent after the data requested by the HTTP request message.

Below, the data transmission method in the CDN network of the embodiment of the present invention is briefly described:

When a terminal user clicks a link to a certain content on the website, the corresponding HTTP request is routed to the edge server. When the edge server checks that it has not cached the content requested by the terminal, it queries the CDN routing device for the area where the requested data is stored. The address information of the node or central node, the CDN routing device returns the address information of the regional node or central node storing the requested data, such as IP address or domain name. Wherein, 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 DNS (Domain Name System, Domain Name System) resolution, which will not be described here.

Afterwards, the edge server requests data from the regional node or central node storing the requested content through an HTTP request, thereby entering step 11. The regional node or central node receives multiple HTTP request messages sent by the edge server, and then enters step 12 regional node Or the central node obtains the data requested by multiple HTTP request messages, and then enters step 13 where the regional nodes or the central node send the data requested by the HTTP request messages through the response message.

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, so that the sequence of data requested by multiple HTTP request messages can be obtained first. The data of the HTTP request is transmitted first, which can improve the efficiency of data transmission.

The data transmission method in the CDN network of the embodiment of the present invention is also applicable to data transmission between regional nodes and central nodes, data transmission between edge servers and other edge servers, and data transmission between regional nodes and other regional nodes.

The data transmission method in the CDN network according to the embodiment of the present invention is described below only by taking the edge server and the network node as examples.

In the data transmission method in the CDN network of the embodiment of the present invention, in step 11 and step 13, the network node can receive the HTTP request message sent by the edge server through a TCP (Transmission Control Protocol) connection, and send a response message to the edge server.

Specifically, the network node may respond to one or more TCP connection requests from the edge server, and establish one or more TCP connections with the edge server. Wherein, 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.

Exemplarily, after the CDN routing device returns the address information of the network node storing the requested data to the edge server, 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 network nodes. In this way, the network node responds to multiple TCP connection requests from the edge server, and establishes multiple TCP connections with the edge server.

Wherein, the number of TCP connections between the network node and the edge server can be determined according to requirements.

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

It can be seen that the value of the flow index indication X-Flow-Index in the response message of the network node is consistent with the value of the flow index indication X-Flow-Index in the HTTP request message of the edge server, and the HTTP request message and response message are different. Strict order is required. Moreover, after the edge server receives the response message from the network node, it indicates that the X-Flow-Index can be associated with the HTTP request message according to the flow index, so as to be associated with the end user, and finally the edge server delivers the data returned from the network node to the end user .

When there are multiple TCP connections between the edge server and the network node, the HTTP request message carries the flow index indication X-Flow-Index and the connection index indication X-Connection-Index, and the response message corresponding to the HTTP request message carries the flow index Indicates X-Flow-Index and connection index indicates X-Connection-Index, where the flow index indicates X-Flow-Index is used to identify the request content of the HTTP request message, and the connection index indicates X-Connection-Index is used to identify the HTTP request message The TCP connection to use.

It can be seen that the values of the connection index indication X-Connection-Index of the HTTP requests initiated successively on the same TCP connection are consistent. Therefore, the HTTP request message and the response message do not need to be strictly ordered, and the HTTP request message and the response message may not be on the same TCP connection to realize parallel data transmission and make full use of the TCP bandwidth.

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

Therefore, when there are multiple TCP connections between the edge server and the network node, the data transmission method in the CDN network of the embodiment of the present invention may also include:

According to the current transmission delays of multiple TCP connections, the network node selects the TCP connection with the smallest transmission delay to send the data requested by the HTTP request message.

Wherein, 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 for waiting for the TCP connection to be 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 by the TCP connection and the bandwidth of the TCP connection. Specifically, the specific manner of determining the transmission delay of the TCP connection can be understood with reference to the current common prior art, and details are not described here.

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 in the order in which the data corresponding to each HTTP request is obtained, and selects the TCP connection with the smallest current transmission delay to transmit the HTTP request message The requested data, and the HTTP request message and response message both extend the flow index indication X-Flow-Index and the connection index indication X-Connection-Index, the HTTP request message and response message do not need to be strictly ordered, the HTTP request message and Response messages 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 (pipeline) method without waiting for the response data from the network node. Receiving response data asynchronously on multiple TCPs can realize parallel data transmission and make full use of TCP bandwidth.

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

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

Or, when there is one TCP connection, 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 when it is necessary to wait for the previously established TCP connection to be idle to send data, the network node will Predict the transmission delay of each TCP with the transmission data, determine the TCP connection with the minimum transmission delay, and predict the delay of the newly established TCP connection according to the RTT (Round-Trip Time, round-trip delay) to the edge server:

If the minimum transmission delay is less than the delay of a newly established TCP connection, the current number of TCP connections is kept stable, and the previously established TCP connection is still waiting to transmit data.

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

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

Among them, the network node can actively establish a TCP connection to the edge server through a response message in response to an HTTP request, or actively establish a TCP connection to the edge server through HTTP POST. Moreover, the X-Flow-Index and X-Connection-Index header fields are carried in the POST message for associating with the previous HTTP request message.

Among them, the maximum number of TCP connections that can be dynamically established between the network node and each edge server can be set, thereby limiting the number of TCP connections that each network node and edge server need to maintain.

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

When the current transmission delays of multiple TCP connections are the same, according to the order in which the TCP connections are established, the first established TCP connection is selected to send the data requested by the HTTP request message.

Therefore, the network node preferentially selects the first established TCP connection to transmit the requested data, and the newly established TCP connection can be gradually recycled, thereby reducing the number of TCP connections that need to be maintained, and reducing the need for edge servers and network nodes to maintain a large number of TCP connections at the same time. s expenses.

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

The number of response messages sent by multiple TCP connections is monitored, and 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 the network node can monitor the number of response messages on each TCP connection according to the actual usage of the TCP connection. If the number of response messages on a certain TCP connection is less than the specified threshold, or the number of response messages on a certain TCP connection is less than the specified threshold relative to the number of response messages on other TCP connections, it means that the number of response messages passed by this TCP connection If the transmission condition of the network path is not good, the network node can dynamically delete the TCP connection and re-establish a new TCP connection.

In addition, there may no longer be traffic between the edge server and a certain area node that has established a connection before, 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 a certain 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 also be noted that, for the data transmission method in the CDN network of the embodiment of the present invention, for a 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 it locally, otherwise The network node may obtain the requested content from the upper layer network node in a manner similar to that obtained by the edge server, which will not be repeated here.

As shown in FIG. 2, corresponding to the data transmission method in the CDN network of the above-mentioned embodiment, an embodiment of the present invention provides a network node, including:

The request receiving unit 21 is configured to receive multiple HTTP hypertext transfer protocol request messages.

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

The transmission unit 23 is used to obtain the data requested by the HTTP request message, and then send the data requested by the HTTP request message through the response message, wherein the order of sending the data requested by multiple HTTP request messages corresponds to the sequence of obtaining multiple HTTP request messages. The sequence of data requested by the HTTP request message.

Wherein, 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 foregoing network nodes may include: regional nodes or central nodes. Regional nodes and central nodes are used to store network data. Optionally, there may be multi-level regional nodes between the edge server and the central node, so as to meet business needs.

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, so that the sequence of data requested by multiple HTTP request messages can be obtained first. The data of the HTTP request is transmitted first, which can improve the efficiency of data transmission.

As shown in Figure 3, the network node in the embodiment of the present invention may also include:

The identification unit 31 is configured to receive the HTTP request message and send the response message through the TCP transmission control protocol connection. When there is one TCP connection, the HTTP request message carries the flow index indication X-Flow-Index, and the response message corresponding to the HTTP request message carries the flow index indication X-Flow-Index, where the flow index indication X-Flow-Index is used to identify the request content of the HTTP request message;

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

Therefore, the HTTP requests initiated successively on the same TCP connection are consistent in the value of the connection index indication X-Connection-Index. After receiving the response message from the network node, the edge server indicates that the X-Flow-Index and the connection index can be associated with the HTTP request message according to the flow index and the X-Connection-Index, so that it can be associated with the end user. Finally, the edge server will receive from the network node The returned data is delivered to the end user.

The network node in the embodiment of the present invention may also include:

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

In summary, since both the HTTP request message and the response message extend the flow index indication X-Flow-Index and the connection index indication X-Connection-Index, the HTTP request message and response message do not need to be strictly ordered. For example, if two end users request content from the same edge server at the same time, the edge server can follow the Pipeline method without waiting for the response data of the network node, and without waiting for the response data of the network node, the edge server directly initiates continuously on multiple TCP connections Request, and then asynchronously receive response data from multiple TCPs, which can realize parallel data transmission and make full use of TCP bandwidth.

The network node in the embodiment of the present invention may also include:

The first establishment unit 33 is used for when there are multiple TCP connections, and the minimum transmission delay in the current transmission delays of multiple TCP connections is greater than the delay of establishing a new TCP connection, then a new TCP connection is established; or, when TCP When there is one connection, and 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.

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

Moreover, the maximum number of TCP connections that can be dynamically established between network nodes and each edge server can be set, thereby limiting the number of TCP connections that need to be maintained by each network node and edge server.

The network node in the embodiment of the present invention may also include:

The second selection unit 34 is configured to select the first established TCP connection to send the data requested by the HTTP request message according to the order in which the TCP connections are established when the current transmission delays of the multiple TCP connections are the same.

Therefore, the network node preferentially selects the first established TCP connection to transmit the requested data, and the TCP connection of the first establishment unit can be gradually recycled, thereby reducing the number of TCP connections that need to be maintained.

The network node in the embodiment of the present invention may also include:

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

It can be seen that there may be no more traffic between the edge server and a certain area node that has established a connection before, so the network node can monitor the traffic on each established TCP connection. If there is no traffic on each TCP connection to a certain 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 solutions provided by the above-mentioned embodiments of the present invention that multiple TCP connections are maintained between the edge server and the network node, and after the network node receives multiple HTTP request messages sent by the edge server, which HTTP request message is obtained first The data of the HTTP request is first transmitted on the TCP connection with the smallest delay, so as to realize parallel data transmission and make full use of the TCP bandwidth.

As shown in Figure 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 no TCP connection has been established with the network node, establish multiple TCP connections with the network node, and send multiple HTTP request messages through the multiple TCP connections.

Step 43: Receive the response message sent by the network node through multiple TCP connections, and obtain the response data of the HTTP request message.

Wherein, the execution subject of the data transmission method in the CDN network in the embodiment of the present invention can be an edge node, and the edge node can be an edge server, 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 foregoing network nodes may include: regional nodes or central nodes. Regional nodes and central nodes are used to store network data. Optionally, there may be multi-level regional nodes between the edge node and the central node, so as to meet the business needs.

As can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention, multiple TCP connections are maintained between the edge node and the network node, and after the network node receives multiple HTTP request messages sent by the edge node, parallel data transmission is realized. Make full use of TCP bandwidth.

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

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

Specifically, step 41 may include:

The edge node checks whether there is already a TCP connection to the corresponding IP address.

If there is already a TCP connection with the corresponding IP address, the edge node directly sends the 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, the default configuration requires the establishment of two TCP connections, and the edge node actively establishes two TCP connections to the corresponding IP addresses.

The edge node can round-select a TCP connection, and submit an HTTP request message to the regional node layer or the central node on the TCP connection. Meanwhile, the HTTP request message carries a flow index indication X-Flow-Index and a connection index indication X-Connection-Index. The flow index indicates X-Flow-Index, which is used to identify the request content of the HTTP request message, and the connection index indicates X-Connection-Index, which is used to identify the TCP connection used by the HTTP request message.

Therefore, the network node can select and transmit the data requested by the HTTP request message through multiple TCPs. Entering step 43, the edge node receives the response message sent by the network node through multiple TCP connections, and obtains the response data of the HTTP request message. Meanwhile, the response message carries the flow index indication X-Flow-Index and the connection index indication X-Connection-Index.

If the network node selects the TCP connection with the smallest transmission delay to transmit the data requested by the HTTP request message, then 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 according to the flow index indication X-Flow-Index and connection index indication X-Connection-Index of the response message, it can be associated with the HTTP request message, and finally associated with the end user. Data returned by network nodes is delivered to end users.

Since the HTTP request message and the response message both extend the flow index indication X-Flow-Index and the connection index indication X-Connection-Index, the HTTP request message and the response message do not need to be strictly ordered. For example, if two end users request content from the same regional node at the same time, the edge node can follow the Pipeline method without waiting for the response data of the regional node or the response data of the network node, and the edge node directly initiates continuously on multiple TCP connections Request, and then asynchronously receive response data from multiple TCPs, which can realize parallel data transmission and make full use of TCP bandwidth.

Optionally, the edge node can also decide whether to cache the data delivered to the end user locally according to the heat replacement algorithm, so that the edge node can serve the same service request of other end users. Heat replacement algorithm, such as LRU (Least Recently Used, least recently used) algorithm, and so on.

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

The number of response messages received by multiple TCP connections is monitored, and when the number of response messages of the TCP connections is less than a predetermined threshold, the corresponding TCP connection is deleted.

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

Specifically, the edge node monitors the number of response messages received from each TCP connection according to the actual usage of the TCP connection. If the number of response messages received on a certain TCP connection is less than the specified threshold, or the number of response messages received on a certain TCP connection is smaller than the specified threshold relative to the number of response messages received on other TCP connections, it indicates that the If the transmission condition of the network path passed by a TCP connection is not good, the edge node can dynamically delete the TCP connection and re-establish a new TCP connection.

Moreover, after the CDN routing server adjusts the routing policy, there will no longer be traffic between the edge node and a certain area node that has established a connection before, so the edge node needs to monitor the traffic on each established TCP connection. If there is no traffic on each TCP connection to a certain IP address after 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, corresponding to the data transmission method in the CDN network of the above-mentioned embodiment, the 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.

The second establishing unit 52 is configured to determine that no TCP connection has been established with the network node, establish multiple TCP connections with the network node, and send multiple HTTP request messages through the multiple TCP connections.

The response receiving unit 53 is configured to receive the response message sent by the network node through multiple TCP connections, and obtain the response data of the HTTP request message.

In the embodiment of the present invention, the edge node may be an edge server, 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 foregoing network nodes may include: regional nodes or central nodes. Regional nodes and central nodes are used to store network data. Optionally, there may be multi-level regional nodes between the edge node and the central node, so as to meet the business needs.

It can be seen from the technical solution provided by the above embodiments of the present invention that multiple TCP connections are maintained between the edge node and the network node to realize parallel data transmission and make full use of the TCP bandwidth.

Specifically, the response receiving unit 53 can also be configured to receive the response message sent by the network node through the TCP connection with the smallest transmission delay among the multiple TCP connections, and obtain the response data of the HTTP request message.

The HTTP request message sent by the second establishment unit 52 carries a flow index indication X-Flow-Index and a connection index indication X-Connection-Index.

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

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

Since the HTTP request message and the response message both extend the flow index indication X-Flow-Index and the connection index indication X-Connection-Index, the HTTP request message and the response message do not need to be strictly ordered. For example, if two end users request content from the same regional node at the same time, the edge node can follow the Pipeline method without waiting for the response data of the regional node or the response data of the network node, and the edge node directly initiates continuously on multiple TCP connections Request, and then asynchronously receive response data from multiple TCPs, which can realize parallel data transmission and make full use of TCP bandwidth.

As shown in Figure 6, the edge node in 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 multiple TCP connections, and delete the corresponding TCP connection when the number of response messages of the TCP connection is less than a predetermined threshold.

It can be seen that the transmission condition of the network path passed by the TCP connection is not good, and the edge node can dynamically delete the TCP connection and re-establish a new TCP connection.

Alternatively, the edge node in this embodiment of the present invention may also include:

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

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 the data requested by the HTTP request messages, and send the data requested by the HTTP request messages through the response message, wherein the sequence of sending the data requested by the multiple HTTP request messages The order corresponds to the order in which the data requested by multiple HTTP request messages are obtained;

The second network node 72 is configured to send multiple HTTP request messages to the first network node 71 and receive data requested by the HTTP request messages sent by the first network node 71 .

In the CDN system in this embodiment of the present invention, the first network node 71 can be understood with reference to the network nodes in the foregoing embodiments. The second network node 72, such as an edge server, can be understood with reference to the edge server in the foregoing embodiments. 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.

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the sequence of data requested by sending multiple HTTP request messages corresponds to the sequence of data requested by multiple HTTP request messages, so that the sequence of data requested by multiple HTTP request messages can be obtained first. The data of the HTTP request is transmitted first, which can improve the efficiency of data transmission.

As shown in FIG. 8 , the edge server 81 serves as a media delivery node and is responsible for media delivery tasks of multiple terminals 82 , and multiple TCP connections are maintained between the edge server 81 and the regional nodes 83 . Moreover, there may be multi-level regional nodes other than the regional node 83, so as to meet the business needs.

As shown in Figure 9, taking edge servers and regional nodes as examples, the data transmission method in the CDN network is specifically described, including:

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

92. The edge server confirms that the requested content is not cached locally according to the URI (Uniform Resource Identifier) information requested by the end user, and the edge server queries the CDN routing device for the address of the regional node or central node that stores the requested content information.

93. The CDN routing server returns to the edge server the location information of the regional node storing the requested content, including the domain name or 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 already a TCP connection to the corresponding IP address: if it does not exist, establish multiple corresponding TCP connections according to the configuration requirements; if there is already a configuration-required TCP connection with the corresponding IP address number, there is no need to establish a new TCP connection separately.

95. The edge server selects a TCP connection, and 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 extends an X-Flow-Index header field in the HTTP request message header as follows:

X-Flow-Index="X-Flow-Index"":"1*DIGIT

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

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

Exemplarily, the HTTP request message between the edge server and the regional 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-Index=1234

X-Connection-Index=1

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

The regional node checks the current transmission bandwidth of each TCP connection to the edge server and the amount of data that needs to be transmitted on each TCP connection. According to the amount of data to be transmitted and the transmission bandwidth, the transmission delay of the TCP connection can be calculated, that is, the required 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 regional nodes transmit the corresponding data first according to which HTTP request data is obtained first, and which TCP connection has the smallest transmission delay, then transmits on the TCP connection, realizing flexible and efficient data transmission, reflecting data priority and delay priority.

The regional node also carries the X-Flow-Index and X-Connection-Index header fields in the response message, and the values of these two header fields are consistent with the values of the header fields in the HTTP request message.

Exemplarily, the response message is as follows:

HTTP/1.1200 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-Index=1234

X-Connection-Index=1

Content-Length: 4125

Message Body

In addition, if the content to be requested has been stored in the memory of the regional node or a storage medium such as a hard disk, the regional node can directly obtain it from the local area; The content of the request.

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

Optionally, in the above step 96, the regional node checks the current transmission bandwidth of each TCP connection to the edge server and the amount of data that still needs 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, determine the TCP connection with the minimum transmission delay, and predict the delay of the newly established TCP connection according to the RTT to the edge server:

If the minimum transmission delay is less than the delay of a newly established TCP connection, the current number of TCP connections is kept stable, and the previously established TCP connection is still waiting to transmit data.

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

Regional nodes can transmit data through the HTTP POST method. The X-Flow-Index and X-Connection-Index header fields are carried in the POST message to associate with the previous HTTP request message. The example of the POST message 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-Index=1234

X-Connection-Index=1

Content-Length: 4125

Message Body

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that according to the principle of which service request data is first obtained, the corresponding data is transmitted first and the transmission delay on that TCP connection is small, then the transmission is carried out on the TCP connection To achieve flexible and efficient data transmission, reflecting data priority and delay priority, reducing the overhead of dynamically deleting and establishing TCP connections, avoiding the impact of TCP slow start on transmission rate, reducing the number of TCP connections that need to be maintained, and improving the speed of each TCP connection Multiplexing and concurrency efficiency.

It should be noted that for the foregoing method embodiments, for the sake of simple description, they are expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence. Because of the present invention, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented through computer programs to instruct related hardware, and the programs can be stored in a computer-readable storage medium. During execution, it may include the processes of the embodiments of the above-mentioned methods. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM) or a random access memory (Random AccessMemory, RAM), etc.

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

Claims (12)

1. the data transmission method in CDN content distributing network, is characterized in that, comprising:

Receive multiple http hypertext transfer protocol request messages;

Obtain the data that multiple described HTTP request messages are asked;

By response message, send the data that multiple described HTTP request messages are asked, wherein, the sequencing that sends the data that multiple described HTTP request messages ask is corresponding to the sequencing that gets the data that multiple described HTTP request messages ask, and is describedly multiplely at least two;

Wherein, described method also comprises: by tcp transmission control protocol, connected and received described HTTP request message and send described response message, described TCP is connected to one or at least two;

When described TCP is connected to one, in described HTTP request message, carry stream index indication X-Flow-Index, in response message corresponding to described HTTP request message, carry described stream index indication X-Flow-Index, wherein, described stream index indication X-Flow-Index is for identifying the request content of HTTP request message;

When described TCP is connected at least two, in described HTTP request message, carry stream index indication X-Flow-Index and join index indication X-Connection-Index, in response message corresponding to described HTTP request message, carry described stream index indication X-Flow-Index and described join index indication X-Connection-Index, wherein, described stream index indication X-Flow-Index is for identifying the request content of HTTP request message, and described join index indication X-Connection-Index connects for the TCP that identifies the use of HTTP request message.

2. method according to claim 1, is characterized in that, when described TCP is connected at least two, described method also comprises:

Select the TCP of propagation delay time minimum to connect the data that transmission HTTP request message is asked.

3. method according to claim 1, is characterized in that, described method also comprises:

When described TCP is connected at least two, if minimum transfer time delay is greater than the time delay of setting up new TCP connection in the current propagation delay time of at least two described TCP connections, sets up new TCP and connect;

Or, when described TCP is connected to one, if being greater than, the current propagation delay time that described TCP connects sets up the time time delay that new TCP connects, and set up new TCP and connect.

4. according to the method described in claim 1 or 3, it is characterized in that, described method also comprises:

When the current propagation delay time that connects as at least two TCP is identical, connect the sequencing of setting up according to TCP, the TCP that selects first to set up connects and sends the data that HTTP request message is asked.

5. according to the method described in claim 1 or 3, it is characterized in that, described method, also comprises:

Monitor described TCP and connect the quantity that sends response message, when the quantity of transmission response message is less than predetermined threshold or does not send response message, delete corresponding TCP and connect.

6. a network node, is characterized in that, comprising:

Request reception unit, for receiving multiple http hypertext transfer protocol request messages;

Acquiring unit, the data of asking for obtaining multiple described HTTP request messages;

Transmission unit, by response message, send the data that multiple described HTTP request messages are asked, wherein, the sequencing that sends the data that multiple described HTTP request messages ask is corresponding to the sequencing that gets the data that multiple described HTTP request messages ask, and is describedly multiplely at least two;

Described network node also comprises:

Identify unit, when receiving described HTTP request message and sending described response message for connecting by tcp transmission control protocol, when described TCP is connected to one, in described HTTP request message, carry stream index indication X-Flow-Index, in response message corresponding to described HTTP request message, carry described stream index indication X-Flow-Index, wherein, described stream index indication X-Flow-Index is for identifying the request content of HTTP request message;

When described TCP is connected at least two, in described HTTP request message, carry stream index indication X-Flow-Index and join index indication X-Connection-Index, in response message corresponding to described HTTP request message, carry described stream index indication X-Flow-Index and described join index indication X-Connection-Index, wherein, described stream index indication X-Flow-Index is for identifying the request content of HTTP request message, and described join index indication X-Connection-Index connects for the TCP that identifies the use of HTTP request message.

7. network node according to claim 6, is characterized in that, described network node also comprises:

The first selected cell, for when described TCP is connected at least two, the current propagation delay time connecting according at least two described TCP, selects the TCP of propagation delay time minimum to connect the data that transmission HTTP request message is asked.

8. network node according to claim 7, is characterized in that, described network node also comprises:

First sets up unit, for when described TCP is connected at least two, if minimum transfer time delay is greater than the time delay of setting up new TCP connection in the current propagation delay time of at least two described TCP connections, sets up new TCP and connects;

Or, when described TCP is connected to one, if being greater than, the current propagation delay time that described TCP connects sets up the time delay that new TCP connects, and set up new TCP and connect.

9. according to the network node described in claim 6 or 8, it is characterized in that, described network node also comprises:

The second selected cell, when identical for the current propagation delay time that connects as at least two described TCP, connects the sequencing of setting up according to TCP, the TCP that selects first to set up connects and sends the data that HTTP request message is asked.

10. according to the network node described in claim 6 or 8, it is characterized in that, described network node also comprises:

Monitoring means, connects for monitoring described TCP the quantity that sends response message, when the quantity of transmission response message is less than predetermined threshold or does not send response message, deletes corresponding TCP and connects.

11. 1 kinds of data transmission systems, is characterized in that, comprise first network node and second network node:

Described first network node, be used for receiving multiple HTTP request messages, obtain the data that described HTTP request message is asked, by response message, send the data that multiple described HTTP request messages are asked, wherein, the sequencing that sends the data that multiple described HTTP request messages ask is corresponding to the sequencing that gets the data that multiple described HTTP request messages ask;

Described second network node, for sending described multiple HTTP request messages to described first network node, and receives the data that described HTTP request message that described first network node sends is asked, and is describedly multiplely at least two;

Described data transmission system also comprises another network node, when this network node receives described HTTP request message and sends described response message for connecting by tcp transmission control protocol, when described TCP is connected to one, in described HTTP request message, carry stream index indication X-Flow-Index, in response message corresponding to described HTTP request message, carry described stream index indication X-Flow-Index, wherein, described stream index indication X-Flow-Index is for identifying the request content of HTTP request message;

When described TCP is connected at least two, in described HTTP request message, carry stream index indication X-Flow-Index and join index indication X-Connection-Index, in response message corresponding to described HTTP request message, carry described stream index indication X-Flow-Index and described join index indication X-Connection-Index, wherein, described stream index indication X-Flow-Index is for identifying the request content of HTTP request message, and described join index indication X-Connection-Index connects for the TCP that identifies the use of HTTP request message.

12. systems according to claim 11, is characterized in that, described first network node is network node as claimed in claim 7 or 8.

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