JP2010273298A - Content distribution system, distribution control device, and distribution control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content distribution system which distributes contents which have been converted into a data format corresponding to a terminal attribute, and performs appropriate content distribution while minimizing the resources of the entire content distribution system. <P>SOLUTION: The content distribution system includes: a first distribution processing device which performs a transcoding process varying, depending on each terminal attribute of a user's terminal device, with respect to untransformed contents held in a content storage device, and performs a real-time transcoding distribution process in response to a content distribution request from the user's terminal device; a distribution control device which monitors the resource load of the first distribution process device, and based on a resource load state when there is the content distribution request, switches the process of distributing contents corresponding to the distribution request, from the real-time transcoding distribution process to a cache distribution process; and a second distribution processing device which, when the cache distribution process is performed, caches transformed contents generated through the transcoding process by the first distribution process device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a content distribution system, and more particularly to a content distribution system capable of suitable distribution while improving the efficiency of system resources of the entire system.

  An example of content delivery technology is CDN (Content Delivery Network) technology. The CDN technology is a technology for solving a delay in content distribution due to simultaneous access to a WEB server that provides digital content such as a moving image or a network load, and a content user (user terminal device) as much as possible to distribute the digital content to be distributed. By providing a network optimized for distributing digital content via the network, the user can enjoy comfortable content browsing (see Non-Patent Document 1).

  On the other hand, when content is distributed to a mobile communication terminal device such as a mobile phone as described in Patent Document 1, it corresponds to an image display function (image display capability) and a data format that are different for each model of the mobile phone. Content delivery is required. That is, when there is a content distribution request from a mobile phone, it is necessary to distribute the converted content that has been converted (transcoding processing) into content in a data format corresponding to the model (image display capability) of the requesting mobile phone.

  However, the conventional content distribution system that requires transcoding processing has the following problems. That is, when content is cached like a CDN, a plurality of contents in a data format corresponding to each model must be generated and cached in advance for one content in order to retain the contents in each data format. Requires a huge storage capacity. In addition, it is necessary to build a system that holds content storage resources according to the number of contents and the number of mobile phone models. Each content has a different data capacity, and the number of contents, the number of models, and the number of accesses It is difficult to predict the optimal system resources for the increase of For this reason, it becomes inefficient in terms of securing and maintaining content storage resources such as a cache server, and it has not been possible to predict system resources, particularly content storage resources, and to design (equipment settings) an efficient system. .

  On the other hand, instead of holding content in multiple data formats for each mobile phone model in advance like a CDN, the content stored in the original data format is transcoded in real time each time a distribution request is made. Content converted to a data format corresponding to each model can also be distributed. However, since multiple types of transcoding processing corresponding to each model of mobile phone must be performed, an excessive processing load occurs due to an increase in the number of contents, the number of models, and an increase in the number of accesses. There has been a problem that the processing capacity of the distribution server or the like that performs the process overflows.

  This overflow may cause a deterioration in the quality of the content to be distributed or a situation in which the content cannot be distributed. Therefore, in order to maintain the quality of the content distribution service, the processing performance (CPU performance and Memory). In other words, in order to prevent overflow, the CPU performance and memory resources that can maintain the processing capability at the maximum processing load must be designed. However, as described above, the increase in the number of contents to be distributed and the number of mobile phone models It was difficult to design a processing capacity that predicted an increase in the number of users and the number of simultaneous distributions. Therefore, if it cannot be predicted, in order to prevent deterioration in quality of the content distribution service due to overflow (system resource depletion) and inability to distribute, it is necessary to secure more (excessive) system resources (CPU performance and memory) than necessary. It was an inefficient system.

  Thus, in content distribution that requires conventional transcoding processing, it is difficult to realize a distribution system that efficiently utilizes the resources of the entire system (content storage resources, processing performance resources such as CPU performance). There has been no content distribution system that makes the best use of system resources while minimizing the amount of resources and appropriately controls quality degradation and inability to distribute.

JP 2008-172319 A JP 2006-222829 A

Japan Patent Office homepage, reference room (other reference information)> standard technology collection> electronic and online advertising> WebN content delivery acceleration technology by CDN (http://www.jpo.go.jp/shiryou/s_sonota/hyoujun_gijutsu/ net_koukoku / 004.html)

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a content distribution system capable of suitable content distribution while improving the efficiency of the entire content distribution system that distributes content converted into a data format corresponding to each terminal attribute of the user. To provide a distribution control device and a distribution control program.

  A content distribution system for distributing content converted into a data format corresponding to each terminal attribute of a user terminal device according to one aspect of the present invention responds to each terminal attribute with respect to the pre-conversion content held in the content storage device. A first distribution processing device having a function of performing different transcoding processing and performing real-time transcoding distribution processing in response to a content distribution request from a user terminal device, and monitoring a resource load of the first distribution processing device And a distribution control device that switches the distribution processing of the requested content from the real-time transcoding distribution processing to the cache distribution processing based on the resource load state at the time of the content distribution request, and the first distribution processing device during the cache distribution processing. Generated through transcoding process And having a second delivery processing apparatus for caching the converted content, a.

  Further, the distribution control device monitors the number of simultaneous distribution processing connections in the real-time transcoding distribution processing, and determines whether or not the number of simultaneous distribution processing connections at the time of content distribution request has reached the allowable number of simultaneous distribution processing connections. If the number of simultaneous distribution processing connections reaches the allowable number of simultaneous distribution processing connections, the distribution process of the content requested to be distributed can be switched from the real-time transcoding distribution process to the cache distribution process.

  Further, the distribution control device monitors the CPU usage rate of the first distribution processing device, determines whether or not the CPU usage rate at the time of content distribution request has reached the allowable CPU usage rate, and allows the allowable CPU usage rate. Can reach the allowable CPU usage rate, the distribution process of the content requested to be distributed can be switched from the real-time transcoding distribution process to the cache distribution process.

  In addition, when the distribution control device switches the distribution processing of the content requested to be distributed from the real-time transcoding distribution processing to the cache distribution processing, it transmits connection information to the second distribution processing device to the user terminal device, The second distribution processing device determines whether or not the converted content corresponding to the content requested to be distributed is registered in the cache in response to the content distribution request transmitted from the user terminal device based on the connection information. In addition, when the cache is not registered, the converted content generated through the transcoding process of the first distribution processing apparatus during the cache distribution process can be cached.

  The content storage device may further include a post-conversion content header storage unit that holds a post-conversion content header for each terminal attribute generated by the transcoding processing for the pre-conversion content, and the real-time transcoding distribution processing includes The post-conversion content distribution packets sequentially generated by the payload conversion processing in the transcoding processing can be combined with the corresponding post-conversion content header information stored in the post-conversion content header storage unit and distributed.

  The content storage device can include a content meta information storage unit that stores content meta information, and a content history storage unit that stores a content distribution request frequency. On the other hand, a distribution policy control unit that assigns real-time transcoding distribution processing or cache distribution processing as a distribution policy for each content can be included. The distribution policy control unit can assign a distribution policy to each content stored in the content storage device using the distribution request frequency for each meta information obtained by analyzing the distribution request frequency for each content for each meta information. it can.

  Further, the distribution policy control unit determines whether or not the free capacity in the cache capacity of the second distribution processing device is smaller than a predetermined value, and if the free capacity is smaller than the predetermined value, the distribution request frequency by meta information is set. Regardless, real-time transcoding distribution processing can be assigned as a distribution policy.

  In addition, the content history storage unit can further store the maximum number of simultaneous distributions of each content, and the distribution policy control unit can determine at least one of the content distribution request frequency and the maximum number of simultaneous distributions from a predetermined threshold value. If it is larger, the update process for changing the distribution policy of the content to which the real-time transcoding distribution process is assigned to the cache distribution process can be performed.

  In addition, the distribution policy control unit converts the distribution policy of the content to which the cache distribution processing is assigned into the real-time transcoding distribution processing when each of the content distribution request frequency and the maximum number of simultaneous distributions is smaller than each predetermined threshold. It is possible to perform an update process that changes to

  Furthermore, according to another aspect of the present invention, there is provided a content distribution method for distributing content converted into a data format corresponding to each terminal attribute of a user terminal device, wherein the first distribution processing device converts the content stored in the content storage device. A step of performing different transcoding processing on the previous content according to each terminal attribute and performing real-time transcoding distribution processing in response to a content distribution request from the user terminal device; A step of monitoring the resource load of the apparatus and switching the distribution process of the content requested for distribution from the real-time transcoding distribution process to the cache distribution process based on the resource load state at the time of the content distribution request; However, the cache of the first distribution processing device during the cache distribution process Characterized in that it comprises the steps of: caching the converted content generated through Nsu coding process, the.

  In addition, in a further aspect of the present invention, a content distribution system that distributes content converted into a data format corresponding to each terminal attribute of a user terminal device is provided for each terminal with respect to the pre-conversion content held in the content storage device. Real-time transcoding distribution processing device having a function of performing different transcoding processing according to attributes and performing real-time transcoding distribution processing in response to a content distribution request from a user terminal device, and real-time transcoding distribution processing device A distribution control device that switches the distribution processing of the requested content from the real-time transcoding distribution processing to the cache distribution processing based on the resource load state at the time of the content distribution request, An interface device that transmits the converted content generated through the transcoding process of the real-time transcoding distribution processing device to the cache distribution processing device based on a cache request transmitted from the cache distribution processing device that caches the converted content during processing; It is characterized by having.

  Furthermore, a distribution control device for a content distribution system according to another aspect of the present invention performs a transcoding process that differs depending on each terminal attribute of a user terminal device, and performs a real-time transcoding distribution process. Including a load information monitoring unit that monitors a resource load of the first distribution processing device, and a resource load state in response to a content distribution request from a user terminal device. Distribution processing control for switching requested content distribution processing from real-time transcoding distribution processing to cache distribution processing distributed through a second distribution processing device that caches converted content according to terminal attributes generated through transcoding processing And having a part The distribution processing control unit transmits connection information to the second distribution processing device to the user terminal device when switching the distribution processing of the content requested to be distributed from the real-time transcoding distribution processing to the cache distribution processing. It is characterized by.

  A distribution control program for a content distribution system according to another aspect of the present invention is a first distribution processing device that performs different transcoding processing according to each terminal attribute of a user terminal device and performs real-time transcoding distribution processing. A distribution control program for a content distribution system including: a first function for monitoring a resource load of a first distribution processing device, and a distribution request based on a resource load state at the time of a content distribution request from a user terminal device A second function for switching the content distribution processing to the cache distribution processing for distributing the converted content according to the terminal attribute generated through the transcoding processing from the real-time transcoding distribution processing through the second distribution processing device that caches , Requesting delivery A third function of transmitting connection information to the second distribution processing device to the user terminal device when the distribution processing of the content is switched from the real-time transcoding distribution processing to the cache distribution processing. And

  According to the present invention, while reducing the resources of the entire content distribution system that distributes the content converted into the data format corresponding to each terminal attribute of the user, quality degradation and distribution stoppage due to exhaustion of system resources, etc. Content distribution that is suitably suppressed is possible.

1 is an overall schematic diagram of a content distribution system to which the present invention is applied. It is a block diagram of the configuration of a content distribution control system to which the present invention is applied. It is a flowchart which shows the whole processing flow of the content delivery system to which this invention is applied. It is a figure which shows an example of the content header storage process after conversion (a) of this invention, and a real-time transcoding process (b). It is a flowchart which shows an example of the delivery process determination process of this invention. It is a flowchart which shows an example of the CDN cache delivery process of this invention. It is a flowchart which shows an example of the delivery policy process according to metadata of this invention. It is a flowchart which shows an example of the delivery policy determination process at the time of the content registration of this invention. It is a flowchart which shows an example of the delivery policy update process of this invention. It is a flowchart following FIG.

  Embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is an overall schematic diagram of a content distribution system 1 to which the present invention is applied. The content distribution system 1 of the present embodiment distributes digital content (moving image, still image, music, etc., hereinafter simply referred to as content) in a data format that matches each terminal attribute of the user terminal device 300. As shown in FIG. 1, a content distribution system 1 includes a content distribution control system 100 that performs distribution control of the entire system and has a transcoding processing function, and a CDN.

  Distribution of the content converted into the data format according to the terminal attribute of the user terminal device 300 of the present embodiment includes real-time transcoding distribution processing (first distribution processing method) and CDN cache distribution processing (second distribution processing method). The two distribution processes are performed. In the following description, a mobile phone is described as an example of the user terminal device 300. In addition, the user terminal device 300 includes a mobile communication terminal device such as a PDA (Personal Digital Assistant) and an information processing terminal device having a communication function and a calculation function such as a personal computer.

  The real-time transcoding distribution process performs the transcoding process in real time in response to a content distribution request from the user terminal device 300, and the content converted into a data format suitable for each terminal attribute of the user terminal device 300 This is a distribution processing method in which (converted content) is distributed through the first network N1 such as the Internet without being cached. The CDN cache distribution process is a distribution processing method in which the converted content subjected to the transcoding process is distributed in a cache through one or a plurality of cache servers 200C arranged on the CDN (second network N2).

  For convenience of explanation, the first distribution processing method is described as distributing the converted content through the Internet (first network N1), and the second distribution processing method is distributed through the CDN (second network N2). There is no need, and the first and second networks may be the same network. In other words, the CDN is a network optimized for distributing digital content having a relatively large data capacity over a network compared to a document or the like. In a broad sense, the CDN is used for content distribution management and content distribution including a charging / authentication system. Although a network including necessary functions is also included, the CDN is not a physically closed network such as a dedicated line, but a network optimized for content distribution formed on the Internet. Even if there are access restrictions, etc., it is only one network constituting the Internet. Therefore, for convenience of explanation, a network in which one or a plurality of cache servers 200C are arranged and performs content distribution by CDN cache distribution processing is referred to as a second network distinguished from the Internet. However, the Internet and CDN are distinguished from each other. It can also be understood as one network without having to.

  The CDN includes one or a plurality of cache servers 200C and a CDN management server 200 that manages the entire CDN. The CDN management server 200 performs distribution route control for allocating an optimal cache server 200C to the user terminal device 300 that has made a content distribution request, and manages content registered in the CDN in cache. Further, the cache server 200C is provided with a post-conversion content storage unit 210C that stores post-conversion content, and the CDN management server 200 performs cache registration of post-conversion content that is cache-registered (stored) in each cache server 200C. A cache registration storage unit 210 for storing information is provided.

  In response to the content distribution request from the user terminal device 300, the CDN management server 200 determines whether the requested content is cache-registered in the CDN, and responds to a content distribution request that is not cache-registered. Thus, a cache registration process for the corresponding converted content is performed with the content distribution control system 100. The cache server 200C receives the distribution processing start instruction transmitted from the CDN management server 200 in response to the content distribution request, and transmits the corresponding converted content stored in the converted content storage unit 210C to the user terminal device Deliver to 300. Note that the CDN of the present embodiment can apply the same configuration and distribution function as those of the conventional CDN, so that the description will focus on the points that are different from the conventional one, and other descriptions will be omitted as appropriate.

  FIG. 2 is a configuration block diagram of the content distribution control system 100 of the present embodiment. The content distribution control system 100 includes a distribution control server 110, a transcoding server 130, a CDN interface server 150, and a storage unit 170. In the example of FIG. 2, each server is illustrated in association with each processing unit and storage unit that configures the content distribution control system 100.

  The distribution control server 110 is a communication processing unit 111 that performs communication control with the user terminal device 300 via the Internet, and the distribution processing of the content requested for distribution in response to the content distribution request from the user terminal device 300 The distribution processing control unit 112 that determines the method, the first load information on the processing capacity of the transcoding server 130, and the number of simultaneous distribution processing connections (second load information) in the real-time transcoding distribution processing in the transcoding server 130 are monitored in real time. The load information monitoring unit 113 that collects and stores these pieces of load information, the content management unit 114 that manages the content to be distributed in the content distribution system 1, and the distribution policy control unit 115 that controls the distribution policy for the distributed content. Including.

  The transcoding server 130 performs a plurality of different types of transcoding processing on content (pre-conversion content) stored in an original or predetermined data format according to each terminal attribute of the user terminal device 300. (Transcoding processing unit) 132, communication processing unit 131 that distributes content in a data format converted according to each terminal attribute (converted content) to the user terminal device 300 via the Internet, and the user terminal device 300 A terminal that stores information such as terminal attributes, for example, attribute information for each model of the mobile phone (information on conversion type (corresponding data format) and image display capability corresponding to each terminal attribute of the user terminal device 300), etc. Attribute storage unit 140.

  The CDN interface server (CDN_IF server) 150 has an interface function with the CDN. Specifically, it performs functions of providing converted content in response to a cache registration request from the CDN management server 200 and collecting and storing each information of the entire CDN. As described above, the CDN management server 200 transmits a cache registration request to the content distribution control system 100 when the content requested for distribution from the user terminal device 300 is not registered in the cache. At this time, the CDN_IF server 150 receives this cache registration request, requests the transcoding server 130 to perform a transcoding process on the corresponding content, and transmits the converted content generated by the transcoding server 130 to the CDN management server 200. To do. These functions are performed by the CDN control unit 152, and communication control with the CDN management server 200 is performed by the communication processing unit 151.

  Further, the CDN_IF server 150 includes the URL information of the CDN management server 200 and storage resource information of each cache server 200C or the entire CDN (information on storage resources for converted content, including information on free capacity in storage capacity). It can be held in a storage unit (not shown). For example, the CDN_IF server 150 can collect and monitor storage resource information from the CDN management server 200 or each cache server 200C periodically (time unit, daily unit, etc.).

  The storage unit 170 is a pre-conversion content data storage unit 171 that stores content in an original or predetermined data format before transcoding processing, and a post-conversion content header storage that stores post-conversion content header information generated by the transcoding processing. Unit 172, a load information storage unit 173 that stores each piece of load information collected by the load information monitoring unit 113 of the distribution control server 110, a content history storage unit 174 that stores content distribution history information, and a distribution policy of the distribution control server 110 The control unit 115 includes a distribution policy storage unit 175 that stores a distribution policy associated with each content, and a content meta information storage unit 176 that stores meta information (metadata) associated with the content.

  In the content distribution system 1 of the present embodiment, for example, content is uploaded from the user terminal 300 or an administrator terminal device of a system operator (not shown) through a content registration page provided by the content management unit 114 of the distribution control server 110 ( be registered. The content management unit 114 stores the uploaded content in the pre-conversion content storage unit 171 in an original data format (for example, a data format at the time of upload) or a predetermined common data format.

  Each content has meta information such as date and time of creation, creator, data format, title, summary, category, etc. as information related to the content. Meta information can be input via a user or a predetermined meta information input field on the content registration page, and when the content is created, the creator or distributor creates the meta information in advance, Can be added to or included in the content as information accompanying the content. The content management unit 114 analyzes the content registered in the content registration process, extracts meta information, and stores it in the content meta information storage unit 176.

  Further, the content distribution control system 100 according to the present embodiment does not hold the converted content itself after the transcoding process, but only converts the converted content header information generated in the transcoding process with respect to the converted content. It is held in the storage unit 172.

  The transcoding process includes 1) header analysis process, 2) payload conversion process, 3) post-conversion header generation process, and 4) conversion for each conversion type corresponding to each terminal attribute with respect to input content (pre-conversion content) The process of combining the post header information and the payload is sequentially performed, and the data in which the post header information and the payload are combined is output as the post-conversion content corresponding to the terminal attribute. Here, the converted content header information is generally generated only after performing a series of transcoding processes. However, the converted content header information is information and terminal attributes necessary for transmitting the distribution packet itself. Information (for example, version, bit rate, packet information, etc.) is included, and if there is no converted content header information, the distribution process cannot be performed.

  Therefore, the converted content header information of each content corresponding to each terminal attribute is stored in advance, and the transcoding process in the real-time transcoding distribution process does not have the process of generating the converted content header information (without performing it) ), The post-conversion content header information is combined with the first delivery packet (first delivery packet) of the content sequentially generated by the payload conversion processing (see FIG. 4B). Therefore, in the transcoding process of the present embodiment, the time from the content distribution request to the distribution process, that is, the time until the first distribution packet of the converted content is transmitted can be shortened, and the transcoding process is completed. Compared to the conventional case where the distribution process is not performed otherwise, the delay from the content distribution request to the content distribution is avoided without depending on the conversion processing time after the content distribution request.

  FIG. 4A is a diagram illustrating an example of generation and storage processing of converted content header information. When content is newly registered, the content management unit 114, together with the above-described storage processing of meta information, A converted content header information generation processing request is output to the transcoding server 130. The transcoding server 130 performs the above processes 1) to 3) on the newly registered content, and associates the generated converted content header information with the converted content header storage unit 172 with each content. Store. As described above, the payload generated in the payload conversion process is discarded without being stored and retained.

  The load information storage unit 173 stores first load information about the processing capability of the transcoding server 130 monitored and collected in real time by the load information monitoring unit 113, for example, CPU usage rate and memory usage rate in time series. At the same time, the number of simultaneous distribution processing connections (number of simultaneous distribution processing requests) in the real-time transcoding distribution processing of the transcoding server 130 is stored in time series as second load information. For example, each load information can be stored in units of time (seconds, minutes, hours), days, weeks, and months, and the number of simultaneous distribution processing connections can be stored for each content. It is possible to store, for each content, the number (maximum number of simultaneous distributions for each content) that one content has simultaneously distributed (requested).

  The content history storage unit 174 stores the distribution request history of each content. For example, the number of distributions of each content (delivery request frequency), a time zone with a large number of distributions, the number of distributions by distribution method, and the maximum number of simultaneous distributions by content are stored for each content. These distribution request histories are managed by the content management unit 114 and are stored in the content history storage unit 174 through a distribution count process, a totaling process, and the like.

  The distribution policy storage unit 175 stores a distribution policy assigned to each content in a distribution policy determination process and a distribution policy update process described later. The distribution policy is a default distribution processing method assigned to all contents stored in the pre-conversion content storage unit 171, and the above-described first distribution processing method or second distribution processing method is a distribution policy for each content. Associated with.

  FIG. 3 is a flowchart showing an example of content distribution processing of the content distribution system 1 of the present embodiment.

  The user terminal device 300 accesses a content distribution page (not shown) provided by the content distribution control system 100 via the Internet (step S1), and selects desired content (step S3). The user's content selection is transmitted to the content distribution control system 100 as a content distribution request, and the distribution control server 110 of the content distribution control system 100 distributes the content requested for distribution based on the load state of the transcoding server 130. A system determination process is performed (step S5). At this time, the content distribution request includes the identification information of the selected content and the attribute information of the user terminal device 300.

  When the distribution control server 110 determines that the requested content distribution processing method is the first distribution processing method, the distribution control server 110 outputs a real-time transcoding distribution processing request for the content to the transcoding server 130. The transcoding server 130 acquires the corresponding content from the pre-conversion content storage unit 171 in response to the distribution processing request, and acquires the corresponding post-conversion content header information from the post-conversion content header storage unit 172. Also, conversion type information is acquired from the terminal attribute storage unit 140 using the attribute information of the user terminal device 300 included in the content distribution request. Then, the real-time transcoding process shown in FIG. 4B is executed using the pre-conversion content, post-conversion content header information, and conversion type. The transcoding server 130 sequentially transmits the distribution packet of the content generated in real time by the transcoding process to the user terminal device 300 through the Internet (step S7).

  On the other hand, when the distribution control server 110 determines the distribution processing method of the requested content as the second distribution processing method, the redirect information including the URL (one-time URL) of the CDN management server 200, the conversion type based on the terminal attribute, and the like. (Connection information) is generated (step S9) and transmitted to the user terminal device 300 (step S11). At this time, the distribution control server 110 acquires the URL of the CDN management server 200 from the CDN_IF server 150 to generate a one-time URL, and includes the conversion type of the content stored in the terminal attribute storage unit 140 in the content distribution request. Acquired based on attribute information.

  The user terminal device 300 accesses the CDN management server 200 that is the redirect destination by automatically reading the one-time URL included in the redirect information or when the user selects the one-time URL of the redirect information. At this time, a content distribution request including the conversion type is transmitted to the CDN management server 200 (CDN) (step S13).

  When receiving the content distribution request including the conversion type, the CDN management server 200 refers to the cache registration information storage unit 210 to determine whether or not the requested content is registered in the cache (step S15). Determination of cache registration is performed using the identification ID and conversion type of the content, and it is determined whether or not content having the same identification ID and the same conversion type is registered in the cache.

  If it is determined in step S15 that the cache is registered, a distribution route determination process is performed to determine an optimal cache server 200C for the user terminal device 300 from the plurality of cache servers 200C. A distribution processing request is output to the cache server 200C. In response to the distribution processing request from the CDN management server 200, the cache server 200C performs distribution processing for distributing the corresponding converted content stored in the converted content storage unit 210C to the user terminal device 300 ( Step S25).

  If it is determined in step S15 that the cache is not registered, the content management server 200 transmits a cache registration request for the content to the content distribution control system 100 (step S17).

  The cache registration request from the CDN management server 200 is received by the CDN_IF server 150. The CDN_IF server 150 requests the transcoding server 130 to perform a transcoding process for the corresponding content, and the transcoding server 130 transcodes the corresponding content. The converted content is generated by performing the coding process (step S19). The generated post-conversion content is output to the CDN_IF server 150 and transmitted to the CDN management server 200 (step S21).

  When the CDN management server 200 receives the converted content in response to the cache registration request, the CDN management server 200 performs cache registration processing of the converted content (step S23), transmits the converted content to each cache server 200C, and stores the converted content. Stored in the unit 210. Then, similarly to the above, a distribution route determination process for determining the optimum cache server 200C for the user terminal device 300 is performed, and a distribution process request is output to the determined cache server 200C. In response to the distribution processing request from the CDN management server 200, the cache server 200C distributes the corresponding converted content stored in the converted content storage unit 210C to the user terminal device 300 during the CDN cache distribution processing. Is performed (step S25).

  Note that the distribution route determination process in the CDN cache distribution process can be performed in the same manner as in the conventional CDN. In addition, the content distribution control system 100 according to the present embodiment can be configured to manage the function of the CDN management server 200, that is, the entire CDN, and perform the distribution route determination function and the cache registration function. In this case, the CDN_IF server 150 has these functions, and when it is determined to be the second distribution processing method, it performs a cache registration check and distribution route determination process, and the optimal cache server 200C for the user terminal device 300 is obtained. The redirect information including the one-time URL can be transmitted to the user terminal device 300 to control the content distribution from the determined cache server 200C.

  In addition, the cache server 200 </ b> C may be configured to have the function of the CDN management server 200 without providing the CDN management server 200. In the content distribution system 1 of the present embodiment, it is sufficient if the converted content is cached and the user terminal device 300 is provided with a cache server that performs the cache distribution processing, and the configuration of the CDN including the CDN management server 200 associated with the cache distribution. Is optional.

<Delivery process decision process>
FIG. 5 is a flowchart showing a processing flow of the distribution processing determination process of the content distribution control system 100 of the present embodiment. This processing is performed by the distribution control server 110, determines the distribution processing method of the content requested to be distributed based on the load state of the transcoding server 130, and performs distribution control in the determined distribution processing method. To do.

  Upon receiving the content distribution request from the user terminal device 300 (step S101), the distribution processing control unit 112 of the distribution control server 110 acquires the requested content distribution policy from the distribution policy storage unit 175 (step S102). . If the acquired distribution policy of the content is the second distribution processing method (step S103), redirect processing to the CDN is performed (step S104).

  On the other hand, when the distribution policy is the first distribution processing method by default, the distribution processing control unit 112 acquires the current number of simultaneous distribution processing connections of the transcoding server 130 (step S105), and the number of simultaneous distribution processing connections is predetermined. It is determined whether or not the threshold value (the number of allowable simultaneous delivery processing connections) has been reached (step S106). When the number of simultaneous distribution processing connections has reached the allowable number of simultaneous distribution connections, the distribution policy is the distribution processing method for the content of the first distribution processing method in order not to increase the processing capacity load of the transcoding server 130 any more. Is switched to the second distribution processing method, and redirect processing to the CDN is performed (step S104).

  When the number of simultaneous distribution processing connections does not reach the number of allowable simultaneous distribution processing connections, for example, the number of simultaneous distribution connections that can be obtained from the network traffic or the like, the distribution processing control unit 112 further performs transcoding. The current CPU usage rate of the server 130 is acquired (step S107), and it is determined whether or not the CPU usage rate exceeds a predetermined threshold (allowable CPU usage rate) (step S108). The CPU usage rate of the transcoding server 130 that performs the transcoding processing and the distribution processing is a predetermined threshold, for example, the maximum allowable CPU usage rate obtained from the CPU performance or a predetermined ratio arbitrarily set to suppress overflow is set to the maximum CPU. If the CPU usage rate upper limit value obtained by multiplying the usage rate is exceeded, the content of the first distribution processing method is set in order to prevent further increase in the processing capacity load of the transcoding server 130. The delivery processing method is switched to the second delivery processing method, and redirection processing to the CDN is performed (step S104).

  On the other hand, if the CPU usage rate does not exceed the predetermined threshold, the transcoding server 130 is requested to perform real-time transcoding distribution processing of the content (step S109), and the transcoding server 130 performs real-time transcoding distribution. Perform the process.

  Here, the real-time transcoding distribution process of the present embodiment is performed in response to a content distribution request from the user terminal device 300, and converted content is generated in response to the content distribution request. That is, the content distribution system 1 according to the present embodiment generates converted content only after a content distribution request is received from the user terminal device 300, including a cache distribution process to be described later, and after conversion after the real-time transcoding distribution process. Does not retain content. In other words, the converted content data itself is not held in advance as the entire system.

<CDN cache distribution processing>
FIG. 6 is a flowchart showing a processing flow of the CDN cache distribution processing method of the content distribution system 1 of the present embodiment. In the CDN cache distribution process of the present embodiment, the content distribution control system 100 transmits redirection information (connection information) including the one-time URL and conversion type of the CDN to the user terminal device 300, and the user terminal device 300 performs this redirection. This is started by making a content distribution request to the CDN based on the information.

  When receiving the content distribution request including the conversion type from the user terminal device 300 (step S301), the CDN management server 200 determines whether or not the requested content is registered in the cache (step S302). If the cache is registered, the cache server 200C that is most suitable for the user terminal device 300 among the plurality of cache servers 200C is determined (step S308), and the determined cache server 200C is stored in the converted content storage unit 210. The stored converted content is distributed to the user terminal device 300 (step S309).

  On the other hand, when it is determined that the requested content is not registered in the cache, the CDN management server 200 determines whether there is a free space in the storage capacity of the CDN (each cache server 200C) (step S303). . If it is determined that there is no free space in the storage capacity of the CDN, an alert (notification that distribution processing cannot be performed) is transmitted to the user terminal device 300, and the distribution processing is terminated (step S304). If it is determined in step S303 that there is free space, the CDN management server 200 transmits a cache registration request for the content to the content distribution control system 100 (step S305).

  When the CDN management server 200 receives the converted content in response to the cache registration request, the CDN management server 200 performs a cache registration process for the converted content (step S306), and the converted content that is newly cache-registered in each of the plurality of cache servers 200C. And stored in the post-conversion content storage unit 210C of the cache server 200C (step S307). In the present embodiment, when a content distribution request is made, whether or not the corresponding content is registered in the cache is determined. When it is determined that the content is not registered in the cache, the CDN cache distribution process is performed (content distribution from the user). The content after conversion of the corresponding terminal attribute is cached in each cache server 200C for the first time (in response to the request).

  Thereafter, the CDN management server 200 determines an optimal cache server 200C for the user terminal device 300 (step S308), and performs processing for distributing the converted content from the determined cache server 200 (step S309).

  The cache registration can include predetermined registration period information. For example, the cache registration is performed for a certain period such as how many days or weeks, and is deleted from the cache registration after a certain period. That is, the corresponding converted content is deleted after a predetermined period from the converted content storage unit 210C of each cache server 200C. This cache deletion process can be centrally managed by the CDN management server 200.

<Delivery policy decision processing>
FIGS. 7 and 8 are diagrams for explaining the distribution policy determination process of the present embodiment. In the present embodiment, when the content is distributed, the first and second distribution processing methods described above are used in advance for the content. Associate as a delivery policy. At this time, using the meta information and content distribution history information of each content, a distribution policy is determined as a default distribution processing method for each content.

  For this reason, in the present embodiment, as pre-processing, the distribution policy control unit 115 performs meta-information distribution policy determination processing as shown in FIG. The distribution policy control unit 115 analyzes the distribution request frequency for each content stored in the content history storage unit 174 using the meta information of each content (step S501), for example, distribution for each category included in the meta information Calculate the request frequency (delivery request frequency by meta information). Then, it is determined whether or not the distribution frequency for each category exceeds a predetermined threshold (distribution frequency threshold), and if it exceeds, the second distribution processing method is assigned to the category (step S502) and exceeded. If not, the first distribution processing method is assigned to the category (step S503). The distribution policy control unit 115 stores the distribution processing method assigned to each piece of meta information in the distribution policy storage unit 175 as a meta information distribution policy.

  FIG. 8 is a flowchart showing the process transition of the distribution policy determination method for each content. When new content is registered (step S701), the distribution policy control unit 115 acquires the storage resource information of the CDN from the CDN_IF server 150, and whether the CDN cache (the converted content storage unit 210C) has free space. It is determined whether or not (step S703).

  If it is determined that there is no predetermined free space in the content storage unit 210C after conversion of the CDN, the real-time transcoding distribution processing method, which is the first distribution processing method, for the newly registered content is distributed to the content. (Step S711) and stored in the distribution policy storage unit 175. At this time, an alert indicating that the storage resources of the CDN are insufficient can be output to an administrator terminal device (not shown) or the like (step S713).

  If it is determined in step S703 that the content storage unit 210C after conversion of the CDN has a predetermined free space, the distribution policy control unit 115 refers to the meta information of the newly registered content, and identifies the corresponding meta information. The distribution policy is determined as the distribution policy for the content (step S703), and the determined distribution policy is stored in the distribution policy storage unit 175.

  Then, the distribution policy control unit 115 determines whether or not the determined distribution policy for newly registered content is the second distribution processing method (step S705), and the CDN cache distribution processing method that is the second distribution processing method. If it is determined that there is, the process is terminated. On the other hand, when it is determined that it is not the second distribution processing method, that is, when it is determined that it is the real-time transcoding distribution processing method that is the first distribution processing method, as shown in FIG. Information generation processing and storage processing are performed, and the processing is terminated (steps S707 and S709).

  Note that the content registered with the second distribution processing method as the distribution policy is not registered in advance for the cache of the converted content into the CDN. That is, the transcoding process is performed in advance, and the converted content corresponding to each terminal attribute is not stored in the converted content storage unit 210C of the cache server 200C, but the content distribution request or the cache distribution process is performed as described above. The cache registration check for the content is performed. At this time, the converted content is cached in the converted content storage unit 210C for the first time, and the converted content is cached in the CDN until the content distribution request or the cache distribution processing is performed as the entire system. Not.

<Delivery policy update process>
FIG. 9 and FIG. 10 are flowcharts showing a processing flow of a distribution policy update process associated with each content. The distribution policy update process is performed for all the registered contents, and the content distribution policy is determined by using the content history information of each content, for example, the maximum number of simultaneous distributions of content and the distribution request frequency (traffic information). The process of updating is performed. The update process can be performed regularly or at an arbitrary timing.

  The distribution policy control unit 115 initializes the registered content search number (step S901), and acquires from the content history storage unit 174 the maximum number of simultaneous content distributions and the distribution request frequency since the previous distribution policy update process (step S903). .

  The distribution policy control unit 115 performs a process of determining whether or not each of the maximum number of simultaneous distributions and the distribution request frequency of the content exceeds a predetermined threshold (steps S905 and S907), and one of these exceeds the threshold. If it is determined that the storage resource information of the CDN is further checked, and there is free space in the converted content storage unit 210C, the second distribution processing method ( (CDN cache distribution process) is allocated, and if there is no free space, the first distribution processing method (real-time transcoding distribution process) is allocated (step S913).

  On the other hand, if it is determined that each of the maximum number of simultaneous distributions and the distribution request frequency of the content does not exceed the predetermined threshold values, the first distribution processing method is assigned (step S909).

  After the update distribution policy is assigned, the distribution policy control unit 115 checks whether or not there is a change to the distribution policy (pre-update distribution policy) currently assigned to the update distribution policy (step S915). ).

  Specifically, the first distribution processing method or the second distribution processing method is assigned as the update distribution policy, and the distribution policy of the content currently assigned is the same as the first distribution processing method or the second distribution processing method. If there is, it is determined that there is no change in the distribution policy, and the distribution policy update process for the next content is performed without performing the process of updating the distribution policy for the content to the update distribution policy (steps S925 and S927).

  On the other hand, when the first distribution processing method is assigned as the update distribution policy and the distribution policy of the content currently assigned is the second distribution processing method, it is determined that the distribution policy is changed to the second distribution processing method. The process proceeds to step S917. In step S917, the content header information after conversion is held in the post-conversion content header storage unit 172 for the first distribution processing for the content associated with the first distribution processing method as the distribution policy as described above. Therefore, a process of deleting the converted content header information of the content updated to the second distribution processing method from the converted content header storage unit 172 is performed. Thereafter, a distribution policy update process for the next content is performed (steps S925 and S927).

  Further, when the second distribution processing method is assigned as the update distribution policy and the distribution policy of the content currently assigned is the first distribution processing method, it is determined that the distribution policy is changed to the first distribution processing method. The process proceeds to step S919. In step S919, for the content associated with the first distribution processing method as the distribution policy as described above, the converted content header information is held in the converted content header storage unit 172 for the first distribution processing. Then, generation processing of converted content header information of the content updated to the first distribution processing method is performed and stored in the converted content header storage unit 172 (step S921). At this time, since the second distribution processing method is assigned to the content, when changing the distribution policy to the first distribution processing method, the distribution policy control unit 115 sends the content to the CDN management server 200 through the CDN_IF server 150. Is registered in the cache, and if it is registered in the cache, the CDN management server 200 is requested to perform a cache deregistration process (a cache deregistration request is transmitted). A process of deleting the corresponding converted content from the converted content storage unit 210 of the cache server 200 is performed (step S923). Thereafter, a distribution policy update process for the next content is performed (steps S925 and S927).

  As described above, the content distribution system 1 according to the present embodiment does not hold the converted content corresponding to each terminal attribute of the user terminal device 300 in advance, and the content before conversion is related to the original or predetermined data format. The transcoding process is performed only when there is a content distribution request from the user terminal device 300, and the converted content corresponding to each terminal attribute is generated. Then, by switching the real-time transcoding distribution processing to the CDN cache distribution processing method according to the load state of the transcoding server 130 and performing distribution, it is possible to suppress the overflow of the processing capacity of the transcoding server 130, and The 200C caches the converted content during the cache distribution process and performs the cache distribution process to the user terminal device 300.

  That is, it is not necessary for one content to be held in a one-to-many relationship for each terminal attribute, and it is possible to favorably suppress the overflow of the processing performance of the transcoding server 130, that is, an increase in the resource load state. In addition, the content after conversion is not cached in advance, but can be cached and distributed only when necessary for the cache distribution processing (content distribution request).

  Therefore, the entire system resources (content storage resources, CPU performance, etc.) for distributing the content converted into the data format corresponding to the terminal attribute of the user are maximized while efficiently using the resources of the entire system. It is possible to distribute content that can be reduced, and can suitably suppress quality degradation and distribution stoppage due to system resource depletion.

  In other words, the transcoding process corresponding to each terminal attribute must perform a plurality of types of transcoding processes for each terminal attribute, and a plurality of transcoding processes are required even for one content. For this reason, the processing load of the transcoding server 130 increases, but in the content distribution system 1 of the present embodiment, the content distribution control system 100 switches to CDN cache distribution according to the processing load of the transcoding server 130. An excessive increase in the server load of transcoding 130 can be suitably suppressed.

  In particular, the content distribution system 1 according to the present embodiment generates the converted content for the first time by the transcoding process when the content distribution request is made without holding the converted content in advance, and the first distribution processing method or the second Delivered using the delivery processing method.

  For this reason, the storage resources can be extremely reduced, and the transcoding server 130 can be designed with a minimum amount of resources, thereby realizing an efficient system resource. That is, since the overflow can be suppressed while maximizing the processing capability of the transcoding server 130 without retaining the content after conversion, the content distribution control system does not have unnecessary processing performance. 100 and CDN storage resources can be reduced as much as possible.

  Also, by setting a distribution policy in advance, it becomes possible to predict the processing load of the transcoding server 130 and the storage resources of the CDN, and a suitable system design can be performed. In addition, when a new content is registered, the storage resource of the CDN is checked, and when there is no free space, real-time transcoding distribution processing is assigned as a distribution policy instead of CDN cache distribution processing. Even if registered, it is possible to suitably avoid and suppress CDN cache delivery quality degradation and inability to deliver due to the shortage of CDN storage resources, and to maintain CDN without holding more storage resources than necessary. It is possible to efficiently use the storage resources.

  Further, the content distribution system 1 of the present embodiment can minimize the resources of the entire system, unlike a load distribution technique such as a conventional load balancer. In other words, the conventional load balancing technique is intended to average the processing load among a plurality of servers and cannot improve the efficiency of the server resource itself, but in this embodiment, the entire system and the system possess Resources such as each device can be made efficient.

  In addition, system resources can be easily predicted by appropriately updating the distribution policy, and transcoding is not performed until a content distribution request is made without holding the converted content in advance at the time of allocation and update of the distribution policy. Since the process is executed, the converted content is generated, and the converted content is stored in the cache server 200C, the system can be realized with extremely fewer storage resources than in the past. In addition, when the distribution policy of the content registered in the cache in the CDN is changed (updated) to the first distribution processing method, the cache registration is deleted, and the converted content storage unit 210C of the cache server 200C performs the corresponding conversion. Since the contents are deleted, the efficiency of the CDN storage resources can be improved.

  Here, in the first embodiment, the distribution policy is determined for each content, and the content distribution in which the distribution processing method is switched or the distribution processing method is switched for each content requested for distribution has been described. As described above, the user terminal device 300 has different terminal attributes, and the converted content is generated according to the number of conversion types corresponding to the terminal attribute. In other words, since a plurality of converted contents corresponding to the terminal attributes are generated even for a single content, it is possible to manage and distribute the contents in pairs of the contents and the terminal attributes.

  Specifically, one content registered in the content distribution system 1 is managed for each terminal attribute. For example, when there are three terminal attributes x, y, and z, one content A is the content Ax. , Content Ay, and content Az are individually managed. If there is a content distribution request for the same content A even for a single content A, the distribution processing method of the content A is determined for each terminal attribute transmitted from the user terminal device 300, and the distribution is performed. Processing can be performed. Also, a different distribution policy is assigned for each terminal attribute, and a plurality of distribution policies for each terminal attribute are associated with one content and stored. In the examples of FIGS. 9 and 10, the terminal attribute and the content are paired, for example, for each of the content Ax, the content Ay, and the content Az, the distribution policy update process based on the maximum number of simultaneous distributions and the distribution request frequencies. Will be carried out.

  Further, the content management unit 114 can further store history information stored for each content for each terminal attribute. That is, in the first embodiment described above, content history information can be managed and stored for each content and each terminal attribute. Therefore, in the content distribution system of the present invention, it is possible to perform distribution control and various processes by managing each content and / or each content for each of a plurality of terminal attributes. Even if one content is managed by each terminal attribute, since the converted content for each terminal attribute is not retained, the same effect as the first embodiment can be obtained, and for each terminal attribute Since one piece of content is managed, it becomes possible to achieve finer control and system resource efficiency. Note that, among a plurality of contents registered in the content distribution system 1, content managed and controlled in units of content and content managed and controlled in units of terminal attributes are mixed as in the first embodiment described above. Alternatively, the content distribution system 1 can be realized by either one of the management / control.

  Note that each terminal attribute of the user terminal device 300 and the conversion type used for the transcoding process do not necessarily have a one-to-one relationship. For example, the same conversion type is associated even if the terminal attributes are different. There is also. That is, if the data format and image display capability corresponding to the content of the user terminal device 300 are the same in other terminal attributes or correspond to the data format, the same conversion type for different terminal attributes And the transcoding process is performed using the conversion type.

  In addition to the above, each server has an operation input unit such as a keyboard, mouse, and scanner, a display unit such as a liquid crystal display, an output unit such as a printer and a speaker, a main storage device (memory), and an auxiliary storage. A device (hard disk or the like) can be provided, and the user terminal device can also be provided with these means. Control of each unit and each device is performed by a control unit (CPU) that controls the server or the entire computer (not shown).

  In the content distribution system 100 according to the present embodiment, the distribution control server 110, the transcoding server 130, and the CDN_IF server 150 are realized by different server devices, respectively. Is also possible. Moreover, it is also possible to realize a distributed system in which each server device and / or each processing unit is distributed to a plurality of information processing devices on a network and connected via a communication line.

  Further, the content distribution processing and distribution control (each step) of the present invention can be provided as a computer-executable program, and the computer on which the program is installed performs the content distribution processing of the present invention. It is possible to operate as an information processing apparatus. For example, the program is stored in an auxiliary storage device (not shown), and a control unit such as a CPU reads the program stored in the auxiliary storage device to the main storage device, and the control unit reads the program read to the main storage device. And execute the processing of the present invention in a computer. The program of the present invention can also be provided in a state of being recorded on a computer-readable recording medium. Computer-readable recording media include optical disks such as CD-ROM, phase change optical disks such as DVD-ROM, magneto-optical disks such as MO (Magnet Optical) and MD (Mini Disk), floppy (registered trademark) disks, Examples include magnetic disks such as removable hard disks, memory cards such as compact flash (registered trademark), smart media, SD memory cards, and memory sticks. A hardware device such as an integrated circuit (IC chip or the like) specially designed and configured for the purpose of the present invention is also included as a recording medium.

  As described above, the present invention has been described according to the preferred embodiments, but various modifications can be made in light of the technology in the technical field without departing from the gist of the present invention. Therefore, the technical scope of the present invention should not be limited to the above-described embodiment, but should be determined based on the description of the claims and equivalents thereof.

1 Content Distribution System 100 Content Distribution Control System 110 Distribution Control Server 111 Communication Processing Unit 112 Distribution Processing Control Unit 113 Load Information Monitoring Unit 114 Content Management Unit 115 Distribution Policy Control Unit 130 Transcoding Server 131 Communication Processing Unit 132 Conversion Processing Unit 140 Terminal Attribute storage unit 150 CDN interface server 151 Communication processing unit 152 Control unit 170 Storage unit 171 Pre-conversion content storage unit 172 Post-conversion content header storage unit 173 Load information storage unit 174 Content history storage unit 175 Distribution policy storage unit 176 Content meta information storage Unit 200 CDN management server 210 cache registration information storage unit 200C cache server 210C converted content storage unit 300 user terminal device

Claims (13)

A content distribution system for distributing content converted into a data format corresponding to each terminal attribute of a user terminal device,
A function of performing different transcoding processing on the pre-conversion content held in the content storage device according to each terminal attribute, and performing real-time transcoding distribution processing in response to a content distribution request from the user terminal device A first distribution processing device for performing;
The resource load of the first distribution processing device is monitored, and the distribution process of the content requested for distribution is switched from the real-time transcoding distribution process to the cache distribution process based on the resource load state at the time of the content distribution request. A delivery control device;
A second distribution processing device that caches the converted content generated through the transcoding processing of the first distribution processing device during the cache distribution processing;
A content distribution system comprising: The delivery control device
Monitoring the number of simultaneous delivery processing connections in the real-time transcoding delivery processing, determining whether the number of simultaneous delivery processing connections at the time of the content delivery request has reached an allowable number of simultaneous delivery processing connections; 2. The content distribution according to claim 1, wherein when the number of connections reaches an allowable simultaneous distribution process, the distribution process of the content requested to be distributed is switched from the real-time transcoding distribution process to the cache distribution process. system. The delivery control device
The CPU usage rate of the first distribution processing device is monitored to determine whether or not the CPU usage rate at the time of the content distribution request has reached an allowable CPU usage rate, and the allowable CPU usage rate is an allowable CPU usage rate 3. The content distribution system according to claim 1, wherein the distribution processing of the content requested to be distributed is switched from the real-time transcoding distribution processing to the cache distribution processing. The distribution control device transmits connection information to the second distribution processing device to the user terminal device when switching the distribution processing of the requested content from the real-time transcoding distribution processing to the cache distribution processing,
Whether the second distribution processing device is cache-registered after conversion content corresponding to the content requested by the content distribution request transmitted from the user terminal device based on the connection information 4. The converted content generated through the transcoding process of the first distribution processing apparatus during the cache distribution process when the cache is not registered is cached. 5. The content distribution system according to one. The content storage device further includes a post-conversion content header storage unit that holds a post-conversion content header for each terminal attribute generated by the transcoding process for the pre-conversion content,
The real-time transcoding distribution process includes:
The distribution packet of the converted content sequentially generated by the payload conversion processing in the transcoding processing is combined with the corresponding converted content header information stored in the converted content header storage unit in advance and distributed. The content distribution system according to any one of claims 1 to 4. The content storage device includes a content meta information storage unit that stores meta information of the content, and a content history storage unit that stores a frequency of distribution requests for the content,
The distribution control device includes a distribution policy control unit that allocates the real-time transcoding distribution process or the cache distribution process as a distribution policy of each content to each of the contents,
The distribution policy control unit assigns a distribution policy to each content stored in the content storage device using a distribution request frequency for each meta information obtained by analyzing a distribution request frequency for each content for each meta information. The content distribution system according to any one of claims 1 to 5, characterized in that: The distribution policy control unit
It is determined whether or not the free capacity in the cache capacity of the second distribution processing device is smaller than a predetermined value, and when the free capacity is smaller than the predetermined value, the real time regardless of the distribution request frequency by meta information 7. The content distribution system according to claim 6, wherein transcoding distribution processing is assigned as a distribution policy. The content history storage unit further stores the maximum number of simultaneous deliveries of each content,
The distribution policy control unit
Update that changes the distribution policy of the content to which the real-time transcoding distribution process is assigned to the cache distribution process when at least one of the content distribution request frequency or the maximum number of simultaneous distributions is greater than a predetermined threshold value 7. The content distribution system according to claim 6, wherein the content distribution system performs processing. The distribution policy control unit
Update processing for changing the content distribution policy to which the cache distribution processing is assigned to the real-time transcoding distribution processing when each of the content distribution request frequency and the maximum number of simultaneous distributions is smaller than each predetermined threshold value The content distribution system according to claim 8, wherein: A content distribution method for distributing content converted into a data format corresponding to each terminal attribute of a user terminal device,
The first distribution processing device performs different transcoding processing on the pre-conversion content held in the content storage device according to each terminal attribute, and real-time transcoding triggered by the content distribution request from the user terminal device Performing the delivery process;
A distribution control device monitors the resource load of the first distribution processing device, and performs distribution processing of the content requested for distribution from the real-time transcoding distribution processing based on the resource load state at the time of the content distribution request. Switching to cache delivery processing;
A second distribution processing device caching the converted content generated through the transcoding processing of the first distribution processing device during the cache distribution processing;
A content distribution method comprising: A content distribution system for distributing content converted into a data format corresponding to each terminal attribute of a user terminal device,
A function of performing different transcoding processing on the pre-conversion content held in the content storage device according to each terminal attribute, and performing real-time transcoding distribution processing in response to a content distribution request from the user terminal device A real-time transcoding distribution processing device to perform;
The resource load of the real-time transcoding distribution processing device is monitored, and the distribution process of the content requested for distribution is changed from the real-time transcoding distribution process to the cache distribution process based on the resource load state at the time of the content distribution request. A distribution control device to be switched;
Based on the cache request transmitted from the cache distribution processing device that caches the converted content during the cache distribution processing, the converted content generated through the transcoding processing of the real-time transcoding distribution processing device is the cache distribution processing. An interface device for transmitting to the device;
A content distribution system comprising: A distribution control device of a content distribution system including a first distribution processing device that performs different transcoding processing according to each terminal attribute of a user terminal device and performs real-time transcoding distribution processing,
A load information monitoring unit for monitoring a resource load of the first distribution processing device;
Based on the resource load state at the time of a content distribution request from the user terminal device, the distribution process of the content requested for distribution depends on the terminal attribute generated from the real-time transcoding distribution process through the transcoding process. A distribution processing control unit that switches to a cache distribution process that distributes through the second distribution processing device that caches the converted content,
The distribution processing control unit
Distribution control for transmitting connection information to the second distribution processing device to the user terminal device when switching the distribution processing of the content requested to be distributed from the real-time transcoding distribution processing to the cache distribution processing. apparatus. A distribution control program for a content distribution system including a first distribution processing device that performs different transcoding processing according to each terminal attribute of a user terminal device and performs real-time transcoding distribution processing,
A first function for monitoring a resource load of the first distribution processing device;
Based on the resource load state at the time of a content distribution request from the user terminal device, the distribution process of the content requested for distribution depends on the terminal attribute generated from the real-time transcoding distribution process through the transcoding process. A second function for switching to a cache distribution process that distributes through the second distribution processing device that caches the converted content;
A third function of transmitting connection information to the second distribution processing device to the user terminal device when switching the distribution processing of the requested content from the real-time transcoding distribution processing to the cache distribution processing;
A distribution control program for realizing a computer.

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