Patent Publication Number: US-11032583-B2

Title: Method and system for improving high availability for live content

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/805,123 filed on Feb. 13, 2019, the contents of which are hereby incorporated by reference. This application is also a continuation-in-part application (CIP) of U.S. patent application Ser. No. 16/151,868 filed Oct. 4, 2018. The Ser. No. 16/151,868 application is also a continuation of Ser. No. 15/078,543, filed Mar. 23, 2016, now U.S. Pat. No. 10,097,863, which is a CIP of Ser. No. 13/006,785, filed Jan. 14, 2011, now U.S. Pat. No. 9,723,073, which claims the benefit of 61/375,836, filed Aug. 22, 2010, and said Ser. No. 15/078,543, filed Mar. 23, 2016, which claims the benefit of 62/140,067, filed Mar. 30, 2015, and which claims the benefit of 62/146,266, filed Apr. 11, 2015. 
    
    
     TECHNICAL FIELD 
     The disclosure generally relates to content delivery networks and particularly to improving content caching in a content delivery network. 
     BACKGROUND 
     Content delivery networks (CDNs) are a vital part of the Internet today, and allow for global content availability and distribution. CDNs store content which may be accessed by user devices near the CDN, and, in this way, allow for distribution of network resources. Acquisition of content is a key element of an effective CDN, aiming to reduce latency between the client requesting content and the CDN delivering said content. 
     A solution, for example, which would identify a content session of a user, and acquire content by following the content session of a single user, may be limited by dependence on that user. In such an example, if a user decides to pause the content, or they have a poor connection, following the specific user&#39;s session would cause all the other users, which are provided with the content based on the activity of the first user, to experience all the lag which the first user suffers from. 
     It would, therefore, be advantageous to provide a solution for CDNs which improves its capabilities in content acquisition. 
     SUMMARY 
     A summary of several example embodiments of the disclosure follows. This summary is provided for the convenience of the reader to provide a basic understanding of such embodiments and does not wholly define the breadth of the disclosure. This summary is not an extensive overview of all contemplated embodiments and is intended to neither identify key or critical elements of all embodiments nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later. For convenience, the term “some embodiments” or “certain embodiments” may be used herein to refer to a single embodiment or multiple embodiments of the disclosure. 
     Certain embodiments disclosed herein include a method for acquiring live content for a content delivery network (CDN). The method comprises the steps of intercepting a content manifest based on a content session initiated by a first user node and a broadcast server, where the content manifest includes at least one content identifier (ID) and its corresponding content chunk; fetching the content chunk to store in a memory of the CDN; receiving a request from a second user node for content of the content session; continuously determining a leader user node between at least the first user node and the second user node; and fetching at least a content chunk based on a content manifest of the leader user node. 
     Certain embodiments disclosed herein also include a non-transitory computer readable medium having stored thereon instructions for causing a processing circuitry to perform a process, the process comprising the steps of intercepting a content manifest based on a content session initiated by a first user node and a broadcast server, where the content manifest includes at least one content identifier (ID) and its corresponding content chunk; fetching the content chunk to store in a memory of the CDN; receiving a request from a second user node for content of the content session; continuously determining a leader user node between at least the first user node and the second user node; and fetching at least a content chunk based on a content manifest of the leader user node. 
     Certain embodiments disclosed herein also include a system for acquiring live content for a content delivery network (CDN). The system comprises: a processing circuitry; and a memory, the memory containing instructions that, when executed by the processing circuitry, configure the system to: intercept a content manifest based on a content session initiated by a first user node and a broadcast server, where the content manifest includes at least one content identifier (ID) and its corresponding content chunk; fetch the content chunk to store in the CDN; receive a request from a second user node for content of the content session; continuously determine a leader user node between at least the first user node and the second user node; and fetch at least a content chunk based on a content manifest of the leader user node. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter disclosed herein is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the disclosed embodiments will be apparent from the following detailed description taken in conjunction with the accompanying drawings. 
         FIG. 1  is a schematic illustration of a plurality of content delivery networks delivering a live broadcast content, implemented in accordance with an embodiment. 
         FIG. 2  is a flowchart of a method for improving content delivery network caching, implemented in accordance with an embodiment. 
         FIG. 3  is a schematic diagram of an SDA according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     It is important to note that the embodiments disclosed herein are only examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed embodiments. Moreover, some statements may apply to some inventive features but not to others. In general, unless otherwise indicated, singular elements may be in plural and vice versa with no loss of generality. In the drawings, like numerals refer to like parts through several views. 
       FIG. 1  is an example schematic diagram  100  illustrating a plurality of content delivery networks delivering live broadcast content, implemented in accordance with an embodiment. 
     In an example embodiment, live content is generated, for example, by a camera  110 . The camera  110  is communicatively connected with a broadcast server  120 . The broadcast server  120  is communicatively connected with a network  101 , which may allow, in certain embodiments, for connection of the broadcast server  120  to the Internet. 
     In an embodiment, the network  101  may be configured to provide connectivity of various sorts, as may be necessary, including, but not limited to, wired and/or wireless connectivity, including, for example, local area networks (LAN), wide area networks (WAN), metro area networks (MAN), world wide web (WWW), Internet, and any combination thereof, as well as cellular connectivity. This would allow a user node (or client device) to connect to the broadcast server  120  and view the content recorded by the camera  110 . 
     Typically, the broadcast server  120  has a limited number of connections the server  120  can sustain. In an embodiment, the number of connections may be significantly lower than the number of user nodes  141 - 146  which wish to view the content. 
     In order to solve this problem, content delivery networks (CDNs)  130  are deployed. The purpose of a CDN is to provide high availability of content to a geographical area which includes user nodes  141 - 146  in physical proximity to the elements of the CDN. For example, the Olympic events are typically broadcast from a single country but viewed around the world. The broadcast server  120  may be located, for example in Brazil, while a first CDN  130 - 1  is located in North America, a second CDN  130 - 2  is located in Europe, and a third CDN  130 -N is located in Asia. It should be readily understood that this example is in no way limiting, and CDNs are not bound to be country based. 
     When a user node  144  requests the live content from the broadcast server  120 , the request is intercepted by a CDN  130 . Each CDN  130  typically includes a service delivery apparatus (SDA)  135  and proxy servers (not shown) and content storage (not shown). The CDN should acquire the content and provide the acquired content to a user node  144 . When, for example, a user node  145  requests to view the content at a later time, the CDN  130 -N may readily supply the requested content, as such content was already requested by user node  144  before. 
     The SDA  135  is a component or otherwise connected to a CDN  130  which is configured to continuously determine what content should be cached by the CDN  130  in order to provide to the local user nodes  144 - 146 . The SDA  135  is discussed in more detail in U.S. Pat. No. 9,723,073 titled “A System for Detection of Content Servers and Caching Popular Content Therein”, assigned to common assignee, the contents of which are incorporated by reference herein. The SDA  135  may be configured as a sniffer, or as a ‘bump-in-the-wire.’ In this example, the SDA  135  is configured as a sniffer. 
     When configured as a sniffer, the SDA  135  is configured to listen to the traffic moving between a content network and the broadcast server  120  without routing packets through the SDA  135 . When the SDA  135  is connected in a sniffer mode, the SDA  135  typically connects to the CDN  130  through a separate communication port to provide content stored therein to a destination (e.g. client device) connected to the content delivery network. 
     Typically, when a first user node  144  requests content from the broadcast server  120 , the server  120  is configured to return a manifest which includes content IDs and corresponding chunks of content which can be served. A user node requests the content chunks based on the content ID, in the order which is specified by the manifest. As this is a live broadcast, the manifest is constantly updated by the broadcast server  120 . 
     When the SDA  135  is configured to intercept the content manifest of a user node  144 , the SDA  135  typically continues to monitor the data session of a user node  144 . This is performed in order to determine, from the manifest, what the available chunks of content are, so that such chunks can be downloaded from the broadcast server  120  to, for example, the CDN  130 -N. The chunks downloaded to CDN  130 -N are stored and delivered to user nodes  145  and  146  when they request delivery of the live broadcast. In an embodiment, a user node  144  is known as the leader, as is the user node from which the SDA  135  bases the content fetching. 
     However, configuring an SDA thus results in a limitation. Essentially, the user nodes  145  and  146  are limited by the bandwidth of the user node  144 . For example, if the user node  144  has low bandwidth, the node  144  requests content at a slower pace than a user node which has higher bandwidth, such as the user node  145 . 
     In order to overcome the bandwidth limitation, according to the disclosed embodiments, the SDA  135  is configured to continuously determine the leader user node, so as to have access to a manifest with as much content as possible. Downloading of the content earlier from the broadcast server  120  to, for example, the CDN  130 -N may result in being able to provide the content to the user nodes at a higher rate. 
     In an example embodiment, some user nodes, such as user node  144  may receive content from more than one CDN, such as CDN  130 -N, where ‘N’ is an integer having a value of ‘2’ or greater. 
       FIG. 2  is an example flowchart  200  of a method for improving content delivery network caching, implemented in accordance with an embodiment. 
     At S 210 , a content manifest is intercepted based on a content session of a user node. The user node is designated as a leader user node. The content session includes a request from the user node to a broadcast server to receive a stream of live content. The content manifest includes at least one content ID and a corresponding content chunk. In some embodiments, the content ID may be further segmented into different resolutions, so that the same content can be delivered at different resolutions. 
     In certain embodiments, it is not uncommon for the resolution of a video content to change throughout the content session, adapting to the conditions of the network and available bandwidth. 
     At S 220 , it is determined if at least one content chunk should be fetched. The determination is based on the content manifest. In some embodiments, a request is sent to the broadcast server requesting the same content in different resolutions. This is performed in order to be ready to supply, to other user nodes, the content, at different resolutions. In some embodiments, the content, at different resolutions, can be delivered depending on the conditions of the network. 
     At S 230 , one or more determined chunks are fetched. In an embodiment, to fetch the chucks, a request is sent to the broadcast server for the content. The request may include the content ID, or content ID and resolution. The fetched chunks are stored by the SDA from its cache memory. In an embodiment, some of the fetched chunks may be saved in a fast access memory, while some other chunks are stored on a slower access storage device of the SDA. The fast access memory includes one of a random-access memory (RAM) and a solid-state drive (SSD). The slower access memory may include magnetic technologies (e.g., HDDs) which are considered relatively slow. It should be noted that also two different types of SSDs can be used, one type is slower than the other. 
     At S 240 , a check is performed to determine if additional content should be requested. In an embodiment, S 240  includes determining if there are additional content IDs on the content manifest which were not yet received. Alternatively, it is checked if additional content should be requested from the broadcast server based on an updated manifest. If additional content should be requested, execution continues at S 250 , otherwise execution terminates. 
     At S 250 , a leader user node is identified. In an embodiment, S 250  includes monitoring requests for content from other user nodes (e.g., a second user node), to determine if another leader user node should be selected in place of the current leader user node. Typically, the leader user node is the user node with the most advanced content manifest, i.e., the user node which has the most future content chunks available to it for download from the broadcast server. Once a leader is determined, execution returns to S 210 . 
     In an embodiment, the method described with reference to  FIG. 2  is performed by the SDA, e.g., the SDA  135 . An example block diagram of the SDA is provided in  FIG. 3 . 
       FIG. 3  is an example schematic diagram of an SDA  135  according to an embodiment. The SDA  135  includes a processing circuitry  310  connected to a memory  320 , a storage  330 , and a network interface  340 . In an embodiment, the components of the SDA  135  may be communicatively connected via a bus  350 . 
     The processing circuitry  310  may be realized as one or more hardware logic components and circuits. For example, and without limitation, illustrative types of hardware logic components that can be used include field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), Application-specific standard products (ASSPs), system-on-a-chip systems (SOCs), graphics processing units (GPUs), tensor processing units (TPUs), general-purpose microprocessors, microcontrollers, digital signal processors (DSPs), and the like, or any other hardware logic components that can perform calculations or other manipulations of information. 
     The memory  320  may be volatile (e.g., RAM, etc.), non-volatile (e.g., ROM, flash memory, etc.), or a combination thereof. 
     In one configuration, software for implementing one or more embodiments disclosed herein may be stored in the storage  330 . In another configuration, the memory  320  is configured to store such software. Software shall be construed broadly to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code). The instructions, when executed by the processing circuitry  310 , cause the processing circuitry  310  to perform the various processes described herein. 
     The storage  330  may be magnetic storage, optical storage, and the like, and may be realized, for example, as flash memory, SSD, or other memory technology, CD-ROM, Digital Versatile Disks (DVDs), or any other medium which can be used to store the desired information. The network interface  340  allows the SDA  135  to communicate with the CDN  130  and the broadcast server  120  ( FIG. 1 ). In an embodiment, the storage  330  may include two type of storage units including a slower access memory and fast access memory as discussed above. The cache of SDA  135  may be part of the storage  330 . 
     It should be understood that the embodiments described herein are not limited to the specific architecture illustrated in  FIG. 3 , and other architectures may be equally used without departing from the scope of the disclosed embodiments. 
     The various embodiments disclosed herein can be implemented as hardware, firmware, software, or any combination thereof. Moreover, the software is preferably implemented as an application program tangibly embodied on a program storage unit or computer readable medium consisting of parts, or of certain devices and/or a combination of devices. The application program may be uploaded to, and executed by, a machine comprising any suitable architecture. Preferably, the machine is implemented on a computer platform having hardware such as one or more central processing units (“CPUs”), a memory, and input/output interfaces. The computer platform may also include an operating system and microinstruction code. The various processes and functions described herein may be either part of the microinstruction code or part of the application program, or any combination thereof, which may be executed by a CPU, whether or not such a computer or processor is explicitly shown. In addition, various other peripheral units may be connected to the computer platform such as an additional data storage unit and a printing unit. Furthermore, a non-transitory computer readable medium is any computer readable medium except for a transitory propagating signal. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the principles of the disclosed embodiment and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosed embodiments, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. 
     It should be understood that any reference to an element herein using a designation such as “first,” “second,” and so forth does not generally limit the quantity or order of those elements. Rather, these designations are generally used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in some manner. Also, unless stated otherwise, a set of elements comprises one or more elements. 
     As used herein, the phrase “at least one of” followed by a listing of items means that any of the listed items can be utilized individually, or any combination of two or more of the listed items can be utilized. For example, if a system is described as including “at least one of A, B, and C,” the system can include A alone; B alone; C alone;  2 A;  2 B;  2 C;  3 A; A and B in combination; B and C in combination; A and C in combination; A, B, and C in combination;  2 A and C in combination; A,  3 B, and  2 C in combination; and the like.