CDN Scale Down

Patent metadata

Field	Value
Publication number	US-2016006836-A1
Application number	US-201414325680-A
Country	US
Kind code	A1
Filing date	Jul 8, 2014
Priority date	Jul 1, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

In one embodiment, a system component in a content delivery network (CDN), the CDN including a request router and edge caches, the request router being operable to determine which edge cache should serve content to a client, the system component including a processor, and a memory to store data used by the processor, wherein the processor is operative to receive a request for content from the client, and based on a decision to shut down a first edge cache after the client has already downloaded some of the content from the first edge cache, participate in a process to transfer the client from downloading the content from the first edge cache to downloading the content from a second edge cache in the middle of the client downloading the content so that the client continues downloading the content from the second edge cache. Related apparatus and methods are also described.

First claim

What is claimed is:

1 . A system component in a content delivery network (CDN), the CDN including a request router and a plurality of edge caches, the request router being operable to determine which one of the edge caches should serve content to a client, the system component comprising: a processor; and a memory to store data used by the processor, wherein the processor is operative to:
receive a request for content from the client; and based on a decision to shut down a first edge cache after the client has already downloaded some of the content from the first edge cache, participate in a process to transfer the client from downloading the content from the first edge cache to downloading the content from a second edge cache in the middle of the client downloading the content so that the client continues downloading the content from the second edge cache.

2 . The system component according to claim 1 , further comprising a cache memory to store the content therein, the cache memory and the processor being comprised in the first edge cache, the processor being operative to serve at least some of the content stored in the cache memory to the client.

3 . The system component according to claim 2 , wherein the processor is operative to redirect the client to the request router so that the client can receive an identification of the second edge cache selected by the request router for the client to continue downloading of the content therefrom.

4 . The system component according to claim 2 , wherein the processor is operative to:
send a request to the request router to select one of the edge caches from which the client will continue downloading of the content; receive an identification of the selected one of the edge caches, being the second edge cache, from the request router; and send the identification of the second edge cache to the client.

5 . The system component according to claim 4 , wherein the processor is operative to: send data to the client to trigger the client to re-request a manifest file; and then send, to the client, a redirect to the second edge cache.

6 . The system component according to claim 2 , wherein the processor is operative to send data to the client to trigger the client to re-request a manifest file.

7 . The system component according to claim 6 , wherein on receipt of re-request of the manifest, the processor is operative to send data to the client to redirect the client to the request router.

8 . The system component according to claim 1 , wherein:
the processor is comprised in the request router; in response to receiving the request for content from the client, the processor is operative to send an identification of the first edge cache to the client in order for the client to retrieve a manifest file and the content from the first edge cache; and select one of the edge caches from which the client will continue downloading of the content.

9 . The system component according to claim 8 , wherein the processor is operative to:
receive another request from the client related to receiving the content; and send an identification of the selected one of the edge caches, being the second edge cache, to the client in order for the client to continue downloading the content from the second edge cache.

10 . The system component according to claim 9 , wherein the other request from the client related to receiving the content is a manifest file request.

11 . The system component according to claim 8 , wherein the processor is operative to:
receive a request from the first edge cache to select one of the edge caches from which the client will continue downloading of the content; and send an identification of the selected one of the edge caches, being the second edge cache, to the first edge cache.

12 . The system component according to claim 1 , wherein the processor is operative to edit a manifest file including location data so that the location data of the content which is still to be downloaded is amended from pointing to the first edge cache to pointing to the second edge cache.

13 . The system component according to claim 1 , wherein the processor is operative to send data about the clients being served by one of the edge caches to an orchestration system which monitors the edge caches to determine whether the CDN should be scaled up or down by adding or removing, respectively, an instance of the edge caches.

14 . The system component according to claim 13 , wherein the processor is operative to send a notification, to the orchestration system, that the first edge cache is no longer serving content to any client.

15 . A client device comprising: a processor; and a memory to store data used by the processor, wherein the processor is operative to:
request content from a first edge cache in a content delivery network (CDN) including a plurality of edge caches; download at least some of the content from the first edge cache; while the first edge cache is still operational, receive data including an identification of a second edge cache in the CDN redirecting downloading the content from the first edge cache to downloading the content from the second edge cache based on a decision to shut down the first edge cache; and continue downloading the content from the second edge cache based on the identification of second edge cache.

16 . The device according to claim 15 , wherein the content includes a plurality of segments, the identification of the second edge cache including a locator of the second edge cache, the processor being operative to:
receive a manifest file from the first edge cache, the manifest file including a plurality of locators of the segments of the content; prepend the locator of the second edge cache to at least some of the locators of the segments of the content yielding a plurality of new locators; and continue downloading the content from the second edge cache based on the new locators of the segments.

17 . The device according to claim 15 , wherein the processor is operative to:
request a first manifest file for at least part of the content from the first edge cache; receive the first manifest file from the first edge cache; request a second manifest file for at least part of the content from the second edge cache based on receiving the identification of the second edge cache selected by a request router for the client device to continue downloading of the content therefrom, the request router being operable to determine which one of the edge caches should serve content to a client; receive the second manifest file from the second edge cache; and continue downloading the content from the second edge cache based on the second manifest file.

18 . The device according to claim 17 , wherein the processor is operative to: receive a trigger from the first edge cache to re-request a manifest file; and then receive, from the first edge cache, a redirect to the second edge cache.

19 . The device according to claim 17 , wherein the processor is operative to:
receive a trigger from the first edge cache to re-request a manifest file; then send a request for a manifest file to the first edge cache based on receiving the trigger; then receive a redirect to the request router; then request a manifest file from the request router; then receive an identification of the second edge cache from request router; then request the second manifest file from second edge cache based on the identification received from request router.

Assignees

• Cisco Tech Inc

Inventors

• Lefaucheur Francois
• Wang Qi

Classifications

• H04L65/80

  Responding to QoS · CPC title

• H04L65/1083

  In-session procedures · CPC title

• H04L67/10

  in which an application is distributed across nodes in the network (software deployment G06F8/60; multiprogramming arrangements G06F9/46) · CPC title

• H04L67/42 Primary

  Electricity · mapped topic

• H04L67/2842

  Electricity · mapped topic