Stream control failover utilizing the sharing of state information within a logical group of stream servers

• US 8,326,967 B2
• Filed: 03/31/2006
• Issued: 12/04/2012
• Est. Priority Date: 04/01/2005
• Status: Active Grant

• Current Assignee: Synamedia Limited
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sherer, W. Paul, Blattman, Kirk, Chou, Hoi-Tauw, Connery, Glenn, Davis, Howard, Kiewlich, Daniel, Major, Robert Drew, Oyler, Mel, Sharma, Neeraj K.
• Primary Examiner(s): Whipple, Brian P
• Application Number:
  US11/394,823
• Publication Number:
  US 20060248212A1
• Time in Patent Office: 2,440 Days
• Field of Search: 709/221, 709/203, 709/227, 709/224, 725/91
• US Class Current: 709/224
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04N 21/2181 comprising remotely distributed storage units, e.g. when movies are replicated over a plurality of video servers distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: H04N 21/23116 involving data replication, e.g. over plural servers synchronization of replicated data G06F11/1658; error detection or correction by means of data replication G06F11/2053; replication in distributed file systems G06F16/10; replication in distributed file systems G06F16/27; replication or mirroring of data in data networks H04L67/1095
• CPC Class Codes: H04N 21/2404 Monitoring of server processing errors or hardware failure error or fault detection G06F11/07; monitoring in general G06F11/30
• CPC Class Codes: H04N 21/266 Channel or content management, e.g. generation and management of keys and entitlement messages in a conditional access system, merging a VOD unicast channel into a multicast channel
• CPC Class Codes: H04N 21/631 Multimode Transmission, e.g. transmitting basic layers and enhancement layers of the content over different transmission paths or transmitting with different error corrections, different keys or with different transmission protocols
• CPC Class Codes: H04N 21/64322 IP

Abstract

A technique for streaming digital video content to multiple clients involves establishing a logical group of IP-connected stream servers, generating state information at multiple stream servers within the logical group, sharing the state information amongst stream servers in the logical group, and using the shared state information to respond to resource failures within the logical group. By sharing state information within the logical group of stream servers, stream servers with the shared state information can quickly take over the active streams from a failed stream server within the logical group. The quick transition of responsibility from one stream server to another enables the streaming network to provide continuous streaming of digital video content to the viewer without interruption.

Claims

1. A method for managing the streaming of digital video content to multiple clients, the method comprising:

establishing a logical group of IP-connected stream servers, wherein the logical group is established by associating each stream server in the logical group with the same group identifier and wherein each stream server in the logical group has an internal IP address that is not exposed to the clients;

establishing one of the stream servers in the logical group as having responsibility for managing session setup, the stream server being referred to herein as the stream service master;

creating connections to the stream service master using the internal IP addresses of the stream servers in the logical group;

assigning a failover IP address to the stream service master, wherein the failover IP address is visible to the clients;

generating state information at multiple stream servers within the logical group;

sharing state information amongst stream servers in the logical group;

detecting a failure of the stream service master;

activating the failover IP address in one of the other stream servers in the logical group in response to the detected failure, wherein the stream server in which the failover IP address is activated becomes the new stream service master; and

at the new master stream service master, using the shared state information to discover information about active streams in the logical group;

wherein the above-identified steps are performed using at least one processor.

2. The method of claim 1 wherein activating the failover IP address causes active TCP connections between the stream service master and the clients to be broken and the stream sessions to continue uninterrupted and wherein TCP connections are reestablished with the new stream service master.

3. The method of claim 1 wherein sharing state information amongst the stream servers in a resiliency group comprises maintaining dedicated state machines for the other stream servers in the logical group.

4. The method of claim 1 further comprising establishing a resiliency group from among the stream servers in the logical group, the resiliency group being a subset of the stream servers in the logical group.

5. The method of claim 4 wherein the state information is shared only amongst the stream servers in the resiliency group.

6. The method of claim 1 wherein the stream state information is shared amongst the stream servers in real time.

7. The method of claim 1 further comprising using the shared state information to manage stream server resources.

8. The method of claim 1 further comprising using the shared state information to assign new streams to the stream servers in the logical group.

9. The method of claim 1 further comprising using the shared state information to service stream requests.

10. The method of claim 1 further comprising using the shared state information in load balancing streams amongst the stream servers in the logical group.

11. The method of claim 1 further comprising:

identifying an attribute of a content element that is streamed to a client; and

selecting a protection mechanism for the content element as a function of the attribute, wherein the protection mechanism enables streaming of the content element to the client in the event of a resource failure.