Computer system and process for transferring multiple high bandwidth streams of data between multiple storage units and multiple applications in a scalable and reliable manner

• US 8,140,755 B2
• Filed: 03/24/2011
• Issued: 03/20/2012
• Est. Priority Date: 12/24/1997
• Status: Expired due to Term

• Current Assignee: Avid Technology Incorporated
• Original Assignee: Avid Technology Incorporated
• Inventors: Peters, Eric C., Rabinowitz, Stanley, Jacobs, Herbert R., Fasciano, Peter J.
• Primary Examiner(s): BATAILLE, PIERRE MICHE
• Application Number:
  US13/070,581
• Publication Number:
  US 20110185019A1
• Time in Patent Office: 362 Days
• Field of Search: 711/114, 711/112, 711/162, 711/113, 711/170, 711/111, 711/165, 711/E12.001, 714/7, 714/6, 714/5, 714/4
• US Class Current: 711/117
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 16/70 of video data
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/51 Discovery or management thereof, e.g. service location protocol [SLP] or web services
• CPC Class Codes: H04N 21/2182 involving memory arrays, e.g. RAID disk arrays RAID arrays per se G06F3/0689; use of parity to protect data in RAID systems G06F11/1008
• CPC Class Codes: H04N 21/23103 using load balancing strategies, e.g. by placing or distributing content on different disks, different memories or different servers storage management G06F3/0604; allocation of resources considering the load in multiprogramming arrangements G06F9/505; techniques for rebalancing the load in a distributed system G06F9/5083; access to distributed or replicated servers, e.g. load balancing, in data networks H04L67/1001
• 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 21/2312 Data placement on disk arrays data placement in general G06F3/0604
• CPC Class Codes: H04N 21/2315 using interleaving
• CPC Class Codes: H04N 21/232 : Content retrieval operation locally within server, e.g. reading video streams from disk arrays storage management G06F3/0604; details of querying and searching of video data from a database G06F16/739
• CPC Class Codes: H04N 21/2393 : involving handling client requests scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/2396 : characterized by admission policies admission control, resource allocation in open networks H04L12/5692; arrangements for network security using user profiles for access control H04L63/102; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/2405 : Monitoring of the internal components or processes of the server, e.g. server load allocation of resources in multiprogramming arrangements G06F9/50; performance measurement of computer activity G06F11/34
• CPC Class Codes: H04N 21/241 : Operating system [OS] processes, e.g. server setup
• CPC Class Codes: H04N 21/262 : Content or additional data distribution scheduling, e.g. sending additional data at off-peak times, updating software modules, calculating the carousel transmission frequency, delaying a video stream transmission, generating play-lists scheduling strategies for dispatcher in multiprogramming arrangements G06F9/4881; arrangements for scheduling broadcast services or broadcast-related services H04H60/06; flow control in packet networks H04L47/10; establishing a time schedule or organising the servicing of application requests H04L67/62
• CPC Class Codes: H04N 21/44004 : involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/442 : Monitoring of processes or resources, e.g. detecting the failure of a recording device, monitoring the downstream bandwidth, the number of times a movie has been viewed, the storage space available from the internal hard disk arrangements for monitoring broadcast services or broadcast-related services H04H60/29; arrangements for identifying or recognising characteristics with a direct linkage to broadcast information H04H60/35; monitoring of user activities for profile generation for accessing a video database G06F16/739; monitoring in wireless networks H04W24/00
• CPC Class Codes: H04N 21/47202 : for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/8456 : by decomposing the content in the time domain, e.g. in time segments
• CPC Class Codes: H04N 7/17336 : Handling of requests in head-ends
• CPC Class Codes: Y10S 707/99953 : Recoverability
• CPC Class Codes: Y10S 707/99956 : File allocation

Abstract

Multiple applications request data from multiple storage units over a computer network. The data is divided into segments and each segment is distributed randomly on one of several storage units, independent of the storage units on which other segments of the media data are stored. At least one additional copy of each segment also is distributed randomly over the storage units, such that each segment is stored on at least two storage units. This random distribution of multiple copies of segments of data improves both scalability and reliability. When an application requests a selected segment of data, the request is processed by the storage unit with the shortest queue of requests. Random fluctuations in the load applied by multiple applications on multiple storage units are balanced nearly equally over all of the storage units. This combination of techniques results in a system which can transfer multiple, independent high-bandwidth streams of data in a scalable manner in both directions between multiple applications and multiple storage units.

Claims

1. A computer implemented process for managing data storage in a system comprising a plurality of clients, each client having a file system through which applications executed on the client systems access data stored in files of the file system, the system further comprising a plurality of independent storage servers, each operating independently of the clients and without central control, and a computer network interconnecting the plurality of independent storage servers and the plurality of clients wherein data of each file stored on the plurality of independent storage servers is divided into segments, with two or more copies of each segment being distributed among the plurality of independent storage servers, such that each segment is stored on at least two of the storage servers, comprising:

maintaining information for each file indicating the storage servers on which the segments of data of the file are stored;

before reading data from a file, accessing, using the client, the information for the file indicating the storage servers on which the segments of the file are stored ,wherein the client uses said information to communicate directly with the storage servers to request the segments of the file; and

after writing data to a file, accessing the storage to update the information for the file indicating the storage servers on which the segments of the file are stored.

2. The process of claim 1, wherein the information for each file indicating the storage servers on which the segments of the file are stored comprises a segment table.

3. The process of claim 2, further comprising storing segment tables for a plurality of files in a catalog.

4. The process of claim 3, wherein the information for each file is stored on a catalog server connected to the computer network in a manner accessible by the plurality of clients.

5. The process of claim 3, wherein the information for each file resides in each client.

6. The process of claim 5, wherein the catalog is distributed among the clients.

7. The process of claim 3, wherein the catalog is stored as a file on the plurality of independent storage servers.

8. The process of claim 2, wherein the segment table comprises, for each segment of a file, an indication of the storage servers on which the segment is stored and the information further comprises, for each segment of a file, an indication of the location on the storage servers where the sement is stored.

9. The process of claim 8, wherein the information for each file is stored on a catalog manager connected to the computer network in a manner accessible by the plurality of clients.

10. The process of claim 8, wherein the information for each file is stored on storage within each of the independent storage servers, wherein the storage within a storage server stores the location of each segment stored on that storage server.

11. The process of claim 8, wherein the information for each file is further stored on a catalog manager connected to the computer network in a manner accessible by the plurality of clients and wherein the catalog manager stores the segment table.

12. The process of claim 1, wherein writing data to a file, by a client, comprises:

selecting, for each segment of the data, at least two of the storage servers for storing the segment; and

sending a request to store each segment of the data to each of the at least two storage servers selected for the segment.

13. The process of claim 1, wherein reading data from, by a client, comprises:

selecting, for each segment of the data, one of the at least two of the storage servers on which the segment is stored; and

sending, for each segment of the data, a request to read the segment of the data to the storage server selected for the segment.

14. The process of claim 1, wherein a catalog server is connected to the computer network in a manner accessible by the plurality of clients and the plurality of independent storage servers, and the process comprises identifying for each segment storage servers associated with the segment from the catalog server.

15. The process of claim 14, wherein the information for each file indicating the storage servers on which the segments of the file are stored comprises a segment table, wherein segment tables for a plurality of files are stored on the catalog server.

16. The process of claim 15, further comprising enabling each of the plurality of independent storage servers to communicate with the catalog server to allow the catalog server to determine whether an independent storage server is available to store data.

17. The process of claim 16, further comprising:

detecting if a storage server has become unavailable, and

copying segments of files stored on the unavailable storage server from other storage servers that store the segments of the files to other available storage servers.

18. The process of claim 16, further comprising:

detecting if a storage server becomes available, and in response to such detection, then enabling client systems to use the available storage server for storing, data.

19. The process of claim 16, further comprising:

the catalog server redistributing segments of files among the independent storage servers using information about available storage servers and the segment tables.

32. The data storage system of claim 1, wherein client code accessed in each client system when reading data from a file instructs the client to:

select, for each segment of the data, one of the at least two of the storage servers on which the segment is stored; and

send, for each segment of the data, a request to read the segment of the data to the storage server selected for the segment.

33. The data storage system of claim 1, further comprising:

a catalog server connected to the computer network in a manner accessible by the plurality of clients and the plurality of independent storage servers.

34. The data storage system of claim 33, wherein the information for each file indicating the storage servers on which the segments of the file are stored comprises a segment table, wherein segment tables for a plurality of files are stored on the catalog server.

35. The data storage system of claim 34, wherein each of the plurality of independent storage servers communicates with the catalog server to allow the catalog server to determine whether an independent storage server is available to store data.

36. The data storage system of claim 35, wherein if a storage server is detected as becoming unavailable, segments of files stored on the unavailable storage server are copied from other storage servers that store the segments of the files to other available storage servers.

37. The data storage system of claim 35, wherein if a storage server is detected as becoming available, then client systems can use the available storage server for storing data.

38. The data storage system of claim 35, wherein the catalog server redistributes segments of files among the independent storage servers using information about available storage servers and the segment tables.

39. The data storage system of claim 1, wherein if a storage server is detected as becoming unavailable, segments of files stored on the unavailable storage server are copied from other storage servers that store the sements of the files to other available storage servers.

20. A data storage system, comprising:

a plurality of client systems, each having a file system through which applications executed on the client systems access data stored in files of the file system;

a plurality of independent storage servers, each operating independently of the client systems and without central control;

a computer network interconnecting the plurality of independent storage servers and the plurality of client systems;

wherein data of each file stored on the plurality of independent storage servers is divided into segments, with two or more copies of each segment being distributed among the plurality of independent storage servers, such that each segment is stored on at least two of the storage servers;

storage maintaining information for each file indicating the storage servers on which the segments of data of the file are stored;

wherein, before reading data from a file, a client system accesses the storage to obtain the information for the file indicating the storage servers on which the segments of the file are stored, and the client system uses said information to communicate directly with the storage servers to request the segments of the file; and

wherein, after writing data to a file, the storage is accessed to update the information for the file indicating the storage servers on which the segments of the file are stored.

21. The data storage system of claim 20, wherein the information for each file indicating the storage servers on which the segments of the file are stored comprises a segment table.

22. The data storage system of claim 21, wherein segment tables for a plurality of files are stored in a catalog.

23. The data storage system of claim 22, wherein the storage is a catalog server connected to the computer network in a manner accessible by the plurality of clients.

24. The data storage system of claim 22, wherein the storage resides in each client.

25. The data storage system of claim 24, wherein the catalog is distributed among the clients.

26. The data storage system of claim 22, wherein the catalog is stored as a file on the plurality of independent storage servers.

27. The data storage system of claim 21, wherein the segment table comprises, for each segment of a file, an indication of the storage servers on which the segment is stored and the information further comprises, for each segment of a file, an indication of the location on the storage servers where the segment is stored.

28. The data storage system of claim 27, wherein the storage maintaining information comprises a catalog manager connected to the computer network in a manner accessible by the plurality of clients.

29. The data storage system of claim 27, wherein the storage maintaining information comprises storage within each of the independent storage servers, wherein the storage within a storage server stores the location of each segment stored on that storage server.

30. The data storage system of claim 27 wherein the storage further comprises a catalog manager connected to the computer network in a manner accessible by the plurality of clients and that stores the segment table.

31. The data storage system of claim 20, wherein client code accessed in each client system when writing data to a file instructs the client to:

select, for each segment of the data, at least two of the storage servers for storing the segment; and

send a request to store each segment of the data to each of the at least two storage servers selected for the segment.