Distributed database system providing data and space management methodology

• US 9,152,666 B2
• Filed: 03/25/2008
• Issued: 10/06/2015
• Est. Priority Date: 11/01/2004
• Status: Active Grant

• Current Assignee: Sybase Incorporated (SAP SE)
• Original Assignee: Sybase Incorporated (SAP SE)
• Inventors: Lin, Mei-Lin Linda, Zhou, Fei, Francis, Joe, Sampath, Srikanth, Ramachandran, Satya N., Varakur, Gangavara Prasad
• Primary Examiner(s): Mofiz, Apu
• Assistant Examiner(s): DAYE, CHELCIE L
• Application Number:
  US12/055,194
• Publication Number:
  US 20080172429A1
• Time in Patent Office: 2,751 Days
• Field of Search: 707/2, 707/782, 718/104, 718/105
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A distributed database system providing data and space management methodology. In one embodiment a system for allocating resources amongst a plurality of database servers sharing resources comprises: an input module for receiving user input for allocating resources shared amongst a plurality of database servers and establishing thresholds for utilization of resources at each database server; a monitoring module at each database server for monitoring local resource utilization at each database server and sending a request for balancing resources to a second database server when local resource utilization reaches an established threshold at a first database server; and a load balancing module for receiving the request for balancing resources and determining whether to adjust resources allocated to the first database server and the second database server in response to the request.

Claims

1. A system for allocating resources amongst a plurality of database servers sharing resources, the system comprising:

a processor; and

a memory storing program logic, that when executed by the processor, causes the processor to perform operations for allocating resources comprising data pages amongst the plurality of database servers, the operations comprising;

receiving user input for allocating resources shared amongst a plurality of database servers and establishing thresholds for utilization of data pages at each database server;

monitoring local resource utilization at a first database server and sending a request for balancing resources to a second database server when local resource utilization reaches an established threshold at the first database server,

wherein the first database server is assigned to the second database server as a fixed partner from the plurality of database servers,

wherein the second database server is configured to receive requests for balancing resources from the first server, and

wherein the second database server is assigned to a third database server as its fixed partner configured to receive requests for balancing resources from the second server; and

receiving the request for balancing resources and determining whether to adjust resources allocated to the first database server and the second database server in response to the request.

2. The system of claim 1, wherein the resources further comprise allocation pages, log pages, and index pages.

3. The system of claim 2, wherein receiving the user input is performed by an input module configured to receive user input specifying a threshold based on number of data pages remaining free at a database server.

4. The system of claim 1, wherein receiving the request is performed by a load balancing module configured to provide available resources allocated to the second database server to the first database server in response to the request, so as to adjust resources between them.

5. The system of claim 4, wherein the load balancing module allocates free data pages available at the second database server to the first database server in response to the request.

6. The system of claim 4, wherein the load balancing module at the second database server forwards the request to a third database server in response to determining that resources allocated to the first database server and second database server cannot be adjusted within thresholds established at the first database server and the second database server.

7. The system of claim 6, wherein the load balancing module at the second database server includes information about resources available at the second database server with the request forwarded to the third database server.

8. The system of claim 6, further comprising:

a module at the third database server for adjusting resources allocated to the first database server, the second database server, and the third database server in response to the request forwarded to the third database server.

9. The system of claim 8, wherein the module at the third database server adjusts free data pages allocated to the first database server, the second database server, and the third database server in response to the forwarded request.

10. The system of claim 1, wherein a load balancing module at a database server sends a notification to a user when resource utilization at all database servers reaches an established threshold.

11. The system of claim 1, wherein the module for tracking suspends a process running at the first database server which is attempting to utilize resources when resource utilization reaches an established threshold applicable to the first database server.

12. In a distributed database system comprising a plurality of database servers sharing resources, a method for allocating resources comprising data pages amongst the plurality of database servers, the method comprising:

receiving, by one or more processors, user input specifying allocation of shared resources amongst a plurality of database servers including established thresholds for utilization of resources at each of the plurality of database servers, wherein a first database server is assigned to a second database server acting as a fixed partner from the plurality of database servers, wherein the first database server sends requests for balancing resources to the second database server, wherein the second database server is assigned to a third database server as its fixed partner;

during operation of the distributed database system, monitoring, by the first database server, local resource utilization at the first database server;

when local resource utilization reaches an established threshold at the first database server, sending, by the first database server, a request for balancing resources to the second database server; and

when the request for balancing resources is received at the second database server, providing, by the second database server, available resources allocated to the second database server to the first database server in response to the request, so as to adjust resources between them.

13. The method of claim 12, wherein the resources further comprise allocation pages, log pages, and index pages.

14. The method of claim 13, wherein the established threshold is based on number of data pages remaining free at a database server.

15. The method of claim 12, wherein providing available resources includes allocating free data pages available at the second database server to the first database server in response to the request.

16. The method of claim 12, wherein providing available resources includes determining whether free data pages are available at the second database server that can be allocated for use at the first database server.

17. The method of claim 16, further comprising:

in response to determining that free data pages are not available at the second database server for allocation to the first database server, forwarding the request for balancing resources to a third database server.

18. The method of claim 17, wherein the request for balancing resources is forwarded to the third database server in response to determining that the resources allocated to the first database server and second database server cannot be adjusted within thresholds established at the first database server and the second database server.

19. The method of claim 17, wherein the second database server includes information about free data pages available at the second database server with the request for balancing resources forwarded to the third database server.

20. The method of claim 17, further comprising:

in response to the forwarded request for balancing resources received at the third database server, adjusting free data pages allocated to the first database server, the second database server.

21. The method of claim 12, further comprising:

when resource utilization at all of the plurality of database servers reaches an established threshold, sending a notification to a user.

22. The method of claim 12, further comprising:

suspending a process running at the first database server which is attempting to utilize resources when resource utilization reaches an established threshold applicable to the first database server.

23. A non-transitory computer-readable medium having processor-executable instructions stored thereon for enabling the processor to perform the method of claim 12.

24. In a distributed database system comprising a plurality of database servers sharing access to data pages, a method for allocating free data pages amongst the plurality of database servers, the method comprising:

assigning, by one or more processors, a quantity of free data pages for use at each of the plurality of database servers;

establishing, by the one or more processors, thresholds at each of said plurality of database servers based on number of free data pages available at each database server;

during operation, when the number of free data pages remaining available reaches an established threshold at the first database server, issuing a request for additional free data pages to a second database server,

wherein the first database server is assigned to the second database server as a fixed partner from the plurality of database servers,

wherein the second database server is configured to receive requests for additional free data pages, and

wherein the second database server is assigned to a third database server as its fixed partner configured to receive requests for balancing resources from the second server; and

providing free data pages assigned to the second database server to the first database server in response to the request, while the number of free data pages available at the second database server remains above an established threshold applicable to the second database server.

25. The method of claim 24, wherein providing free data pages includes determining a quantity of free data pages that can be provided to the first database server in response to the request.

26. The method of claim 25, wherein determining a quantity of free data pages that can be provided includes providing half the free data pages then remaining available at the second database to the first database server in response to the request.

27. The method of claim 24, wherein said wherein providing free data pages includes determining whether the number of free data pages available at the second database server more than a specified number of pages above an established threshold.

28. The method of claim 24, wherein establishing thresholds includes specifying a buffer zone of free data pages corresponding to each established threshold and providing free data pages includes providing free data pages available at the second server while the number of free data pages available at the second database server remains above the buffer zone applicable at the second database server.

29. The method of claim 28, wherein the buffer zone comprises a user specified number of free data pages.

30. The method of claim 24, further comprising:

forwarding the request from the second database server to a third database server in response to determining that a sufficient number of free data pages are not available at the second database server.

31. The method of claim 30, wherein said forwarding step includes indicating the number of free data pages available at the first database server and the second database server.

32. The method of claim 30, further comprising:

in response to determining that sufficient free data pages are available at the third database server, providing a quantity of free data pages to the first database server and the second database server.

33. The method of claim 24, wherein assigning a quantity of free data pages includes assigning a quantity based on total number of free data pages and number of database servers in the distributed database system.

34. The method of claim 24, wherein establishing thresholds includes establishing at least two thresholds at each of the plurality of database servers.

35. The method of claim 34, wherein issuing a request includes issuing the request when the number of free data pages reaches a first threshold at the first database server.

36. The method of claim 35, further comprising:

freezing use of additional free data pages at the first database server when the number of free data pages reaches a second threshold at the first database server.

37. A non-transitory computer-readable medium having processor-executable instructions stored thereon for allocating free data pages amongst a plurality of database servers, the instructions comprising:

Instructions to cause one or more processors to assign a quantity of free data pages for use at each of the plurality of database servers;

instructions to cause one or more processors to establish thresholds at each of said plurality of database servers based on number of free data pages available at each database server;

instructions to cause one or more processors to issue a request for additional free data pages to a second database server when the number of free data pages remaining available reaches an established threshold at a first database server,

wherein the first database server is assigned to the second database server as a fixed partner from the plurality of database servers,

wherein the second database server is configured to receive requests for additional free data pages from the first database server, and

wherein the second database server is assigned to a third database server as its fixed partner configured to receive requests for additional free data pages from the second; and

instructions to cause one or more processors to provide free data pages assigned to the second database server to the first database server in response to the request, while the number of free data pages available at the second database server remains above an established threshold applicable to the second database server.

38. A computer storage medium encoded with a computer program, the program comprising instructions that when executed by one or more processors cause the one or more processors to perform operations comprising:

receiving user input specifying allocation of shared resources amongst a plurality of database servers including established thresholds for utilization of resources at each of said plurality of database servers,

wherein a first database server is assigned to a second database server as its fixed partner from the plurality of database servers,

wherein the second database server is configured to receive which requests for balancing resources from the first server, and

wherein the second database server is assigned to a third database server as its fixed partner configured to receive requests for balancing resources from the second server;

during operation of the distributed database system, monitoring local resource utilization at each database server;

when local resource utilization reaches an established threshold at the first database server, sending a request for balancing resources to the second database server, based on the assigned designated database server for the first database server; and

when the request for balancing resources is received at the second database server, providing available resources allocated to the second database server to the first database server in response to the request, so as to adjust resources between them.