MANAGING RESOURCE ALLOCATION IN HIERARCHICAL QUOTA SYSTEM

• US 20150188840A1
• Filed: 12/29/2014
• Published: 07/02/2015
• Est. Priority Date: 12/31/2013
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Xiao, Chunjun, Yi, Ming, Guo, Zhao Hui
• Granted Patent: US 11,003,497 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2209/504 Resource capping
• CPC Class Codes: G06F 9/50 Allocation of resources, e.g. of the central processing unit [CPU]
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method for managing resource allocation in a hierarchical quota system, comprising n layers of quota nodes, n being a positive integer greater than 1, and comprises at a first quota node in an i^th layer of quota nodes, in response to receiving a resource allocation request from a user, determining whether an amount of requested resources exceeds a first quota; if the amount of requested resources does not exceed the first quota, determining whether the first node holds a quota delegation for the first quota node; if the first node holds the quota delegation, determining whether the amount of requested resources exceeds a second quota specified by the quota delegation for the first quota node; if the amount of requested resources does not exceed the second quota, allocating the requested resources to the user.

Claims

1. A method for managing resource allocation in a hierarchical quota system, the hierarchical quota system comprising ‘

n’

layers of quota nodes from top to bottom, n being a positive integer greater than 1, the method comprising;

at a first quota node in an i^th layer of quota nodes, in response to receiving a resource allocation request from a user, determining whether an amount of requested resources exceeds a first quota defined by an administrator at the first quota node, wherein ‘

n′

’

is a positive integer greater than 1 and less than or equal to n;

if the amount of requested resources does not exceed the first quota, determining whether the first node supports a quota delegation for the first quota node;

if the first node supports the quota delegation, determining whether the amount of requested resources exceeds a second quota specified by the quota delegation for the first quota node; and

if the amount of requested resources does not exceed the second quota, allocating the requested resources to the user.

2. The method according to claim 1, wherein allocating requested resources to the user comprises:

subtracting an amount of allocated resources from the first quota and the second quota thereby updating the first quota and the second quota; and

updating the amount of resources allocated to the user.

3. The method according to claim 1, further comprising:

if the first node does not support the quota delegation, creating a first quota delegation request for obtaining the quota delegation, the first quota delegation request comprising at least

an identifier of the user,

a first minimum share requested value and

a first maximum share requested value, wherein the first minimum share requested value indicating the amount of resources requested by the user, and the first maximum share requested value indicating the first quota; and

sending the first quota delegation request to a second quota node in an i^th-1 layer of quota nodes directly associated with the first quota node.

4. The method according to claim 3, further comprising:

(a) in response to receiving the request, determining whether the second quota node supports a quota delegation for the second quota node;

(b) if the second quota node does not support the quota delegation for the second quota node, sending a request for obtaining the quota delegation for the second quota node to a third quota node in an i^th-2 layer of quota nodes directly associated with the second quota node; and

(c) if the second quota node supports the quota delegation for the second quota node, sending a response to the first quota node to grant the quota delegation for the first quota node.

5. The method according to claim 4, wherein step (b) is executed iteratively until a quota node in a first layer of the quota nodes is associated with the second quota node;

and

wherein the quota nodes in the first layer amend, in response to the quota delegation requests from respective quota nodes in a second layer of quota nodes associated with the quota nodes in the first layer, shares requested by the quota delegation requests from the first quota.

6. The method according to claim 5, wherein a quota database record for a respective user is maintained at each quota node in the n layer of quota nodes, the quota database record comprising at least:

a user identifier field configured to identify a user to which the quota database record corresponds;

a quota field comprising the first quota set by the administrator and the second quota specified by the quota delegation for the first quota node, the second quota being less than or equal to the first quota;

a resource use count field configured to indicate the amount of resources allocated on a current quota node and quota nodes in a lower layer associated with the current quota node;

a delegation flag field configured to indicate whether a respective quota delegation has been granted to each quota node in the lower layer directly associated with the current quota node, and status of the respective quota delegation; and

a reserved share field configured to indicate shares reserved for each quota node in the lower layer supporting the quota delegation in the first quota and the second quota.

7. The method according to claim 6, wherein the status of the quota delegation comprises one of ungranted status, granted status and revoked status.

8. The method according to claim 4, wherein determining whether the second quota node has a quota delegation for the second quota node comprises:

looking up a quota database record for the user at the second quota node to determine whether a quota field of the quota database record for the user comprises a valid second quota.

9. The method according to claim 8, further comprises:

if determining the quota field of the quota database record for the user at the second quota node comprises the valid second quota, amending shares reserved for the first quota node from the first quota and the second quota, the shares reserved being greater than or equal to the first minimum share requested value and less than or equal to the first maximum share requested value.

10. The method according to claim 9, further comprises:

creating a first temporary quota database record, wherein the first temporary quota database record comprising at least

the identifier of the user and

the shares reserved for the first quota node; and

sending the first temporary quota database record to the first quota node.

11. The method according to claim 10, further comprising:

in response to receiving the first temporary quota database record, caching the shares reserved for the first quota node in the quota field of the quota database record for the user as a second quota for the quota field.

12. The method according to claim 11, further comprises:

determining whether the amount of resources requested by the user exceeds a quota specified by a quota delegation for the first quota node by

determining whether the amount of requested resources exceeds the second quota in the quota field of the quota database record for the user at the first quota node;

if the amount of requested resources exceeds the second quota, determining whether the first quota node has granted quota delegations to quota nodes in an i^th+1 layer of quota nodes directly associated with the first quota node; and

if the first quota node does not grant quota delegation to the quota nodes in the i^th+1 layer, sending from the first quota node to the second quota node a first quota delegation adjustment request for adjusting the second quota;

the first quota delegation adjustment request comprising at least

an identifier of the user;

a second minimum share requested value;

a second maximum share requested value; and

wherein the second minimum share requested value is a difference between the amount of resources requested by the user and the second quota in the quota field of the quota database record for the user at the first quota node, and the second maximum share requested value is a difference between the second quota and the first quota in the quota field of the quota database record for the user at the first quota node.

13. The method according to claim 12, wherein in response to receiving the first quota delegation adjustment request, the second quota node is configured for:

(d) checking a delegation flag field in the quota database record for the user at the second quota node to determine a status of the quota delegation for the first quota node; and

(e) if the status of the quota delegation for the first quota node is a granted, checking whether a second quota in a quota field of a quota database record for the user at the second quota node is greater than or equal to the second minimum share requested value requested by the first quota delegation adjustment request; and

(f) if the status of the quota delegation for the first quota node is a revoked, sending a first quota delegation revocation request to the first quota node, the first quota delegation revocation request comprising at least the identifier of the user.

14. The method according to claim 13, further comprising:

if the second quota in the quota field of the quota database record for the user at the second quota node is greater than or equal to the second minimum share requested value, at the second quota node;

amending the shares reserved for the first quota node for the first quota delegation adjustment request from the second quota and the first quota in the quota field in the quota database record for the user;

adding the reserved shares to a sub-field for the first quota node in the reserved shares field of the quota database record; and

sending to the first quota node a response to the first quota delegation adjustment request, the response comprising at least the shares reserved for the first quota node.

15. The method according to claim 13, further comprising:

if the second quota in the quota field of the quota database record for the user at the second quota node is less than the second minimum share requested value, recalling quota delegations from at least one or more quota nodes other than the first quota node in the lower layer of quota nodes directly associated with the second quota node, until the second quota is greater than or equal to the second minimum share value.

16. The method according to claim 15, wherein recalling a quota delegation from the at least one or more quota nodes in the lower layer directly associated with the second quota node comprises:

sending a first quota delegation recalling request from the second quota node to a fourth quota node in the lower layer of quota nodes directly associated with the second quota node.

17. The method according to claim 16, further comprising:

in response to receiving the first quota delegation recalling request, performing at the fourth quota node;

checking a delegation flag field in a quota database record for the user at the fourth quota node to determine whether respective quota delegations have been granted to the quota nodes in the lower layer of quota nodes;

if the respective quota delegations have been granted to the quota nodes in the lower layer, recalling all the respective quota delegations;

resetting as invalid the second quota in the quota field of the quota database record for the user at the fourth quota node; and

sending a quota delegation recalling response to the second quota node, the quota delegation recalling response comprising at least a total amount of resources consumed by the user on the fourth quota node and all child nodes associated therewith.

18. The method according to claim 17, further comprising:

in response to receiving the quota delegation recalling response, updating, by the second quota node, a quota database record for the user at the second quota node, comprising;

updating a total amount of resource consumption contained in the quota delegation recalling response to sub-fields corresponding to the fourth quota node in a resource use count field of the quota database record for the user; and

adding shares reserved for a quota delegation for the fourth quota node, from which the total amount of resource consumption has been subtracted, to the first quota and the second quota in the quota field of the quota database record for the user at the second quota node.

19. The method according to claim 16, further comprising:

recalling, by the second quota node, all quota delegations other than the quota delegation held by the first quota node from the quota nodes in the lower layer directly associated with the second quota node;

determining whether a second quota in a quota field of a quota database record for the user at the second quota node is less than the second minimum share requested value; and

if the second quota is less than the second minimum share requested value, checking the first quota of the quota field in the quota database record for the user at the second quota node.

20. The method according to claim 19, further comprising:

(g) if the first quota is less than the second minimum share requested value requested by the first quota delegation adjustment request, rejecting the first quota delegation adjustment request; and

(h) if the first quota is greater than or equal to the second minimum share requested value requested by the first quota delegation adjustment request, sending a second quota delegation adjustment request from the second quota node to a third quota node in an i^th-2 layer of quota nodes directly associated with the second quota node.