DEVICE AND METHOD FOR ACQUIRING RESOURCE LOCK

• US 20130144853A1
• Filed: 10/10/2012
• Published: 06/06/2013
• Est. Priority Date: 12/02/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kohno, Noriaki
• Granted Patent: US 8,898,127 B2
• Time in Patent Office: Days
• US Class Current: 707/704
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: G06Q 40/02 Banking, e.g. interest calculation or account maintenance credit or loans G06Q40/03

Abstract

A lock control device receives a lock acquisition request from an application and transmits a lock acquisition request to a DBMS, receives a lock acquisition response from the DBMS, and transmits a lock acquisition response to the application, and each time, acquires statistical time information including the lock request counter, subsequent lock request counter, lock request time, lock acquisition time, initial lock acquisition time, and subsequent lock request time. The statistical processing device calculates the lock request count for each resource, subsequent lock request count for each resource, average lock wait time, and average lock acquisition delay expectation time, based on the statistical time information. Based on these values, the statistical processing device calculates an evaluation value which is the degree of expectation for the time eliminated from the lock wait time when lock acquisition is postponed, and outputs the lock order of the resources arranged in order of smallest evaluation value to a lock order table.

Claims

1. A device for acquiring resource locks for a plurality of resources in a specific order, comprising:

a generating component that generates a time exclusion expectation, the time exclusion expectation comprising an expectation for a length of time that is excluded from a time for retaining a lock on a resource when acquisition of the resource lock is postponed, for each resource of a plurality of resources; and

a determining component that determines a specific order such that resources with a higher time exclusion expectation generated by the generating component will be assigned later in the order.

2. The device according to claim 1, wherein the generating component generates a time exclusion expectation that includes a lock wait time exclusion expectation, the lock wait time exclusion expectation comprising the expectation for a length of lock waiting time for another resource, excluded from the time for retaining a lock on the resource when acquisition of the resource lock is postponed, for each resource of a plurality of resources.

3. The device according to claim 2, wherein the generating component generates a time exclusion expectation that includes a pre-use time exclusion expectation, the pre-use time exclusion expectation comprising the expectation for a length of time until all resources are used, excluded from the time for retaining a lock on the resource when acquisition of the resource lock is postponed, for each resource of a plurality of resources.

4. The device according to claim 3, further comprising a retrieving component that retrieves a number of times that acquisition of each resource lock has been requested by an application program that uses each resource of a plurality of resources;

wherein the generating component generates a lock retaining time exclusion expectation based on the number of times that each resource has been retrieved by the retrieving component, for each resource of the plurality of resources.

5. The device according to claim 3, further comprising:

a retrieving component that retrieves an acquisition time where software acquires a lock for each resource, and a request time where acquisition of the lock for each resource is requested for software that manages a plurality of resources when an application program that uses various resources from a plurality of resources request acquisition of the resource lock;

wherein the generating component generates a lock waiting time exclusion expectation based on the request time and the acquisition time retrieved by the retrieving component, for each resource of the plurality of resources.

6. The device according to claim 3, further comprising:

a retrieving component that retrieves a number of times that acquisition of each resource lock has been requested as a second or subsequent request for acquisition of a resource lock, by an application program that uses each resource of a plurality of resources;

wherein the generating component generates a lock pre-use time exclusion expectation based on the number of times that each resource has been retrieved by the retrieving component, for each resource of the plurality of resources.

7. The device according to claim 3, further comprising:

a retrieving component that retrieves the acquisition time that each resource lock was acquired, when acquisition of each resource lock is requested as a first request for acquisition of a resource lock, by an application program that uses each resource of a plurality of resources, and retrieves the request time for requesting acquisition of each resource lock, when an application program request acquisition of each resource lock as a second or subsequent request for acquisition of a resource lock;

wherein the generating component generates a pre-use time exclusion expectation based on the acquisition time and the request time retrieved by the retrieving component, for each resource of the plurality of resources.

8. A device for acquiring resource locks for a plurality of resources in a specific order for a plurality of resources, comprising:

a memory that stores a pre-established order as a specific order;

a retrieving component that when acquisition of a specific resource lock has been requested as a first request for acquisition of resource lock by an application program that uses specific resources from a plurality of resources, retrieves as a first request time a time of a request for acquisition of locking other resources with regard to software that manages a plurality of resources, if other resources which are resources for which a lock is not being acquired and that are resources with a earlier order than specific resources, and are scheduled to be used by the application program, for a pre-established order, retrieves as the first acquisition time a time that another resource lock was acquired by the software, subsequently retrieves as a first request time the time that acquisition of a lock for specific resources was requested with regard to the software, retrieves as the first acquisition time the time that specific resource lock was acquired by the software, and retrieves as the second acquisition time the time that a specific resource lock was acquired; and

for the case where acquisition of a specific resource lock has been requested as a second or subsequent request for acquisition of resource lock by an application program that uses specific resources from a plurality of resources, retrieves as the first request time the time of a request for acquisition of locking other resources with regard to software that manages a plurality of resources, if other resources which are resources for which a lock is not being acquired and that are resources with a earlier order than specific resources, and are scheduled to be used by an application program that manages a plurality of resources, for a pre-established order, retrieves as the first acquisition time the time that another resource lock was acquired by the software, subsequently retrieves as the second request time the time that acquisition of a specific resource lock was requested with regards to the software, retrieves as the first acquisition time the time that specific resource lock was acquired by the software, and retrieves as the first acquisition time the time that a specific resource lock was acquired;

a generating component that generates a lock waiting time exclusion expectation which is an expectation for the length of time of waiting for locking of other resources that is excluded from the time of retaining the lock on each resource by postponing acquisition of each resource lock, based on the time retrieved as the first request time by the retrieving component based on each resource from a plurality of resources and based on the time retrieved as the first acquired time by the retrieving component, and generates a pre-use time exclusion expectation which is an expectation of the length of time until each resource is used excluding the time for retaining each resource lock by postponing acquisition of the lock for each resource, based on the time retrieved as the second request time by the retrieving component and the time retrieved as the second acquisition time by the retrieving component; and

an updating component that updates the pre-established order recorded in the memory such that resources with a larger total expectation obtained based on the lock wait time exclusion expectation produced by the generating component and the pre-use time exclusion expectation are assigned to be later in the order.

9. A method for acquiring resource locks for a plurality of resources in a specific order for a plurality of resources, comprising:

generating a time exclusion expectation which is an expectation for a length of time that is excluded from a time for retaining a lock on the resource for a case where acquisition of the resource lock is postponed, for each resource of a plurality of resources; and

determining a specific order such that resources with a higher time exclusion expectation that was generated will be assigned later in the order.

10. The method according to claim 9, wherein the generating generates a time exclusion expectation that includes a lock wait time exclusion expectation, the lock wait time exclusion expectation comprising the expectation for a length of lock waiting time for another resource, excluded from the time for retaining a lock on the resource when acquisition of the resource lock is postponed, for each resource of a plurality of resources.

11. The method according to claim 10, wherein the generating generates a time exclusion expectation that includes a pre-use time exclusion expectation, the pre-use time exclusion expectation comprising the expectation for a length of time until all resources are used, excluded from the time for retaining a lock on the resource when acquisition of the resource lock is postponed, for each resource of a plurality of resources.

12. The method according to claim 11, further comprising retrieving a number of times that acquisition of each resource lock has been requested by an application program that uses each resource of a plurality of resources;

wherein the generating generates a lock retaining time exclusion expectation based on the number of times that each resource has been retrieved, for each resource of the plurality of resources.

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

retrieving an acquisition time where software acquires a lock for each resource, and a request time where acquisition of the lock for each resource is requested for software that manages a plurality of resources when an application program that uses various resources from a plurality of resources request acquisition of the resource lock;

wherein the generating generates a lock waiting time exclusion expectation based on the request time and the retrieved acquisition time, for each resource of the plurality of resources.

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

retrieving a number of times that acquisition of each resource lock has been requested as a second or subsequent request for acquisition of a resource lock, by an application program that uses each resource of a plurality of resources;

wherein the generating generates a lock pre-use time exclusion expectation based on the number of times that each resource has been retrieved, for each resource of the plurality of resources.

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

retrieving the acquisition time that each resource lock was acquired, when acquisition of each resource lock is requested as a first request for acquisition of a resource lock, by an application program that uses each resource of a plurality of resources, and retrieves the request time for requesting acquisition of each resource lock, when an application program request acquisition of each resource lock as a second or subsequent request for acquisition of a resource lock;

wherein the generating generates a pre-use time exclusion expectation based on the retrieved acquisition time and the request time, for each resource of the plurality of resources.

16. A program causing function of the computer, as a device for acquiring resource locks for a plurality of resources in a specific order for a plurality of resources, wherein:

the computer is made to function as;

a generating part that generates a time exclusion expectation which is an expectation for the length of time that is excluded from a time for retaining a lock on the resource for the case where acquisition of the resource lock is postponed, for each resource of a plurality of resources; and

a determining part that determines a specific order such that resources with a higher time exclusion expectation generated by the generating part will be assigned later in the order.