Job management in presence of implicit dependency

• US 7,516,458 B2
• Filed: 07/31/2002
• Issued: 04/07/2009
• Est. Priority Date: 07/31/2002
• Status: Expired due to Fees

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Klotzek, Hans-Georg, Babutzka, Dieter
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): PRICE, NATHAN E
• Application Number:
  US10/210,196
• Publication Number:
  US 20040025163A1
• Time in Patent Office: 2,442 Days
• Field of Search: 718/102, 718/104, 718/106
• US Class Current: 718/106
• CPC Class Codes: G06F 2209/506 Constraint
• CPC Class Codes: G06F 9/5038 considering the execution order of a plurality of tasks, e.g. taking priority or time dependency constraints into consideration scheduling strategies G06F9/4881 and subgroups

Abstract

Methods, systems, and computer program products for job management in the presence of implicit dependency. In a situation where static dependency exists between a first computer job and a second computer job as an initial start condition for the second job, where the start of the second job depends on the completion of the first job, a scheduler determines whether the first job has created a child job, in which case the initial start condition is changed into an adjusted start condition by adding an implicit dependency, whereby the start of the second job is made further to depend at least on the completion of the child job.

Claims

1. A computer-implemented method, comprising:

receiving in a scheduler an initial definition of dependencies between jobs, the initial dependencies including a static dependency between a first job and a second job as an initial start condition for the second job, the static dependency specifying that the start of the second job depends on the completion of the first job;

starting the first job by action of the scheduler after the receiving of the initial definition of dependencies;

receiving an indication of completion of the started first job and an indication of an execution of at least one child job dynamically created by the started first job without being initiated by action of the scheduler;

detecting, at the scheduler, a unique identifier of the at least one child job, the at least one child job not being represented in the initial definition of dependencies between jobs or in any dependency in the initial definition of dependencies between jobs, and the child job completing after the started first job completes;

if the scheduler detects that the started first job has created the at least one child job, changing the initial start condition into an adjusted start condition for the second job by adding an implicit dependency on the at least one child job to the definition of dependencies, the implicit dependency specifying that the start of the second job is made further to depend at least on the completion of the at least one child job;

receiving an indication of completion of the at least one child job; and

executing the second job in response to at least the indication of completion of the at least one child job.

2. The method of claim 1, wherein:

in the initial start condition, the start of the second job depends on an error-free completion of the first job; and

in the adjusted start condition, the start of the second job depends on an error-free completion of the child job.

3. The method of claim 1, further comprising:

dynamically adding a dynamic dependency between the started first job and the child job, the dynamic dependency indicating that the child job is dynamically dependent on the started first job;

receiving status information about the started first job by polling computers in a computer installation; and

determining whether the started first job has created a child job by evaluating the received status information.

4. The method of claim 1, further comprising:

receiving status information about the started first job by receiving notifications from computers in a computer installation; and

detecting that the started first job has created a child job by evaluating the received status information.

5. The method of claim 1, further comprising:

starting the second job when the adjusted start condition is satisfied.

6. The method of claim 1, wherein the first job is started on a first computer and the second job is started on a distinct second computer.

7. The method of claim 6, wherein:

detecting that the started first job has created a child job comprises detecting that the started first job has created a child job on a distinct third computer.

8. The method of claim 1, wherein:

the first job is started on a first computer; and

detecting that the started first job has created a child job comprises detecting that the started first job has created a child job on a distinct second computer.

9. A method for job management in a computer installation where a static dependency exists between a first job and a second job as an initial start condition for the second job so that the start of the second job depends on the completion of the first job, the method comprising:

starting the first job using a local job administration program; and

sending status information about the started first job from the local job administration program to a scheduler, the status information indicating a unique identifier of a child job dynamically created by the first job without being initiated by action of the local job administration program or the scheduler, the child job not being represented in a static dependency as part of an initial start condition for the second job and the child job completing after the started first job completes, to enable the scheduler to change the initial start condition for the second job into an adjusted start condition for the second job by adding an implicit dependency to the initial start condition of the second job so that the start of the second job is made further to depend at least on the completion of the child job.

10. The method of claim 9, wherein:

in the initial start condition, the start of the second job depends on an error-free completion of the started first job; and

in the adjusted start condition, the start of the second job depends on an error-free completion of the child job.

11. The method of claim 9, wherein the local job administration program is running on a first computer, the method further comprising:

sending the status information to a scheduler running on a distinct second computer.

12. A system for managing jobs, the system comprising:

a processor operable to execute computer program instructions;

a data store that includes a representation of jobs including child jobs and dependencies including static dependencies and implicit dependencies, the representation having an initial state, the static dependencies being those dependencies that are represented in the initial state of the representation;

computer program instructions for tracking a current status of jobs and for updating the representation to reflect the current status of jobs, including the status of jobs that are started by other jobs and not by the system for managing jobs; and

computer program instructions using the representation to avoid starting a second job when the data store indicates that the second job has an implicit dependency on a uniquely identified first job that is not completed, the implicit dependency being a dependency that arose from the dynamic creation of the first job by a started parent job without being initiated by action of the system for managing jobs, the creation of the first job not being represented by any of the static dependencies, the first job not being represented in the initial representation of jobs and dependencies, the first job not being included in any dependency in the initial representation of jobs and dependencies, and the first job completing after the started parent job completes;

the indication of the implicit dependency of the second job on the first job being added to the dependencies included in the data store after the creation of the first job by the parent job, the implicit dependency indicating a start condition so that the start of the second job is made to depend, at least in part, on the completion of the first job.

13. The system of claim 12, wherein:

the first job is scheduled to be run on a first computer; and

the second job is scheduled to be run on a distinct second computer.

14. A computer program product, tangibly embodied in a machine-readable storage device, for job management in the presence of child jobs, the computer program product comprising instructions operable to cause data processing apparatus to:

receive in a scheduler an initial definition of dependencies between jobs, the initial dependencies including a static dependency between a first job and a second job as an initial start condition for the second job, the static dependency specifying that the start of the second job depends on the completion of the first job;

start the first job by action of the scheduler after the initial definition of dependencies is received;

receive an indication of completion of the started first job and an indication of an execution of at least one child job dynamically created by the started first job without being initiated by action of the scheduler;

detect, at the scheduler, a unique identifier of at least one child job, the at least one child job not being represented in the initial definition of dependencies between jobs or in any dependency in the initial definition of dependencies between jobs, and the child job completing after the started first job completes;

change the initial start condition into an adjusted start condition for the second job by adding an implicit dependency on the at least one child job to the definition of dependencies, if the scheduler detects that the started first job has created the child job, the implicit dependency specifying that the start of the second job is made further to depend at least on the completion of the at least one child job;

receive an indication of completion of the at least one child job; and

execute the second job in response to at least the indication of completion of the at least one child job.

15. The computer program product of claim 14, wherein:

in the initial start condition, the start of the second job depends on an error-free completion of the started first job; and

in the adjusted start condition, the start of the second job depends on an error-free completion of the at least one child job.

16. The computer program product of claim 14, further comprising instructions to:

dynamically add a dynamic dependency between the started first job and the child job, the dynamic dependency indicating that the child job is dynamically dependent on started first job;

receive status information about the started first job by polling computers in a computer installation; and

determine whether the started first job has created a child job by evaluating the received status information.

17. The computer program product of claim 14, further comprising instructions to:

receive status information about the started first job by receiving notifications from computers in a computer installation; and

detect that the started first job has created a child job by evaluating the received status information.

18. The computer program product of claim 14, further comprising instructions to:

start the second job when the adjusted start condition is satisfied.

19. The computer program product of claim 14, wherein the started first job is started on a first computer and the second job is started on a distinct second computer.

20. The computer program product of claim 19, wherein:

instructions to detect that the first job has created a child job comprises instructions to detect that the started first job has created at least one child job on a distinct third computer.

21. The computer program product of claim 14, wherein:

the first job is started on a first computer; and

instructions to detect that the started first job has created a child job comprise instructions to detect that the started first job has created a child job on a distinct second computer.

22. A computer program product, tangibly embodied in a machine-readable storage device, for job management in a computer installation where a static dependency exists between a first job and a second job as an initial start condition for the second job, so that the start of the second job depends on the completion of the first job, the computer program product comprising instructions operable to cause data processing apparatus to:

start the first job using a local job administration program; and

send status information about the first job from the local job administration program to a scheduler, the status information indicating a unique identifier of a child job dynamically created by the started first job without being initiated by action of the local job administration program or the scheduler, the child job not being represented in a static dependency as part of an initial start condition for the second job and the child job completing after the started first job completes, to enable the scheduler to change the initial start condition for the second job into an adjusted start condition for the second job by adding an implicit dependency to the initial start condition of the second job so that the start of the second job further depends on the completion of the child job.

23. The computer program product of claim 22, wherein:

in the initial start condition, the start of the second job depends on an error-free completion of the started first job; and

in the adjusted start condition, the start of the second job depends on an error-free completion of the at least one child job.

24. The computer program product of claim 22, further comprising instructions to:

start the first job using a local job administration program on a first computer; and

send the status information to a scheduler running on a distinct second computer.

25. A computer program product, tangibly embodied in a machine-readable storage device, for managing jobs, the computer program product comprising instructions operable to cause data processing apparatus to:

establish a representation of jobs including child jobs and dependencies including static dependencies and implicit dependencies, the representation having an initial state, the static dependencies being dependencies represented in the initial state of the representation;

track current status of jobs and update the representation to reflect the current status of jobs, including the status of dynamically-created jobs that are started by other started jobs without being initiated by action of the program product for managing jobs, the dynamically-created jobs not being represented in the initial state of the representation;

detect the creation of dynamically-created jobs and, as a consequence, change all start conditions that involve a parent job of a dynamically-created job so that the condition on the respective parent job becomes a condition on both the respective parent job and the dynamically-created job; and

use the representation to avoid starting a second job when the representation indicates that the second job has an implicit dependency on a uniquely identified first job that is not completed, the implicit dependency being a dependency that arose from the dynamic creation of the first job by a parent job and not by the program product for managing jobs, the dynamic creation of the first job not being represented in the initial state of the representation or by any of the static dependencies, and the first job completing after the parent job completes.

26. The computer program product of claim 25, further comprising instructions to:

cause the first job to be run on a first computer; and

cause the second job be run on a distinct second computer.