COMPUTING SESSION WORKLOAD SCHEDULING AND MANAGEMENT OF PARENT-CHILD TASKS

• US 20160011906A1
• Filed: 09/23/2015
• Published: 01/14/2016
• Est. Priority Date: 11/20/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chin, Alicia E., Hu, Yonggang, Hu, Zhenhua, Lin, Zhimin, Lam, Jason T. S.
• Granted Patent: US 9,658,887 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2209/484 Precedence
• CPC Class Codes: G06F 9/485 Task life-cycle, e.g. stopping, restarting, resuming execution G06F9/4881 takes precedence
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/5005 to service a request
• 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
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: G06F 9/524 Deadlock detection or avoidance

Abstract

A single workload scheduler schedules sessions and tasks having a tree structure to resources, wherein the single workload scheduler has scheduling control of the resources and the tasks of the parent-child workload sessions and tasks. The single workload scheduler receives a request to schedule a child session created by a scheduled parent task that when executed results in a child task; the scheduled parent task is dependent on a result of the child task. The single workload scheduler receives a message from the scheduled parent task yielding a resource based on the resource not being used by the scheduled parent task, schedules tasks to backfill the resource, and returns the resource yielded by the scheduled parent task to the scheduled parent task based on receiving a resume request from the scheduled parent task or determining dependencies of the scheduled parent task have been met.

Claims

1. A method for parent-child scheduling and management of a computer workload, the method comprising:

scheduling, by a single workload scheduler, a parent task of a parent-child workload submitted by a client application, on a resource available to the single workload scheduler, wherein the single workload scheduler controls the scheduling on the resource available to the single workload scheduler;

receiving, by the single workload scheduler, a request to schedule a child task of the parent task of the parent-child workload, wherein the parent task of the parent-child workload is dependent on a result of the child task;

receiving, by the single workload scheduler, a message from the parent task of the parent-child workload yielding the resource to the single workload scheduler;

receiving by the single workload scheduler, a resume request from the parent task; and

returning, by the single workload scheduler, the resource yielded by the parent task to the parent task.

2. The method of claim 1, wherein returning the resource yielded by the scheduled parent task to the scheduled parent task is automatically returned based on determining one or more dependencies of the scheduled parent task have been met.

3. The method of claim 1, wherein the single workload scheduler is implemented as a master workload scheduler operating in a hierarchy with one or more slave workload schedulers, wherein the one or more slave workload schedulers receive the parent-child workload to schedule, based at lease in part on information from the master workload scheduler.

4. The method of claim 1, wherein the single workload scheduler is one of a plurality of single workload schedulers within a grid of computing resources, and wherein the single workload scheduler schedules the parent-child workload independent of workloads for other workload schedulers of the plurality of workload schedulers.

5. The method of claim 1, wherein the child task is created by another client application, and wherein the child task is associated with an existing task of the client application, forming a parent-child relationship.

6. The method of claim 1, wherein returning, by the single workload scheduler, the resource yielded by the parent task to the parent task, further comprises:

sending, by the single workload scheduler, a notification to the parent task requesting a resume of the resource yielded, wherein the notification indicates the resource yielded is available for the parent task to use.

7. The method of claim 1, wherein scheduling, by the single workload scheduler, the parent task of the parent-child workload submitted by the client application, further comprises:

scheduling a task of the parent-child workload to a resource allocated to a root session of a tree structure, wherein the scheduling of the parent-child workload shares the resource allocated to the root session of the tree structure.

8. The method of claim 1, wherein scheduling, by a single workload scheduler, the parent task of the parent-child workload, further comprises:

preempting, by a single workload scheduler, a task from a lowest descendent of an original task of a tree structure of the parent-child workflow submitted by the client application, having a fewest number of tasks, wherein the original task of the tree structure is a root task of the tree structure.

9. The method of claim 1, further comprising:

determining if a task is eligible to run on either of a free resource or the resource yielded to the single workload scheduler; and

scheduling the task to run on the resource yielded to the single workload scheduler in preference to the free resource.

10. The method of claim 1, further comprising:

assigning a preemption rank to a position of a scheduled task in a tree structure, wherein the scheduled task in a lowest position of the tree structure is assigned a lowest rank; and

selecting for preemption, the scheduled task having the lowest rank.