MODIFIED BACKFILL SCHEDULER AND A METHOD EMPLOYING FREQUENCY CONTROL TO REDUCE PEAK CLUSTER POWER REQUIREMENTS

• US 20140137122A1
• Filed: 11/13/2012
• Published: 05/15/2014
• Est. Priority Date: 11/13/2012
• Status: Abandoned Application

• Current Assignee: Bull HN Information Systems Incorporated (Atos SE)
• Original Assignee: Bull HN Information Systems Incorporated (Atos SE)
• Inventors: Egolf, David A., Guenthner, Russell W.
• Application Number:
  US13/675,219
• Publication Number:
  US 20140137122A1
• Time in Patent Office: Days
• US Class Current: 718/102
• CPC Class Codes: G06F 9/4893 taking into account power or heat criteria power management in computers in general G06F1/3203; thermal management in computers in general G06F1/206
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method is disclosed for reducing peak power usage in a large computer system with multiple nodes by identifying jobs which can be scheduled to run at reduced frequency in order to reduce total power usage during certain time periods. The backfill scheduler of the computer system'"'"'s operating system performs steps providing for selected jobs on selected nodes of the computer system to be run at reduced frequency such that those jobs are partially processed during previously underutilized holes in the computer system schedule in order to reduce overall peak power during a period of processing.

Claims

1. ) A method performed by a backfill job scheduler scheduling running of a plurality of jobs on a computer system having multiple nodes, the method providing for reducing peak computer system power usage during running of the plurality of jobs, the computer system providing to the scheduler with the capability of controlling processor frequency of operation for one or more selected nodes of the multiple nodes of the computer system, a reduction in node processor frequency typically resulting in reduced power usage on that node during the period of reduced frequency, the steps of the method comprising:

a) assigning a first possible schedule executable by the scheduler which specifies a first scheduled order for running the plurality of jobs within a first amount of time;

b) modifying the first possible schedule by having the scheduler perform a backfilling operation that produces a second schedule having a second scheduled order for running the plurality of jobs within a scheduled second amount of time, the scheduled second amount of time being less than the first amount of time;

c) the scheduler examining the second schedule and identifying holes occurring in scheduled time allocated in the second schedule during which one or more individual nodes are not being fully utilized, for creating a list of holes wherein each entry for each hole in the list of holes identifies an underutilized node and an underutilized time period during which the node is not being fully utilized;

d) the scheduler further examining or searching the second schedule of step c and identifying those jobs which utilize the underutilized nodes during adjacent time periods in the second schedule, each adjacent time period representing a period of time adjacent in time to each node'"'"'s associated underutilized periods of time, those jobs being identified or designated as adjacent jobs by the scheduler; and

e) the scheduler modifying frequency control parameters included in the second schedule to reduce the frequency of operation of the nodes which are scheduled to run one or more of the identified adjacent jobs during at least a portion of the adjacent time periods to move processing time of those identified adjacent jobs into the holes in the scheduled time in the second schedule, and to reduce power usage on the node during the adjacent time periods.

2. ) A method performable by a job scheduler of a computer system with multiple nodes, for reducing peak computer system power usage while running a plurality of jobs, the scheduler including within its control parameters a capability of controlling frequency of operation of selected nodes of the multiple nodes of the computer system, the steps of the method comprising:

a) the scheduler first assigning a first possible schedule for running that plurality of jobs;

b) the scheduler next identifying holes in time in the first possible schedule, the holes being one or more periods of time during which one or more specific nodes of the computer system are not being fully utilized;

c) the scheduler then identifying one or more adjacent jobs assigned in the first possible schedule to utilize those same one or more specific nodes during periods of time adjacent to the holes in the periods of time in the first possible schedule; and

d) the scheduler modifying frequency control parameters included in the first possible schedule so as to reduce the frequency of operation of the nodes which are scheduled to run the one or more of the identified adjacent jobs during at least a portion of the period of time adjacent to the holes in the periods of time to move processing time of those adjacent jobs on their assigned nodes into the holes in the periods of time.

3. ) A method for potentially reducing peak power usage on a computer system comprising the steps of:

a) providing to one or more users of the computer system an option facility or mechanism within the computer system for specifying permission to apply specific power management techniques during processing of one or more selected jobs by the computer system; and

,

b) generating billing information for the user of the computer system at a reduced rate, compared to a normally applied rate of billing for running jobs, as a consequence of user selection of the option that allows application of the specific power management techniques during processing of the selected jobs by the computer system.

4. ) A method performable by a backfill job scheduler of a computer system having multiple nodes, for reducing peak computer system power usage while running a plurality of jobs, the scheduler including within control parameters associated therewith, the capability of controlling frequency of operation for selected nodes of the multiple nodes of the computer system, the steps of the method comprising:

a) the scheduler assigning a first possible schedule which specifies a first scheduled order for running that plurality of jobs within in a first amount of time;

b) next, the scheduler modifying that first possible schedule by performing a backfilling operation to produce a second schedule having a second scheduled order for running that plurality of jobs within a second amount of time, the second amount of time being less than the first amount of time;

c) the scheduler then examining the second schedule and identifying holes in scheduled time within the second schedule during which one or more individual nodes are not being fully utilized, for identifying a plurality of underutilized holes, each identified hole in the plurality of holes identifying the underutilized node and the underutilized time period during which the node is not being fully utilized;

d) the scheduler further examining the second schedule and identifying jobs which utilize the underutilized nodes during adjacent time periods, each of the adjacent time periods being a period of time adjacent in time to each node'"'"'s associated underutilized periods of time in the second schedule, the jobs being identified or designated as adjacent jobs by the scheduler;

e) the scheduler modifying frequency control parameters in the second schedule so as to reduce the frequency of operation of the nodes which are scheduled to run one or more of the identified adjacent jobs during at least a portion of the adjacent time periods so as to move processing time of those identified adjacent jobs into the holes in scheduled time in the second schedule; and

,

f) the scheduler again examining and then modifying the second schedule so as to reduce peak power usage by reducing frequency of operation of one or more nodes during the first time period while still maintaining expected completion of the plurality of jobs within the first time period.

5. ) An enhanced backfill scheduler for use in a cluster computer system having multiple nodes, the enhanced scheduler enabling reduction of peak computer system power while running a plurality of jobs over a period of time, the computer system providing within control parameters used by the scheduler a capability of controlling frequency of operation for selected nodes of the multiple nodes of the computer system, the enhanced scheduler running on either the cluster computer system itself or on another computer system and the scheduler comprising:

a) a first table storing a first possible schedule assigned by the scheduler for the plurality of jobs on the cluster computer system, the first possible schedule specifying a first scheduled order for running that plurality of jobs in a first amount of time;

b) the scheduler including a backing filling mechanism for modifying the first possible schedule by performing a backfilling operation to generates a second schedule in a second table having a second scheduled order for running that plurality of jobs in a second amount of time, the second amount of time being less than the first amount of time;

c) the scheduler further including a search mechanism for examining the second schedule and identifying holes in scheduled time occurring in the second schedule during which one or more individual nodes are not being fully utilized, for identifying a plurality of holes with each entry for each hole in the list of holes designating the underutilized node and the underutilized time period during which that node is not being fully utilized;

d) the search mechanism being operative to further examine the second schedule and identify jobs which utilize the underutilized nodes during adjacent time periods, each of the adjacent time periods being a period of time adjacent in time in the second schedule to each node'"'"'s associated underutilized periods of time, the jobs being identified by the search mechanism as adjacent jobs;

e) the scheduler invoking the capability for controlling frequency of operation to modify frequency control parameters included in the second schedule of the second table to reduce the frequency of operation of the nodes which are scheduled to run one or more of the identified adjacent jobs during at least a portion of the adjacent time periods to move processing time of those identified adjacent jobs into the holes in the scheduled time of the second schedule; and

f) the search mechanism further operating to reexamine and then modify the second schedule of the second table to reduce peak power usage by reducing the frequency of operation of one or more nodes during determined periods of time specified in the second table while still completing the plurality of jobs within the first time period.