Scheduling storage unit maintenance tasks in a dispersed storage network
View Patent ↗A method for execution by a dispersed storage and task (DST) execution unit includes generating low-load prediction data, which includes selecting a time period corresponding to a predicted low-load, based on a plurality of historical load samplings. Maintenance task scheduling data is generated based on the low-load prediction data. Generating the maintenance task scheduling data includes assigning a maintenance task to a scheduled time that is within the time period corresponding to the predicted low-load. The maintenance task is executed at the scheduled time.
1. A method for execution by a dispersed storage and task (DST) execution unit that includes a processor, the method comprises:
generating low-load prediction data based on a plurality of historical load samplings, wherein generating the low-load prediction data includes selecting a time period corresponding to a predicted low-load;
generating maintenance task scheduling data based on the low-load prediction data, wherein generating the maintenance task scheduling data includes assigning a maintenance task to a scheduled time that is within the time period corresponding to the predicted low-load;
generating current load data by comparing at least one load reading taken at a time before the time period to a low-load threshold;
executing the maintenance task at the scheduled time when the at least one load reading compares unfavorably to the low-load threshold; and
when the at least one load reading compares favorably to the low-load threshold:
executing the maintenance task at an updated time that is earlier than the scheduled time; and
delaying execution of an access request received via a network by rescheduling the execution of the access request from an original time to a later time in response to the at least one load reading comparing favorably to the low-load threshold, wherein the later time is selected based on the updated time and an expected execution duration of the maintenance task.
2. The method of claim 1 , wherein the plurality of historical load samplings include load readings taken from at least one of: a central processing unit (CPU) of the DST execution unit or a memory device of the DST execution unit.
3. The method of claim 1 , further comprising:
updating historical load data that includes the plurality of historical load samplings in response to a predetermined time interval elapsing by adding at least one current load reading to the plurality of historical load samplings.
4. The method of claim 1 , wherein the generating the low-load prediction data includes determining a cyclical load pattern based on the historical load samplings, and wherein selecting the time period is based on a minimum of the cyclical load pattern.
5. The method of claim 4 , wherein the low-load prediction data includes a plurality of time periods corresponding to a plurality of predicted low-loads, wherein the plurality of time periods are based on a plurality of recurring minimums of the cyclical load pattern, wherein the plurality of time periods are separated by a fixed interval corresponding to a frequency of the cyclical load pattern, and wherein generating the maintenance task scheduling data includes assigning a recurring maintenance task to the plurality of time periods.
6. The method of claim 1 , wherein the maintenance task includes scanning a namespace of the DST execution unit.
7. The method of claim 1 , wherein the maintenance task includes rebuilding missing data slices stored in the DST execution unit.
8. The method of claim 1 , further comprising:
generating current load data by comparing at least one load reading taken during the time period corresponding to the predicted low-load to the low-load prediction data;
wherein the maintenance task is executed at the scheduled time when the at least one load reading compares favorably to the low-load prediction data; and
wherein the maintenance task is rescheduled for execution at a future time that is later than the time period corresponding to the predicted low-load when the at least one load reading compares unfavorably to the low-load prediction data.
9. A processing system of a dispersed storage and task (DST) execution unit comprises:
at least one processor;
a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to:
generate low-load prediction data based on a plurality of historical load samplings, wherein generating the low-load prediction data includes selecting a time period corresponding to a predicted low-load;
generate maintenance task scheduling data based on the low-load prediction data, wherein generating the maintenance task scheduling data includes assigning a maintenance task to a scheduled time that is within the time period corresponding to the predicted low-load;
generate current load data by comparing at least one load reading taken at a time before the time period to a low-load threshold;
execute the maintenance task at the scheduled time when the at least one load reading compares unfavorably to the low-load threshold; and
when the at least one load reading compares favorably to the low-load threshold:
execute the maintenance task at an updated time that is earlier than the scheduled time; and
delay execution of an access request received via a network by rescheduling the execution of the access request from an original time to a later time in response to the at least one load reading comparing favorably to the low-load threshold, wherein the later time is selected based on the updated time and an expected execution duration of the maintenance task.
10. The processing system claim 9 , wherein the plurality of historical load samplings include load readings taken from at least one of: a central processing unit (CPU) of the DST execution unit or a memory device of the DST execution unit.
11. The processing system of claim 9 , wherein the operational instructions, when executed by the at least one processor, further cause the processing system to:
update historical load data that includes the plurality of historical load samplings in response to a predetermined time interval elapsing by adding at least one current load reading to the plurality of historical load samplings.
12. The processing system of claim 9 , wherein the generating the low-load prediction data includes determining a cyclical load pattern based on the historical load samplings, and wherein selecting the time period is based on a minimum of the cyclical load pattern.
13. The processing system of claim 12 , wherein the low-load prediction data includes a plurality of time periods corresponding to a plurality of predicted low-loads, wherein the plurality of time periods are based on a plurality of recurring minimums of the cyclical load pattern, wherein the plurality of time periods are separated by a fixed interval corresponding to a frequency of the cyclical load pattern, and wherein generating the maintenance task scheduling data includes assigning a recurring maintenance task to the plurality of time periods.
14. The processing system of claim 9 , wherein the maintenance task includes scanning a namespace of the DST execution unit.
15. The processing system of claim 9 , wherein the maintenance task includes rebuilding missing data slices stored in the DST execution unit.
16. The processing system of claim 9 , wherein the operational instructions, when executed by the at least one processor, further cause the processing system to:
generate current load data by comparing at least one load reading taken during the time period corresponding to the predicted low-load to the low-load prediction data;
wherein the maintenance task is executed at the scheduled time when the at least one load reading compares favorably to the low-load prediction data; and
wherein the maintenance task is rescheduled for execution at a future time that is later than the time period corresponding to the predicted low-load when the at least one load reading compares unfavorably to the low-load prediction data.
17. A non-transitory computer readable storage medium comprises:
at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to:
generate low-load prediction data based on a plurality of historical load samplings, wherein generating the low-load prediction data includes selecting a time period corresponding to a predicted low-load;
generate maintenance task scheduling data based on the low-load prediction data, wherein generating the maintenance task scheduling data includes assigning a maintenance task to a scheduled time that is within the time period corresponding to the predicted low-load;
generate current load data by comparing at least one load reading taken at a time before the time period to a low-load threshold;
execute the maintenance task at the scheduled time when the at least one load reading compares unfavorably to the low-load threshold; and
when the at least one load reading compares favorably to the low-load threshold:
execute the maintenance task at an updated time that is earlier than the scheduled time; and
delay execution of an access request received via a network by rescheduling the execution of the access request from an original time to a later time in response to the at least one load reading comparing favorably to the low-load threshold, wherein the later time is selected based on the updated time and an expected execution duration of the maintenance task.