Intermittent sampling of storage access frequency

摘要

The intermittent sampling of storage access frequency is performed by determining a duration of a collection window and a duration of an observation window within the collection window. A position of the observation window within the collection window is randomly selected, and frequencies of accesses of one or more storage objects during the observation window are observed. When a new access of a given storage object occurs, a delta time for the given storage object is calculated as the time of the observed access minus the timestamp of the most recent observed prior access of the given storage object. Optionally, the delta time of two sequential accesses of a given storage object in two different observation windows may be calculated as if the two different observation windows are immediately adjacent to each other.

主权项

1. A computer program product for intermittent sampling of storage access frequency, the computer program product comprising:
a non-transitory computer readable storage medium having computer readable program code embodied therewith, the program code executable by a processor to:monitor frequencies of accesses of one or more storage objects intermittently by:
determining a duration of a collection window; determining a duration of an observation window within the collection window; avoiding omission of periodic activity of the frequencies of accesses in the collection window due to harmonic aliasing by randomly selecting a starting position of the observation window within the collection window, wherein the observation window is a fixed width that begins and ends within the collection window; observing frequencies of accesses of the one or more storage objects during the observation window; reducing temporary storage used to store observed frequencies of accesses via the intermittent monitoring; and approximating the frequencies of accesses for each of the one or more storage objects that occur through continuous monitoring using the frequencies of accesses observed through the intermittent monitoring, wherein the frequencies of access is approximated for a given storage object to determine a level in the storage hierarchy in which to store the given storage object.