Adaptive, time-based synchronization mechanism for an integrated posix file system
AssigneeInternational Business Machines Corporation
InventorsDavid Leroy Johnson, Michael Lawrence Nordstrom, John Christopher Ripstra
Life of this patent
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Abstract
Synchronization software in a computer operating system evaluates with respect to an exposure goal the ages of byte stream files queued for synchronization, and dynamically adjusts synchronization (“sync”) capacity in response to the evaluation. The synchronization of byte stream files occurs at rates responsive to the sync capacity. Several parameters are used to adjust sync capacity: a lead time, the number of active sync tasks, and the priority of the sync tasks. These parameters are adjusted in a manner to impact system performance to the least extent possible.
Claims30
In an operating system of a computer, a method for synchronizing byte stream files to a direct-access storage device, comprising the steps of:
- detecting alteration of a byte stream file in a main memory of said computer, said alteration not yet reflected in a copy of said byte stream file stored in a non-volatile direct access storage medium at a time said alteration is detected;
- adding information identifying said byte stream file having said alteration to a synchronization list;
- evaluating, at a predetermined interval, an age represented by a time difference between a byte stream file identified in said synchronization list and a predetermined exposure goal;
- adjusting a sync capacity in response to said age of a byte stream file identified in said synchronization list;
- and
- initiating synchronization of a byte stream file identified in said synchronization list in response to said age and said exposure goal, synchronization of byte stream files occurring at rates responsive to said sync capacity.
A system in an operating system of a computer for synchronizing byte stream files to a direct-access storage device, comprising:
- a synchronization list on which is stored information identifying an alteration of a byte stream file detected by said operating system, said alteration not yet reflected in a copy of said byte stream file stored in a non-volatile direct access storage medium at a time said alteration is detected;
- an evaluator task evaluating, during an evaluation cycle occurring at a predetermined interval, an age represented by a time difference between a byte stream file identified in said synchronization list and a predetermined exposure goal, said evaluator task adjusting a sync capacity in response to said age of a byte stream file identified in said synchronization list, said evaluator task initiating a synchronization of a byte stream file identified by said information in said synchronization list in response to said age and said exposure goal;
- and
- one or more synchronization tasks collectively synchronizing byte stream files in said synchronization list for which synchronization has been initiated at rates responsive to said sync capacity, synchronization of byte stream files occurring at rates responsive to said sync capacity.
A computer program product for a computer operating system for synchronizing byte stream files to a direct-access storage device, comprising at least one signal-bearing medium carrying in computer-detectable format thereon:
- a synchronization list on which is stored information identifying an alteration of a byte stream file detected by said operating system, said alteration not yet reflected in a copy of said byte stream file stored in a non-volatile direct access storage medium at a time said alteration is detected;
- an evaluator task evaluating, during an evaluation cycle occurring at a predetermined interval, an age represented by a time difference between a byte stream file identified in said synchronization list and a predetermined exposure goal, said evaluator task adjusting a sync capacity in response to said age of a byte stream file identified in said synchronization list, said evaluator task initiating a synchronization of a byte stream file identified by said information in said synchronization list in response to said age and said exposure goal;
- and
- one or more synchronization tasks collectively synchronizing byte stream files in said synchronization list for which synchronization has been initiated at rates responsive to said sync capacity, synchronization of byte stream files occurring at rates responsive to said sync capacity.
Dependencies are inferred from the claim text.