Circular log amnesia detection

A computer-implemented method performed by a computing system for performing amnesia detection in a circular log, wherein the circular log includes a plurality of records that are each categorized into an interval of a plurality of intervals, each of the plurality of intervals including one or more of the plurality of records, wherein some records of the circular log have been removed in response to one or more prior checkpoint triggers, the computer-implemented method comprising:

• an act of detecting a request for information from a record;
• an act of determining that the record identified in the request is not presently in the circular log;
• and
• an act of accessing information preserved about records that have been previously removed from the circular log to verify whether the preserved information indicates that the record identified in the request had ever existed in the circular log.

A computer program product comprising one or more computer-readable media having thereon computer-executable instructions that, when executed by one or more processors of a computing system, cause the computing system to perform a method for detection whether amnesia has occurred in a circular log that includes a plurality of records that are each categorized into an interval of a plurality of intervals, each of the plurality of intervals including one or more of the plurality of records, wherein some records of the circular log have been removed in response to one or more prior checkpoint triggers, computer-executable instructions comprising:

• one or more computer-executable instructions for determining that a record identified in a request is not presently in the circular log;
• one or more computer-executable instructions for accessing information preserved about records that have been previously removed from the circular log to verify whether the preserved information indicates that the record identified in the request had ever existed in the circular log;
• and
• one or more computer-executable instructions for branching processing flow depending on a result of whether the preserved information indicates that the record identified in the request had ever existed in the circular log, wherein the branching instructions cause execution to proceed to one or more computer-executable instructions that detect amnesia if the preserved information does not indicate that the record ever existed in the circular log, and cause execution to proceed to one or more computer-executable instructions that avoids a detection of amnesia if the preserved information does indicate that the record once existed in the circular log.