VARIABLE DURATION NON-EVENT PATTERN MATCHING

• US 20140201225A1
• Filed: 03/15/2013
• Published: 07/17/2014
• Est. Priority Date: 01/15/2013
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Deshmukh, Unmesh Anil, Srinivasan, Anand
• Granted Patent: US 9,098,587 B2
• Time in Patent Office: Days
• US Class Current: 707/758
• CPC Class Codes: G06F 16/20 of structured data, e.g. relational data
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06F 16/953 Querying, e.g. by the use of web search engines

Abstract

Techniques for performing non-event pattern matching on continuous event streams using variable duration. The duration value used in non-event pattern matching can be variable. Accordingly, a first pattern match candidate can have a different associated duration from a second pattern match candidate for matches arising from events received via an event stream. In certain embodiments, the duration for a candidate pattern match may be based upon one or more attributes of an event that started the candidate pattern match or based upon an expression (e.g., an arithmetic expression) involving one or more attributes of the event.

Claims

1. A method comprising:

determining, by a computing device, that a first event received by the computing device via an event stream causes a first pattern match candidate to be started for a pattern;

computing, by the computing device, a first duration for the first pattern match candidate;

determining, by the computing device, that a second event received via the event stream causes a second pattern match candidate to be started for the pattern; and

computing, by the computing device, a second duration for the second pattern match candidate, the second duration being different from the first duration.

2. The method of claim 1 wherein:

the first event and the second event comprise an attribute;

computing the first duration comprises;

determining a first value of the attribute of the first event; and

using the first value to compute the first duration; and

computing the second duration comprises;

determining a second value of the attribute of the second event, the second value being different from the first value; and

using the second value to compute the second duration.

3. The method of claim 1 wherein:

the first event and the second event comprise an attribute;

computing the first duration comprises;

determining a first value of the attribute of the first event; and

evaluating an expression using the first value to compute the first duration; and

computing the second duration comprises;

determining a second value of the attribute of the second event, the second value being different from the first value; and

evaluating the expression using the second value to compute the second duration.

4. The method of claim 1 further comprising:

determining, after the first time duration for the first event has passed, whether the first pattern match candidate has matched the pattern; and

upon determining that the first pattern match candidate has matched the pattern, outputting information indicative of a non-event occurrence corresponding to the first pattern match candidate.

5. The method of claim 1 further comprising:

determining a first expiration time for the first pattern match candidate based upon a first time associated with the first event and the first duration;

associating the first expiration time with the first pattern match candidate;

determining a second expiration time for the second pattern match candidate based upon a second time associated with the second event and the second duration; and

associating the second expiration time with the second pattern match candidate.

6. The method of claim 5 further comprising:

determining, at or after the first expiration time associated with the first pattern match candidate, whether the first pattern match candidate has matched the pattern; and

upon determining that the first pattern match candidate has matched the pattern, outputting information indicative of a non-event occurrence corresponding to the first pattern match candidate.

7. A computing device comprising:

a memory; and

a set of processing units, wherein one or more processing units from the set of processing units are adapted to;

determine that a first event received by the computing device via an event stream causes a first pattern match candidate to be started for a pattern;

compute a first duration for the first pattern match candidate;

determine that a second event received via the event stream causes a second pattern match candidate to be started for the pattern; and

compute a second duration for the second pattern match candidate, the second duration being different from the first duration.

8. The computing device of claim 7 wherein the one or more processing units from the set of processing units are adapted to:

determine a first value of an attribute of the first event; and

use the first value to compute the first duration;

determine a second value of the attribute of the second event, the second value being different from the first value; and

use the second value to compute the second duration.

9. The computing device of claim 7 wherein the one or more processing units from the set of processing units are adapted to:

determine a first value of an attribute of the first event; and

evaluate an expression using the first value to compute the first duration;

determine a second value of the attribute of the second event, the second value being different from the first value; and

evaluating the expression using the second value to compute the second duration.

10. The computing device of claim 7 wherein the one or more processing units from the set of processing units are further adapted to:

determine, after the first time duration for the first event has passed, whether the first pattern match candidate has matched the pattern; and

upon determining that the first pattern match candidate has matched the pattern, output information indicative of a non-event occurrence corresponding to the first pattern match candidate.

11. The computing device of claim 7 wherein the one or more processing units from the set of processing units are further adapted to:

determine a first expiration time for the first pattern match candidate based upon a first time associated with the first event and the first duration;

associate the first expiration time with the first pattern match candidate;

determine a second expiration time for the second pattern match candidate based upon a second time associated with the second event and the second duration; and

associate the second expiration time with the second pattern match candidate.

12. The computing device of claim 11 wherein the one or more processing units from the set of processing units are adapted to:

determine the first expiration time by adding the first duration to the first time associated with the first event; and

determine the second expiration time by adding the second duration to the second time associated with the second event.

13. The computing device of claim 11 wherein the one or more processing units from the set of processing units are further adapted to:

determine, at or after the first expiration time associated with the first pattern match candidate, whether the first pattern match candidate has matched the pattern; and

upon determining that the first pattern match candidate has matched the pattern, output information indicative of a non-event occurrence corresponding to the first pattern match candidate.

14. A computer-readable memory storing a plurality of instructions executable by one or more processing units, the plurality of instructions comprising:

instructions that cause at least one processing unit from the one or more processing units to determine that a first event received via an event stream causes a first pattern match candidate to be started for a pattern;

instructions that cause at least one processing unit from the one or more processing units to compute a first duration for the first pattern match candidate;

instructions that cause at least one processing unit from the one or more processing units to determine that a second event received via the event stream causes a second pattern match candidate to be started for the pattern; and

instructions that cause at least one processing unit from the one or more processing units to compute a second duration for the second pattern match candidate, the second duration being different from the first duration.

15. The computer-readable memory of claim 14 wherein:

the instructions that cause at least one processing unit from the one or more processing units to compute the first duration comprise;

instructions that cause at least one processing unit from the one or more processing units to determine a first value of an attribute of the first event; and

instructions that cause at least one processing unit from the one or more processing units to use the first value to compute the first duration; and

the instructions that cause at least one processing unit from the one or more processing units to compute the second duration comprise;

instructions that cause at least one processing unit from the one or more processing units to determine a second value of the attribute of the second event, the second value being different from the first value; and

instructions that cause at least one processing unit from the one or more processing units to use the second value to compute the second duration.

16. The computer-readable memory of claim 14 wherein:

the instructions that cause at least one processing unit from the one or more processing units to compute the first duration comprise;

instructions that cause at least one processing unit from the one or more processing units to determine a first value of an attribute of the first event; and

instructions that cause at least one processing unit from the one or more processing units to evaluate an expression using the first value to compute the first duration; and

instructions that cause at least one processing unit from the one or more processing units to compute the second duration comprise;

instructions that cause at least one processing unit from the one or more processing units to determine a second value of the attribute of the second event, the second value being different from the first value; and

instructions that cause at least one processing unit from the one or more processing units to evaluate the expression using the second value to compute the second duration.

17. The computer-readable memory of claim 14 wherein the plurality of instructions further comprises:

instructions that cause at least one processing unit from the one or more processing units to determine, after the first time duration for the first event has passed, whether the first pattern match candidate has matched the pattern; and

instructions that cause at least one processing unit from the one or more processing units to, upon determining that the first pattern match candidate has matched the pattern, output information indicative of a non-event occurrence corresponding to the first pattern match candidate.

18. The computer-readable memory of claim 14 wherein the plurality of instructions further comprises:

instructions that cause at least one processing unit from the one or more processing units to determine a first expiration time for the first pattern match candidate based upon a first time associated with the first event and the first duration;

instructions that cause at least one processing unit from the one or more processing units to associate the first expiration time with the first pattern match candidate;

instructions that cause at least one processing unit from the one or more processing units to determine a second expiration time for the second pattern match candidate based upon a second time associated with the second event and the second duration; and

instructions that cause at least one processing unit from the one or more processing units to associate the second expiration time with the second pattern match candidate.

19. The computer-readable memory of claim 18 wherein;

instructions that cause at least one processing unit from the one or more processing units to determine the first expiration time comprise instructions that cause at least one processing unit from the one or more processing units to determine the first expiration time by adding the first duration to the first time associated with the first event; and

instructions that cause at least one processing unit from the one or more processing units to determine the second expiration time comprise instructions that cause at least one processing unit from the one or more processing units to determine the second expiration time by adding the second duration to the second time associated with the second event.

20. The computer-readable memory of claim 18 wherein the plurality of instructions further comprises:

instructions that cause at least one processing unit from the one or more processing units to determine, at or after the first expiration time associated with the first pattern match candidate, whether the first pattern match candidate has matched the pattern; and

instructions that cause at least one processing unit from the one or more processing units to, upon determining that the first pattern match candidate has matched the pattern, output information indicative of a non-event occurrence corresponding to the first pattern match candidate.