DATA STREAM MANAGEMENT SYSTEMS

• US 20140379712A1
• Filed: 03/08/2012
• Published: 12/25/2014
• Est. Priority Date: 03/08/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lafuente Alvarez, Luis Maria
• Granted Patent: US 10,055,483 B2
• Time in Patent Office: Days
• US Class Current: 707/736
• CPC Class Codes: G06F 16/24539 using cached or materialised query results
• CPC Class Codes: G06F 16/24568 Data stream processing; Continuous queries
• CPC Class Codes: G06F 16/3331 Query processing
• CPC Class Codes: G06F 16/335 Filtering based on additional data, e.g. user or group profiles filtering in web context G06F16/9535, G06F16/9536
• CPC Class Codes: G06F 16/35 Clustering; Classification

Abstract

A method is carried out by a data stream management system suitable for executing continuous queries on input data streams. Primary continuous queries are executed by, or provisioned to be executed by, the data stream management system on one or more input data streams in order to produce one or more output data streams. In the method, at least one secondary continuous query is generated for execution on the data stream management system on one or more input data streams. The generated secondary continuous queries are different from the primary continuous queries, and the secondary continuous queries are generated based on the at least one primary continuous query. The generation of secondary continuous queries notably enables, when ad-hoc continuous queries are requested, to quickly start outputting data streams for these ad-hoc queries. Data stream management systems and computer programs are also disclosed.

Claims

1. A method, carried out by a data stream management system, the data stream management system being suitable for executing continuous queries on input data streams, and at least one continuous query, here referred to as at least one primary continuous query, is one of executed by and provisioned to be executed by, the data stream management system on at least one input data stream to produce at least one output data stream, the method comprising:

a generating procedure comprising generating at least one additional continuous query, here referred to as at least one secondary continuous query, for execution on the data stream management system on at least one input data stream;

each one of the at least one generated secondary continuous query being different from each one of the at least one primary continuous query; and

the generating procedure generating the at least one secondary continuous query based on the at least one primary continuous query.

2. The method of claim 1, wherein the generating procedure is executed at least following the reception, by the data stream management system, of a request, from an external application, for executing, on the data stream management system, at least one new primary continuous query;

and

in the generating procedure, the generating the at least one secondary continuous query being based on the at least one received new primary continuous query.

3. The method of claim 1, further comprising:

a selecting procedure comprising selecting, amongst the at least one secondary continuous query, at least one preferred secondary continuous query.

4. The method of claim 3, wherein the selecting procedure takes into account at least one of:

expected memory resources for executing, by the data stream management system, the at least one secondary continuous query;

expected processing resources for executing, by the data stream management system, the at least one secondary continuous query; and

likelihood that the at least one secondary continuous query is requested by an external application.

5. The method of claim 1, further comprising:

executing the at least one secondary continuous query on the data stream management system.

6. The method of claim 3, further comprising:

executing the at least one preferred secondary continuous query on the data stream management system.

7. The method of claim 5, further comprising:

determining that more resources than available are required for executing, on the data stream management system, at least one continuous query newly requested by external applications; and

interrupting the execution of at least one secondary continuous query.

8. The method of claim 7, further comprising resuming the execution of an interrupted secondary continuous query one of:

when determining that sufficient resources are available for executing on the data stream management system at least one secondary continuous query; and

when receiving, from an external application, a request for executing on the data stream management system a continuous query that matches the interrupted secondary continuous query.

9. The method of claim 5, further comprising:

receiving, from an external application, a request for executing on the data stream management system a continuous query;

determining that the continuous query for which a request for execution has been received matches a continuous query already executed on the data stream management system as a secondary continuous query; and

starting to send, to at least one of the external application from which the request has been received and any other external application, at least one output data stream resulting from the execution of said matching secondary continuous query.

10. The method of claim 1, wherein, in the generating procedure,

(i) a first group of input data streams comprises the input data streams of which at least some data is used in a filtering condition in the at least one primary continuous query;

(ii) a second group of input data streams comprises the input data streams of which no data is used in a filtering condition in the at least one primary continuous query but of which at least some data is used in the at least one primary continuous query;

(iii) a third group of input data streams comprises the input data streams of which no data is used in the at least one primary continuous query;

(iv) a first group of data components comprises the data components of the first group input data streams which are used in a filtering condition and the data components of said first group input data streams which are included in at least one output data stream;

(v) a second group of data components comprises, if the number of second group input data streams is not zero, data components of said second group input data streams; and

(vi) a third group of data components comprises, if the number of third group input data streams is not zero, data components of said third group input data streams;

the generating the at least one secondary continuous query based on the at least one primary continuous query comprises at least one of;

(a) combining a value of the first group data components which has not been filtered out with second group data components to generate a combination that is not used by any of the at least one primary continuous query;

(b) repeating step (a) until all possible combinations have been generated;

(c) combining a value of the first group data components which has been filtered out with second group data components to generate a combination that is not used by any of the at least one primary continuous query;

(d) repeating step (c) until all possible combinations have been generated;

(e) combining a value of the first group data components which has not been filtered out with third group data components to generate a combination that is not used by any of the at least one primary continuous query;

(f) repeating step (e) until all possible combinations have been generated;

(g) combining a value of the first group data components which has been filtered out with third group data components to generate a combination that is not used by any of the at least one primary continuous query; and

(h) repeating step (g) until all possible combinations have been generated.

11. The method of claim 10, wherein, in the generating procedure, the generating of the at least one secondary continuous query is based on the at least one primary continuous query comprises carrying out, successively, steps (a), (b), (c), (d), (e), (f), (g) and (h).

12. A data stream management system comprising at least one network node, the data stream management system being suitable for executing continuous queries on input data streams, and, at least one continuous query, here referred to as the at least one primary continuous query, is one of executed by and provisioned to be executed by, the data stream management system on at least one input data stream to produce at least one output data stream, the data stream management system comprising:

a generating unit configured for generating at least one additional continuous query, here referred to as the at least one secondary continuous query, for execution on the data stream management system on at least one input data stream;

each one of the at least one generated secondary continuous query being different from each one of the at least one primary continuous query; and

the generating unit generating the at least one secondary continuous query based on the at least one primary continuous query.

13. The data stream management system of claim 12, wherein the generating unit is further configured for generating the at least one additional continuous query at least following the reception, by the data stream management system, of a request, from an external application, for executing, on the data stream management system, at least one new primary continuous query;

and

the generating of the at least one secondary continuous query being based on the at least one received new primary continuous query.

14. The data stream management system of claim 12, further comprising a selecting unit configured for selecting, amongst the at least one secondary continuous query, at least one preferred secondary continuous query.

15. The data stream management system of claim 14, wherein the selecting unit is further configured to execute a process that takes into account at least one of:

expected memory resources for executing, by the data stream management system, the at least one secondary continuous query;

expected processing resources for executing, by the data stream management system, the at least one secondary continuous query; and

likelihood that the at least one secondary continuous query is requested by an external application.

16. The data stream management system of claim 12, further configured for executing the at least one secondary continuous query on the data stream management system.

17. The data stream management system of claim 14, further configured for executing the at least one preferred secondary continuous queries on the data stream management system.

18. The data stream management system of claim 14, further configured for:

determining that more resources than available are required for executing, on the data stream management system, at least one continuous query newly requested by external applications; and

interrupting the execution of at least one secondary continuous query.

19. The data stream management system of claim 18, further configured for resuming the execution of an interrupted secondary continuous query one of:

when determining that sufficient resources are available for executing on the data stream management system at least one secondary continuous query; and

when receiving, from an external application, a request for executing on the data stream management system a continuous query that matches the interrupted secondary continuous query.

20. The data stream management system of claim 16, further configured for:

receiving, from an external application, a request for executing on the data stream management system a continuous query;

determining that the continuous query for which a request for execution has been received matches a continuous query already executed on the data stream management system as a secondary continuous query; and

starting to send, to at least one of the external application from which the request has been received and any other external application, at least one output data stream resulting from the execution of said matching secondary continuous query.

21. The data stream management system of claim 12, wherein the generating unit is further configured such that,

(i) a first group of input data streams comprises the input data streams of which at least some data is used in a filtering condition in the at least one primary continuous query;

(ii) a second group of input data streams comprises the input data streams of which no data is used in a filtering condition in the at least one primary continuous query but of which at least some data is used in the at least one primary continuous query;

(iii) a third group of input data streams comprises the input data streams of which the data components is not used in the at least one primary continuous query;

(iv) a first group of data components comprises the data components of the first group input data streams which are used in a filtering condition and the data components of said first group input data streams which are included in at least one output data stream;

(v) a second group of data components comprises, if the number of second group input data streams is not zero, data components of said second group input data streams; and

(vi) a third group of data components comprises, if the number of third group input data streams is not zero, data components of said third group input data streams;

the generating the at least one secondary continuous query based on the at least one primary continuous query comprises the execution of at least one process of;

(a) combining a value of the first group data components which has not been filtered out with second group data components to generate a combination that is not used by any of the at least one primary continuous query;

(b) repeating the process (a) until all possible combinations have been generated;

(c) combining a value of the first group data components which has been filtered out with second group data components to generate a combination that is not used by any of the at least one primary continuous query;

(d) repeating the process (c) until all possible combinations have been generated;

(e) combining a value of the first group data components which has not been filtered out with third group data components to generate a combination that is not used by any of the at least one primary continuous query;

(f) repeating the process (e) until all possible combinations have been generated;

(g) combining a value of the first group data components which have been filtered out with third group data components to generate a combination that is not used by any of the at least one primary continuous query; and

(h) repeating the process (g) until all possible combinations have been generated.

22. The data stream management system of claim 21, wherein the generating unit is further configured such that the generating the at least one secondary continuous query based on the at least one primary continuous query comprises carrying out, successively, the execution of processes (a), (b), (c), (d), (e), (f), (g) and (h).

23. A computer program product comprising computer-executable instructions executable by a data stream management system, the data stream management system being suitable for executing continuous queries on input data streams, and, at least one continuous query, here referred to as the at least one primary continuous query, is one of executed by and provisioned to be executed by, the data stream management system on at least one input data stream to produce at least one output data stream, when the computer-executable instructions are executed by the data stream management system, the data stream management system is caused to:

generate at least one additional continuous query, here referred to as the at least one secondary continuous query, for execution on the data stream management system on at least one input data stream;

each one of the at least one generated secondary continuous query being different from each one of the at least one primary continuous query; and

generate the at least one secondary continuous query based on the at least one primary continuous query.

24. (canceled)