Event processing query language including retain clause
View Patent ↗An event processor can use event processing queries to operate an event. Event processing queries can include a “retain” clause that limits the amount of data over which the query is run.
1. A computer implemented system for real time event processing, comprising:
a computer, including a processor and a computer readable storage medium;
an event processor which executes on the computer, and which is configured to
receive data as a plurality of event streams, and
interpret statements or queries written in an event processing language, against the event streams, to query or process the data therein,
wherein at least some of the statements or queries include, as part of the statement or query, a retain clause that defines an extent of data in a data stream which should be retained in memory and over which the statement or query should be interpreted, and
wherein at least one statement or query defines its extent as a sliding window of stream data, over which the statement or query is processed;
a plurality of event listeners, each of which can be associated with a statement or query to receive notifications when that statement or query is satisfied; and
wherein, while the data streams are being received at the event processor, the event processor interprets each statement or query provided thereto, to
retain in memory a set of data defined by the retain clause included as part of the statement or query,
query or process the retained data as further defined by the statement or query,
determine if the statement or query is satisfied, and
notify associated listeners as appropriate.
2. The computer implemented system of claim 1 , wherein the retain clause is interpreted by the event processor to limit the query to a certain time period of the events, as defined by the retain clause.
3. The computer implemented system of claim 1 , wherein the retain clause is interpreted by the event processor to limit the query to a certain number of events.
4. The computer implemented system of claim 1 , wherein the event processor further includes pattern matching functionality, including determining any matching clause in the statement or query, and querying or processing the statement or query according to the pattern defined therein.
5. The computer implemented system of claim 1 , wherein the event processor determines any output clause in the statement or query that can limit the output of the query, and processes the statement or query accordingly.
6. The computer implemented system of claim 5 , wherein the event processor processes the statement or query accordingly to the output clause by holding output of the statement or query until a specified amount of time has passed, or a specified number of events have been received.
7. A computer implemented method for real time event processing, comprising the steps of:
using an event processor to
receive data as a plurality of event streams, and
interpret statements or queries written in an event processing language, against the event streams, to query or process the data therein,
wherein at least some of the statements or queries include, as part of the statement or query, a retain clause that defines an extent of data in a data stream which should be retained in memory and over which the statement or query should be interpreted, and
wherein at least one statement or query defines its extent as a sliding window of stream data, over which the statement or query is processed;
providing a plurality of event listeners, each of which can be associated with a statement or query to receive notifications when that statement or query is satisfied; and
while the data streams are being received at the event processor, interpreting each statement or query provided thereto, to
retain in memory a set of data defined by the retain clause included as part of the statement or query,
query or process the retained data as further defined by the statement or query,
determine if the statement or query is satisfied, and
notify associated listeners as appropriate.
8. The computer implemented method of claim 7 , wherein the retain clause is interpreted by the event processor to limit the query to a certain time period of the events, as defined by the retain clause.
9. The computer implemented method of claim 7 , wherein the retain clause is interpreted by the event processor to limit the query to a certain number of events.
10. The computer implemented method of claim 7 , wherein the event processor further includes pattern matching functionality, including determining any matching clause in the statement or query, and querying or processing the statement or query according to the pattern defined therein.
11. The computer implemented method of claim 7 , wherein the event processor determines any output clause in the statement or query that can limit the output of the query, and processes the statement or query accordingly.
12. The computer implemented method of claim 11 , wherein the event processor processes the statement or query accordingly to the output clause by holding output of the statement or query until a specified amount of time has passed, or a specified number of events have been received.
13. A non-transitory computer readable storage medium including code to:
use an event processor to
receive data as a plurality of event streams, and
interpret statements or queries written in an event processing language, against the event streams, to query or process the data therein,
wherein at least some of the statements or queries include, as part of the statement or query, a retain clause that defines an extent of data in a data stream which should be retained in memory and over which the statement or query should be interpreted, and
wherein at least one statement or query defines its extent as a sliding window of stream data, over which the statement or query is processed;
provide a plurality of event listeners, each of which can be associated with a statement or query to receive notifications when that statement or query is satisfied; and
while the data streams are being received at the event processor, interpret each statement or query provided thereto, to
retain in memory a set of data defined by the retain clause included as part of the statement or query,
query or process the retained data as further defined by the statement or query,
determine if the statement or query is satisfied, and
notify associated listeners as appropriate.
14. The non-transitory computer readable storage medium of claim 13 , wherein the retain clause is interpreted by the event processor to limit the query to a certain time period of the events, as defined by the retain clause.
15. The non-transitory computer readable storage medium of claim 13 , wherein the retain clause is interpreted by the event processor to limit the query to a certain number of events.
16. The non-transitory computer readable storage medium of claim 13 , wherein the event processor further includes pattern matching functionality, including determining any matching clause in the statement or query, and querying or processing the statement or query according to the pattern defined therein.
17. The non-transitory computer readable storage medium of claim 13 , wherein the event processor determines any output clause in the statement or query that can limit the output of the query, and processes the statement or query accordingly.
18. The non-transitory computer readable storage medium of claim 17 , wherein the event processor processes the statement or query accordingly to the output clause by holding output of the statement or query until a specified amount of time has passed, or a specified number of events have been received.