Esper is a lightweight, open-source library for CEP (Complex Event Processing) and ESP (Event Stream Processing) applications developed by EsperTech Inc.
It is available for Java as Esper, and for .NET as NEsper under the GPL V2 license.
Questions tagged [esper]
536 questions
1
vote
0 answers
Maven dependency listed in pom.xml, but not recognizing methods in Package com.espertech.esperio
Maven dependency listed in pom.xml, but not recognizing methods in Package com.espertech.esperio
com.espertech
…
roni762583
- 75
- 7
1
vote
1 answer
How can i order events with esper?
I want to order events with a value;
So i have found eseper but i couldn't figure out the solution.
I found a example from internet and tried to customize it but failed.
Here are the codes i've tried.
SampleEvent.java
public class SampleEvent {
…
Sehun Park
- 113
- 1
- 2
- 11
1
vote
1 answer
How to avoid data getting doubled or tripled with the number of client connections
I'm using blazeDs pub/sub methodology and flex_sdk_4.1 to develop a flex application that displays data grid and chart for real time events generated using esper. The messageHandler() written in actionscript retrieves the events passed through JMS.…
Ria
- 225
- 1
- 7
- 18
1
vote
1 answer
Is there any examples or documentation for dockerizing esper application?
Is there any sample code or configuration file available for dockerizing esper application ?
1
vote
1 answer
Esper EPL - Differentiate deleted events from released events in a timed window
I count events within a timed window. If more than 5 events arrive at that window, then I want to discard them all. Otherwise, the events are released after the waiting time.
My code goes something like this:
// Create a timed window of 10…
Pcgomes
- 184
- 7
1
vote
1 answer
How to trigger esper as soon as the number of events exceed a threshold within time interval
I'd like to trigger esper as soon as it receives X number of events during an interval of Y minutes. I used this query but it triggers esper only 5 minutes after having received the first event and only if it's more then 10:
select count(*) as…
Peppe
- 315
- 5
- 13
1
vote
1 answer
Optional values with Esper
Is there any support in Esper for properties with Optional values?
I'm building a POC with Esper, using Scala, and I have the EPL query working with non-optional values. I have a simple object that I'm using to test with:
case class…
smur89
- 329
- 1
- 3
- 15
1
vote
1 answer
How to update and select from a table atomically in Esper?
I create a table that store the latest financial ticks, I would like to atomically select and calculate some ticks that meeting certain conditions immediately after updating the tick table.
Is there any method in Esper can achieve this…
jdnull
- 11
- 3
1
vote
2 answers
Instance method not called when declaring a Class-type instance variable and call an instance method in Esper
I'm writing an application that has an instance of a class that contains the esper engine. There are a number of instance variables that I would like to read and set using instance method calls from the EPL in the engine. I don't get any…
Jim Broiles
- 353
- 2
- 12
1
vote
1 answer
How to "create" a Map literal in Esper?
If I have an event type that has a column of type java.util.Map, how can I in EPL create a literal for use in an INSERT, to achieve something like:
insert into Event(id,myMap) select 1 as id, {'A':2,'B':3};
I know this is the right syntax or even…
user2123288
- 1,103
- 1
- 13
- 22
1
vote
1 answer
Cumulocity Event Language (CEL): Computing the Total Energy Consumption from the Battery Level Signal
My device registered on the Cumulocity IoT Platform has a signal for the current battery level: DLValues => battery_level
I want to compute the total energy consumption from this signal. The energy consumption between two battery level measurements…
eanbmu
- 11
- 2
1
vote
1 answer
Esper: Chaining property access and method calls in EPL queries
I am currently struggling to get some Esper EPL queries to work. The queries are looking like this:
select a.center.distance(b.center) as delta
from pattern [
every-distinct(a.id, b.id) (
a=org.example.PositionEvent ->…
Simon Lehmann
- 10,737
- 4
- 41
- 53
1
vote
1 answer
Linear Regression Using CEP
What is the best approach to achieve a linear regression using CEP ?. We have tried two different options.
We do want to have the algorithm working in real time.
Basic code for both approach :
create context IntervalSpanning3Seconds start…
Jorge
- 238
- 1
- 10
1
vote
2 answers
Difference between pattern matching algorithms used in CEP and Rule Engine like drools , siddhi?
Pattern matching algorithms are main in rule engine or Complex Event Stream processing engine. As i studied drools rule engine uses rete algorithm for pattern matching. What does Complex Event Stream Processing engines like siddhi , FlinkCEP and…
Murali krishna
- 823
- 1
- 8
- 23
1
vote
2 answers
Excessive memory usage in esper while aggregating values over 60 minutes using a context
I want to aggregate sensor values for each hour of the day. The time information comes from timestamps in the event stream. To that end, I've created four EPL statements:
The first statement declares a context that partitions events by sensorId
The…
Eiríkur Fannar Torfason
- 1,010
- 7
- 15