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
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how to record the arrival time of an event in esper
I want to record a data processing time in esper and I choose Bollinger Band as example. In Bollinger Band, there is called Moving Average (MA). that MA obtained from the result of calculate the stock price average. In this case, I set…
user0550
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Using Arrays in Esper CEP
Below is our Esper EPL statement:
insert rstream into SelectedFieldsStream
select rstream feedId as feedId
, data.inputEvents.inputEventCount as inputCounts
, data.inputEvents.inputEvent[1].name as inputName
…
user2444292
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Mongo not updating documents that were not in the DB when I launched my server
I'm working with Mongo and Esper in Java. Once I launched the esper server, I start adding documents and in one of my listeners I have to update some of those documents (one per time). The problem is that Mongo only updates those documents if they…
user2417250
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Does WSO2 CEP with Esper engine support JMS Queues?
I want to send events to WSO2 CEP through ActiveMQ 'Queue'. Also i want to receive events in ActiveMQ 'Queue' processed by WSO2 CEP . I am wondering whether this is possible with Esper Engine ?
madhurika
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Twitter4j and Esper : throwing error at main java.lang.NoClassDefFoundError
I'm following a tutorial http://www.javacodegeeks.com/2012/03/twitter4j-and-esper-tracking-user.html. But when I'm trying to compile the project it gives me follwoing error:
Exception in thread "main" java.lang.NoClassDefFoundError:…
Zelig
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esper: select from where statement event when no matches in where
I am trying to use a select statement where the values of a field depend on values from 2 windows. Also a where statement is used at the end to filter out event from 1 wiondow. Eg.
Select
coalesce(B.field1,0) + A.field1 as…
puneet
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Should you use the equals method or compare the event type IDs for EventType in Esper?
I am trying to check if two of Esper's EventType objects are equal. By equal I mean that they are the same event types with the same properties.
I was wondering what is the best way to do it. Is it safe to use the equals method, like…
robingrindrod
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How to pipelined the Map-input-stream as events directly to WSO2-CEP without selecting or using the "Input mapping type"?
I am using WSO2-CEP with Esper(as runtime),Esper processed queries on Map as siddhi on tuples."Input Mapping type" basically declares the type of input conversion required for e.g XML-Mapping: XML to Map or Tuple.I have run an sample by converting…
sumit chauhan
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Esper deployment on jboss as 7.X, event type or class name not found
I have developed a java ee project to be deployed on jboss as 7 server.
scenario is
A java ee project in which ejb module contains execution classes.
some of the pojo events are defined in another plain java project lets say p1
and p1 is…
Chaturvedi Dewashish
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How to handle in Esper if the source is sending xml event files with 2 or more different schemas?
public ParseEvents()
{
String classpathLocation_plm = "com/esper/Resources/dataPkt.xsd";
String classpathLocation_status = "com/esper/Resources/helloPkt.xsd";
URL schemaURL_plm =…
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1 answer
Esper When to Know Time Window has ended
In Java Esper I would like to know when exactly has the timer on the time window ended. In other words, for example, in the EPL statement (taken from the esper home page):
select avg(price) from org.myapp.event.OrderEvent.win:time(30 sec)
The…
jonathan1987
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Esper EPL leftouter join forwarding to other stream
I have implemented ESPER for my application need of CEP. While using EPL I encountered a specific scenario which is as follows:
I have combined two events with left outer join to make sure each event from first can trigger the statement and only…
Chaturvedi Dewashish
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Java math DescriptiveStatistics remove value
I am new to Java and have been using it with Esper CEP engine. This question is however unrelated to Esper, its more of a Java question.
First, my class :-
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import…
sajal
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httpadapter in Esper CEP implementation
I need to send data to a web page from esper engine using httpadapter. I followed the steps mentioned in examples. Somehow it didn't wwork. I need to send using plain java object. Also let me know how to configure web server for the request and…
Chaturvedi Dewashish
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Esper: Using start/end-timestamps with POJOs or runtime defined event types
I am trying to use the time interval algebra methods on event types directly, which, according to the docs, should be possible. I first tried to define some event types using the create schema syntax, like this:
create schema BaseEvent as (time…
Simon Lehmann
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