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
0
votes
1 answer
Filtering by aggregate function
I am trying to raise an event when the average value of a field is over a threshold for a minute. I have the object defined as:
class Heartbeat
{
public string Name;
public int Heartbeat;
}
My condition is defined as
select avg(Heartbeat)…
user1132294
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1 answer
Complex Event processing with Esper and Twitter gives twitter4j.internal.org.json.JSONException: A JSONArray text must start with '['
Hi, I m trying example from http://www.mulesoft.org/connectors/es... But it is giving following Exception . Caused by:
twitter4j.internal.org.json.JSONException: A JSONArray text must start
with '[' at 1 [character 2 line 1] at
…
Pramod R
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1 answer
Does my use case be implemented using Esper CEP
For the requirements of my project, I have been suggested to use User Esper CEP engine. However, after going through some documentation of Esper, I don't think, it suits to my use case. Can anybody explain how Esper can be used given the below…
prasadsh
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1 answer
Using Talib in AlgoTrader with Esper
I have installed the open source version of AlgoTrader
https://code.google.com/p/algo-trader/
and I am working on developing new strategy 'stochF' using the Talib library.
http://ta-lib.org/
I was able to run the moving average example from…
Nema Tikaja
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votes
1 answer
detect when a ship change draught to over 11 meters from under 11 mesters
Working with ESPER CEM and maritime ais tracks. I want to detect when a ship change draught to over 11 meters from under 11 mesters.
select new from pattern [every new=VoyageReport(draught < 11) -> (VoyageReport(mmsi=new.mmsi and draught >…
Krogsa
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votes
1 answer
Can Camel run Esper with parallelProcessing?
I have recently started using Camel with Esper. I know from the documentation that some Camel patterns, like Multicast, for example, can be run using the parallelProcessing method, which creates a pool of 10 threads to run that pattern by default.…
Flame_Phoenix
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1 answer
Creating an Esper long running process or service
I'd like to create an Esper engine long running process but I'm not sure of Esper's threading model nor the model I should implement to do this. Naively I tried the following:
public class EsperTest {
/**
* @param args the command line arguments
…
D-Dᴙum
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1 answer
Esper expression not working
I am currently learning Esper expressions and I am quite confused. I have a simple example that simulates a Humidity sensor that streams numbers every few secnods. With my reading I did a quite complex example:
select avg(value), 'Humidity' as…
Flame_Phoenix
- 16,489
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Esper nested collection
I faced issue with nested collection in Esper.
I have model like this:
myClass3{
String value;
}
myClass2{
Set class2Value;
}
myClass{
Set class1Value;
}
and try to use query like:
select * from myClass where…
iwan
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0
votes
1 answer
detecting missing events in esper
I have a situation where I would like to detect when a source has not sent event into the systems for more than 24 hours. When this pattern is recognized, I would like to be able to retrieve the last know event (which may be days) the source did…
user2219560
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0
votes
1 answer
EPL Esper select from java Set
I am writing select query for EPL Esper, and I need to add where clause based on info from object which stores in java set.
myCalss2{
int prop1;
String prop2;
}
class myClass{
int someFiled;
boolean foo;
Set…
iwan
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- 6
0
votes
1 answer
CEP --- is there a big difference between Oracle EPL and what is offered by ESPER?
I'm new to CEP and looking into playing with ESPER. I was doing some general googling on the topic and came a cross this:
http://docs.oracle.com/cd/E13157_01/wlevs/docs30/pdf/epl_guide.pdf
And also…
niken
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votes
2 answers
Esper Alert query not triggering
I am using Esper to generate the alert message based on the esper query's which gets fired.
I am using Map as a java object to bind all the log messages and that is defined in the external esper config xml file as follows.
Shantanoo K
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Esper doesn't accept new statements in a later phase
As the headers says, we have problems building a project with Esper in combination with RabbitMQ. Therefore we need to use the amqp adapters of Esperio (version 4.10).
We’ve started from the basics in the manual, but for some reason our queries…
user1919031
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0
votes
1 answer
Esper generating episodes
I would like to use Esper to generate episodes of events. I am trying to detect the changes in robot movement during each time period and was wondering what would be the best way of implementation.
The rules for generation of episodes from the…
Jasonojh
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