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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1 answer
Connect Esper with PostgreSQL
(1) I need to connect Esper database adapter to my project. Im using this
as guide, but I do not know where to locate the configuration file because im getting this error: Cannot locate configuration information for database 'db1'
This is what i…
Juan Manuel
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2 answers
Esper pattern timer:interval() is not working
I have this basic POC code. I can see the events getting published but not getting any alert in listeners.
In the code below, none of the the statements pattern1 or pattern2 is getting alerted.
Config's setInternalTimerEnabled is by default is True…
impossible
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1 answer
How to emit last window from Esper's ext_timed_batch
I use ext_timed_batch to aggregate batch data into windows. It works, the only problem I have is how to emit the last window after all events are processed. Take this code:
public static void main(String[] args) {
EPServiceProvider engine =…
Oliv
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1 answer
Reuse an stream in esper in several queries
I'm trying to use EsperIO to load some information from database and use it in other queries with different conditions. To do it I'm using the following code:
ConfigurationDBRef dbConfig = new ConfigurationDBRef();
…
doctore
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Will ESPER CEP work on Hadoop or Spark platform
I have used ESPER CEP in standalone system. Is ESPER cloud compatible? Will it run on Hadoop or Spark Platforms
Thanks
Krishna
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1 answer
Cant use user defined function return value in where clause
I have a UDF in Esper which returns an int
getVal(int val){
//doing stuff
return val;
}
if i do this
select getVal(eventAttribute) from Event
it returns
{getVal(eventAttribute)=3 } //3 example could be anything
However if i specify
select…
wandapong
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1 answer
The concept groupwin is like the unaligned windows?
groupwin
I use the meaning in esper:
This view groups events into sub-views by the value returned by the specified expression or the combination of values returned by a list of expressions.
I think it is that you have the ability to operate by…
陶加涛
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1 answer
CEP generate Measurement/Event not in UTC time but in Local
All Measurements came with a time-stamp (event time) of when the measurement was created. Some of these measurements are artificial ones, meaning that they are not created by the device itself, but by a CEP rule running inside the CoT.
The "normal"…
b00b0
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1 answer
Invoke method once in thumbling window but output all contained events
How can I invoke a method like
select udf(a,b) from Event.win:length_batch(5)
and print the window of size 5 out again. Say i send the following events:
runtime.sendEvent(new Event(1,2));
runtime.sendEvent(new Event(3,4));
runtime.sendEvent(new…
wandapong
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1 answer
Can someone explain what Data Flows are used to in Esper?
I read about Data Flows in the esper docs and dont understand where in the application it should be used.
create dataflow HelloWorldDataFlow
BeaconSource -> helloworld.stream { text: 'hello world' , iterations: 1}
LogSink(helloworld.stream)…
eternalStud
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Does cloud compatible complex event proceesing (CEP) framework exist?
I have used ESPER's Complex Event Processing (CEP) framework for my work. It is working in standalone system very well. I do not know whether any cloud compatible CEP framework exists or not. By cloud compatible, i mean, it should scale on multiple…
Krishna
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1
vote
1 answer
Data Analyzing-Stream Processing (Storm) and Complex Event Processing
I m doing some research on stream processing combined with complex event processing.I want to use an open source software to work on Apache's Storm.I have found CEP engines like Esper,Siddhi,Sase+ but i am looking for something to work specifically…
Hmmas
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1 answer
Property 'price' is not available for write access
I am getting following error while performing update operation:
Property 'price' is not available for write access.
updateStatement :
update istream FaultyStream set price = 100 where id = 7;
My Event class implements java.io.Serializable.…
aru007
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0 answers
Is pipelining possible in ESPER CEP?
I am new to ESPER.
I just want to know if pipelining is possible in Esper.
I have a listener which monitors temperature difference. Suppose there are two cases :
Difference in temperatures is 10 degrees.
spike in temperature is above 2%.
Now…
Aman Srivastava
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1 answer
Esper very simple context and aggregation
I have a quite simple problem to modelize and I don't have experience in Esper, so I may be headed the wrong way so I'd like some insight.
Here's the scenario: I have one stream of events "ParkingEvent", with two types of events "SpotTaken" and…
Gaetan L.
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