Stack Overflow
Stack Overflow

Questions tagged [esper]

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.

536 questions
2
votes
1 answer

Esper Compare With Previous event

I am new with Esper so i am unable to solve a simple problem. All i have to do is to get the difference of current close of bar with the previous close of bar. Whats the smartest way to approach this problem in esper? Result= CurrentBar.Close -…
Ahmad.Masood
  • 1,289
  • 3
  • 21
  • 40
2
votes
2 answers

CEP how to detect and report duplicates in a stream?

Is there a way to detect and report duplicates in a stream ? example: A stream of user login data containing tuples with user name and IP address. The goal is to detect login by the same user from different IP within the last 10 seconds. I have…
ron
  • 418
  • 4
  • 12
2
votes
0 answers

Rules engine or events processing

I have a customer management system used by businesses to store customer data and some other info. I want my system to send an email to the user (business owner) in several cases like the following: If one week after the signup the user (business…
Alex
  • 1,041
  • 3
  • 14
  • 32
2
votes
2 answers

CEP with Esper on Android?

Are there any libraries that target CEP on Android devices, e.g. an Esper version for Android?
Dida
  • 21
  • 2
1
vote
2 answers

CEP: source for real-time events or data feeds?

I am searching for free event sources that I can use within my java-application. I am looking for something similar to YahooFinance, where one can query a bunch of stock info and retrieve the result as csv. Ideally, an API or a URL with some query…
user445218
  • 87
  • 1
  • 6
1
vote
1 answer

Is there a way to get time since insert of an event in NEsper?

I'm trying to use NEsper and I want to create statements that takes time since insert as a return field. ex: select avg((insertTime - now)) as timeElapsed from Blah.win:time(1 min) Is this possible? I can hack around getting insertTime but is there…
teriyaki
  • 155
  • 8
1
vote
0 answers

Exception handling with messaging

I have a system that receives MSMQ messages and performs (close to) real-time analysis using NEsper. It is possible that some messages come late and perhaps in different order. This situation shall be flagged up and reported. Write not this is how…
oleksii
  • 35,458
  • 16
  • 93
  • 163
1
vote
2 answers

Esper Engine : Same table created again when running JUNIT test cases

I am using Esper 8.8. The following code is used to initialize SQL and register all events - EPCompiler compiler = EPCompilerProvider.getCompiler(); Configuration configuration = new Configuration(); …
Sushil
  • 327
  • 1
  • 3
  • 20
1
vote
2 answers

Get Previous and New EventBean with Esper Continuous Query

I am new to Esper and trying to get old and new EventBean while updating data. However, I am getting old EventBean is always null. Is there any configuration missing due to the old EventBean being null? public class TestApp1 { public static…
Sushil
  • 327
  • 1
  • 3
  • 20
1
vote
1 answer

Context Issue in Esper 8.8 - Does not seem to be working

I have been working on reviving a relatively old project that was on Esper v5.1. I upgraded to 8.8.0 and made all relevant changes. Overall, code base seems to be running well. Where I need some advice is on context. I create context on start of…
Fergus Incrisis
  • 55
  • 1
  • 5
1
vote
1 answer

Esper js expression declaration

I am following the example in Esper documentation to create an expression following js dialect Here's my EPL declaration expression float js:IOU(xBottom1,yBottom1, xTop1, yTop1, xBottom2, yBottom2, xTop2, yTop2) [ IOU(xBottom1,yBottom1, xTop1,…
Ahmed Awad
  • 95
  • 8
1
vote
1 answer

Is there something like select explode in esper epl?

I have the following declarations of schemas (event types) create json schema DetectedObjects as (tracking_id int, class_id int, class_name string, confidence double, bbox_xywh int[], rois string[], lc string[], rois_oc string[]); create map…
Ahmed Awad
  • 95
  • 8
1
vote
1 answer

current_timestamp() cached results at WHERE clause. Is this the expected behavior?

At Esper online (8.5 - https://esper-epl-tryout.appspot.com/epltryout/mainform.html) It seems that current_timestamp() single row method is acting as a cached one when it is present at WHERE section. I don’t remember this behavior before (I think…
Perrolobo
  • 543
  • 3
  • 14
1
vote
1 answer

Connecting two Esper instances running in different JVMs (client / server mode?)

I have one host running a JVM that runs an Esper service. I have another host in which I'd like to connect to the esper service running in the first JVM. I.e. I'd like to be able to do something like this: EPServiceProvider epService =…
Paul Cager
  • 1,910
  • 14
  • 21
1
vote
2 answers

Esper - how to build dissent "statement factory"?

using Esper engine - I find myself write lots of String SQLs, and do lots of string actions to insert query to EPStatement object. What is the best practice to build queries in more convenient way? maybe build queries not with pure strings but with…
Eya
  • 2,183
  • 2
  • 12
  • 5
1 2
3
…
35 36