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Questions tagged [nesper]

NEsper is a CLR-based component for building CEP and ESP engines.

NEsper is a CLR-based component for building CEP and ESP engines. NEsper is based upon the Esper baseline, but includes customizations that are specific to the .NET CLR.

See http://esper.codehaus.org/about/nesper/nesper.html

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NEsper issue with regexp

I have been stuck here for a good while and seem to nail the problem to incorrect NEsper behaviour with regex. I wrote a simple project to reproduce the issue and it is available from github. In a nutshell, NEsper allows me to pump messages (events)…
oleksii
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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
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Is there any examples or documentation for dockerizing esper application?

Is there any sample code or configuration file available for dockerizing esper application ?
Santhosh Parampottupadam
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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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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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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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Output snapshot in Esper

I created an std:unique(Id) window in esper as in select * from MyData.std:unique(Id) where rate > 0 output snapshot every 60 seconds; What I expected was that at the end of every 60 seconds, I will get a list of all Data rows: Id: 5 Rate: 20 …
Fergus Incrisis
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Linear Regression in Esper - Group By

Esper provides a function of linear regression [stat:linest(,)]. Example looks like (and this works great): select * from StockTickEvent.win:time(10 seconds).stat:linest(price, offer) However, I am trying to get a linear regression of all…
Fergus Incrisis
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Esper How To Join Tables

I m sure that this statement works in Esper: /* query from table TableA when receive event PriceEvent */ ON PriceEvent p SELECT a.SymbolA, p.price FROM TableA a WHERE a.Symbol = p.Symbol But this statement throws error: /* join table TableA with…
littlecodefarmer758
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How to batch events in Esper based on a shared property

I am trying to batch together a bunch of events from a time window based on a matching property (User). Say, for example, the following events pass through esper in 1 second: User | File A      | a1.sys A      | a2.inf A      | a3.sys B…
beterthanlife
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How can I remove elements from a stream

I currently have an order object. We can assume it has three fields called orderId, state and price. class Order { public int orderId; public String state; public int filled; } Through out the life time of the order the state and…
chollida
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Is there an advantage to using a custom event sender vs the runtime sender

Using esper or nesper I can issue events either from the runtime directly like so: EPRuntime runtime = provider.getEPRuntime(); MyCustomEvent e = new MyCustomEvent("foo"); runtime.sendEvent(order); or I can use a custom event sender like…
chollida
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Esper absence of event for dynamic list

I'm trying to figure out a basic scenario to determine if I should base an alerting application on Esper. I have a set of sensors that change dynamically over time. Each of these are configured with a timeout that defines how often I should receive…
kfuglsang
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Esper EPL aggregation with custom function

I am trying to do an aggregation with Esper 8.8.0 EPL using the following code. When ProductEvent is published then I am trying to save it into a table after converting the complete ProductEvent bean object into json. Is there any way I can pass…
Sushil
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How to limit memory consumption in Esper Window

I have the following query window in my application. I want an update on when the Employee event is coming the first time (a new Employee ) OR if there is any update for an existing Employee. My application is getting a lot of updates and I suspect…
Sushil
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