Scripting StreamInsight queries

re: Scripting StreamInsight queries

Anon44761 — Tue, 24 Jan 2012 10:40:14 GMT

Hello,

I have the same problem as Cormac. I want to use the following query:

from i in input1 where isEqualTo50(i.X) select i"

where isEqualTo50 is a static function but i have the following error:

The name isEqualTo50 does not exist in the current context

Is there a way to do this?

Thank you for your help,

re: Scripting StreamInsight queries

Cormac — Wed, 11 Jan 2012 05:57:45 GMT

Thanks for the great technique. I just came across it recently.

One question though. I found a few useful query patterns on Linqpads sample streaminsight queries. One of them is DetectSpikes() for example and it's signature is...

CepStream<SpikeEvent> DetectSpikes<TInput>(

CepStream<TInput> inputStream, int threshold, double ratio,

TimeSpan windowSize, TimeSpan hopSize,

Expression<Func<TInput, int>> fieldSelector)

If I wanted to try to parse something like this...

"from e in DetectSpikes(inputstream, 40, 0.5, TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(1), w => double.Parse(w.strValue)) select e"

No surprise I get an error "The name 'DetectSpikes' does not exist in the current context". Is there any way to get this to work.

Thanks for your help,

re: Scripting StreamInsight queries

Klaus Aschenbrenner — Tue, 23 Nov 2010 12:33:53 GMT

Hello,

Do you also have an example available how to use the provided class "QueryTemplateScripter"?

Thanks for your help

Klaus Aschenbrenner

http://www.csharp.at | twitter.com/Aschenbrenner

re: Scripting StreamInsight queries

Colin Meek — Thu, 02 Sep 2010 16:22:53 GMT

@David: Thanks for the pointers! C# REPL looks pretty cool.

The app domain solution works well for 'remote' StreamInsight server instances since we can connect to the same server instance from the separate app domain. It doesn't work as smoothly for an 'embedded' StreamInsight server since the server and the query expression cannot cross the boundary -- they aren't serializable. I've been toying with an alternate solution for the embedded case that exploits the query expression serialization support buried in the StreamInsight client SDK... I'll let you know if I can figure it out.

-Colin

re: Scripting StreamInsight queries

David Cuccia — Wed, 01 Sep 2010 23:28:31 GMT

Cool! Thanks for sharing.

In related work, you might be aware of the C# REPL recently released by the Mono team as well:

www.mono-project.com/CsharpRepl

Also, I ran across this post by Ayende recently:

ayende.com/.../runtime-code-compilation-amp-collectible-assemblies-are-no-go.aspx

He found that he could not un-load the compiled queries, which became a memory leak. Work-around was to compile in a separate app domain and dump that process when the size got too big. Any thoughts?

David