Re: processWindowFunction

Posted by vino yang on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/processWindowFunction-tp22366p22401.html

Hi antonio,

Yes, ProcessWindowFunction is a very low level window function. 

It allows you to access the data in the window and allows you to customize the output of the window. 

So if you use it, while giving you flexibility, you need to think about other things, which may require you to write more processing logic.

Generally speaking, sliding windows usually have some data that is repeated, but a common mode is to apply a reduce function on it to get your calculation results. 

If you only send data, there will definitely be some duplication.

Thanks, vino.

antonio saldivar <[hidden email]> 于2018年8月17日周五 下午12:01写道：

Hi Vino

thank you for the information, actually I am using a trigger alert and processWindowFunction to send my results, but when my window slides or ends it sends again the objects and I an getting duplicated data

El jue., 16 ago. 2018 a las 22:05, vino yang (<[hidden email]>) escribió:

Hi Antonio,

What results do not you want to get when creating each window? 

Examples of the use of ProcessWindowFunction are included in many test files in Flink's project, such as SideOutputITCase.scala or WindowTranslationTest.scala.

For more information on ProcessWindowFunction, you can refer to the official website.[1]

[1]: https://ci.apache.org/projects/flink/flink-docs-release-1.6/dev/stream/operators/windows.html#processwindowfunction

Thanks, vino.

antonio saldivar <[hidden email]> 于2018年8月17日周五 上午6:24写道：

Hello

I am implementing a data stream where I use sliding windows but I am stuck because I need to set values to my object based on some if statements in my process function  and send the object to the next step but I don't want results every time a window is creating 

if anyone has a good example on this that can help me