[ 
https://issues.apache.org/jira/browse/SPARK-22552?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

sachin malhotra updated SPARK-22552:
------------------------------------
    Description: 
When unioning multiple kafka streams I learned that the resulting dataframe 
only contains the data that exists in the dataframe that initiated the union 
i.e. if df1.union(df2) (or a chaining of unions) the result will only contain 
the rows that exist in df1.

Now to be more specific this occurs when data comes in during the same 
micro-batch for all three streams. If you wait for each single row to be 
processed for each stream the union does return the right results. 

For example, if you have 3 kafka streams and you:

send message 1 to stream 1, WAIT for batch to finish, send message 2 to stream 
2, 

  was:
When unioning multiple kafka streams I learned that the resulting dataframe 
only contains the data that exists in the dataframe that initiated the union 
i.e. if df1.union(df2) (or a chaining of unions) the result will only contain 
the rows that exist in df1.

Now to be more specific this occurs when data comes in during the same 
micro-batch for all three streams. If you wait for each single row to be 
processed for each stream the union does return the right results. 


> Cannot Union multiple kafka streams
> -----------------------------------
>
>                 Key: SPARK-22552
>                 URL: https://issues.apache.org/jira/browse/SPARK-22552
>             Project: Spark
>          Issue Type: Bug
>          Components: Structured Streaming
>    Affects Versions: 2.2.0
>            Reporter: sachin malhotra
>            Assignee: Shixiong Zhu
>             Fix For: 2.3.0, 2.2.2
>
>
> When unioning multiple kafka streams I learned that the resulting dataframe 
> only contains the data that exists in the dataframe that initiated the union 
> i.e. if df1.union(df2) (or a chaining of unions) the result will only contain 
> the rows that exist in df1.
> Now to be more specific this occurs when data comes in during the same 
> micro-batch for all three streams. If you wait for each single row to be 
> processed for each stream the union does return the right results. 
> For example, if you have 3 kafka streams and you:
> send message 1 to stream 1, WAIT for batch to finish, send message 2 to 
> stream 2, 



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to