[ 
https://issues.apache.org/jira/browse/SPARK-24095?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Hyukjin Kwon resolved SPARK-24095.
----------------------------------
    Resolution: Incomplete

> Spark Streaming performance drastically drops when when saving dataframes 
> with withColumn
> -----------------------------------------------------------------------------------------
>
>                 Key: SPARK-24095
>                 URL: https://issues.apache.org/jira/browse/SPARK-24095
>             Project: Spark
>          Issue Type: Bug
>          Components: Structured Streaming
>    Affects Versions: 2.3.0
>            Reporter: brian wang
>            Priority: Major
>              Labels: bulk-closed
>
> We have a Spark Streaming application which is streaming data from Kafka and 
> ingesting the data in HDFS after a series of transformations. We are using 
> Spark SQL to do the transformations and storing the data into HDFS at two 
> stages. The ingestion to Spark which we do at the second stage is drastically 
> reducing the performance of the application.
> There are close to 40 Million transactions per hour in the incoming data. WE 
> have observed a performance bottleneck in the write to hdfs.
> Can you please help us optimize the application performance?
> This is a critical issue since it is holding our deployment to production 
> cluster and we are running behind the schedule in production deployment.
>  
> Answer: First Stage Save
> test_Transformed_DOW.cache().withColumn("test_class_map", udf(test_class_map, 
> StringType())(array(test_class))).write.mode("append").option("header","true").csv("/hive/warehouse/test")
> Second Stage Save
> test_Data_Final=spark.sql("select test1,test2,test3...... when int(seats)>=2 
> then 1 when int(seats) < 2 then 0 end as seats from 
> test_Data_Unpivoted").write.format("parquet").mode("append").saveAsTable("test_Data_Output")
> It is the first save stage which is slowing our spark application's 
> performance if we enable it. If we disable it, the application seems to catch 
> up with the incoming data flow.
>  
>  



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org

Reply via email to