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New Contributor
Posts: 4
Registered: ‎10-14-2016
Accepted Solution

How to run spark sql in parallel?

We are doing spark programming in java language. The ‘DataFrame’ has been stored in temporary table and we are running multiple queries from this temporary table inside loop. The quires are running in sequential order. We need to run in parallel from temporary table. Please find code snippet below.

 

Thanks in advance for your cooperation.

 

HiveContext hiveContext = new HiveContext(sparkContext);

              String mainQueryHql = getFileContent(mainQueryFilePath);

              DataFrame df = hiveContext.sql(mainQueryHql).persist(StorageLevel.MEMORY_AND_DISK_SER());

              df.show();

              System.out.println("Total Records in Main Query " + df.count());

             

              df.registerTempTable(tempTable);

              ArrayList<DataFrame> dataFrameList = new ArrayList();

             

              DataFrame dfSubQuery = null;

              String subQuires = getFileContent(subQueryFilePath);

             

              String[] alQuires = subQuires.split(";");

             

              for(int i=0; i<alQuires.length; i++) {

                     System.out.println("Query no " + i +" is : " + alQuires[i]);

                     logger.debug("Query no " + i +" is : " + alQuires[i]);

                     dfSubQuery = hiveContext.sql(alQuires[i]);                   

                     dfSubQuery.show();

                     dataFrameList.add(dfSubQuery);

              }

Cloudera Employee
Posts: 97
Registered: ‎05-10-2016

Re: How to run spark sql in parallel?

There is nothing native within Spark to handle running queries in parallel.  Instead you can take a look at Java concurrency and in particular Futures[1] which will allow you to start queries in parallel and check status later.

 

1.  https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/Future.html

 

 

New Contributor
Posts: 4
Registered: ‎10-14-2016

Re: How to run spark sql in parallel?

Thanks Hubbarja, Will check and respond very shortly.
New Contributor
Posts: 3
Registered: ‎11-22-2016

Re: How to run spark sql in parallel?

Hi Kamalakanta,

 

I am also in need of a solution for this problem.

Have you checked with Java Concurrency and Futures ? or else do u got any other solution?

Please share the solution.

I am also in need of executing the sparksql in parallel(similar to your program).

 

 

Thanks in advance

New Contributor
Posts: 4
Registered: ‎10-14-2016

Re: How to run spark sql in parallel?

Please use Future interface in your code. Request to explorebelow mentioned object or interfaces.

java.util.concurrent.ExecutionException;
java.util.concurrent.ExecutorService;
java.util.concurrent.Executors;
java.util.concurrent.Future;

 

You can get more information from below mentioned URLs.

https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/Future.html

 

 

New Contributor
Posts: 4
Registered: ‎10-14-2016

Re: How to run spark sql in parallel?

New Contributor
Posts: 3
Registered: ‎11-22-2016

Re: How to run spark sql in parallel?

[ Edited ]

It will be of great help to me.
Thanks a lot Kamalakanta :)

 

I have some more doubts regarding running spark SQL queries in parallel.