Hi All,  
Here we have one application, it needs to extract different columns from 6 hive tables, and then does some easy calculation, there is around 100,000 number of rows in each table,finally need to output another table or file (with format of consistent columns) .
 However, after lots of days trying, the spark hive job is unthinkably slow - sometimes almost frozen. There is 5 nodes for spark cluster.  Could anyone offer some help, some idea or clue is also good. 
Thanks in advance~
Zhiliang