How to reduce the amount of trace info the Spark runtime produces?
The default is too verbose,
How to turn off it, and turn on it when I need.
Thanks
Verbose mode
scala> val la = sc.parallelize(List(12,4,5,3,4,4,6,781))
scala> la.collect
15/01/28 09:57:24 INFO SparkContext: Starting job: collect at <console>:15
15/01/28 09:57:24 INFO DAGScheduler: Got job 3 (collect at <console>:15) with 1 output
...
15/01/28 09:57:24 INFO Executor: Running task 0.0 in stage 3.0 (TID 3)
15/01/28 09:57:24 INFO Executor: Finished task 0.0 in stage 3.0 (TID 3). 626 bytes result sent to driver
15/01/28 09:57:24 INFO DAGScheduler: Stage 3 (collect at <console>:15) finished in 0.002 s
15/01/28 09:57:24 INFO DAGScheduler: Job 3 finished: collect at <console>:15, took 0.020061 s
res5: Array[Int] = Array(12, 4, 5, 3, 4, 4, 6, 781)
Silent mode(expected)
scala> val la = sc.parallelize(List(12,4,5,3,4,4,6,781))
scala> la.collect
res5: Array[Int] = Array(12, 4, 5, 3, 4, 4, 6, 781)