Eric Maynard demonstrates that moving data across Hadoop clusters can be sped up by using Spark:
By leveraging Spark for distribution, we can achieve the same results much more quickly and with the same amount of code. By keeping data in HDFS throughout the process, we were able to ingest the same data as before in about 36 seconds. Let’s take a look at Spark code which produced equivalent results as the bash script shown above — note that a more parameterized version of this code code and of all code referenced in this article can be found down below in the Resources section.
Read the whole thing.