[SPARK-4477] remove numpy from RDDSampler of PySpark

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.8.1, 0.9.1, 1.0.2, 1.1.0, 1.2.0
• Fix Version/s: 1.2.0
• Component/s: PySpark
• Target Version/s: 1.2.0, 1.3.0
• Assignee: Davies Liu
• Reporter: Davies Liu
• Created: 19/Nov/14 00:55
• Updated: 21/Nov/14 00:40
• Resolved: 21/Nov/14 00:40

Description

In RDDSampler, it try use numpy to gain better performance for possion(), but the number of call of random() is only (1+faction) * N in the pure python implementation of possion(), so there is no much performance gain from numpy.

numpy is not a dependent of pyspark, so it maybe introduce some problem, such as there is no numpy installed in slaves, but only installed master, as reported in xxxx.

It also complicate the code a lot, so we may should remove numpy from RDDSampler.

Issue Links

• relates to: SPARK-927 PySpark sample() doesn't work if numpy is installed on master but not on workers
• links to: [Github] Pull Request #3351 (davies)