[BEAM-4783] Add bundleSize parameter to control splitting of Spark sources (useful for Dynamic Allocation)

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0, 2.9.0
• Fix Version/s: 2.11.0
• Component/s: runner-spark
• Assignee: Kyle Winkelman
• Reporter: Kyle Winkelman
• Created: 13/Jul/18 15:01
• Updated: 08/Feb/19 11:13
• Resolved: 08/Feb/19 11:13

Description

When the spark-runner is used along with the configuration spark.dynamicAllocation.enabled=true the SourceRDD does not detect this. It then falls back to the value calculated in this description:
// when running on YARN/SparkDeploy it's the result of max(totalCores, 2).
// when running on Mesos it's 8.
// when running local it's the total number of cores (local = 1, local[N] = N,
// local[*] = estimation of the machine's cores).
// ** the configuration "spark.default.parallelism" takes precedence over all of the above **
So in most cases this default is quite small. This is an issue when using a very large input file as it will only get split in half.

I believe that when Dynamic Allocation is enable the SourceRDD should use the DEFAULT_BUNDLE_SIZE and possibly expose a SparkPipelineOptions that allows you to change this DEFAULT_BUNDLE_SIZE.

Issue Links

• links to: GitHub Pull Request #6181
• links to: GitHub Pull Request #6884
• links to: GitHub Pull Request #7690