Chi Cao Minh bab78fc80e Parallel indexing single dim partitions (#8925) ...

* Parallel indexing single dim partitions

Implements single dimension range partitioning for native parallel batch
indexing as described in #8769. This initial version requires the
druid-datasketches extension to be loaded.

The algorithm has 5 phases that are orchestrated by the supervisor in
`ParallelIndexSupervisorTask#runRangePartitionMultiPhaseParallel()`.
These phases and the main classes involved are described below:

1) In parallel, determine the distribution of dimension values for each
   input source split.

   `PartialDimensionDistributionTask` uses `StringSketch` to generate
   the approximate distribution of dimension values for each input
   source split. If the rows are ungrouped,
   `PartialDimensionDistributionTask.UngroupedRowDimensionValueFilter`
   uses a Bloom filter to skip rows that would be grouped. The final
   distribution is sent back to the supervisor via
   `DimensionDistributionReport`.

2) The range partitions are determined.

   In `ParallelIndexSupervisorTask#determineAllRangePartitions()`, the
   supervisor uses `StringSketchMerger` to merge the individual
   `StringSketch`es created in the preceding phase. The merged sketch is
   then used to create the range partitions.

3) In parallel, generate partial range-partitioned segments.

   `PartialRangeSegmentGenerateTask` uses the range partitions
   determined in the preceding phase and
   `RangePartitionCachingLocalSegmentAllocator` to generate
   `SingleDimensionShardSpec`s.  The partition information is sent back
   to the supervisor via `GeneratedGenericPartitionsReport`.

4) The partial range segments are grouped.

   In `ParallelIndexSupervisorTask#groupGenericPartitionLocationsPerPartition()`,
   the supervisor creates the `PartialGenericSegmentMergeIOConfig`s
   necessary for the next phase.

5) In parallel, merge partial range-partitioned segments.

   `PartialGenericSegmentMergeTask` uses `GenericPartitionLocation` to
   retrieve the partial range-partitioned segments generated earlier and
   then merges and publishes them.

* Fix dependencies & forbidden apis

* Fixes for integration test

* Address review comments

* Fix docs, strict compile, sketch check, rollup check

* Fix first shard spec, partition serde, single subtask

* Fix first partition check in test

* Misc rewording/refactoring to address code review

* Fix doc link

* Split batch index integration test

* Do not run parallel-batch-index twice

* Adjust last partition

* Split ITParallelIndexTest to reduce runtime

* Rename test class

* Allow null values in range partitions

* Indicate which phase failed

* Improve asserts in tests

2019-12-09 23:05:49 -08:00

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main/java/org/apache/druid

Parallel indexing single dim partitions (#8925)

2019-12-09 23:05:49 -08:00

test

Parallel indexing single dim partitions (#8925)

2019-12-09 23:05:49 -08:00