[SPARK-2406][SQL] Initial support for using ParquetTableScan to read HiveMetaStore tables.

This PR adds an experimental flag `spark.sql.hive.convertMetastoreParquet` that when true causes the planner to detects tables that use Hive's Parquet SerDe and instead plans them using Spark SQL's native `ParquetTableScan`.

Author: Michael Armbrust <michael@databricks.com>
Author: Yin Huai <huai@cse.ohio-state.edu>

Closes #1819 from marmbrus/parquetMetastore and squashes the following commits:

1620079 [Michael Armbrust] Revert "remove hive parquet bundle"
cc30430 [Michael Armbrust] Merge remote-tracking branch 'origin/master' into parquetMetastore
4f3d54f [Michael Armbrust] fix style
41ebc5f [Michael Armbrust] remove hive parquet bundle
a43e0da [Michael Armbrust] Merge remote-tracking branch 'origin/master' into parquetMetastore
4c4dc19 [Michael Armbrust] Fix bug with tree splicing.
ebb267e [Michael Armbrust] include parquet hive to tests pass (Remove this later).
c0d9b72 [Michael Armbrust] Avoid creating a HadoopRDD per partition.  Add dirty hacks to retrieve partition values from the InputSplit.
8cdc93c [Michael Armbrust] Merge pull request #8 from yhuai/parquetMetastore
a0baec7 [Yin Huai] Partitioning columns can be resolved.
1161338 [Michael Armbrust] Add a test to make sure conversion is actually happening
212d5cd [Michael Armbrust] Initial support for using ParquetTableScan to read HiveMetaStore tables.
[SPARK-2169] Don't copy appName / basePath everywhere.

Instead of keeping copies in all pages, just reference the values
kept in the base SparkUI instance (by making them available via
getters).

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #1252 from vanzin/SPARK-2169 and squashes the following commits:

4412fc6 [Marcelo Vanzin] Simplify UIUtils.headerSparkPage signature.
4e5d35a [Marcelo Vanzin] [SPARK-2169] Don't copy appName / basePath everywhere.
Removed .travis.yml file since we are not using Travis.
[SPARK-3103] [PySpark] fix saveAsTextFile() with utf-8

bugfix: It will raise an exception when it try to encode non-ASCII strings into unicode. It should only encode unicode as "utf-8".

Author: Davies Liu <davies.liu@gmail.com>

Closes #2018 from davies/fix_utf8 and squashes the following commits:

4db7967 [Davies Liu] fix saveAsTextFile() with utf-8
[SPARK-2718] [yarn] Handle quotes and other characters in user args.

Due to the way Yarn runs things through bash, normal quoting doesn't
work as expected. This change applies the necessary voodoo to the user
args to avoid issues with bash and special characters.

The change also uncovered an issue with the event logger app name
sanitizing code; it wasn't cleaning up all "bad" characters, so
sometimes it would fail to create the log dirs. I just added some
more bad character replacements.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #1724 from vanzin/SPARK-2718 and squashes the following commits:

cc84b89 [Marcelo Vanzin] Review feedback.
c1a257a [Marcelo Vanzin] Add test for backslashes.
55571d4 [Marcelo Vanzin] Unbreak yarn-client.
515613d [Marcelo Vanzin] [SPARK-2718] [yarn] Handle quotes and other characters in user args.
[mllib] DecisionTree: treeAggregate + Python example bug fix

Small DecisionTree updates:
* Changed main DecisionTree aggregate to treeAggregate.
* Fixed bug in python example decision_tree_runner.py with missing argument (since categoricalFeaturesInfo is no longer an optional argument for trainClassifier).
* Fixed same bug in python doc tests, and added tree.py to doc tests.

CC: mengxr

Author: Joseph K. Bradley <joseph.kurata.bradley@gmail.com>

Closes #2015 from jkbradley/dt-opt2 and squashes the following commits:

b5114fa [Joseph K. Bradley] Fixed python tree.py doc test (extra newline)
8e4665d [Joseph K. Bradley] Added tree.py to python doc tests.  Fixed bug from missing categoricalFeaturesInfo argument.
b7b2922 [Joseph K. Bradley] Fixed bug in python example decision_tree_runner.py with missing argument.  Changed main DecisionTree aggregate to treeAggregate.
85bbc1f [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-opt2
66d076f [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-opt2
a0ed0da [Joseph K. Bradley] Renamed DTMetadata to DecisionTreeMetadata.  Small doc updates.
3726d20 [Joseph K. Bradley] Small code improvements based on code review.
ac0b9f8 [Joseph K. Bradley] Small updates based on code review. Main change: Now using << instead of math.pow.
db0d773 [Joseph K. Bradley] scala style fix
6a38f48 [Joseph K. Bradley] Added DTMetadata class for cleaner code
931a3a7 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-opt2
797f68a [Joseph K. Bradley] Fixed DecisionTreeSuite bug for training second level.  Needed to update treePointToNodeIndex with groupShift.
f40381c [Joseph K. Bradley] Merge branch 'dt-opt1' into dt-opt2
5f2dec2 [Joseph K. Bradley] Fixed scalastyle issue in TreePoint
6b5651e [Joseph K. Bradley] Updates based on code review.  1 major change: persisting to memory + disk, not just memory.
2d2aaaf [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-opt1
26d10dd [Joseph K. Bradley] Removed tree/model/Filter.scala since no longer used.  Removed debugging println calls in DecisionTree.scala.
356daba [Joseph K. Bradley] Merge branch 'dt-opt1' into dt-opt2
430d782 [Joseph K. Bradley] Added more debug info on binning error.  Added some docs.
d036089 [Joseph K. Bradley] Print timing info to logDebug.
e66f1b1 [Joseph K. Bradley] TreePoint * Updated doc * Made some methods private
8464a6e [Joseph K. Bradley] Moved TimeTracker to tree/impl/ in its own file, and cleaned it up.  Removed debugging println calls from DecisionTree.  Made TreePoint extend Serialiable
a87e08f [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-opt1
c1565a5 [Joseph K. Bradley] Small DecisionTree updates: * Simplification: Updated calculateGainForSplit to take aggregates for a single (feature, split) pair. * Internal doc: findAggForOrderedFeatureClassification
b914f3b [Joseph K. Bradley] DecisionTree optimization: eliminated filters + small changes
b2ed1f3 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-opt
0f676e2 [Joseph K. Bradley] Optimizations + Bug fix for DecisionTree
3211f02 [Joseph K. Bradley] Optimizing DecisionTree * Added TreePoint representation to avoid calling findBin multiple times. * (not working yet, but debugging)
f61e9d2 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-timing
bcf874a [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-timing
511ec85 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into dt-timing
a95bc22 [Joseph K. Bradley] timing for DecisionTree internals
[SPARK-2850] [SPARK-2626] [mllib] MLlib stats examples + small fixes

Added examples for statistical summarization:
* Scala: StatisticalSummary.scala
** Tests: correlation, MultivariateOnlineSummarizer
* python: statistical_summary.py
** Tests: correlation (since MultivariateOnlineSummarizer has no Python API)

Added examples for random and sampled RDDs:
* Scala: RandomAndSampledRDDs.scala
* python: random_and_sampled_rdds.py
* Both test:
** RandomRDDGenerators.normalRDD, normalVectorRDD
** RDD.sample, takeSample, sampleByKey

Added sc.stop() to all examples.

CorrelationSuite.scala
* Added 1 test for RDDs with only 1 value

RowMatrix.scala
* numCols(): Added check for numRows = 0, with error message.
* computeCovariance(): Added check for numRows <= 1, with error message.

Python SparseVector (pyspark/mllib/linalg.py)
* Added toDense() function

python/run-tests script
* Added stat.py (doc test)

CC: mengxr dorx  Main changes were examples to show usage across APIs.

Author: Joseph K. Bradley <joseph.kurata.bradley@gmail.com>

Closes #1878 from jkbradley/mllib-stats-api-check and squashes the following commits:

ea5c047 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
dafebe2 [Joseph K. Bradley] Bug fixes for examples SampledRDDs.scala and sampled_rdds.py: Check for division by 0 and for missing key in maps.
8d1e555 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
60c72d9 [Joseph K. Bradley] Fixed stat.py doc test to work for Python versions printing nan or NaN.
b20d90a [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
4e5d15e [Joseph K. Bradley] Changed pyspark/mllib/stat.py doc tests to use NaN instead of nan.
32173b7 [Joseph K. Bradley] Stats examples update.
c8c20dc [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
cf70b07 [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
0b7cec3 [Joseph K. Bradley] Small updates based on code review.  Renamed statistical_summary.py to correlations.py
ab48f6e [Joseph K. Bradley] RowMatrix.scala * numCols(): Added check for numRows = 0, with error message. * computeCovariance(): Added check for numRows <= 1, with error message.
65e4ebc [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
8195c78 [Joseph K. Bradley] Added examples for random and sampled RDDs: * Scala: RandomAndSampledRDDs.scala * python: random_and_sampled_rdds.py * Both test: ** RandomRDDGenerators.normalRDD, normalVectorRDD ** RDD.sample, takeSample, sampleByKey
064985b [Joseph K. Bradley] Merge remote-tracking branch 'upstream/master' into mllib-stats-api-check
ee918e9 [Joseph K. Bradley] Added examples for statistical summarization: * Scala: StatisticalSummary.scala ** Tests: correlation, MultivariateOnlineSummarizer * python: statistical_summary.py ** Tests: correlation (since MultivariateOnlineSummarizer has no Python API)
[SPARK-3108][MLLIB] add predictOnValues to StreamingLR and fix predictOn

It is useful in streaming to allow users to carry extra data with the prediction, for monitoring the prediction error for example. freeman-lab

Author: Xiangrui Meng <meng@databricks.com>

Closes #2023 from mengxr/predict-on-values and squashes the following commits:

cac47b8 [Xiangrui Meng] add classtag
2821b3b [Xiangrui Meng] use mapValues
0925efa [Xiangrui Meng] add predictOnValues to StreamingLR and fix predictOn
[SPARK-3114] [PySpark] Fix Python UDFs in Spark SQL.

This fixes SPARK-3114, an issue where we inadvertently broke Python UDFs in Spark SQL.

This PR modifiers the test runner script to always run the PySpark SQL tests, irrespective of whether SparkSQL itself has been modified.  It also includes Davies' fix for the bug.

Closes #2026.

Author: Josh Rosen <joshrosen@apache.org>
Author: Davies Liu <davies.liu@gmail.com>

Closes #2027 from JoshRosen/pyspark-sql-fix and squashes the following commits:

9af2708 [Davies Liu] bugfix: disable compression of command
0d8d3a4 [Josh Rosen] Always run Python Spark SQL tests.
[SPARK-3116] Remove the excessive lockings in TorrentBroadcast

Author: Reynold Xin <rxin@apache.org>

Closes #2028 from rxin/torrentBroadcast and squashes the following commits:

92c62a5 [Reynold Xin] Revert the MEMORY_AND_DISK_SER changes.
03a5221 [Reynold Xin] [SPARK-3116] Remove the excessive lockings in TorrentBroadcast
Fix typo in decision tree docs

Candidate splits were inconsistent with the example.

Author: Matt Forbes <matt@tellapart.com>

Closes #1837 from emef/tree-doc and squashes the following commits:

3be14a1 [Matt Forbes] Fix typo in decision tree docs
[SPARK-3072] YARN - Exit when reach max number failed executors

In some cases on hadoop 2.x the spark application master doesn't properly exit and hangs around for 10 minutes after its really done.  We should make sure it exits properly and stops the driver.

Author: Thomas Graves <tgraves@apache.org>

Closes #2022 from tgravescs/SPARK-3072 and squashes the following commits:

665701d [Thomas Graves] Exit when reach max number failed executors
[SPARK-3089] Fix meaningless error message in ConnectionManager

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #2000 from sarutak/SPARK-3089 and squashes the following commits:

02dfdea [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into SPARK-3089
e759ce7 [Kousuke Saruta] Improved error message when closing SendingConnection
[SPARK-3128][MLLIB] Use streaming test suite for StreamingLR

Refactored tests for streaming linear regression to use existing  streaming test utilities. Summary of changes:
- Made ``mllib`` depend on tests from ``streaming``
- Rewrote accuracy and convergence tests to use ``setupStreams`` and ``runStreams``
- Added new test for the accuracy of predictions generated by ``predictOnValue``

These tests should run faster, be easier to extend/maintain, and provide a reference for new tests.

mengxr tdas

Author: freeman <the.freeman.lab@gmail.com>

Closes #2037 from freeman-lab/streamingLR-predict-tests and squashes the following commits:

e851ca7 [freeman] Fixed long lines
50eb0bf [freeman] Refactored tests to use streaming test tools
32c43c2 [freeman] Added test for prediction
SPARK-2333 - spark_ec2 script should allow option for existing security group

    - Uses the name tag to identify machines in a cluster.
    - Allows overriding the security group name so it doesn't need to coincide with the cluster name.
    - Outputs the request id's of up to 10 pending spot instance requests.

Author: Vida Ha <vida@databricks.com>

Closes #1899 from vidaha/vida/ec2-reuse-security-group and squashes the following commits:

c80d5c3 [Vida Ha] wrap retries in a try catch block
b2989d5 [Vida Ha] SPARK-2333: spark_ec2 script should allow option for existing security group
Move a bracket in validateSettings of SparkConf

Move a bracket in validateSettings of SparkConf

Author: hzw19900416 <carlmartinmax@gmail.com>

Closes #2012 from hzw19900416/codereading and squashes the following commits:

e717fb6 [hzw19900416] Move a bracket in validateSettings of SparkConf
[SPARK-2790] [PySpark] fix zip with serializers which have different batch sizes.

If two RDDs have different batch size in serializers, then it will try to re-serialize the one with smaller batch size, then call RDD.zip() in Spark.

Author: Davies Liu <davies.liu@gmail.com>

Closes #1894 from davies/zip and squashes the following commits:

c4652ea [Davies Liu] add more test cases
6d05fc8 [Davies Liu] Merge branch 'master' into zip
813b1e4 [Davies Liu] add more tests for failed cases
a4aafda [Davies Liu] fix zip with serializers which have different batch sizes.
[SPARK-3136][MLLIB] Create Java-friendly methods in RandomRDDs

Though we don't use default argument for methods in RandomRDDs, it is still not easy for Java users to use because the output type is either `RDD[Double]` or `RDD[Vector]`. Java users should expect `JavaDoubleRDD` and `JavaRDD[Vector]`, respectively. We should create dedicated methods for Java users, and allow default arguments in Scala methods in RandomRDDs, to make life easier for both Java and Scala users. This PR also contains documentation for random data generation. brkyvz

Author: Xiangrui Meng <meng@databricks.com>

Closes #2041 from mengxr/stat-doc and squashes the following commits:

fc5eedf [Xiangrui Meng] add missing comma
ffde810 [Xiangrui Meng] address comments
aef6d07 [Xiangrui Meng] add doc for random data generation
b99d94b [Xiangrui Meng] add java-friendly methods to RandomRDDs
[SPARK-2468] Netty based block server / client module

Previous pull request (#1907) was reverted. This brings it back. Still looking into the hang.

Author: Reynold Xin <rxin@apache.org>

Closes #1971 from rxin/netty1 and squashes the following commits:

b0be96f [Reynold Xin] Added test to make sure outstandingRequests are cleaned after firing the events.
4c6d0ee [Reynold Xin] Pass callbacks cleanly.
603dce7 [Reynold Xin] Upgrade Netty to 4.0.23 to fix the DefaultFileRegion bug.
88be1d4 [Reynold Xin] Downgrade to 4.0.21 to work around a bug in writing DefaultFileRegion.
002626a [Reynold Xin] Remove netty-test-file.txt.
db6e6e0 [Reynold Xin] Revert "Revert "[SPARK-2468] Netty based block server / client module""
[MLLIB] minor update to word2vec

very minor update Ishiihara

Author: Xiangrui Meng <meng@databricks.com>

Closes #2043 from mengxr/minor-w2v and squashes the following commits:

be649fd [Xiangrui Meng] remove map because we only need append
eccefcc [Xiangrui Meng] minor updates to word2vec