Move .java files in `src/main/scala` to `src/main/java` root, except for `package-info.java` (to stay next to package.scala)

Author: Sean Owen <sowen@cloudera.com>

Closes #8736 from srowen/SPARK-10576.

`ApplicationMaster` no longer has the `--num-executors` flag, and had an undocumented `--properties-file` configuration option.

cc srowen

Author: Erick Tryzelaar <erick.tryzelaar@gmail.com>

Closes #8754 from erickt/master.

This PR is in conflict with #8535 and #8573. Will update this one when they are merged.

Author: zsxwing <zsxwing@gmail.com>

Closes #8642 from zsxwing/expand-nest-join.

Alternative to PR #6122; in this case the refactored out classes are replaced by inner classes with the same name for backwards binary compatibility

   * process in a lighter-weight, backwards-compatible way

Author: Edoardo Vacchi <uncommonnonsense@gmail.com>

Closes #6356 from evacchi/sqlctx-refactoring-lite.

Or Hive can't read it back correctly.

Thanks vanzin for report this.

Author: Davies Liu <davies@databricks.com>

Closes #8674 from davies/positive_nano.

Fixes bug where IndexToString output schema was DoubleType. Correct me if I'm wrong, but it doesn't seem like the output needs to have any "ML Attribute" metadata.

Author: Nick Pritchard <nicholas.pritchard@falkonry.com>

Closes #8751 from pnpritchard/SPARK-10573.

[SPARK-3382](https://issues.apache.org/jira/browse/SPARK-3382) added a ```convergenceTol``` parameter for GradientDescent-based methods in Scala. We need that parameter in Python; otherwise, Python users will not be able to adjust that behavior (or even reproduce behavior from previous releases since the default changed).

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8457 from yanboliang/spark-10194.

The default value of hive metastore version is 1.2.1 but the documentation says the value of `spark.sql.hive.metastore.version` is 0.13.1.
Also, we cannot get the default value by `sqlContext.getConf("spark.sql.hive.metastore.version")`.

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

Closes #8739 from sarutak/SPARK-10584.

This is a follow-up of https://github.com/apache/spark/pull/8317.

When speculation is enabled, there may be multiply tasks writing to the same path. Generally it's OK as we will write to a temporary directory first and only one task can commit the temporary directory to target path.

However, when we use direct output committer, tasks will write data to target path directly without temporary directory. This causes problems like corrupted data. Please see [PR comment](https://github.com/apache/spark/pull/8191#issuecomment-131598385) for more details.

Unfortunately, we don't have a simple flag to tell if a output committer will write to temporary directory or not, so for safety, we have to disable any customized output committer when `speculation` is true.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #8687 from cloud-fan/direct-committer.

A few Identifiable types did override their toString method but without using the parent implementation. As a consequence, the uid was not present anymore in the toString result. It is the default behaviour.

This patch is a quick fix. The question of enforcement is still up.

No tests have been written to verify the toString method behaviour. That would be long to do because all types should be tested and not only those which have a regression now.

It is possible to enforce the condition using the compiler by making the toString method final but that would introduce unwanted potential API breaking changes (see jira).

Author: Bertrand Dechoux <BertrandDechoux@users.noreply.github.com>

Closes #8062 from BertrandDechoux/SPARK-9720.

Finish deprecating Bagel; remove reference to nonexistent example

Author: Sean Owen <sowen@cloudera.com>

Closes #8731 from srowen/SPARK-10222.

This is a followup to #8499 which adds a Scalastyle rule to mandate the use of SparkHadoopUtil's JobContext accessor methods and fixes the existing violations.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #8521 from JoshRosen/SPARK-10330-part2.

Adding STDDEV support for DataFrame using 1-pass online /parallel algorithm to compute variance. Please review the code change.

Author: JihongMa <linlin200605@gmail.com>
Author: Jihong MA <linlin200605@gmail.com>
Author: Jihong MA <jihongma@jihongs-mbp.usca.ibm.com>
Author: Jihong MA <jihongma@Jihongs-MacBook-Pro.local>

Closes #6297 from JihongMA/SPARK-SQL.

Fix a few Java API test style issues: unused generic types, exceptions, wrong assert argument order

Author: Sean Owen <sowen@cloudera.com>

Closes #8706 from srowen/SPARK-10547.

https://issues.apache.org/jira/browse/SPARK-10554

Fixes NPE when ShutdownHook tries to cleanup temporary folders

Author: Nithin Asokan <Nithin.Asokan@Cerner.com>

Closes #8720 from nasokan/SPARK-10554.

[SPARK-10566] [CORE] SnappyCompressionCodec init exception handling masks important error information

When throwing an IllegalArgumentException in SnappyCompressionCodec.init, chain the existing exception. This allows potentially important debugging info to be passed to the user.

Manual testing shows the exception chained properly, and the test suite still looks fine as well.

This contribution is my original work and I license the work to the project under the project's open source license.

Author: Daniel Imfeld <daniel@danielimfeld.com>

Closes #8725 from dimfeld/dimfeld-patch-1.

This PR addresses (SPARK-9014)[https://issues.apache.org/jira/browse/SPARK-9014]
Added functionality: `Column` object in Python now supports exponential operator `**`
Example:
```
from pyspark.sql import *
df = sqlContext.createDataFrame([Row(a=2)])
df.select(3**df.a,df.a**3,df.a**df.a).collect()
```
Outputs:
```
[Row(POWER(3.0, a)=9.0, POWER(a, 3.0)=8.0, POWER(a, a)=4.0)]
```

Author: 0x0FFF <programmerag@gmail.com>

Closes #8658 from 0x0FFF/SPARK-9014.

This commit ensures if an assertion fails within a thread, it will ultimately fail the test. Otherwise we end up potentially masking real bugs by not propagating assertion failures properly.

Author: Andrew Or <andrew@databricks.com>

Closes #8723 from andrewor14/fix-threading-suite.

1. Hide `LocalNodeIterator` behind the `LocalNode#asIterator` method
2. Add tests for this

Author: Andrew Or <andrew@databricks.com>

Closes #8708 from andrewor14/local-hash-join-follow-up.

[SPARK-9992] [SPARK-9994] [SPARK-9998] [SQL] Implement the local TopK, sample and intersect operators

This PR is in conflict with #8535. I will update this one when #8535 gets merged.

Author: zsxwing <zsxwing@gmail.com>

Closes #8573 from zsxwing/more-local-operators.

[SPARK-7142] [SQL] Minor enhancement to BooleanSimplification Optimizer rule. Incorporate review comments

Adding changes suggested by cloud-fan  in #5700

cc marmbrus

Author: Yash Datta <Yash.Datta@guavus.com>

Closes #8716 from saucam/bool_simp.

When we cast string to boolean in hive, it returns `true` if the length of string is > 0, and spark SQL follows this behavior.

However, this behavior is very different from other SQL systems:

1. [presto](https://github.com/facebook/presto/blob/master/presto-main/src/main/java/com/facebook/presto/type/VarcharOperators.java#L89-L118) will return `true` for 't' 'true' '1', `false` for 'f' 'false' '0', throw exception for others.
2. [redshift](http://docs.aws.amazon.com/redshift/latest/dg/r_Boolean_type.html) will return `true` for 't' 'true' 'y' 'yes' '1', `false` for 'f' 'false' 'n' 'no' '0', null for others.
3. [postgresql](http://www.postgresql.org/docs/devel/static/datatype-boolean.html) will return `true` for 't' 'true' 'y' 'yes' 'on' '1', `false` for 'f' 'false' 'n' 'no' 'off' '0', throw exception for others.
4. [vertica](https://my.vertica.com/docs/5.0/HTML/Master/2983.htm) will return `true` for 't' 'true' 'y' 'yes' '1', `false` for 'f' 'false' 'n' 'no' '0', null for others.
5. [impala](http://www.cloudera.com/content/cloudera/en/documentation/cloudera-impala/latest/topics/impala_boolean.html) throw exception when try to cast string to boolean.
6. mysql, oracle, sqlserver don't have boolean type

Whether we should change the cast behavior according to other SQL system or not is not decided yet, this PR is a test to see if we changed, how many compatibility tests will fail.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #8698 from cloud-fan/string2boolean.

Just fixing a typo in exception message, raised when attempting to pickle SparkContext.

Author: Icaro Medeiros <icaro.medeiros@gmail.com>

Closes #8724 from icaromedeiros/master.

See this thread for background:
http://search-hadoop.com/m/q3RTt0rWvIkHAE81

We should check the range of partition Id and provide meaningful message through exception.

Alternatively, we can use abs() and modulo to force the partition Id into legitimate range. However, expectation is that user should correct the logic error in his / her code.

Author: tedyu <yuzhihong@gmail.com>

Closes #8703 from tedyu/master.

jira: https://issues.apache.org/jira/browse/SPARK-8530

add python API for MinMaxScaler
jira for MinMaxScaler: https://issues.apache.org/jira/browse/SPARK-7514

Author: Yuhao Yang <hhbyyh@gmail.com>

Closes #7150 from hhbyyh/pythonMinMax.

If hadoopFsRelationSuites's "test all data types" is too flaky we can disable it for now.

https://issues.apache.org/jira/browse/SPARK-10540

Author: Yin Huai <yhuai@databricks.com>

Closes #8705 from yhuai/SPARK-10540-ignore.

Changes:
* Make Scala doc for StringIndexerInverse clearer.  Also remove Scala doc from transformSchema, so that the doc is inherited.
* MetadataUtils.scala: “ Helper utilities for tree-based algorithms” —> not just trees anymore

CC: holdenk mengxr

Author: Joseph K. Bradley <joseph@databricks.com>

Closes #8679 from jkbradley/doc-fixes-1.5.

We should document options in public API doc. Otherwise, it is hard to find out the options without looking at the code. I tried to make `DefaultSource` private and put the documentation to package doc. However, since then there exists no public class under `source.libsvm`, the Java package doc doesn't show up in the generated html file (http://bugs.java.com/bugdatabase/view_bug.do?bug_id=4492654). So I put the doc to `DefaultSource` instead. There are several minor updates in this PR:

1. Do `vectorType == "sparse"` only once.
2. Update `hashCode` and `equals`.
3. Remove inherited doc.
4. Delete temp dir in `afterAll`.

Lewuathe

Author: Xiangrui Meng <meng@databricks.com>

Closes #8699 from mengxr/SPARK-10537.

Add Python API for ```MultilayerPerceptronClassifier```.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8067 from yanboliang/SPARK-9773.

LinearRegression and LogisticRegression lack of some Params for Python, and some Params are not shared classes which lead we need to write them for each class. These kinds of Params are list here:
```scala
HasElasticNetParam
HasFitIntercept
HasStandardization
HasThresholds
```
Here we implement them in shared params at Python side and make LinearRegression/LogisticRegression parameters peer with Scala one.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8508 from yanboliang/spark-10026.

[SPARK-10518] [DOCS] Update code examples in spark.ml user guide to use LIBSVM data source instead of MLUtils

I fixed to use LIBSVM data source in the example code in spark.ml instead of MLUtils

Author: y-shimizu <y.shimizu0429@gmail.com>

Closes #8697 from y-shimizu/SPARK-10518.

Previously, project/plugins.sbt explicitly set scalaVersion to 2.10.4. This can cause issues when using a version of sbt that is compiled against a different version of Scala (for example sbt 0.13.9 uses 2.10.5). Removing this explicit setting will cause build files to be compiled and run against the same version of Scala that sbt is compiled against.

Note that this only applies to the project build files (items in project/), it is distinct from the version of Scala we target for the actual spark compilation.

Author: Ahir Reddy <ahirreddy@gmail.com>

Closes #8709 from ahirreddy/sbt-scala-version-fix.

Before this fix, `MyDenseVectorUDT.typeName` gives `mydensevecto`, which is not desirable.

Author: Cheng Lian <lian@databricks.com>

Closes #8640 from liancheng/spark-10472/udt-type-name.

Missing method of ml.feature are listed here:
```StringIndexer``` lacks of parameter ```handleInvalid```.
```StringIndexerModel``` lacks of method ```labels```.
```VectorIndexerModel``` lacks of methods ```numFeatures``` and ```categoryMaps```.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8313 from yanboliang/spark-10027.

[SPARK-10023] [ML] [PySpark] Unified DecisionTreeParams checkpointInterval between Scala and Python API.

"checkpointInterval" is member of DecisionTreeParams in Scala API which is inconsistency with Python API, we should unified them.
```
member of DecisionTreeParams <-> Scala API
shared param for all ML Transformer/Estimator <-> Python API
```
Proposal:
"checkpointInterval" is also used by ALS, so we make it shared params at Scala.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8528 from yanboliang/spark-10023.

ShuffleManager implementations are currently not given type information for
the key, value and combiner classes. Serialization of shuffle objects relies
on objects being JavaSerializable, with methods defined for reading/writing
the object or, alternatively, serialization via Kryo which uses reflection.

Serialization systems like Avro, Thrift and Protobuf generate classes with
zero argument constructors and explicit schema information
(e.g. IndexedRecords in Avro have get, put and getSchema methods).

By serializing the key, value and combiner class names in ShuffleDependency,
shuffle implementations will have access to schema information when
registerShuffle() is called.

Author: Matt Massie <massie@cs.berkeley.edu>

Closes #7403 from massie/shuffle-classtags.

pyspark.sql.types.Row implements ```__getitem__```

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #8333 from yanboliang/spark-7544.

This change brings it to par with `branch-1.5` (and 1.5.0 release)

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes #8704 from shivaram/ec2-1.5-update.

`LeftOutputIterator` and `RightOutputIterator` are symmetrically identical and can share a lot of code. If someone makes a change in one but forgets to do the same thing in the other we'll end up with inconsistent behavior. This patch also adds inline comments to clarify the intention of the code.

Author: Andrew Or <andrew@databricks.com>

Closes #8596 from andrewor14/smoj-cleanup.

this PR :
1.  Enhance reflection in RBackend. Automatically matching a Java array to Scala Seq when finding methods. Util functions like seq(), listToSeq() in R side can be removed, as they will conflict with the Serde logic that transferrs a Scala seq to R side.

2.  Enhance the SerDe to support transferring  a Scala seq to R side. Data of ArrayType in DataFrame
after collection is observed to be of Scala Seq type.

3.  Support ArrayType in createDataFrame().

Author: Sun Rui <rui.sun@intel.com>

Closes #8458 from sun-rui/SPARK-10049.