[https://issues.apache.org/jira/browse/SPARK-20796](https://issues.apache.org/jira/browse/SPARK-20796)
the location of start-master.sh in spark-standalone.md should be "sbin/start-master.sh" rather than "bin/start-master.sh".

Author: liuzhaokun <liu.zhaokun@zte.com.cn>

Closes #18027 from liu-zhaokun/sbin.

## What changes were proposed in this pull request?
Add docs and examples for ```ml.stat.Correlation``` and ```ml.stat.ChiSquareTest```.

## How was this patch tested?
Generate docs and run examples manually, successfully.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17994 from yanboliang/spark-20505.

## What changes were proposed in this pull request?

SPARK-13973 incorrectly removed the required PYSPARK_DRIVER_PYTHON_OPTS=notebook from documentation to use pyspark with Jupyter notebook. This patch corrects the documentation error.

## How was this patch tested?

Tested invocation locally with
```bash
PYSPARK_DRIVER_PYTHON=jupyter PYSPARK_DRIVER_PYTHON_OPTS=notebook ./bin/pyspark
```

Author: Andrew Ray <ray.andrew@gmail.com>

Closes #18001 from aray/patch-1.

## What changes were proposed in this pull request?

Any Dataset/DataFrame batch query with the operation `withWatermark` does not execute because the batch planner does not have any rule to explicitly handle the EventTimeWatermark logical plan.
The right solution is to simply remove the plan node, as the watermark should not affect any batch query in any way.

Changes:
- In this PR, we add a new rule `EliminateEventTimeWatermark` to check if we need to ignore the event time watermark. We will ignore watermark in any batch query.

Depends upon:
- [SPARK-20672](https://issues.apache.org/jira/browse/SPARK-20672). We can not add this rule into analyzer directly, because streaming query will be copied to `triggerLogicalPlan ` in every trigger, and the rule will be applied to `triggerLogicalPlan` mistakenly.

Others:
- A typo fix in example.

## How was this patch tested?

add new unit test.

Author: uncleGen <hustyugm@gmail.com>

Closes #17896 from uncleGen/SPARK-20373.

## What changes were proposed in this pull request?

After SPARK-10997, client mode Netty RpcEnv doesn't require to start server, so port configurations are not used any more, here propose to remove these two configurations: "spark.executor.port" and "spark.am.port".

## How was this patch tested?

Existing UTs.

Author: jerryshao <sshao@hortonworks.com>

Closes #17866 from jerryshao/SPARK-20605.

## What changes were proposed in this pull request?

Add a new `spark-hadoop-cloud` module and maven profile to pull in object store support from `hadoop-openstack`, `hadoop-aws` and `hadoop-azure` (Hadoop 2.7+) JARs, along with their dependencies, fixing up the dependencies so that everything works, in particular Jackson.

It restores `s3n://` access to S3, adds its `s3a://` replacement, OpenStack `swift://` and azure `wasb://`.

There's a documentation page, `cloud_integration.md`, which covers the basic details of using Spark with object stores, referring the reader to the supplier's own documentation, with specific warnings on security and the possible mismatch between a store's behavior and that of a filesystem. In particular, users are advised be very cautious when trying to use an object store as the destination of data, and to consult the documentation of the storage supplier and the connector.

(this is the successor to #12004; I can't re-open it)

## How was this patch tested?

Downstream tests exist in [https://github.com/steveloughran/spark-cloud-examples/tree/master/cloud-examples](https://github.com/steveloughran/spark-cloud-examples/tree/master/cloud-examples)

Those verify that the dependencies are sufficient to allow downstream applications to work with s3a, azure wasb and swift storage connectors, and perform basic IO & dataframe operations thereon. All seems well.

Manually clean build & verify that assembly contains the relevant aws-* hadoop-* artifacts on Hadoop 2.6; azure on a hadoop-2.7 profile.

SBT build: `build/sbt -Phadoop-cloud -Phadoop-2.7 package`
maven build `mvn install -Phadoop-cloud -Phadoop-2.7`

This PR *does not* update `dev/deps/spark-deps-hadoop-2.7` or `dev/deps/spark-deps-hadoop-2.6`, because unless the hadoop-cloud profile is enabled, no extra JARs show up in the dependency list. The dependency check in Jenkins isn't setting the property, so the new JARs aren't visible.

Author: Steve Loughran <stevel@apache.org>
Author: Steve Loughran <stevel@hortonworks.com>

Closes #17834 from steveloughran/cloud/SPARK-7481-current.

[SPARK-20015][SPARKR][SS][DOC][EXAMPLE] Document R Structured Streaming (experimental) in R vignettes and R & SS programming guide, R example

## What changes were proposed in this pull request?

Add
- R vignettes
- R programming guide
- SS programming guide
- R example

Also disable spark.als in vignettes for now since it's failing (SPARK-20402)

## How was this patch tested?

manually

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #17814 from felixcheung/rdocss.

Add PCA and SVD to PySpark's wrappers for `RowMatrix` and `IndexedRowMatrix` (SVD only).

Based on #7963, updated.

## How was this patch tested?

New doc tests and unit tests. Ran all examples locally.

Author: MechCoder <manojkumarsivaraj334@gmail.com>
Author: Nick Pentreath <nickp@za.ibm.com>

Closes #17621 from MLnick/SPARK-6227-pyspark-svd-pca.

## What changes were proposed in this pull request?

Updating R Programming Guide

## How was this patch tested?

manually

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #17816 from felixcheung/r22relnote.

[SPARK-20521][DOC][CORE] The default of 'spark.worker.cleanup.appDataTtl' should be 604800 in spark-standalone.md

## What changes were proposed in this pull request?

Currently, our project needs to be set to clean up the worker directory cleanup cycle is three days.
When I follow http://spark.apache.org/docs/latest/spark-standalone.html, configure the 'spark.worker.cleanup.appDataTtl' parameter, I configured to 3 * 24 * 3600.
When I start the spark service, the startup fails, and the worker log displays the error log as follows:

2017-04-28 15:02:03,306 INFO Utils: Successfully started service 'sparkWorker' on port 48728.
Exception in thread "main" java.lang.NumberFormatException: For input string: "3 * 24 * 3600"
	at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
	at java.lang.Long.parseLong(Long.java:430)
	at java.lang.Long.parseLong(Long.java:483)
	at scala.collection.immutable.StringLike$class.toLong(StringLike.scala:276)
	at scala.collection.immutable.StringOps.toLong(StringOps.scala:29)
	at org.apache.spark.SparkConf$$anonfun$getLong$2.apply(SparkConf.scala:380)
	at org.apache.spark.SparkConf$$anonfun$getLong$2.apply(SparkConf.scala:380)
	at scala.Option.map(Option.scala:146)
	at org.apache.spark.SparkConf.getLong(SparkConf.scala:380)
	at org.apache.spark.deploy.worker.Worker.<init>(Worker.scala:100)
	at org.apache.spark.deploy.worker.Worker$.startRpcEnvAndEndpoint(Worker.scala:730)
	at org.apache.spark.deploy.worker.Worker$.main(Worker.scala:709)
	at org.apache.spark.deploy.worker.Worker.main(Worker.scala)

**Because we put 7 * 24 * 3600 as a string, forced to convert to the dragon type,  will lead to problems in the program.**

**So I think the default value of the current configuration should be a specific long value, rather than 7 * 24 * 3600,should be 604800. Because it would mislead users for similar configurations, resulting in spark start failure.**

## How was this patch tested?
manual tests

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: 郭小龙 10207633 <guo.xiaolong1@zte.com.cn>
Author: guoxiaolong <guo.xiaolong1@zte.com.cn>
Author: guoxiaolongzte <guo.xiaolong1@zte.com.cn>

Closes #17798 from guoxiaolongzte/SPARK-20521.

## What changes were proposed in this pull request?

Add a new section for fpm
Add Example for FPGrowth in scala and Java

updated: Rewrite transform to be more compact.

## How was this patch tested?

local doc generation.

Author: Yuhao Yang <yuhao.yang@intel.com>

Closes #17130 from hhbyyh/fpmdoc.

## What changes were proposed in this pull request?

Add hyper link in the SparkR programming guide.

## How was this patch tested?

Build doc and manually check the doc link.

Author: wangmiao1981 <wm624@hotmail.com>

Closes #17805 from wangmiao1981/doc.

## What changes were proposed in this pull request?

add link to svmLinear in the SparkR programming document.

## How was this patch tested?

Build doc manually and click the link to the document. It looks good.

Author: wangmiao1981 <wm624@hotmail.com>

Closes #17797 from wangmiao1981/doc.

## What changes were proposed in this pull request?

Add `spark.fpGrowth` to SparkR programming guide.

## How was this patch tested?

Manual tests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17775 from zero323/SPARK-20208-FOLLOW-UP.

This change does a more thorough redaction of sensitive information from logs and UI
Add unit tests that ensure that no regressions happen that leak sensitive information to the logs.

The motivation for this change was appearance of password like so in `SparkListenerEnvironmentUpdate` in event logs under some JVM configurations:
`"sun.java.command":"org.apache.spark.deploy.SparkSubmit ... --conf spark.executorEnv.HADOOP_CREDSTORE_PASSWORD=secret_password ..."
`
Previously redaction logic was only checking if the key matched the secret regex pattern, it'd redact it's value. That worked for most cases. However, in the above case, the key (sun.java.command) doesn't tell much, so the value needs to be searched. This PR expands the check to check for values as well.

## How was this patch tested?

New unit tests added that ensure that no sensitive information is present in the event logs or the yarn logs. Old unit test in UtilsSuite was modified because the test was asserting that a non-sensitive property's value won't be redacted. However, the non-sensitive value had the literal "secret" in it which was causing it to redact. Simply updating the non-sensitive property's value to another arbitrary value (that didn't have "secret" in it) fixed it.

Author: Mark Grover <mark@apache.org>

Closes #17725 from markgrover/spark-20435.

## What changes were proposed in this pull request?

Simple documentation change to remove explicit vendor references.

## How was this patch tested?

NA

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: anabranch <bill@databricks.com>

Closes #17695 from anabranch/remove-vendor.

## What changes were proposed in this pull request?

- Add `rollup` and `cube` methods and corresponding generics.
- Add short description to the vignette.

## How was this patch tested?

- Existing unit tests.
- Additional unit tests covering new features.
- `check-cran.sh`.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17728 from zero323/SPARK-20437.

## What changes were proposed in this pull request?

Pregel-based iterative algorithms with more than ~50 iterations begin to slow down and eventually fail with a StackOverflowError due to Spark's lack of support for long lineage chains.

This PR causes Pregel to checkpoint the graph periodically if the checkpoint directory is set.
This PR moves PeriodicGraphCheckpointer.scala from mllib to graphx, moves PeriodicRDDCheckpointer.scala, PeriodicCheckpointer.scala from mllib to core
## How was this patch tested?

unit tests, manual tests
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Author: ding <ding@localhost.localdomain>
Author: dding3 <ding.ding@intel.com>
Author: Michael Allman <michael@videoamp.com>

Closes #15125 from dding3/cp2_pregel.

## What changes were proposed in this pull request?

Just added the Maven `test`goal.

## How was this patch tested?

No test needed, just a trivial documentation fix.

Author: Armin Braun <me@obrown.io>

Closes #17756 from original-brownbear/SPARK-20455.

This patch bumps the master branch version to `2.3.0-SNAPSHOT`.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #17753 from JoshRosen/SPARK-20453.

[SPARK-20401][DOC] In the spark official configuration document, the 'spark.driver.supervise' configuration parameter specification and default values are necessary.

## What changes were proposed in this pull request?
Use the REST interface submits the spark job.
e.g.
curl -X  POST http://10.43.183.120:6066/v1/submissions/create --header "Content-Type:application/json;charset=UTF-8" --data'{
    "action": "CreateSubmissionRequest",
    "appArgs": [
        "myAppArgument"
    ],
    "appResource": "/home/mr/gxl/test.jar",
    "clientSparkVersion": "2.2.0",
    "environmentVariables": {
        "SPARK_ENV_LOADED": "1"
    },
    "mainClass": "cn.zte.HdfsTest",
    "sparkProperties": {
        "spark.jars": "/home/mr/gxl/test.jar",
        **"spark.driver.supervise": "true",**
        "spark.app.name": "HdfsTest",
        "spark.eventLog.enabled": "false",
        "spark.submit.deployMode": "cluster",
        "spark.master": "spark://10.43.183.120:6066"
    }
}'

**I hope that make sure that the driver is automatically restarted if it fails with non-zero exit code.
But I can not find the 'spark.driver.supervise' configuration parameter specification and default values from the spark official document.**
## How was this patch tested?

manual tests

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: 郭小龙 10207633 <guo.xiaolong1@zte.com.cn>
Author: guoxiaolong <guo.xiaolong1@zte.com.cn>
Author: guoxiaolongzte <guo.xiaolong1@zte.com.cn>

Closes #17696 from guoxiaolongzte/SPARK-20401.

Hello
PR #10991 removed the built-in history view from Spark Standalone, so the history server is no longer useful to Yarn or Mesos only.

Author: Hervé <dud225@users.noreply.github.com>

Closes #17709 from dud225/patch-1.

## What changes were proposed in this pull request?

Typos at a couple of place in the docs.

## How was this patch tested?

build including docs

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: ymahajan <ymahajan@snappydata.io>

Closes #17690 from ymahajan/master.

## What changes were proposed in this pull request?

Note that you shouldn't manually add dependencies on org.apache.kafka artifacts

## How was this patch tested?

Doc only change, did jekyll build and looked at the page.

Author: cody koeninger <cody@koeninger.org>

Closes #17675 from koeninger/SPARK-20036.

[SPARK-19740][MESOS] Add support in Spark to pass arbitrary parameters into docker when running on mesos with docker containerizer

## What changes were proposed in this pull request?

Allow passing in arbitrary parameters into docker when launching spark executors on mesos with docker containerizer tnachen

## How was this patch tested?

Manually built and tested with passed in parameter

Author: Ji Yan <jiyan@Jis-MacBook-Air.local>

Closes #17109 from yanji84/ji/allow_set_docker_user.

## What changes were proposed in this pull request?

This PR proposes corrections related to JSON APIs as below:

- Rendering links in Python documentation
- Replacing `RDD` to `Dataset` in programing guide
- Adding missing description about JSON Lines consistently in `DataFrameReader.json` in Python API
- De-duplicating little bit of `DataFrameReader.json` in Scala/Java API

## How was this patch tested?

Manually build the documentation via `jekyll build`. Corresponding snapstops will be left on the codes.

Note that currently there are Javadoc8 breaks in several places. These are proposed to be handled in https://github.com/apache/spark/pull/17477. So, this PR does not fix those.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17602 from HyukjinKwon/minor-json-documentation.

## What changes were proposed in this pull request?

1. Omitted space between the sentences: `... on static data.The Spark SQL engine will ...` -> `... on static data. The Spark SQL engine will ...`
2. Omitted colon in Output Model section.

## How was this patch tested?

None.

Author: Lee Dongjin <dongjin@apache.org>

Closes #17564 from dongjinleekr/feature/fix-programming-guide.

## What changes were proposed in this pull request?

Since SPARK-18112 and SPARK-13446, Apache Spark starts to support reading Hive metastore 2.0 ~ 2.1.1. This updates the docs.

## How was this patch tested?

N/A

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #17612 from dongjoon-hyun/metastore.

## What changes were proposed in this pull request?

Add documentation for adding master url in multi host, port format for standalone cluster with high availability with zookeeper.
Referring documentation [Standby Masters with ZooKeeper](http://spark.apache.org/docs/latest/spark-standalone.html#standby-masters-with-zookeeper)

## How was this patch tested?

Documenting the functionality already present.

Author: MirrorZ <chandrika3437@gmail.com>

Closes #17584 from MirrorZ/master.

## What changes were proposed in this pull request?

1. '/applications/[app-id]/stages' in rest api.status should add description '?status=[active|complete|pending|failed] list only stages in the state.'

Now the lack of this description, resulting in the use of this api do not know the use of the status through the brush stage list.

2.'/applications/[app-id]/stages/[stage-id]' in REST API,remove redundant description ‘?status=[active|complete|pending|failed] list only stages in the state.’.
Because only one stage is determined based on stage-id.

code:
  GET
  def stageList(QueryParam("status") statuses: JList[StageStatus]): Seq[StageData] = {
    val listener = ui.jobProgressListener
    val stageAndStatus = AllStagesResource.stagesAndStatus(ui)
    val adjStatuses = {
      if (statuses.isEmpty()) {
        Arrays.asList(StageStatus.values(): _*)
      } else {
        statuses
      }
    };

## How was this patch tested?

manual tests

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: 郭小龙 10207633 <guo.xiaolong1@zte.com.cn>

Closes #17534 from guoxiaolongzte/SPARK-20218.

## What changes were proposed in this pull request?

Add spark.mesos.task.labels configuration option to add mesos key:value labels to the executor.

 "k1:v1,k2:v2" as the format, colons separating key-value and commas to list out more than one.

Discussion of labels with mgummelt at #17404

## How was this patch tested?

Added unit tests to verify labels were added correctly, with incorrect labels being ignored and added a test to test the name of the executor.

Tested with: `./build/sbt -Pmesos mesos/test`

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: Kalvin Chau <kalvin.chau@viasat.com>

Closes #17413 from kalvinnchau/mesos-labels.

## What changes were proposed in this pull request?

- Fixed bug in Java API not passing timeout conf to scala API
- Updated markdown docs
- Updated scala docs
- Added scala and Java example

## How was this patch tested?
Manually ran examples.

Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #17539 from tdas/SPARK-20224.

## What changes were proposed in this pull request?

Adding documentation to point to Kubernetes cluster scheduler being developed out-of-repo in https://github.com/apache-spark-on-k8s/spark
cc rxin srowen tnachen ash211 mccheah erikerlandson

## How was this patch tested?

Docs only change

Author: Anirudh Ramanathan <foxish@users.noreply.github.com>
Author: foxish <ramanathana@google.com>

Closes #17522 from foxish/upstream-doc.

…ucceeded|failed|unknown]

## What changes were proposed in this pull request?

'/applications/[app-id]/jobs' in rest api.status should be'[running|succeeded|failed|unknown]'.
now status is '[complete|succeeded|failed]'.
but '/applications/[app-id]/jobs?status=complete' the server return 'HTTP ERROR 404'.
Added '?status=running' and '?status=unknown'.
code ：
public enum JobExecutionStatus {
RUNNING,
SUCCEEDED,
FAILED,
UNKNOWN;

## How was this patch tested?

 manual tests

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: guoxiaolongzte <guo.xiaolong1@zte.com.cn>

Closes #17507 from guoxiaolongzte/SPARK-20190.

## What changes were proposed in this pull request?

Add docs and examples for spark.ml.feature.Imputer. Currently scala and Java examples are included. Python example will be added after https://github.com/apache/spark/pull/17316

## How was this patch tested?

local doc generation and example execution

Author: Yuhao Yang <yuhao.yang@intel.com>

Closes #17324 from hhbyyh/imputerdoc.

# What changes were proposed in this pull request?

It seems there are several non-breaking spaces were inserted into several `.md`s and they look breaking rendering markdown files.

These are different. For example, this can be checked via `python` as below:

```python
>>> " "
'\xc2\xa0'
>>> " "
' '
```

_Note that it seems this PR description automatically replaces non-breaking spaces into normal spaces. Please open a `vi` and copy and paste it into `python` to verify this (do not copy the characters here)._

I checked the output below in  Sapari and Chrome on Mac OS and, Internal Explorer on Windows 10.

**Before**

![2017-04-03 12 37 17](https://cloud.githubusercontent.com/assets/6477701/24594655/50aaba02-186a-11e7-80bb-d34b17a3398a.png)
![2017-04-03 12 36 57](https://cloud.githubusercontent.com/assets/6477701/24594654/50a855e6-186a-11e7-94e2-661e56544b0f.png)

**After**

![2017-04-03 12 36 46](https://cloud.githubusercontent.com/assets/6477701/24594657/53c2545c-186a-11e7-9a73-00529afbfd75.png)
![2017-04-03 12 36 31](https://cloud.githubusercontent.com/assets/6477701/24594658/53c286c0-186a-11e7-99c9-e66b1f510fe7.png)

## How was this patch tested?

Manually checking.

These instances were found via

```
grep --include=*.scala --include=*.python --include=*.java --include=*.r --include=*.R --include=*.md --include=*.r -r -I " " .
```

in Mac OS.

It seems there are several instances more as below:

```
./docs/sql-programming-guide.md:        │   ├── ...
./docs/sql-programming-guide.md:        │   │
./docs/sql-programming-guide.md:        │   ├── country=US
./docs/sql-programming-guide.md:        │   │   └── data.parquet
./docs/sql-programming-guide.md:        │   ├── country=CN
./docs/sql-programming-guide.md:        │   │   └── data.parquet
./docs/sql-programming-guide.md:        │   └── ...
./docs/sql-programming-guide.md:            ├── ...
./docs/sql-programming-guide.md:            │
./docs/sql-programming-guide.md:            ├── country=US
./docs/sql-programming-guide.md:            │   └── data.parquet
./docs/sql-programming-guide.md:            ├── country=CN
./docs/sql-programming-guide.md:            │   └── data.parquet
./docs/sql-programming-guide.md:            └── ...
./sql/core/src/test/README.md:│   ├── *.avdl                  # Testing Avro IDL(s)
./sql/core/src/test/README.md:│   └── *.avpr                  # !! NO TOUCH !! Protocol files generated from Avro IDL(s)
./sql/core/src/test/README.md:│   ├── gen-avro.sh             # Script used to generate Java code for Avro
./sql/core/src/test/README.md:│   └── gen-thrift.sh           # Script used to generate Java code for Thrift
```

These seems generated via `tree` command which inserts non-breaking spaces. They do not look causing any problem for rendering within code blocks and I did not fix it to reduce the overhead to manually replace it when it is overwritten via `tree` command in the future.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17517 from HyukjinKwon/non-breaking-space.

…anges.

## What changes were proposed in this pull request?

Document compression way little detail changes.
1.spark.eventLog.compress add 'Compression will use spark.io.compression.codec.'
2.spark.broadcast.compress add 'Compression will use spark.io.compression.codec.'
3,spark.rdd.compress add 'Compression will use spark.io.compression.codec.'
4.spark.io.compression.codec add 'event log describe'.

eg
Through the documents, I don't know  what is compression mode about 'event log'.

## How was this patch tested?

manual tests

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: 郭小龙 10207633 <guo.xiaolong1@zte.com.cn>

Closes #17498 from guoxiaolongzte/SPARK-20177.

Fixed a few typos.

There is one more I'm not sure of:

```
        Append mode uses watermark to drop old aggregation state. But the output of a
        windowed aggregation is delayed the late threshold specified in `withWatermark()` as by
        the modes semantics, rows can be added to the Result Table only once after they are
```

Not sure how to change `is delayed the late threshold`.

Author: Seigneurin, Alexis (CONT) <Alexis.Seigneurin@capitalone.com>

Closes #17443 from aseigneurin/typos.

[SPARK-20107][DOC] Add spark.hadoop.mapreduce.fileoutputcommitter.algorithm.version option to configuration.md

## What changes were proposed in this pull request?

Add `spark.hadoop.mapreduce.fileoutputcommitter.algorithm.version` option to `configuration.md`.
Set `spark.hadoop.mapreduce.fileoutputcommitter.algorithm.version=2` can speed up [HadoopMapReduceCommitProtocol.commitJob](https://github.com/apache/spark/blob/v2.1.0/core/src/main/scala/org/apache/spark/internal/io/HadoopMapReduceCommitProtocol.scala#L121) for many output files.

All cloudera's hadoop 2.6.0-cdh5.4.0 or higher versions(see: https://github.com/cloudera/hadoop-common/commit/1c1236182304d4075276c00c4592358f428bc433 and https://github.com/cloudera/hadoop-common/commit/16b2de27321db7ce2395c08baccfdec5562017f0) and apache's hadoop 2.7.0 or higher versions support this improvement.

More see:

1. [MAPREDUCE-4815](https://issues.apache.org/jira/browse/MAPREDUCE-4815): Speed up FileOutputCommitter#commitJob for many output files.
2. [MAPREDUCE-6406](https://issues.apache.org/jira/browse/MAPREDUCE-6406): Update the default version for the property mapreduce.fileoutputcommitter.algorithm.version to 2.

## How was this patch tested?

Manual test and exist tests.

Author: Yuming Wang <wgyumg@gmail.com>

Closes #17442 from wangyum/SPARK-20107.

Section ```Data type mapping between R and Spark``` was put in the wrong place in SparkR doc currently, we should move it to a separate section.

## What changes were proposed in this pull request?
Before this PR:
![image](https://cloud.githubusercontent.com/assets/1962026/24340911/bc01a532-126a-11e7-9a08-0d60d13a547c.png)

After this PR:
![image](https://cloud.githubusercontent.com/assets/1962026/24340938/d9d32a9a-126a-11e7-8891-d2f5b46e0c71.png)

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17440 from yanboliang/sparkr-doc.