changed "form" to "from" in 3 documentation entries for Kafka integration

Author: Peter Klipfel <peter@klipfel.me>

Closes #3691 from peterklipfel/master and squashes the following commits:

0fe7fc5 [Peter Klipfel] fixed spelling errors in documentation

This commit exists to close the following pull requests on Github:

Closes #3488 (close requested by 'pwendell')
Closes #2939 (close requested by 'marmbrus')
Closes #3173 (close requested by 'marmbrus')

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #3676 from adrian-wang/countexpr and squashes the following commits:

dc5765b [Daoyuan Wang] add rule to fold count(expr) if expr is not null

[SPARK-4742][SQL] The name of Parquet File generated by AppendingParquetOutputFormat should be zero padded

When I use Parquet File as a output file using ParquetOutputFormat#getDefaultWorkFile, the file name is not zero padded while RDD#saveAsText does zero padding.

Author: Sasaki Toru <sasakitoa@nttdata.co.jp>

Closes #3602 from sasakitoa/parquet-zeroPadding and squashes the following commits:

6b0e58f [Sasaki Toru] Merge branch 'master' of git://github.com/apache/spark into parquet-zeroPadding
20dc79d [Sasaki Toru] Fixed the name of Parquet File generated by AppendingParquetOutputFormat

Fix bug when query like:
```
  test("save join to table") {
    val testData = sparkContext.parallelize(1 to 10).map(i => TestData(i, i.toString))
    sql("CREATE TABLE test1 (key INT, value STRING)")
    testData.insertInto("test1")
    sql("CREATE TABLE test2 (key INT, value STRING)")
    testData.insertInto("test2")
    testData.insertInto("test2")
    sql("SELECT COUNT(a.value) FROM test1 a JOIN test2 b ON a.key = b.key").saveAsTable("test")
    checkAnswer(
      table("test"),
      sql("SELECT COUNT(a.value) FROM test1 a JOIN test2 b ON a.key = b.key").collect().toSeq)
  }
```

Author: Cheng Hao <hao.cheng@intel.com>

Closes #3673 from chenghao-intel/spark_4825 and squashes the following commits:

e8cbd56 [Cheng Hao] alternate the pattern matching order for logical plan:CTAS
e004895 [Cheng Hao] fix bug

This is fixed by SPARK-4318 #3184

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #3445 from adrian-wang/emptyaggr and squashes the following commits:

982575e [Daoyuan Wang] enable empty aggr test case

So the optimizations are not valid. Also I think the optimization here is rarely encounter, so removing them will not have influence on performance.

Can we merge #3445 before I add a comparison test case from this?

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #3675 from adrian-wang/sumempty and squashes the following commits:

42df763 [Daoyuan Wang] sum and avg on empty table should always return null

a follow up of #3547
/cc marmbrus

Author: scwf <wangfei1@huawei.com>

Closes #3563 from scwf/rnc and squashes the following commits:

9395661 [scwf] remove unnecessary condition

Inserting data of type including `ArrayType.containsNull == false` or `MapType.valueContainsNull == false` or `StructType.fields.exists(_.nullable == false)` into Hive table will fail because `Cast` inserted by `HiveMetastoreCatalog.PreInsertionCasts` rule of `Analyzer` can't handle these types correctly.

Complex type cast rule proposal:

- Cast for non-complex types should be able to cast the same as before.
- Cast for `ArrayType` can evaluate if
  - Element type can cast
  - Nullability rule doesn't break
- Cast for `MapType` can evaluate if
  - Key type can cast
  - Nullability for casted key type is `false`
  - Value type can cast
  - Nullability rule for value type doesn't break
- Cast for `StructType` can evaluate if
  - The field size is the same
  - Each field can cast
  - Nullability rule for each field doesn't break
- The nested structure should be the same.

Nullability rule:

- If the casted type is `nullable == true`, the target nullability should be `true`

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #3150 from ueshin/issues/SPARK-4293 and squashes the following commits:

e935939 [Takuya UESHIN] Merge branch 'master' into issues/SPARK-4293
ba14003 [Takuya UESHIN] Merge branch 'master' into issues/SPARK-4293
8999868 [Takuya UESHIN] Fix a test title.
f677c30 [Takuya UESHIN] Merge branch 'master' into issues/SPARK-4293
287f410 [Takuya UESHIN] Add tests to insert data of types ArrayType / MapType / StructType with nullability is false into Hive table.
4f71bb8 [Takuya UESHIN] Make Cast be able to handle complex types.

fix a TODO in Analyzer:
// TODO: pass this in as a parameter
val fixedPoint = FixedPoint(100)

Author: Jacky Li <jacky.likun@huawei.com>

Closes #3499 from jackylk/config and squashes the following commits:

4c1252c [Jacky Li] fix scalastyle
820f460 [Jacky Li] pass maxIterations in as a parameter

Whitelist more hive unit test:

"create_like_tbl_props"
"udf5"
"udf_java_method"
"decimal_1"
"udf_pmod"
"udf_to_double"
"udf_to_float"
"udf7" (this will fail in Hive 0.12)

Author: Cheng Hao <hao.cheng@intel.com>

Closes #3522 from chenghao-intel/unittest and squashes the following commits:

f54e4c7 [Cheng Hao] work around to clean up the hive.table.parameters.default in reset
16fee22 [Cheng Hao] Whitelist more unittest

Unpersist a uncached RDD, will not raise exception, for example:
```
val data = Array(1, 2, 3, 4, 5)
val distData = sc.parallelize(data)
distData.unpersist(true)
```

But the `SchemaRDD` will raise exception if the `SchemaRDD` is not cached. Since `SchemaRDD` is the subclasses of the `RDD`, we should follow the same behavior.

Author: Cheng Hao <hao.cheng@intel.com>

Closes #3572 from chenghao-intel/try_uncache and squashes the following commits:

50a7a89 [Cheng Hao] SchemaRDD.unpersist() should not raise exception if it is not persisted

Important updates to the streaming programming guide
- Make the fault-tolerance properties easier to understand, with information about write ahead logs
- Update the information about deploying the spark streaming app with information about Driver HA
- Update Receiver guide to discuss reliable vs unreliable receivers.

Author: Tathagata Das <tathagata.das1565@gmail.com>
Author: Josh Rosen <joshrosen@databricks.com>
Author: Josh Rosen <rosenville@gmail.com>

Closes #3653 from tdas/streaming-doc-update-1.2 and squashes the following commits:

f53154a [Tathagata Das] Addressed Josh's comments.
ce299e4 [Tathagata Das] Minor update.
ca19078 [Tathagata Das] Minor change
f746951 [Tathagata Das] Mentioned performance problem with WAL
7787209 [Tathagata Das] Merge branch 'streaming-doc-update-1.2' of github.com:tdas/spark into streaming-doc-update-1.2
2184729 [Tathagata Das] Updated Kafka and Flume guides with reliability information.
2f3178c [Tathagata Das] Added more information about writing reliable receivers in the custom receiver guide.
91aa5aa [Tathagata Das] Improved API Docs menu
5707581 [Tathagata Das] Added Pythn API badge
b9c8c24 [Tathagata Das] Merge pull request #26 from JoshRosen/streaming-programming-guide
b8c8382 [Josh Rosen] minor fixes
a4ef126 [Josh Rosen] Restructure parts of the fault-tolerance section to read a bit nicer when skipping over the headings
65f66cd [Josh Rosen] Fix broken link to fault-tolerance semantics section.
f015397 [Josh Rosen] Minor grammar / pluralization fixes.
3019f3a [Josh Rosen] Fix minor Markdown formatting issues
aa8bb87 [Tathagata Das] Small update.
195852c [Tathagata Das] Updated based on Josh's comments, updated receiver reliability and deploying section, and also updated configuration.
17b99fb [Tathagata Das] Merge remote-tracking branch 'apache-github/master' into streaming-doc-update-1.2
a0217c0 [Tathagata Das] Changed Deploying menu layout
67fcffc [Tathagata Das] Added cluster mode + supervise example to submitting application guide.
e45453b [Tathagata Das] Update streaming guide, added deploying section.
192c7a7 [Tathagata Das] Added more info about Python API, and rewrote the checkpointing section.

Modified ScalaReflection.schemaFor to take primary constructor of Product when there are multiple constructors.  Added test to suite which failed before but works now.

Needed for [https://github.com/apache/spark/pull/3637]

CC: marmbrus

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

Closes #3646 from jkbradley/sql-reflection and squashes the following commits:

796b2e4 [Joseph K. Bradley] Modified ScalaReflection.schemaFor to take primary constructor of Product when there are multiple constructors.  Added test to suite which failed before but works now.

Author: Zhang, Liye <liye.zhang@intel.com>

Closes #2793 from liyezhang556520/uniformHashMap and squashes the following commits:

5884735 [Zhang, Liye] [CORE]codeStyle: uniform ConcurrentHashMap define in StorageLevel.scala

cc kayousterhout

I have a few outstanding questions from compiling this documentation:
- What's the difference between NO_PREF and ANY?  I understand the implications of the ordering but don't know what an example of each would be
- Why is NO_PREF ahead of RACK_LOCAL?  I would think it'd be better to schedule rack-local tasks ahead of no preference if you could only do one or the other.  Is the idea to wait longer and hope for the rack-local tasks to turn into node-local or better?
- Will there be a datacenter-local locality level in the future?  Apache Cassandra for example has this level

Author: Andrew Ash <andrew@andrewash.com>

Closes #2519 from ash211/SPARK-3526 and squashes the following commits:

44cff28 [Andrew Ash] Link to spark.locality parameters rather than copying the list
6d5d966 [Andrew Ash] Stay focused on Spark, no astronaut architecture mumbo-jumbo
20e0e31 [Andrew Ash] SPARK-3526 Add section about data locality to the tuning guide

This commit exists to close the following pull requests on Github:

Closes #2883 (close requested by 'pwendell')
Closes #3364 (close requested by 'pwendell')
Closes #4458 (close requested by 'pwendell')
Closes #1574 (close requested by 'andrewor14')
Closes #2546 (close requested by 'andrewor14')
Closes #2516 (close requested by 'andrewor14')
Closes #154 (close requested by 'andrewor14')

The driver hangs sometimes when we coalesce RDD partitions. See JIRA for more details and reproduction.

This is because our use of empty string as default preferred location in `CoalescedRDDPartition` causes the `TaskSetManager` to schedule the corresponding task on host `""` (empty string). The intended semantics here, however, is that the partition does not have a preferred location, and the TSM should schedule the corresponding task accordingly.

Author: Andrew Or <andrew@databricks.com>

Closes #3633 from andrewor14/coalesce-preferred-loc and squashes the following commits:

e520d6b [Andrew Or] Oops
3ebf8bd [Andrew Or] A few comments
f370a4e [Andrew Or] Fix tests
2f7dfb6 [Andrew Or] Avoid using empty string as default preferred location

Hi all - I've renamed the unhelpfully named variable and added a comment clarifying what's actually happening.

Author: Ilya Ganelin <ilya.ganelin@capitalone.com>

Closes #3666 from ilganeli/SPARK-4569B and squashes the following commits:

1810394 [Ilya Ganelin] [SPARK-4569] Rename 'externalSorting' in Aggregator
e2d2092 [Ilya Ganelin] [SPARK-4569] Rename 'externalSorting' in Aggregator
d7cefec [Ilya Ganelin] [SPARK-4569] Rename 'externalSorting' in Aggregator
5b3f39c [Ilya Ganelin] [SPARK-4569] Rename  in Aggregator

sometimes I switch between different version and do not want to rebuild spark, so I rename assembly.jar into .jar.bak, but still caught by `compute-classpath.sh`

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #3641 from adrian-wang/jar and squashes the following commits:

45cbfd0 [Daoyuan Wang] ensure .jar at end of line

Currently this doesn't do anything in other modes, so we might as well just disable it rather than having the user mistakenly rely on it.

Author: Andrew Or <andrew@databricks.com>

Closes #3615 from andrewor14/dynamic-allocation-yarn-only and squashes the following commits:

ce6487a [Andrew Or] Allow requesting / killing executors only in YARN mode

tdas looks like streaming already refers to the supervise mode. The link from there is broken though.

Author: Andrew Or <andrew@databricks.com>

Closes #3627 from andrewor14/document-supervise and squashes the following commits:

9ca0908 [Andrew Or] Wording changes
2b55ed2 [Andrew Or] Document standalone cluster supervise mode

Current HistoryPage have links only to previous page or next page.
I suggest to add index to access history pages easily.

I implemented like following pics.

If there are many pages, current page +/- N pages, head page and last page are indexed.

![2014-11-10 16 13 25](https://cloud.githubusercontent.com/assets/4736016/4986246/9c7bbac4-6937-11e4-8695-8634d039d5b6.png)
![2014-11-10 16 03 21](https://cloud.githubusercontent.com/assets/4736016/4986210/3951bb74-6937-11e4-8b4e-9f90d266d736.png)
![2014-11-10 16 03 39](https://cloud.githubusercontent.com/assets/4736016/4986211/3b196ad8-6937-11e4-9f81-74bc0a6dad5b.png)
![2014-11-10 16 03 49](https://cloud.githubusercontent.com/assets/4736016/4986213/40686138-6937-11e4-86c0-41100f0404f6.png)
![2014-11-10 16 04 04](https://cloud.githubusercontent.com/assets/4736016/4986215/4326c9b4-6937-11e4-87ac-0f30c86ec6e3.png)

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

Closes #3194 from sarutak/history-page-indexing and squashes the following commits:

15d3d2d [Kousuke Saruta] Simplified code
c93932e [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into history-page-indexing
1c2f605 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into history-page-indexing
76b05e3 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into history-page-indexing
b2240f8 [Kousuke Saruta] Fixed style
ec7922e [Kousuke Saruta] Simplified code
755a004 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into history-page-indexing
cfa242b [Kousuke Saruta] Added index to HistoryPage

[SPARK-4161]Spark shell class path is not correctly set if "spark.driver.extraClassPath" is set in defaults.conf

Author: GuoQiang Li <witgo@qq.com>

Closes #3050 from witgo/SPARK-4161 and squashes the following commits:

abb6fa4 [GuoQiang Li] move usejavacp opt to spark-shell
89e39e7 [GuoQiang Li] review commit
c2a6f04 [GuoQiang Li] Spark shell class path is not correctly set if "spark.driver.extraClassPath" is set in defaults.conf

Accumulators keep thread-local copies of themselves.  These copies were only cleared at the beginning of a task.  This meant that (a) the memory they used was tied up until the next task ran on that thread, and (b) if a thread died, the memory it had used for accumulators was locked up forever on that worker.

This PR clears the thread-local copies of accumulators at the end of each task, in the tasks finally block, to make sure they are cleaned up between tasks.  It also stores them in a ThreadLocal object, so that if, for some reason, the thread dies, any memory they are using at the time should be freed up.

Author: Nathan Kronenfeld <nkronenfeld@oculusinfo.com>

Closes #3570 from nkronenfeld/Accumulator-Improvements and squashes the following commits:

a581f3f [Nathan Kronenfeld] Change Accumulators to private[spark] instead of adding mima exclude to get around false positive in mima tests
b6c2180 [Nathan Kronenfeld] Include MiMa exclude as per build error instructions - this version incompatibility should be irrelevent, as it will only surface if a master is talking to a worker running a different version of spark.
537baad [Nathan Kronenfeld] Fuller refactoring as intended, incorporating JR's suggestions for ThreadLocal localAccums, and keeping clear(), but also calling it in tasks' finally block, rather than just at the beginning of the task.
39a82f2 [Nathan Kronenfeld] Clear local copies of accumulators as soon as we're done with them

This small commit makes the `(?)` web UI help link into a superscript, which should address feedback that the current design makes it look like an error occurred or like information is missing.

Before:

![image](https://cloud.githubusercontent.com/assets/50748/5370611/a3ed0034-7fd9-11e4-870f-05bd9faad5b9.png)

After:

![image](https://cloud.githubusercontent.com/assets/50748/5370602/6c5ca8d6-7fd9-11e4-8d1a-568d71290aa7.png)

Author: Josh Rosen <joshrosen@databricks.com>

Closes #3659 from JoshRosen/webui-help-sup and squashes the following commits:

bd72899 [Josh Rosen] Use <sup> tag for help icon in web UI page header.

Author: Reynold Xin <rxin@databricks.com>

Closes #3657 from rxin/conf-update and squashes the following commits:

7370eab [Reynold Xin] Config updates for the new shuffle transport.

It's been reported that when the number of disks is large and the number of nodes is small, Netty network throughput is low compared with NIO. We suspect the problem is that only a small number of disks are utilized to serve shuffle files at any given point, due to connection reuse. This patch adds a new config parameter to specify the number of concurrent connections between two peer nodes, default to 2.

Author: Reynold Xin <rxin@databricks.com>

Closes #3625 from rxin/SPARK-4740 and squashes the following commits:

ad4241a [Reynold Xin] Updated javadoc.
f33c72b [Reynold Xin] Code review feedback.
0fefabb [Reynold Xin] Use double check in synchronization.
41dfcb2 [Reynold Xin] Added test case.
9076b4a [Reynold Xin] Fixed two NPEs.
3e1306c [Reynold Xin] Minor style fix.
4f21673 [Reynold Xin] [SPARK-4740] Create multiple concurrent connections between two peer nodes in Netty.

Allocate enough room for type byte as well as message, to avoid tripping assertion about capacity of the buffer

Author: Sean Owen <sowen@cloudera.com>

Closes #3650 from srowen/SPARK-4805 and squashes the following commits:

9e1d502 [Sean Owen] Allocate enough room for type byte as well as message, to avoid tripping assertion about capacity of the buffer

Author: Sandy Ryza <sandy@cloudera.com>

Closes #3426 from sryza/sandy-spark-4567 and squashes the following commits:

cb4b8d2 [Sandy Ryza] SPARK-4567. Make SparkJobInfo and SparkStageInfo serializable

[SPARK-4714] BlockManager.dropFromMemory() should check whether block has been removed after synchronizing on BlockInfo instance.

After synchronizing on the `info` lock in the `removeBlock`/`dropOldBlocks`/`dropFromMemory` methods in BlockManager, the block that `info` represented may have already removed.

The three methods have the same logic to get the `info` lock:
```
   info = blockInfo.get(id)
   if (info != null) {
     info.synchronized {
       // do something
     }
   }
```

So, there is chance that when a thread enters the `info.synchronized` block, `info` has already been removed from the `blockInfo` map by some other thread who entered `info.synchronized` first.

The `removeBlock` and `dropOldBlocks` methods are idempotent, so it's safe for them to run on blocks that have already been removed.
But in `dropFromMemory` it may be problematic since it may drop block data which already removed into the diskstore, and this calls data store operations that are not designed to handle missing blocks.

This patch fixes this issue by adding a check to `dropFromMemory` to test whether blocks have been removed by a racing thread.

Author: hushan[胡珊] <hushan@xiaomi.com>

Closes #3574 from suyanNone/refine-block-concurrency and squashes the following commits:

edb989d [hushan[胡珊]] Refine code style and comments position
55fa4ba [hushan[胡珊]] refine code
e57e270 [hushan[胡珊]] add check info is already remove or not while having gotten info.syn

This commit removes the GC time for each task from the set of
optional, additional metrics, and instead always shows it for
each task.

cc pwendell

Author: Kay Ousterhout <kayousterhout@gmail.com>

Closes #3622 from kayousterhout/gc_time and squashes the following commits:

15ac242 [Kay Ousterhout] Make TaskDetailsClassNames private[spark]
e71d893 [Kay Ousterhout] [SPARK-4765] Make GC time always shown in UI.

In HashShuffleReader.scala and HashShuffleWriter.scala, no need to judge "dep.aggregator.isEmpty" again as this is judged by "dep.aggregator.isDefined"

In SortShuffleWriter.scala, "dep.aggregator.isEmpty"  is better than "!dep.aggregator.isDefined" ?

Author: maji2014 <maji3@asiainfo.com>

Closes #3553 from maji2014/spark-4691 and squashes the following commits:

bf7b14d [maji2014] change a elegant way for SortShuffleWriter.scala
10d0cf0 [maji2014] change a elegant way
d8f52dc [maji2014] code optimization for judgement

This PR adds a --wait flag to the `./sbin/stop-all.sh` script.

Author: jbencook <jbenjamincook@gmail.com>

Closes #3567 from jbencook/master and squashes the following commits:

d05c5bb [jbencook] [SPARK-874] adding a --wait flag

Sorry if this is a little premature with 1.2 still not out the door, but it will make other work like SPARK-4136 and SPARK-2089 a lot easier.

Author: Sandy Ryza <sandy@cloudera.com>

Closes #3215 from sryza/sandy-spark-4338 and squashes the following commits:

1c5ac08 [Sandy Ryza] Update building Spark docs and remove unnecessary newline
9c1421c [Sandy Ryza] SPARK-4338. Ditch yarn-alpha.

Different from Hive 0.12.0, in Hive 0.13.1 UDF/UDAF/UDTF (aka Hive function) objects should only be initialized once on the driver side and then serialized to executors. However, not all function objects are serializable (e.g. GenericUDF doesn't implement Serializable). Hive 0.13.1 solves this issue with Kryo or XML serializer. Several utility ser/de methods are provided in class o.a.h.h.q.e.Utilities for this purpose. In this PR we chose Kryo for efficiency. The Kryo serializer used here is created in Hive. Spark Kryo serializer wasn't used because there's no available SparkConf instance.

Author: Cheng Hao <hao.cheng@intel.com>
Author: Cheng Lian <lian@databricks.com>

Closes #3640 from chenghao-intel/udf_serde and squashes the following commits:

8e13756 [Cheng Hao] Update the comment
74466a3 [Cheng Hao] refactor as feedbacks
396c0e1 [Cheng Hao] avoid Simple UDF to be serialized
e9c3212 [Cheng Hao] update the comment
19cbd46 [Cheng Hao] support udf instance ser/de after initialization

[SPARK-3154][STREAMING] Replace ConcurrentHashMap with mutable.HashMap and remove @volatile from 'stopped'

Since `sequenceNumberToProcessor` and `stopped` are both protected by the lock `sequenceNumberToProcessor`, `ConcurrentHashMap` and `volatile` is unnecessary. So this PR updated them accordingly.

Author: zsxwing <zsxwing@gmail.com>

Closes #3634 from zsxwing/SPARK-3154 and squashes the following commits:

0d087ac [zsxwing] Replace ConcurrentHashMap with mutable.HashMap and remove @volatile from 'stopped'

This is the code refactor and follow ups for #2570

Author: Cheng Hao <hao.cheng@intel.com>

Closes #3336 from chenghao-intel/createtbl and squashes the following commits:

3563142 [Cheng Hao] remove the unused variable
e215187 [Cheng Hao] eliminate the compiling warning
4f97f14 [Cheng Hao] fix bug in unittest
5d58812 [Cheng Hao] revert the API changes
b85b620 [Cheng Hao] fix the regression of temp tabl not found in CTAS

Author: Jacky Li <jacky.likun@huawei.com>

Closes #3630 from jackylk/remove and squashes the following commits:

150e7e0 [Jacky Li] remove unnecessary import

...umented default is incorrect for YARN

Author: Sandy Ryza <sandy@cloudera.com>

Closes #3624 from sryza/sandy-spark-4770 and squashes the following commits:

bd81a3a [Sandy Ryza] SPARK-4770. [DOC] [YARN] spark.scheduler.minRegisteredResourcesRatio documented default is incorrect for YARN