[[SPARK-9093] Fix single-quotes strings in SparkR - ASF JIRA](https://issues.apache.org/jira/browse/SPARK-9093)

This is the result of lintr at the rivision:01155162
[[SPARK-9093] The result of lintr at 01155162](https://gist.github.com/yu-iskw/8c47acf3202796da4d01)

Author: Yu ISHIKAWA <yuu.ishikawa@gmail.com>

Closes #7439 from yu-iskw/SPARK-9093 and squashes the following commits:

61c391e [Yu ISHIKAWA] [SPARK-9093][SparkR] Fix single-quotes strings in SparkR

Currently we will stop project collapse when the lower projection has nondeterministic expressions. However it's overkill sometimes, we should be able to optimize `df.select(Rand(10)).select('a)` to `df.select('a)`

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7445 from cloud-fan/non-deterministic and squashes the following commits:

0deaef6 [Wenchen Fan] Improve project collapse with nondeterministic expressions

Measure lower and upper bounds for task time and use them for validation. This PR also implements `Stopwatch.toString`. This suite should finish in less than 1 second.

jkbradley pwendell

Author: Xiangrui Meng <meng@databricks.com>

Closes #7457 from mengxr/SPARK-9126 and squashes the following commits:

4b40faa [Xiangrui Meng] simplify tests
739f5bd [Xiangrui Meng] do not assert on time taken by Thread.sleep()

This PR copies the RandomForest implementation from spark.mllib to spark.ml.  Note that this includes the DecisionTree implementation, but not the GradientBoostedTrees one (which will come later).

I essentially copied a minimal amount of code to spark.ml, removed the use of bins (and only used splits), and modified code only as much as necessary to get it to compile.  The spark.ml implementation still uses some spark.mllib classes (privately), which can be moved in future PRs.

This refactoring will be helpful in extending the node representation to include more information, such as class probabilities.

Specifically:
* Copied code from spark.mllib to spark.ml:
  * mllib.tree.DecisionTree, mllib.tree.RandomForest copied to ml.tree.impl.RandomForest (main implementation)
  * NodeIdCache (needed to use splits instead of bins)
  * TreePoint (use splits instead of bins)
* Added ml.tree.LearningNode used in RandomForest training (needed vars)
* Removed bins from implementation, and only used splits
* Small fix in JavaDecisionTreeRegressorSuite

CC: mengxr  manishamde  codedeft chouqin

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

Closes #7294 from jkbradley/dt-move-impl and squashes the following commits:

48749be [Joseph K. Bradley] cleanups based on code review, mostly style
bea9703 [Joseph K. Bradley] scala style fixes.  added some scala doc
4e6d2a4 [Joseph K. Bradley] removed unnecessary use of copyValues, setParent for trees
9a4d721 [Joseph K. Bradley] cleanups. removed InfoGainStats from ml, using old one for now.
836e7d4 [Joseph K. Bradley] Fixed test suite failures
bd5e063 [Joseph K. Bradley] fixed bucketizing issue
0df3759 [Joseph K. Bradley] Need to remove use of Bucketizer
d5224a9 [Joseph K. Bradley] modified tree and forest to use moved impl
cc01823 [Joseph K. Bradley] still editing RF to get it to work
19143fb [Joseph K. Bradley] More progress, but not done yet.  Rebased with master after 1.4 release.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7291 from cloud-fan/row and squashes the following commits:

a11addf [Wenchen Fan] move hashCode back to internal row
2de6180 [Wenchen Fan] making apply() call to get()
fbe1b24 [Wenchen Fan] add null check
ebdf148 [Wenchen Fan] address comments
25ef087 [Wenchen Fan] remove duplicated equals method for Row

[SPARK-8857][SPARK-8859][Core]Add an internal flag to Accumulable and send internal accumulator updates to the driver via heartbeats

This PR includes the following changes:

1. Remove the thread local `Accumulators.localAccums`. Instead, all Accumulators in the executors will register with its TaskContext.
2. Add an internal flag to Accumulable. For internal Accumulators, their updates will be sent to the driver via heartbeats.

Author: zsxwing <zsxwing@gmail.com>

Closes #7448 from zsxwing/accumulators and squashes the following commits:

c24bc5b [zsxwing] Add comments
bd7dcf1 [zsxwing] Add an internal flag to Accumulable and send internal accumulator updates to the driver via heartbeats

**Symptom.** If an executor in an application times out, `HeartbeatReceiver` attempts to kill it. After this happens, however, the application never gets an executor back even when there are cluster resources available.

**Cause.** The issue is that `sc.killExecutor` automatically assumes that the application wishes to adjust its resource requirements permanently downwards. This is not the intention in `HeartbeatReceiver`, however, which simply wants a replacement for the expired executor.

**Fix.** Differentiate between the intention to kill and the intention to replace an executor with a fresh one. More details can be found in the commit message.

Author: Andrew Or <andrew@databricks.com>

Closes #7107 from andrewor14/heartbeat-no-kill and squashes the following commits:

1cd2cd7 [Andrew Or] Add regression test for SPARK-8119
25a347d [Andrew Or] Reuse more code in scheduler backend
31ebd40 [Andrew Or] Differentiate between kill and replace

Mesos supports framework authentication and role to be set per framework, which the role is used to identify the framework's role which impacts the sharing weight of resource allocation and optional authentication information to allow the framework to be connected to the master.

Author: Timothy Chen <tnachen@gmail.com>

Closes #4960 from tnachen/mesos_fw_auth and squashes the following commits:

0f9f03e [Timothy Chen] Fix review comments.
8f9488a [Timothy Chen] Fix rebase
f7fc2a9 [Timothy Chen] Add mesos role, auth and secret.

andrewor14 davies vanzin can you take a look at this? thanks

Author: Lianhui Wang <lianhuiwang09@gmail.com>

Closes #7438 from lianhuiwang/SPARK-8646 and squashes the following commits:

cb3f12d [Lianhui Wang] add whitespace
6d874a6 [Lianhui Wang] support pyspark for yarn-client

Example exception (new part at bottom, clearly demarcated):

```
org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 0.0 failed 1 times, most recent failure: Lost task 0.0 in stage 0.0 (TID 0, localhost): java.lang.RuntimeException: uh-oh!
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37$$anonfun$38$$anonfun$apply$mcJ$sp$2.apply(DAGSchedulerSuite.scala:880)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37$$anonfun$38$$anonfun$apply$mcJ$sp$2.apply(DAGSchedulerSuite.scala:880)
	at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
	at org.apache.spark.util.Utils$.getIteratorSize(Utils.scala:1640)
	at org.apache.spark.rdd.RDD$$anonfun$count$1.apply(RDD.scala:1099)
	at org.apache.spark.rdd.RDD$$anonfun$count$1.apply(RDD.scala:1099)
	at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1777)
	at org.apache.spark.SparkContext$$anonfun$runJob$5.apply(SparkContext.scala:1777)
	at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:63)
	at org.apache.spark.scheduler.Task.run(Task.scala:70)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:744)

Driver stacktrace:
	at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1298)
	at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1289)
	at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1288)
	at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
	at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
	at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1288)
	at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:755)
	at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:755)
	at scala.Option.foreach(Option.scala:236)
	at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:755)
	at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1509)
	at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1470)
	at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1459)
	at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
	at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:560)
	at org.apache.spark.SparkContext.runJob(SparkContext.scala:1744)
	at org.apache.spark.SparkContext.runJob(SparkContext.scala:1762)
	at org.apache.spark.SparkContext.runJob(SparkContext.scala:1777)
	at org.apache.spark.SparkContext.runJob(SparkContext.scala:1791)
	at org.apache.spark.rdd.RDD.count(RDD.scala:1099)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37$$anonfun$38.apply$mcJ$sp(DAGSchedulerSuite.scala:880)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37$$anonfun$38.apply(DAGSchedulerSuite.scala:880)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37$$anonfun$38.apply(DAGSchedulerSuite.scala:880)
	at org.scalatest.Assertions$class.intercept(Assertions.scala:997)
	at org.scalatest.FunSuite.intercept(FunSuite.scala:1555)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37.apply$mcV$sp(DAGSchedulerSuite.scala:879)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37.apply(DAGSchedulerSuite.scala:878)
	at org.apache.spark.scheduler.DAGSchedulerSuite$$anonfun$37.apply(DAGSchedulerSuite.scala:878)
	at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
	at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
	at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
	at org.scalatest.Transformer.apply(Transformer.scala:22)
	at org.scalatest.Transformer.apply(Transformer.scala:20)
	at org.scalatest.FunSuiteLike$$anon$1.apply(FunSuiteLike.scala:166)
	at org.apache.spark.SparkFunSuite.withFixture(SparkFunSuite.scala:42)
	at org.scalatest.FunSuiteLike$class.invokeWithFixture$1(FunSuiteLike.scala:163)
	at org.scalatest.FunSuiteLike$$anonfun$runTest$1.apply(FunSuiteLike.scala:175)
	at org.scalatest.FunSuiteLike$$anonfun$runTest$1.apply(FunSuiteLike.scala:175)
	at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
	at org.scalatest.FunSuiteLike$class.runTest(FunSuiteLike.scala:175)
	at org.apache.spark.scheduler.DAGSchedulerSuite.org$scalatest$BeforeAndAfter$$super$runTest(DAGSchedulerSuite.scala:70)
	at org.scalatest.BeforeAndAfter$class.runTest(BeforeAndAfter.scala:200)
	at org.apache.spark.scheduler.DAGSchedulerSuite.org$scalatest$BeforeAndAfterEach$$super$runTest(DAGSchedulerSuite.scala:70)
	at org.scalatest.BeforeAndAfterEach$class.runTest(BeforeAndAfterEach.scala:255)
	at org.apache.spark.scheduler.DAGSchedulerSuite.runTest(DAGSchedulerSuite.scala:70)
	at org.scalatest.FunSuiteLike$$anonfun$runTests$1.apply(FunSuiteLike.scala:208)
	at org.scalatest.FunSuiteLike$$anonfun$runTests$1.apply(FunSuiteLike.scala:208)
	at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:413)
	at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:401)
	at scala.collection.immutable.List.foreach(List.scala:318)
	at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
	at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:396)
	at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:483)
	at org.scalatest.FunSuiteLike$class.runTests(FunSuiteLike.scala:208)
	at org.scalatest.FunSuite.runTests(FunSuite.scala:1555)
	at org.scalatest.Suite$class.run(Suite.scala:1424)
	at org.scalatest.FunSuite.org$scalatest$FunSuiteLike$$super$run(FunSuite.scala:1555)
	at org.scalatest.FunSuiteLike$$anonfun$run$1.apply(FunSuiteLike.scala:212)
	at org.scalatest.FunSuiteLike$$anonfun$run$1.apply(FunSuiteLike.scala:212)
	at org.scalatest.SuperEngine.runImpl(Engine.scala:545)
	at org.scalatest.FunSuiteLike$class.run(FunSuiteLike.scala:212)
	at org.apache.spark.scheduler.DAGSchedulerSuite.org$scalatest$BeforeAndAfter$$super$run(DAGSchedulerSuite.scala:70)
	at org.scalatest.BeforeAndAfter$class.run(BeforeAndAfter.scala:241)
	at org.apache.spark.scheduler.DAGSchedulerSuite.org$scalatest$BeforeAndAfterAll$$super$run(DAGSchedulerSuite.scala:70)
	at org.scalatest.BeforeAndAfterAll$class.liftedTree1$1(BeforeAndAfterAll.scala:257)
	at org.scalatest.BeforeAndAfterAll$class.run(BeforeAndAfterAll.scala:256)
	at org.apache.spark.scheduler.DAGSchedulerSuite.run(DAGSchedulerSuite.scala:70)
	at org.scalatest.tools.Framework.org$scalatest$tools$Framework$$runSuite(Framework.scala:462)
	at org.scalatest.tools.Framework$ScalaTestTask.execute(Framework.scala:671)
	at sbt.ForkMain$Run$2.call(ForkMain.java:294)
	at sbt.ForkMain$Run$2.call(ForkMain.java:284)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:744)
```

Author: Aaron Davidson <aaron@databricks.com>

Closes #7028 from aarondav/stack-trace and squashes the following commits:

4714664 [Aaron Davidson] [SPARK-8644] Include call site in SparkException stack traces thrown by job failures

Author: jerryshao <saisai.shao@intel.com>
Author: Saisai Shao <saisai.shao@intel.com>

Closes #5060 from jerryshao/SPARK-6304 and squashes the following commits:

89b01f5 [jerryshao] Update the unit test to add more cases
275d252 [jerryshao] Address the comments
7cc146d [jerryshao] Address the comments
2624723 [jerryshao] Fix rebase conflict
45befaa [Saisai Shao] Update the unit test
bbc1c9c [Saisai Shao] Fix checkpointing doesn't retain driver port issue

This builds on #7433 but also removes LeafNode/UnaryNode. These are slightly more complicated to remove. I had to change some abstract classes to traits in order for it to work.

The problem with LeafNode/UnaryNode is that they are often mixed in at the end of an Expression, and then the toString function actually gets resolved to the ones defined in TreeNode, rather than in Expression.

Author: Reynold Xin <rxin@databricks.com>

Closes #7434 from rxin/remove-binary-unary-leaf-node and squashes the following commits:

9e8a4de [Reynold Xin] Generator should not be foldable.
3135a8b [Reynold Xin] SortOrder should not be foldable.
9c589cf [Reynold Xin] Fixed one more test case...
2225331 [Reynold Xin] Aggregate expressions should not be foldable.
16b5c90 [Reynold Xin] [SPARK-9085][SQL] Remove LeafNode, UnaryNode, BinaryNode from TreeNode.

JIRA: https://issues.apache.org/jira/browse/SPARK-6941

Author: Yijie Shen <henry.yijieshen@gmail.com>

Closes #7342 from yijieshen/SPARK-6941 and squashes the following commits:

f82cbe7 [Yijie Shen] reorder import
dd67e40 [Yijie Shen] resolve comments
09518af [Yijie Shen] fix import order in DataframeSuite
0c635d4 [Yijie Shen] make match more specific
9df388d [Yijie Shen] move check into PreWriteCheck
847ab20 [Yijie Shen] Detect insertion error in DataSourceStrategy

Cleanup maven for a clean import in scala-ide / eclipse.

* remove groovy plugin which is really not needed at all
* add-source from build-helper-maven-plugin is not needed as recent version of scala-maven-plugin do it automatically
* add lifecycle-mapping plugin to hide a few useless warnings from ide

Author: Jan Prach <jendap@gmail.com>

Closes #7375 from jendap/clean-project-import-in-scala-ide and squashes the following commits:

c4b4c0f [Jan Prach] fix whitespaces
5a83e07 [Jan Prach] Revert "remove java compiler warnings from java tests"
312007e [Jan Prach] scala-maven-plugin itself add scala sources by default
f47d856 [Jan Prach] remove spark-1.4-staging repository
c8a54db [Jan Prach] remove java compiler warnings from java tests
999a068 [Jan Prach] remove some maven warnings in scala ide
80fbdc5 [Jan Prach] remove groovy and gmavenplus plugin

Jira https://issues.apache.org/jira/browse/SPARK-8995

In PR #6981we noticed that we cannot cast date strings that contains a time, like '2015-03-18 12:39:40' to date. Besides it's not possible to cast a string like '18:03:20' to a timestamp.

If a time is passed without a date, today is inferred as date.

Author: Tarek Auel <tarek.auel@googlemail.com>
Author: Tarek Auel <tarek.auel@gmail.com>

Closes #7353 from tarekauel/SPARK-8995 and squashes the following commits:

14f333b [Tarek Auel] [SPARK-8995] added tests for daylight saving time
ca1ae69 [Tarek Auel] [SPARK-8995] style fix
d20b8b4 [Tarek Auel] [SPARK-8995] bug fix: distinguish between 0 and null
ef05753 [Tarek Auel] [SPARK-8995] added check for year >= 1000
01c9ff3 [Tarek Auel] [SPARK-8995] support for time strings
34ec573 [Tarek Auel] fixed style
71622c0 [Tarek Auel] improved timestamp and date parsing
0e30c0a [Tarek Auel] Hive compatibility
cfbaed7 [Tarek Auel] fixed wrong checks
71f89c1 [Tarek Auel] [SPARK-8995] minor style fix
f7452fa [Tarek Auel] [SPARK-8995] removed old timestamp parsing
30e5aec [Tarek Auel] [SPARK-8995] date and timestamp cast
c1083fb [Tarek Auel] [SPARK-8995] cast date strings like '2015-01-01 12:15:31' to date or timestamp

https://issues.apache.org/jira/browse/SPARK-8893

> What does `sc.parallelize(1 to 3).repartition(p).collect` return? I would expect `Array(1, 2, 3)` regardless of `p`. But if `p` < 1, it returns `Array()`. I think instead it should throw an `IllegalArgumentException`.

> I think the case is pretty clear for `p` < 0. But the behavior for `p` = 0 is also error prone. In fact that's how I found this strange behavior. I used `rdd.repartition(a/b)` with positive `a` and `b`, but `a/b` was rounded down to zero and the results surprised me. I'd prefer an exception instead of unexpected (corrupt) results.

Author: Daniel Darabos <darabos.daniel@gmail.com>

Closes #7285 from darabos/patch-1 and squashes the following commits:

decba82 [Daniel Darabos] Allow repartitioning empty RDDs to zero partitions.
97de852 [Daniel Darabos] Allow zero partition count in HashPartitioner
f6ba5fb [Daniel Darabos] Use require() for simpler syntax.
d5e3df8 [Daniel Darabos] Require positive number of partitions in HashPartitioner
897c628 [Daniel Darabos] Require positive maxPartitions in CoalescedRDD

JIRA: https://issues.apache.org/jira/browse/SPARK-8807

Add between operator in SparkR.

Author: Liang-Chi Hsieh <viirya@appier.com>

Closes #7356 from viirya/add_r_between and squashes the following commits:

7f51b44 [Liang-Chi Hsieh] Add test for non-numeric column.
c6a25c5 [Liang-Chi Hsieh] Add between function.

We don't support the complex expression keys in the rollup/cube, and we even will not report it if we have the complex group by keys, that will cause very confusing/incorrect result.

e.g. `SELECT key%100 FROM src GROUP BY key %100 with ROLLUP`

This PR adds an additional project during the analyzing for the complex GROUP BY keys, and that projection will be the child of `Expand`, so to `Expand`, the GROUP BY KEY are always the simple key(attribute names).

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

Closes #7343 from chenghao-intel/expand and squashes the following commits:

1ebbb59 [Cheng Hao] update the comment
827873f [Cheng Hao] update as feedback
34def69 [Cheng Hao] Add more unit test and comments
c695760 [Cheng Hao] fix bug of incorrect result for rollup

based on https://github.com/apache/spark/pull/7348

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7420 from cloud-fan/type-check and squashes the following commits:

7633fa9 [Wenchen Fan] revert
fe169b0 [Wenchen Fan] improve test
03b70da [Wenchen Fan] enhance implicit type cast

- `BinaryType` for `Length`
- `FormatNumber`

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

Closes #7034 from chenghao-intel/expression and squashes the following commits:

e534b87 [Cheng Hao] python api style issue
601bbf5 [Cheng Hao] add python API support
3ebe288 [Cheng Hao] update as feedback
52274f7 [Cheng Hao] add support for udf_format_number and length for binary

JIRA: https://issues.apache.org/jira/browse/SPARK-9060

This PR reverts:
* https://github.com/apache/spark/commit/31bd30687bc29c0e457c37308d489ae2b6e5b72a (SPARK-8359)
* https://github.com/apache/spark/commit/24fda7381171738cbbbacb5965393b660763e562 (SPARK-8677)
* https://github.com/apache/spark/commit/4b5cfc988f23988c2334882a255d494fc93d252e (SPARK-8800)

Author: Yin Huai <yhuai@databricks.com>

Closes #7426 from yhuai/SPARK-9060 and squashes the following commits:

651264d [Yin Huai] Revert "[SPARK-8359] [SQL] Fix incorrect decimal precision after multiplication"
cfda7e4 [Yin Huai] Revert "[SPARK-8677] [SQL] Fix non-terminating decimal expansion for decimal divide operation"
2de9afe [Yin Huai] Revert "[SPARK-8800] [SQL] Fix inaccurate precision/scale of Decimal division operation"

Add stopwatches for easy instrumentation of MLlib algorithms. This is based on the `TimeTracker` used in decision trees. The distributed version uses Spark accumulator. jkbradley

Author: Xiangrui Meng <meng@databricks.com>

Closes #7415 from mengxr/SPARK-9018 and squashes the following commits:

40b4347 [Xiangrui Meng] == -> ===
c477745 [Xiangrui Meng] address Joseph's comments
f981a49 [Xiangrui Meng] add stopwatches

This implements minimal R formula support as a feature transformer. Both numeric and string labels are supported, but features must be numeric for now.

cc mengxr

Author: Eric Liang <ekl@databricks.com>

Closes #7381 from ericl/spark-8774-1 and squashes the following commits:

d1959d2 [Eric Liang] clarify comment
2db68aa [Eric Liang] second round of comments
dc3c943 [Eric Liang] address comments
5765ec6 [Eric Liang] fix style checks
1f361b0 [Eric Liang] doc
fb0826b [Eric Liang] [SPARK-8774] Add R model formula with basic support as a transformer

These traits are not super useful, and yet cause problems with toString in expressions due to the orders they are mixed in.

Author: Reynold Xin <rxin@databricks.com>

Closes #7433 from rxin/remove-binary-node and squashes the following commits:

1881f78 [Reynold Xin] [SPARK-9086][SQL] Remove BinaryNode from TreeNode.

[SPARK-9071][SQL] MonotonicallyIncreasingID and SparkPartitionID should be marked as nondeterministic.

I also took the chance to more explicitly define the semantics of deterministic.

Author: Reynold Xin <rxin@databricks.com>

Closes #7428 from rxin/non-deterministic and squashes the following commits:

a760827 [Reynold Xin] [SPARK-9071][SQL] MonotonicallyIncreasingID and SparkPartitionID should be marked as nondeterministic.

I meet a problem. When I submit some tasks, the thread spark-dynamic-executor-allocation should seed the message about "requestTotalExecutors", and the new executor should start. But I meet a problem about this thread, like:

2015-07-14 19:02:17,461 | WARN  | [spark-dynamic-executor-allocation] | Error sending message [message = RequestExecutors(1)] in 1 attempts
java.util.concurrent.TimeoutException: Futures timed out after [120 seconds]
        at scala.concurrent.impl.Promise$DefaultPromise.ready(Promise.scala:219)
        at scala.concurrent.impl.Promise$DefaultPromise.result(Promise.scala:223)
        at scala.concurrent.Await$$anonfun$result$1.apply(package.scala:107)
        at scala.concurrent.BlockContext$DefaultBlockContext$.blockOn(BlockContext.scala:53)
        at scala.concurrent.Await$.result(package.scala:107)
        at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:102)
        at org.apache.spark.rpc.RpcEndpointRef.askWithRetry(RpcEndpointRef.scala:78)
        at org.apache.spark.scheduler.cluster.YarnSchedulerBackend.doRequestTotalExecutors(YarnSchedulerBackend.scala:57)
        at org.apache.spark.scheduler.cluster.CoarseGrainedSchedulerBackend.requestTotalExecutors(CoarseGrainedSchedulerBackend.scala:351)
        at org.apache.spark.SparkContext.requestTotalExecutors(SparkContext.scala:1382)
        at org.apache.spark.ExecutorAllocationManager.addExecutors(ExecutorAllocationManager.scala:343)
        at org.apache.spark.ExecutorAllocationManager.updateAndSyncNumExecutorsTarget(ExecutorAllocationManager.scala:295)
        at org.apache.spark.ExecutorAllocationManager.org$apache$spark$ExecutorAllocationManager$$schedule(ExecutorAllocationManager.scala:248)

when after some minutes, I find a new ApplicationMaster start,  and tasks submitted start to run. The tasks Completed. And after long time (eg, ten minutes), the number of executor  does not reduce to zero.  I use the default value of "spark.dynamicAllocation.minExecutors".

Author: KaiXinXiaoLei <huleilei1@huawei.com>

Closes #7352 from KaiXinXiaoLei/dym and squashes the following commits:

3603631 [KaiXinXiaoLei] change logError to logWarning
efc4f24 [KaiXinXiaoLei] change file

Replace Akka Serialization with Spark Serializer and add unit tests.

Author: zsxwing <zsxwing@gmail.com>

Closes #7159 from zsxwing/remove-akka-serialization and squashes the following commits:

fc0fca3 [zsxwing] Merge branch 'master' into remove-akka-serialization
cf81a58 [zsxwing] Fix the code style
73251c6 [zsxwing] Add test scope
9ef4af9 [zsxwing] Add AkkaRpcEndpointRef.hashCode
433115c [zsxwing] Remove final
be3edb0 [zsxwing] Support deserializing RpcEndpointRef
ecec410 [zsxwing] Replace Akka Serialization with Spark Serializer

Fixes implementation of `explainedVariance` and `r2` to be consistent with their definitions as described in [SPARK-9005](https://issues.apache.org/jira/browse/SPARK-9005).

Author: Feynman Liang <fliang@databricks.com>

Closes #7361 from feynmanliang/SPARK-9005-RegressionMetrics-bugs and squashes the following commits:

f1112fc [Feynman Liang] Add explainedVariance formula
1a3d098 [Feynman Liang] SROwen code review comments
08a0e1b [Feynman Liang] Fix pyspark tests
db8605a [Feynman Liang] Style fix
bde9761 [Feynman Liang] Fix RegressionMetrics tests, relax assumption predictor is unbiased
c235de0 [Feynman Liang] Fix RegressionMetrics tests
4c4e56f [Feynman Liang] Fix RegressionMetrics computation of explainedVariance and r2

fix teardown to skip table delete if hive context is null

Author: Steve Loughran <stevel@hortonworks.com>

Closes #7425 from steveloughran/stevel/patches/SPARK-9070-JavaDataFrameSuite-NPE and squashes the following commits:

1982d38 [Steve Loughran] SPARK-9070 JavaDataFrameSuite teardown NPEs if setup failed

jkbradley I put the elastic net under the **Algorithm guide** section. Also add the formula of elastic net in mllib-linear `mllib-linear-methods#regularizers`.

dbtsai I left the code tab for you to add example code. Do you think it is the right place?

Author: Shuo Xiang <shuoxiangpub@gmail.com>

Closes #6504 from coderxiang/elasticnet and squashes the following commits:

f6061ee [Shuo Xiang] typo
90a7c88 [Shuo Xiang] Merge remote-tracking branch 'upstream/master' into elasticnet
0610a36 [Shuo Xiang] move out the elastic net to ml-linear-methods
8747190 [Shuo Xiang] merge master
706d3f7 [Shuo Xiang] add python code
9bc2b4c [Shuo Xiang] typo
db32a60 [Shuo Xiang] java code sample
aab3b3a [Shuo Xiang] Merge remote-tracking branch 'upstream/master' into elasticnet
a0dae07 [Shuo Xiang] simplify code
d8616fd [Shuo Xiang] Update the definition of elastic net. Add scala code; Mention Lasso and Ridge
df5bd14 [Shuo Xiang] use wikipeida page in ml-linear-methods.md
78d9366 [Shuo Xiang] address comments
8ce37c2 [Shuo Xiang] Merge branch 'elasticnet' of github.com:coderxiang/spark into elasticnet
8f24848 [Shuo Xiang] Merge branch 'elastic-net-doc' of github.com:coderxiang/spark into elastic-net-doc
998d766 [Shuo Xiang] Merge branch 'elastic-net-doc' of github.com:coderxiang/spark into elastic-net-doc
89f10e4 [Shuo Xiang] Merge remote-tracking branch 'upstream/master' into elastic-net-doc
9262a72 [Shuo Xiang] update
7e07d12 [Shuo Xiang] update
b32f21a [Shuo Xiang] add doc for elastic net in sparkml
937eef1 [Shuo Xiang] Merge remote-tracking branch 'upstream/master' into elastic-net-doc
180b496 [Shuo Xiang] Merge remote-tracking branch 'upstream/master'
aa0717d [Shuo Xiang] Merge remote-tracking branch 'upstream/master'
5f109b4 [Shuo Xiang] Merge remote-tracking branch 'upstream/master'
c5c5bfe [Shuo Xiang] Merge remote-tracking branch 'upstream/master'
98804c9 [Shuo Xiang] fix bug in topBykey and update test

This is a minor fixing for #7355 to allow spaces in the beginning and ending of string parsed to `Interval`.

Author: Liang-Chi Hsieh <viirya@appier.com>

Closes #7390 from viirya/fix_interval_string and squashes the following commits:

9eb6831 [Liang-Chi Hsieh] Use trim instead of modifying regex.
57861f7 [Liang-Chi Hsieh] Fix scala style.
815a9cb [Liang-Chi Hsieh] Slightly modify regex to allow spaces in the beginning and ending of string.

https://issues.apache.org/jira/browse/SPARK-8221

One concern is the result would be negative if the divisor is not positive( i.e pmod(7, -3) ), but the behavior is the same as hive.

Author: zhichao.li <zhichao.li@intel.com>

Closes #6783 from zhichao-li/pmod2 and squashes the following commits:

7083eb9 [zhichao.li] update to the latest type checking
d26dba7 [zhichao.li] add pmod

We can keep expressions' mutable states in generated class(like `SpecificProjection`) as member variables, so that we can read and modify them inside codegened expressions.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7392 from cloud-fan/mutable-state and squashes the following commits:

eb3a221 [Wenchen Fan] fix order
73144d8 [Wenchen Fan] naming improvement
318f41d [Wenchen Fan] address more comments
d43b65d [Wenchen Fan] address comments
fd45c7a [Wenchen Fan] Support mutable state in code gen expressions

JIRA: https://issues.apache.org/jira/browse/SPARK-8840

Currently the type coercion rules don't include float type. This PR simply adds it.

Author: Liang-Chi Hsieh <viirya@appier.com>

Closes #7280 from viirya/add_r_float_coercion and squashes the following commits:

c86dc0e [Liang-Chi Hsieh] For comments.
dbf0c1b [Liang-Chi Hsieh] Implicitly convert Double to Float based on provided schema.
733015a [Liang-Chi Hsieh] Add test case for DataFrame with float type.
30c2a40 [Liang-Chi Hsieh] Update test case.
52b5294 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into add_r_float_coercion
6f9159d [Liang-Chi Hsieh] Add another test case.
8db3244 [Liang-Chi Hsieh] schema also needs to support float. add test case.
0dcc992 [Liang-Chi Hsieh] Add float coercion on SparkR.

This adds Pylint checks to PySpark.

For now this lazy installs using easy_install to /dev/pylint (similar to the pep8 script).
We still need to figure out what rules to be allowed.

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7241 from MechCoder/pylint and squashes the following commits:

2fc7291 [MechCoder] Remove pylint test fail
6d883a2 [MechCoder] Silence warnings and make pylint tests fail to check if it works in jenkins
f3a5e17 [MechCoder] undefined-variable
ca8b749 [MechCoder] Minor changes
71629f8 [MechCoder] remove trailing whitespace
8498ff9 [MechCoder] Remove blacklisted arguments and pointless statements check
1dbd094 [MechCoder] Disable all checks for now
8b8aa8a [MechCoder] Add pylint configuration file
7871bb1 [MechCoder] [SPARK-8706] [PySpark] [Project infra] Add pylint checks to PySpark

If running the following codes, the task table will be broken because accumulators aren't escaped.
```
val a = sc.accumulator(1, "<table>")
sc.parallelize(1 to 10).foreach(i => a += i)
```

Before this fix,

<img width="1348" alt="screen shot 2015-07-13 at 8 02 44 pm" src="https://cloud.githubusercontent.com/assets/1000778/8649295/b17c491e-299b-11e5-97ee-4e6a64074c4f.png">

After this fix,

<img width="1355" alt="screen shot 2015-07-13 at 8 14 32 pm" src="https://cloud.githubusercontent.com/assets/1000778/8649337/f9e9c9ec-299b-11e5-927e-35c0a2f897f5.png">

Author: zsxwing <zsxwing@gmail.com>

Closes #7369 from zsxwing/SPARK-9012 and squashes the following commits:

a83c9b6 [zsxwing] Escape Accumulators in the task table

Improves the performance of LocalPrefixSpan by implementing optimizations proposed in [SPARK-8997](https://issues.apache.org/jira/browse/SPARK-8997)

Author: Feynman Liang <fliang@databricks.com>
Author: Feynman Liang <feynman.liang@gmail.com>
Author: Xiangrui Meng <meng@databricks.com>

Closes #7360 from feynmanliang/SPARK-8997-improve-prefixspan and squashes the following commits:

59db2f5 [Feynman Liang] Merge pull request #1 from mengxr/SPARK-8997
91e4357 [Xiangrui Meng] update LocalPrefixSpan impl
9212256 [Feynman Liang] MengXR code review comments
f055d82 [Feynman Liang] Fix failing scalatest
2e00cba [Feynman Liang] Depth first projections
70b93e3 [Feynman Liang] Performance improvements in LocalPrefixSpan, fix tests

JIRA: https://issues.apache.org/jira/browse/SPARK-8279

Author: Yijie Shen <henry.yijieshen@gmail.com>

Closes #6938 from yijieshen/udf_round_3 and squashes the following commits:

07a124c [Yijie Shen] remove useless def children
392b65b [Yijie Shen] add negative scale test in DecimalSuite
61760ee [Yijie Shen] address reviews
302a78a [Yijie Shen] Add dataframe function test
31dfe7c [Yijie Shen] refactor round to make it readable
8c7a949 [Yijie Shen] rebase & inputTypes update
9555e35 [Yijie Shen] tiny style fix
d10be4a [Yijie Shen] use TypeCollection to specify wanted input and implicit cast
c3b9839 [Yijie Shen] rely on implict cast to handle string input
b0bff79 [Yijie Shen] make round's inner method's name more meaningful
9bd6930 [Yijie Shen] revert accidental change
e6f44c4 [Yijie Shen] refactor eval and genCode
1b87540 [Yijie Shen] modify checkInputDataTypes using foldable
5486b2d [Yijie Shen] DataFrame API modification
2077888 [Yijie Shen] codegen versioned eval
6cd9a64 [Yijie Shen] refactor Round's constructor
9be894e [Yijie Shen] add round functions in o.a.s.sql.functions
7c83e13 [Yijie Shen] more tests on round
56db4bb [Yijie Shen] Add decimal support to Round
7e163ae [Yijie Shen] style fix
653d047 [Yijie Shen] Add math function round