SPARK-1589: Fix the incorrect compare

JIRA: https://issues.apache.org/jira/browse/SPARK-1589

Author: zsxwing <zsxwing@gmail.com>

Closes #508 from zsxwing/SPARK-1589 and squashes the following commits:

570c67a [zsxwing] SPARK-1589: Fix the incorrect compare
[Fix #79] Replace Breakable For Loops By While Loops

Author: Sandeep <sandeep@techaddict.me>

Closes #503 from techaddict/fix-79 and squashes the following commits:

e3f6746 [Sandeep] Style changes
07a4f6b [Sandeep] for loop to While loop
0a6d8e9 [Sandeep] Breakable for loop to While loop
SPARK-1587 Fix thread leak

mvn test fails (intermittently) due to thread leak - since scalatest runs all tests in same vm.

Author: Mridul Muralidharan <mridulm80@apache.org>

Closes #504 from mridulm/resource_leak_fixes and squashes the following commits:

a5d10d0 [Mridul Muralidharan] Prevent thread leaks while running tests : cleanup all threads when SparkContext.stop is invoked. Causes tests to fail
7b5e19c [Mridul Muralidharan] Prevent NPE while running tests
SPARK-1601 & SPARK-1602: two bug fixes related to cancellation

This should go into 1.0 since it would return wrong data when the bug happens (which is pretty likely if cancellation is used). Test case attached.

1. Do not put partially executed partitions into cache (in task killing).

2. Iterator returned by CacheManager#getOrCompute was not an InterruptibleIterator, and was thus leading to uninterruptible jobs.

Thanks @aarondav and @ahirreddy for reporting and helping debug.

Author: Reynold Xin <rxin@apache.org>

Closes #521 from rxin/kill and squashes the following commits:

401033f [Reynold Xin] Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/spark into kill
7a7bdd2 [Reynold Xin] Add a new line in the end of JobCancellationSuite.scala.
35cd9f7 [Reynold Xin] Fixed a bug that partially executed partitions can be put into cache (in task killing).
[SPARK-1610] [SQL] Fix Cast to use exact type value when cast from BooleanType to NumericTy...

...pe.

`Cast` from `BooleanType` to `NumericType` are all using `Int` value.
But it causes `ClassCastException` when the casted value is used by the following evaluation like the code below:

``` scala
scala> import org.apache.spark.sql.catalyst._
import org.apache.spark.sql.catalyst._

scala> import types._
import types._

scala> import expressions._
import expressions._

scala> Add(Cast(Literal(true), ShortType), Literal(1.toShort)).eval()
java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Short
	at scala.runtime.BoxesRunTime.unboxToShort(BoxesRunTime.java:102)
	at scala.math.Numeric$ShortIsIntegral$.plus(Numeric.scala:72)
	at org.apache.spark.sql.catalyst.expressions.Add$$anonfun$eval$2.apply(arithmetic.scala:58)
	at org.apache.spark.sql.catalyst.expressions.Add$$anonfun$eval$2.apply(arithmetic.scala:58)
	at org.apache.spark.sql.catalyst.expressions.Expression.n2(Expression.scala:114)
	at org.apache.spark.sql.catalyst.expressions.Add.eval(arithmetic.scala:58)
	at .<init>(<console>:17)
	at .<clinit>(<console>)
	at .<init>(<console>:7)
	at .<clinit>(<console>)
	at $print(<console>)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at scala.tools.nsc.interpreter.IMain$ReadEvalPrint.call(IMain.scala:734)
	at scala.tools.nsc.interpreter.IMain$Request.loadAndRun(IMain.scala:983)
	at scala.tools.nsc.interpreter.IMain.loadAndRunReq$1(IMain.scala:573)
	at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:604)
	at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:568)
	at scala.tools.nsc.interpreter.ILoop.reallyInterpret$1(ILoop.scala:760)
	at scala.tools.nsc.interpreter.ILoop.interpretStartingWith(ILoop.scala:805)
	at scala.tools.nsc.interpreter.ILoop.command(ILoop.scala:717)
	at scala.tools.nsc.interpreter.ILoop.processLine$1(ILoop.scala:581)
	at scala.tools.nsc.interpreter.ILoop.innerLoop$1(ILoop.scala:588)
	at scala.tools.nsc.interpreter.ILoop.loop(ILoop.scala:591)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:882)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:837)
	at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:837)
	at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135)
	at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:837)
	at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:83)
	at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:96)
	at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:105)
	at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)
```

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

Closes #533 from ueshin/issues/SPARK-1610 and squashes the following commits:

70f36e8 [Takuya UESHIN] Fix Cast to use exact type value when cast from BooleanType to NumericType.
Small changes to release script
SPARK-1488. Squash more language feature warnings in new commits by importing implicitConversion

A recent commit reintroduced some of the same warnings that SPARK-1488 resolved. These are just a few more of the same changes to remove these warnings.

Author: Sean Owen <sowen@cloudera.com>

Closes #528 from srowen/SPARK-1488.2 and squashes the following commits:

62d592c [Sean Owen] More feature warnings in tests
4e2e94b [Sean Owen] Squash more language feature warnings in new commits by importing implicitConversion
SPARK-1611: Fix incorrect initialization order in AppendOnlyMap

JIRA: https://issues.apache.org/jira/browse/SPARK-1611

Author: zsxwing <zsxwing@gmail.com>

Closes #534 from zsxwing/SPARK-1611 and squashes the following commits:

96af089 [zsxwing] SPARK-1611: Fix incorrect initialization order in AppendOnlyMap
Spark 1490 Add kerberos support to the HistoryServer

Here I've added the ability for the History server to login from a kerberos keytab file so that the history server can be run as a super user and stay up for along period of time while reading the history files from HDFS.

Author: Thomas Graves <tgraves@apache.org>

Closes #513 from tgravescs/SPARK-1490 and squashes the following commits:

e204a99 [Thomas Graves] remove extra logging
5418daa [Thomas Graves] fix typo in config
0076b99 [Thomas Graves] Update docs
4d76545 [Thomas Graves] SPARK-1490 Add kerberos support to the HistoryServer
SPARK-1494 Don't initialize classes loaded by MIMA excludes, attempt 2

[WIP]

Looks like scala reflection was invoking the static initializer:
```
...
	at org.apache.spark.sql.test.TestSQLContext$.<init>(TestSQLContext.scala:25)
	at org.apache.spark.sql.test.TestSQLContext$.<clinit>(TestSQLContext.scala)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:270)
	at scala.reflect.runtime.JavaMirrors$JavaMirror.javaClass(JavaMirrors.scala:500)
	at scala.reflect.runtime.JavaMirrors$JavaMirror.tryJavaClass(JavaMirrors.scala:505)
	at scala.reflect.runtime.SymbolLoaders$PackageScope.lookupEntry(SymbolLoaders.scala:109)
...
```

Need to make sure that this doesn't change the exclusion semantics before merging.

Author: Michael Armbrust <michael@databricks.com>

Closes #526 from marmbrus/mima and squashes the following commits:

8168dea [Michael Armbrust] Spurious change
afba262 [Michael Armbrust] Prevent Scala reflection from running static class initializer.
Fix Scala Style

Any comments are welcome

Author: Sandeep <sandeep@techaddict.me>

Closes #531 from techaddict/stylefix-1 and squashes the following commits:

7492730 [Sandeep] Pass 4
98b2428 [Sandeep] fix rxin suggestions
b5e2e6f [Sandeep] Pass 3
05932d7 [Sandeep] fix if else styling 2
08690e5 [Sandeep] fix if else styling
SPARK-1104: kill Process in workerThread of ExecutorRunner

As reported in https://spark-project.atlassian.net/browse/SPARK-1104

By @pwendell: "Sometimes due to large shuffles executors will take a long time shutting down. In particular this can happen if large numbers of shuffle files are around (this will be alleviated by SPARK-1103, but nonetheless...).

The symptom is you have DEAD workers sitting around in the UI and the existing workers keep trying to re-register but can't because they've been assumed dead."

In this patch, I add lines in the handler of InterruptedException in workerThread of executorRunner, so that the process.destroy() and process.waitFor() can only block the workerThread instead of blocking the worker Actor...

---------

analysis: process.destroy() is a blocking method, i.e. it only returns when all shutdownHook threads return...so calling it in Worker thread will make Worker block for a long while....

about what will happen on the shutdown hooks when the JVM process is killed: http://www.tutorialspoint.com/java/lang/runtime_addshutdownhook.htm

Author: CodingCat <zhunansjtu@gmail.com>

Closes #35 from CodingCat/SPARK-1104 and squashes the following commits:

85767da [CodingCat] add null checking and remove unnecessary killProce
3107aeb [CodingCat] address Aaron's comments
eb615ba [CodingCat] kill the process when the error happens
0accf2f [CodingCat] set process to null after killed it
1d511c8 [CodingCat] kill Process in workerThread
SPARK-1438 RDD.sample() make seed param optional

copying form previous pull request https://github.com/apache/spark/pull/462

Its probably better to let the underlying language implementation take care of the default . This was easier to do with python as the default value for seed in random and numpy random is None.

In Scala/Java side it might mean propagating an Option or null(oh no!) down the chain until where the Random is constructed. But, looks like the convention in some other methods was to use System.nanoTime. So, followed that convention.

Conflict with overloaded method in sql.SchemaRDD.sample which also defines default params.
sample(fraction, withReplacement=false, seed=math.random)
Scala does not allow more than one overloaded to have default params. I believe the author intended to override the RDD.sample method and not overload it. So, changed it.

If backward compatible is important, 3 new method can be introduced (without default params) like this
sample(fraction)
sample(fraction, withReplacement)
sample(fraction, withReplacement, seed)

Added some tests for the scala RDD takeSample method.

Author: Arun Ramakrishnan <smartnut007@gmail.com>

This patch had conflicts when merged, resolved by
Committer: Matei Zaharia <matei@databricks.com>

Closes #477 from smartnut007/master and squashes the following commits:

07bb06e [Arun Ramakrishnan] SPARK-1438 fixing more space formatting issues
b9ebfe2 [Arun Ramakrishnan] SPARK-1438 removing redundant import of random in python rddsampler
8d05b1a [Arun Ramakrishnan] SPARK-1438 RDD . Replace System.nanoTime with a Random generated number. python: use a separate instance of Random instead of seeding language api global Random instance.
69619c6 [Arun Ramakrishnan] SPARK-1438 fix spacing issue
0c247db [Arun Ramakrishnan] SPARK-1438 RDD language apis to support optional seed in RDD methods sample/takeSample
[SPARK-1592][streaming] Automatically remove streaming input blocks

The raw input data is stored as blocks in BlockManagers. Earlier they were cleared by cleaner ttl. Now since streaming does not require cleaner TTL to be set, the block would not get cleared. This increases up the Spark's memory usage, which is not even accounted and shown in the Spark storage UI. It may cause the data blocks to spill over to disk, which eventually slows down the receiving of data (persisting to memory become bottlenecked by writing to disk).

The solution in this PR is to automatically remove those blocks. The mechanism to keep track of which BlockRDDs (which has presents the raw data blocks as a RDD) can be safely cleared already exists. Just use it to explicitly remove blocks from BlockRDDs.

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

Closes #512 from tdas/block-rdd-unpersist and squashes the following commits:

d25e610 [Tathagata Das] Merge remote-tracking branch 'apache/master' into block-rdd-unpersist
5f46d69 [Tathagata Das] Merge remote-tracking branch 'apache/master' into block-rdd-unpersist
2c320cd [Tathagata Das] Updated configuration with spark.streaming.unpersist setting.
2d4b2fd [Tathagata Das] Automatically removed input blocks
[SQL] Add support for parsing indexing into arrays in SQL.

Author: Michael Armbrust <michael@databricks.com>

Closes #518 from marmbrus/parseArrayIndex and squashes the following commits:

afd2d6b [Michael Armbrust] 100 chars
c3d6026 [Michael Armbrust] Add support for parsing indexing into arrays in SQL.
Check if event is actually added before releasing semaphore
Merge github.com:apache/spark into stage-info-test-fix