Fail to upload resource to viewfs in spark-1.4
JIRA Link: https://issues.apache.org/jira/browse/SPARK-8657

Author: Tao Li <litao@sogou-inc.com>

Closes #7125 from litao-buptsse/SPARK-8657-for-master and squashes the following commits:

65b13f4 [Tao Li] [SPARK-8657] [YARN] Fail to upload resource to viewfs

Just a baby step towards making it more efficient.

Author: Reynold Xin <rxin@databricks.com>

Closes #7282 from rxin/SPARK-8888 and squashes the following commits:

3da51ae [Reynold Xin] [SPARK-8888][SQL] Use java.util.HashMap in DynamicPartitionWriterContainer.

We need a new data type to represent time intervals. Because we can't determine how many days in a month, so we need 2 values for interval: a int `months`, a long `microseconds`.

The interval literal syntax looks like:
`interval 3 years -4 month 4 weeks 3 second`

Because we use number of 100ns as value of `TimestampType`, so it may not makes sense to support nano second unit.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7226 from cloud-fan/interval and squashes the following commits:

632062d [Wenchen Fan] address comments
ac348c3 [Wenchen Fan] use case class
0342d2e [Wenchen Fan] use array byte
df9256c [Wenchen Fan] fix style
fd6f18a [Wenchen Fan] address comments
1856af3 [Wenchen Fan] support interval type

Author: Davies Liu <davies@databricks.com>

Closes #7272 from davies/fix_projection and squashes the following commits:

075ef76 [Davies Liu] fix codegen with BroadcastHashJion

To make UDF developers understood, throw an exception when unsupported Map<K,V> types used in Hive UDF. This fix is the same with #7248.

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #7257 from maropu/ThrowExceptionWhenMapUsed and squashes the following commits:

916099a [Takeshi YAMAMURO] Fix style errors
7886dcc [Takeshi YAMAMURO] Throw an exception when Map<> used in Hive UDF

JIRA: https://issues.apache.org/jira/browse/SPARK-8785

Currently, the parquet schema merging (`ParquetRelation2.readSchema`) may spend much time to merge duplicate schema. We can select only non duplicate schema and merge them later.

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

Closes #7182 from viirya/improve_parquet_merging and squashes the following commits:

5cf934f [Liang-Chi Hsieh] Refactor it to make it faster.
f3411ea [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into improve_parquet_merging
a63c3ff [Liang-Chi Hsieh] Improve Parquet schema merging.

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

Closes #7287 from sun-rui/SPARK-8894 and squashes the following commits:

da63898 [Sun Rui] [SPARK-8894][SPARKR][DOC] Example code errors in SparkR documentation.

Author: Kashif Rasul <kashif.rasul@gmail.com>

Closes #7269 from kashif/SPARK-8872 and squashes the following commits:

2d5457f [Kashif Rasul] added R code for FP Int type
3de6808 [Kashif Rasul] added verification results from R for FPGrowthSuite

 To fix Spark Streaming unit test with maven build. Previously the name and path of maven generated jar is different from sbt, which will lead to following exception. This fix keep the same behavior with both Maven and sbt build.

```
Failed to find Spark Streaming Kafka assembly jar in /home/xyz/spark/external/kafka-assembly
You need to build Spark with  'build/sbt assembly/assembly streaming-kafka-assembly/assembly' or 'build/mvn package' before running this program
```

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

Closes #5632 from jerryshao/SPARK-7050 and squashes the following commits:

74b068d [jerryshao] Fix mvn build issue

Remove the `OverrideFunctionRegistry` from the Spark SQL, as the subclasses of `FunctionRegistry` have their own way to the delegate to the right underlying `FunctionRegistry`.

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

Closes #7260 from chenghao-intel/override and squashes the following commits:

164d093 [Cheng Hao] enable the function registry
2ca8459 [Cheng Hao] remove the OverrideFunctionRegistry

Fixed comment given by rxin

Author: Tijo Thomas <tijoparacka@gmail.com>

Closes #7281 from tijoparacka/modification_for_python_style and squashes the following commits:

6334e21 [Tijo Thomas] removed space
3de4cd8 [Tijo Thomas] python Style update

As a baby step towards no megamorphic InternalRow.

Author: Reynold Xin <rxin@databricks.com>

Closes #7277 from rxin/remove-empty-row and squashes the following commits:

594100e [Reynold Xin] [SPARK-8879][SQL] Remove EmptyRow class.

Author: Reynold Xin <rxin@databricks.com>

Closes #7273 from rxin/bitwise-unittest and squashes the following commits:

60c5667 [Reynold Xin] [SPARK-8878][SQL] Improve unit test coverage for bitwise expressions.

https://issues.apache.org/jira/browse/SPARK-8868

Author: Yin Huai <yhuai@databricks.com>

Closes #7262 from yhuai/SPARK-8868 and squashes the following commits:

cb58780 [Yin Huai] Andrew's comment.
e456857 [Yin Huai] Josh's comments.
5122e65 [Yin Huai] If types of all columns are NullTypes, do not use serializer2.

Let UTF8String work with binary buffer. Before we have better idea on manage the lifecycle of UTF8String in Row, we still do the copy when calling `UnsafeRow.get()` for StringType.

cc rxin JoshRosen

Author: Davies Liu <davies@databricks.com>

Closes #7197 from davies/unsafe_string and squashes the following commits:

51b0ea0 [Davies Liu] fix test
50c1ebf [Davies Liu] remove optimization for upper/lower case
315d491 [Davies Liu] Merge branch 'master' of github.com:apache/spark into unsafe_string
93fce17 [Davies Liu] address comment
e9ff7ba [Davies Liu] clean up
67ec266 [Davies Liu] fix bug
7b74b1f [Davies Liu] fallback to String if local dependent
ab7857c [Davies Liu] address comments
7da92f5 [Davies Liu] handle local in toUpperCase/toLowerCase
59dbb23 [Davies Liu] revert python change
d1e0716 [Davies Liu] Merge branch 'master' of github.com:apache/spark into unsafe_string
002e35f [Davies Liu] rollback hashCode change
a87b7a8 [Davies Liu] improve toLowerCase and toUpperCase
76e794a [Davies Liu] fix test
8b2d5ce [Davies Liu] fix tests
fd3f0a6 [Davies Liu] bug fix
c4e9c88 [Davies Liu] Merge branch 'master' of github.com:apache/spark into unsafe_string
c45d921 [Davies Liu] address comments
175405f [Davies Liu] unsafe UTF8String

The type alias was there because initially when I moved Row around, I didn't want to do massive changes to the expression code. But now it should be pretty easy to just remove it. One less concept to worry about.

Author: Reynold Xin <rxin@databricks.com>

Closes #7270 from rxin/internalrow and squashes the following commits:

72fc842 [Reynold Xin] [SPARK-8876][SQL] Remove InternalRow type alias in expressions package.

JIRA: https://issues.apache.org/jira/browse/SPARK-8794

Currently `PrunedScan` works only when followed by project or filter operations. However, even if there is a `Sample` between these operations and `PrunedScan`, `PrunedScan` should work too.

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

Closes #7228 from viirya/sample_prunedscan and squashes the following commits:

ede7cd8 [Liang-Chi Hsieh] Keep PrunedScanSuite untouched.
6f05d30 [Liang-Chi Hsieh] Move unit test to FilterPushdownSuite.
5f32473 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into sample_prunedscan
7e4ba76 [Liang-Chi Hsieh] Use Optimzier for push down projection and filter.
0686830 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into sample_prunedscan
df82785 [Liang-Chi Hsieh] Make PrunedScan work on Sample.

In LinearRegression and LogisticRegression, we use Breeze's optimizers (LBFGS and OWLQN). We check the State.value to see the current objective. However, Breeze's documentation makes it sound like value and adjustedValue differ for some optimizers, possibly including OWLQN: https://github.com/scalanlp/breeze/blob/26faf622862e8d7a42a401aef601347aac655f2b/math/src/main/scala/breeze/optimize/FirstOrderMinimizer.scala#L36
If that is the case, then we should use adjustedValue instead of value. This is relevant to SPARK-8538 and SPARK-8539, where we will provide the objective trace to the user.

Author: DB Tsai <dbt@netflix.com>

Closes #7245 from dbtsai/SPARK-8845 and squashes the following commits:

fa4c91e [DB Tsai] address feedback
e6caac1 [DB Tsai] java style multiline comment
b10c574 [DB Tsai] address feedback
c9ff81e [DB Tsai] first commit

Add std, mean to StandardScalerModel
getVectors, findSynonyms to Word2Vec Model
setFeatures and getFeatures to hashingTF

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7086 from MechCoder/missing_model_methods and squashes the following commits:

9fbae90 [MechCoder] Add type
6e3d6b2 [MechCoder] [SPARK-8704] Add missing methods in StandardScaler (ML and PySpark)

Distributed generation of single-consequent association rules from a RDD of frequent itemsets. Tests referenced against `R`'s implementation of A Priori in [arules](http://cran.r-project.org/web/packages/arules/index.html).

Author: Feynman Liang <fliang@databricks.com>

Closes #7005 from feynmanliang/fp-association-rules-distributed and squashes the following commits:

466ced0 [Feynman Liang] Refactor AR generation impl
73c1cff [Feynman Liang] Make rule attributes public, remove numTransactions from FreqItemset
80f63ff [Feynman Liang] Change default confidence and optimize imports
04cf5b5 [Feynman Liang] Code review with @mengxr, add R to tests
0cc1a6a [Feynman Liang] Java compatibility test
f3c14b5 [Feynman Liang] Fix MiMa test
764375e [Feynman Liang] Fix tests
1187307 [Feynman Liang] Almost working tests
b20779b [Feynman Liang] Working implementation
5395c4e [Feynman Liang] Fix imports
2d34405 [Feynman Liang] Partial implementation of distributed ar
83ace4b [Feynman Liang] Local rule generation without pruning complete
69c2c87 [Feynman Liang] Working local implementation, now to parallelize../..
4e1ec9a [Feynman Liang] Pull FreqItemsets out, refactor type param, tests
69ccedc [Feynman Liang] First implementation of association rule generation

Otherwise the script will crash with

    - Downloading boto...
    Traceback (most recent call last):
      File "ec2/spark_ec2.py", line 148, in <module>
        setup_external_libs(external_libs)
      File "ec2/spark_ec2.py", line 128, in setup_external_libs
        if hashlib.md5(tar.read()).hexdigest() != lib["md5"]:
      File "/usr/lib/python3.4/codecs.py", line 319, in decode
        (result, consumed) = self._buffer_decode(data, self.errors, final)
    UnicodeDecodeError: 'utf-8' codec can't decode byte 0x8b in position 1: invalid start byte

In case of an utf8 env setting.

Author: Simon Hafner <hafnersimon@gmail.com>

Closes #7215 from reactormonk/branch-1.4 and squashes the following commits:

e86957a [Simon Hafner] [SPARK-8821] [EC2] Switched to binary mode

(cherry picked from commit 83a621a5)
Signed-off-by: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Follow up for https://github.com/apache/spark/pull/5946

Currently we iterate over indices and values in SparseVector and can be vectorized.

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7222 from MechCoder/sparse_optim and squashes the following commits:

dcb51d3 [MechCoder] [SPARK-8823] [MLlib] [PySpark] Optimizations for SparseVector dot product

Add numNodes and depth to treeModels, add treeWeights to ensemble Models.
Add __repr__ to all models.

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #7095 from MechCoder/missing_methods_tree and squashes the following commits:

23b08be [MechCoder] private [spark]
38a0860 [MechCoder] rename pyTreeWeights to javaTreeWeights
6d16ad8 [MechCoder] Fix Python 3 Error
47d7023 [MechCoder] Use np.allclose and treeEnsembleModel -> TreeEnsembleMethods
819098c [MechCoder] [SPARK-8711] [ML] Add additional methods ot PySpark ML tree models

Updated MLlib Data Types Local Matrix section to include information on sparse matrices, added sparse matrix examples to the Scala and Java examples, and added Python examples for both dense and sparse matrices.

Author: Mike Dusenberry <mwdusenb@us.ibm.com>

Closes #6958 from dusenberrymw/Improve_MLlib_Local_Matrix_Documentation and squashes the following commits:

ceae407 [Mike Dusenberry] Updated MLlib Data Types Local Matrix section to include information on sparse matrices, added sparse matrix examples to the Scala and Java examples, and added Python examples for both dense and sparse matrices.

Add Java unit test for PCA transformer

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #7184 from yanboliang/spark-8788 and squashes the following commits:

9d1a2af [Yanbo Liang] address comments
b34451f [Yanbo Liang] Add Java unit test for PCA transformer

(This finishes the job by removing the version overridden by Hadoop profiles.)

See discussion at https://github.com/apache/spark/pull/6994#issuecomment-119113167

Author: Sean Owen <sowen@cloudera.com>

Closes #7261 from srowen/SPARK-6731.2 and squashes the following commits:

5a3f59e [Sean Owen] Finish updating Commons Math3 to 3.4.1 from 3.1.1

when publishing releases. We named it as 'release-profile' because that is
the Maven convention. However, it turns out this special name causes several
other things to kick-in when we are creating releases that are not desirable.
For instance, it triggers the javadoc plugin to run, which actually fails
in our current build set-up.

The fix is just to rename this to a different profile to have no
collateral damage associated with its use.

[SPARK-8759][SQL] add default eval to binary and unary expression according to default behavior of nullable

We have `nullSafeCodeGen` to provide default code generation for binary and unary expression, and we can do the same thing for `eval`.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #7157 from cloud-fan/refactor and squashes the following commits:

f3987c6 [Wenchen Fan] refactor Expression

See the jira https://issues.apache.org/jira/browse/SPARK-5562

Author: Alok  Singh <singhal@Aloks-MacBook-Pro.local>
Author: Alok  Singh <singhal@aloks-mbp.usca.ibm.com>
Author: Alok Singh <“singhal@us.ibm.com”>

Closes #7064 from aloknsingh/aloknsingh_SPARK-5562 and squashes the following commits:

259a0a7 [Alok Singh] change as per the comments by @jkbradley
be48491 [Alok  Singh] [SPARK-5562][MLlib] re-order import in alphabhetical order
c01311b [Alok  Singh] [SPARK-5562][MLlib] fix the newline typo
b271c8a [Alok  Singh] [SPARK-5562][Mllib] As per github discussion with jkbradley. We would like to simply things.
7c06251 [Alok  Singh] [SPARK-5562][MLlib] modified the JavaLDASuite for test passing
c710cb6 [Alok  Singh] fix the scala code style to have space after :
2572a08 [Alok  Singh] [SPARK-5562][MLlib] change the import xyz._ to the import xyz.{c1, c2} ..
ab55fbf [Alok  Singh] [SPARK-5562][MLlib] Change as per Sean Owen's comments https://github.com/apache/spark/pull/7064/files#diff-9236d23975e6f5a5608ffc81dfd79146
9f4f9ea [Alok  Singh] [SPARK-5562][MLlib] LDA should handle empty document.

The current implementation can't handle List<> as a return type in Hive UDF and
throws meaningless Match Error.
We assume an UDF below;
public class UDFToListString extends UDF {
public List<String> evaluate(Object o)
{ return Arrays.asList("xxx", "yyy", "zzz"); }
}
An exception of scala.MatchError is thrown as follows when the UDF used;
scala.MatchError: interface java.util.List (of class java.lang.Class)
at org.apache.spark.sql.hive.HiveInspectors$class.javaClassToDataType(HiveInspectors.scala:174)
at org.apache.spark.sql.hive.HiveSimpleUdf.javaClassToDataType(hiveUdfs.scala:76)
at org.apache.spark.sql.hive.HiveSimpleUdf.dataType$lzycompute(hiveUdfs.scala:106)
at org.apache.spark.sql.hive.HiveSimpleUdf.dataType(hiveUdfs.scala:106)
at org.apache.spark.sql.catalyst.expressions.Alias.toAttribute(namedExpressions.scala:131)
at org.apache.spark.sql.catalyst.planning.PhysicalOperation$$anonfun$collectAliases$1.applyOrElse(patterns.scala:95)
at org.apache.spark.sql.catalyst.planning.PhysicalOperation$$anonfun$collectAliases$1.applyOrElse(patterns.scala:94)
at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:33)
at scala.collection.TraversableLike$$anonfun$collect$1.apply(TraversableLike.scala:278)
...
To make udf developers more understood, we need to throw a more suitable exception.

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #7248 from maropu/FixBugInHiveInspectors and squashes the following commits:

1c3df2a [Takeshi YAMAMURO] Fix comments
56305de [Takeshi YAMAMURO] Fix conflicts
92ed7a6 [Takeshi YAMAMURO] Throw an exception when java list type used
2844a8e [Takeshi YAMAMURO] Apply comments
7114a47 [Takeshi YAMAMURO] Add TODO comments in UDFToListString of HiveUdfSuite
fdb2ae4 [Takeshi YAMAMURO] Add StringToUtf8 to comvert String into UTF8String
af61f2e [Takeshi YAMAMURO] Remove a new type
7f812fd [Takeshi YAMAMURO] Fix code-style errors
6984bf4 [Takeshi YAMAMURO] Apply review comments
93e3d4e [Takeshi YAMAMURO] Add a blank line at the end of UDFToListString
ee232db [Takeshi YAMAMURO] Support List as a return type in Hive UDF
1e82316 [Takeshi YAMAMURO] Apply comments
21e8763 [Takeshi YAMAMURO] Add TODO comments in UDFToListString of HiveUdfSuite
a488712 [Takeshi YAMAMURO] Add StringToUtf8 to comvert String into UTF8String
1c7b9d1 [Takeshi YAMAMURO] Remove a new type
f965c34 [Takeshi YAMAMURO] Fix code-style errors
9406416 [Takeshi YAMAMURO] Apply review comments
e21ce7e [Takeshi YAMAMURO] Add a blank line at the end of UDFToListString
e553f10 [Takeshi YAMAMURO] Support List as a return type in Hive UDF

This reverts commit 82cf3315.

Conflicts:
	pom.xml

This is a workaround for MSHADE-148, which leads to an infinite loop when building Spark with maven 3.3.x. This was originally caused by #6441, which added a bunch of test dependencies on the spark-core test module. Recently, it was revealed by #7193.

This patch adds a `-Prelease` profile. If present, it will set `createDependencyReducedPom` to true. The consequences are:
- If you are releasing Spark with this profile, you are fine as long as you use maven 3.2.x or before.
- If you are releasing Spark without this profile, you will run into SPARK-8781.
- If you are not releasing Spark but you are using this profile, you may run into SPARK-8819.
- If you are not releasing Spark and you did not include this profile, you are fine.

This is all documented in `pom.xml` and tested locally with both versions of maven.

Author: Andrew Or <andrew@databricks.com>

Closes #7219 from andrewor14/fix-maven-build and squashes the following commits:

1d37e87 [Andrew Or] Merge branch 'master' of github.com:apache/spark into fix-maven-build
3574ae4 [Andrew Or] Review comments
f39199c [Andrew Or] Create a -Prelease profile that flags `createDependencyReducedPom`

JIRA: https://issues.apache.org/jira/browse/SPARK-8463

Currently, at the reading path, `DriverRegistry` is used to load needed jdbc driver at executors. However, at the writing path, we also need `DriverRegistry` to load jdbc driver.

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

Closes #6900 from viirya/jdbc_write_driver and squashes the following commits:

16cd04b [Liang-Chi Hsieh] Use DriverRegistry to load jdbc driver at writing path.

Adding a function checkConstraints which will check for the constraints to be applied on the dataframe / dataframe schema. Function called before storing the dataframe to an external storage. Function added in the corresponding datasource API.
cc rxin marmbrus

Author: animesh <animesh@apache.spark>

This patch had conflicts when merged, resolved by
Committer: Michael Armbrust <michael@databricks.com>

Closes #7013 from animeshbaranawal/8072 and squashes the following commits:

f70dd0e [animesh] Change IO exception to Analysis Exception
fd45e1b [animesh] 8072: Fix Style Issues
a8a964f [animesh] 8072: Improving on previous commits
3cc4d2c [animesh] Fix Style Issues
1a89115 [animesh] Fix Style Issues
98b4399 [animesh] 8072 : Moved the exception handling to ResolvedDataSource specific to parquet format
7c3d928 [animesh] 8072: Adding check to DataFrameWriter.scala

This PR adds regression test for https://issues.apache.org/jira/browse/SPARK-8588 (fixed by https://github.com/apache/spark/commit/457d07eaa023b44b75344110508f629925eb6247).

Author: Yin Huai <yhuai@databricks.com>

This patch had conflicts when merged, resolved by
Committer: Michael Armbrust <michael@databricks.com>

Closes #7103 from yhuai/SPARK-8588-test and squashes the following commits:

eb5f418 [Yin Huai] Add a query test.
c61a173 [Yin Huai] Regression test for SPARK-8588.

PySpark PowerIterationClustering test failure due to bad demo data.
If the data is small,  PowerIterationClustering will behavior indeterministic.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #7177 from yanboliang/spark-8765 and squashes the following commits:

392ae54 [Yanbo Liang] fix model.assignments output
5ec3f1e [Yanbo Liang] fix PySpark PowerIterationClustering test issue

This reverts commit 25f574eb. After speaking to some users and developers, we realized that FP-growth doesn't meet the requirement for frequent sequence mining. PrefixSpan (SPARK-6487) would be the correct algorithm for it. feynmanliang

Author: Xiangrui Meng <meng@databricks.com>

Closes #7240 from mengxr/SPARK-7212.revert and squashes the following commits:

2b3d66b [Xiangrui Meng] Revert "[SPARK-7212] [MLLIB] Add sequence learning flag"

[SPARK-6707] [CORE] [MESOS] Mesos Scheduler should allow the user to specify constraints based on slave attributes

Currently, the mesos scheduler only looks at the 'cpu' and 'mem' resources when trying to determine the usablility of a resource offer from a mesos slave node. It may be preferable for the user to be able to ensure that the spark jobs are only started on a certain set of nodes (based on attributes).

For example, If the user sets a property, let's say `spark.mesos.constraints` is set to `tachyon=true;us-east-1=false`, then the resource offers will be checked to see if they meet both these constraints and only then will be accepted to start new executors.

Author: Ankur Chauhan <achauhan@brightcove.com>

Closes #5563 from ankurcha/mesos_attribs and squashes the following commits:

902535b [Ankur Chauhan] Fix line length
d83801c [Ankur Chauhan] Update code as per code review comments
8b73f2d [Ankur Chauhan] Fix imports
c3523e7 [Ankur Chauhan] Added docs
1a24d0b [Ankur Chauhan] Expand scope of attributes matching to include all data types
482fd71 [Ankur Chauhan] Update access modifier to private[this] for offer constraints
5ccc32d [Ankur Chauhan] Fix nit pick whitespace
1bce782 [Ankur Chauhan] Fix nit pick whitespace
c0cbc75 [Ankur Chauhan] Use offer id value for debug message
7fee0ea [Ankur Chauhan] Add debug statements
fc7eb5b [Ankur Chauhan] Fix import codestyle
00be252 [Ankur Chauhan] Style changes as per code review comments
662535f [Ankur Chauhan] Incorporate code review comments + use SparkFunSuite
fdc0937 [Ankur Chauhan] Decline offers that did not meet criteria
67b58a0 [Ankur Chauhan] Add documentation for spark.mesos.constraints
63f53f4 [Ankur Chauhan] Update codestyle - uniform style for config values
02031e4 [Ankur Chauhan] Fix scalastyle warnings in tests
c09ed84 [Ankur Chauhan] Fixed the access modifier on offerConstraints val to private[mesos]
0c64df6 [Ankur Chauhan] Rename overhead fractions to memory_*, fix spacing
8cc1e8f [Ankur Chauhan] Make exception message more explicit about the source of the error
addedba [Ankur Chauhan] Added test case for malformed constraint string
ec9d9a6 [Ankur Chauhan] Add tests for parse constraint string
72fe88a [Ankur Chauhan] Fix up tests + remove redundant method override, combine utility class into new mesos scheduler util trait
92b47fd [Ankur Chauhan] Add attributes based constraints support to MesosScheduler

Spark standalone master web UI show "Alive Workers" total core, total used cores and "Alive workers" total memory, memory used.
But the JSON API page "http://MASTERURL:8088/json" shows "ALL workers"  core, memory number.
This webUI data is not sync with the JSON API.
The proper way is to sync the number with webUI and JSON API.

Author: Wisely Chen <wiselychen@appier.com>

Closes #7038 from thegiive/SPARK-8656 and squashes the following commits:

9e54bf0 [Wisely Chen] Change variable name to camel case
2c8ea89 [Wisely Chen] Change some styling and add local variable
431d2b0 [Wisely Chen] Worker List should contain DEAD node also
8b3b8e8 [Wisely Chen] [SPARK-8656] Fix the webUI and JSON API number is not synced

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

Closes #7234 from adrian-wang/exchangeclean and squashes the following commits:

b093ec9 [Daoyuan Wang] remove unused code