...e user, reads the file back from the DFS, and compares word counts on the local and DFS versions. Useful for verifying DFS correctness.

Author: RJ Nowling <rnowling@gmail.com>

Closes #3347 from rnowling/dfs_read_write_test and squashes the following commits:

af8ccb7 [RJ Nowling] Don't use java.io.File since DFS may not be POSIX-compatible
b0ef9ea [RJ Nowling] Fix string style
07c6132 [RJ Nowling] Fix string style
7d9a8df [RJ Nowling] Fix string style
f74c160 [RJ Nowling] Fix else statement style
b9edf12 [RJ Nowling] Fix spark wc style
44415b9 [RJ Nowling] Fix local wc style
94a4691 [RJ Nowling] Fix space
df59b65 [RJ Nowling] Fix if statements
1b314f0 [RJ Nowling] Add scaladoc
a931d70 [RJ Nowling] Fix import order
0c89558 [RJ Nowling] Add example that reads a local file, writes to a DFS path provided by the user, reads the file back from the DFS, and compares word counts on the local and DFS versions. Useful for verifying DFS correctness.

Author: Shilei <shilei.qian@intel.com>

Closes #6779 from qiansl127/MD5 and squashes the following commits:

11fcdb2 [Shilei] Fix the indent
04bd27b [Shilei] Add codegen
da60eb3 [Shilei] Remove checkInputDataTypes function
9509ad0 [Shilei] Format code
12c61f4 [Shilei] Accept only BinaryType for Md5
1df0b5b [Shilei] format to scala type
60ccde1 [Shilei] Add more test case
b8c73b4 [Shilei] Rewrite the type check for Md5
c166167 [Shilei] Add md5 function

This is a follow-up of [SPARK-3288](https://issues.apache.org/jira/browse/SPARK-3288).

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

Closes #6896 from ueshin/issues/SPARK-8476 and squashes the following commits:

89251d8 [Takuya UESHIN] Make inc/decDiskBytesSpilled in TaskMetrics private[spark].

andrewor14 can you take a look?thanks

Author: Lianhui Wang <lianhuiwang09@gmail.com>

Closes #6873 from lianhuiwang/SPARK-8430 and squashes the following commits:

51c47ca [Lianhui Wang] update andrewor's comments
2b27b19 [Lianhui Wang] support UnsafeShuffleManager

JIRA: https://issues.apache.org/jira/browse/SPARK-8207

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

Closes #6721 from viirya/expr_bin and squashes the following commits:

07e1c8f [Liang-Chi Hsieh] Remove AbstractUnaryMathExpression and let BIN inherit UnaryExpression.
0677f1a [Liang-Chi Hsieh] For comments.
cf62b95 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
0cf20f2 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
dea9c12 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
d4f4774 [Liang-Chi Hsieh] Add @ignore_unicode_prefix.
7a0196f [Liang-Chi Hsieh] Fix python style.
ac2bacd [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
a0a2d0f [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
4cb764d [Liang-Chi Hsieh] For comments.
0f78682 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
c0c3197 [Liang-Chi Hsieh] Add bin to FunctionRegistry.
824f761 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_bin
50e0c3b [Liang-Chi Hsieh] Add math function bin(a: long): string.

Otherwise, extra params get ignored in `PipelineModel.transform`. jkbradley

Author: Xiangrui Meng <meng@databricks.com>

Closes #6622 from mengxr/SPARK-8087 and squashes the following commits:

0e4c8c4 [Xiangrui Meng] fix merge issues
26fc1f0 [Xiangrui Meng] address comments
e607a04 [Xiangrui Meng] merge master
b85b57e [Xiangrui Meng] fix examples/compile
d6f7891 [Xiangrui Meng] rename defaultCopyWithParams to defaultCopy
84ec278 [Xiangrui Meng] remove setter checks due to generics
2cf2ed0 [Xiangrui Meng] snapshot
291814f [Xiangrui Meng] OneVsRest.copy
1dfe3bd [Xiangrui Meng] PipelineModel.copy should copy stages

…f the existing java direct stream api

Author: cody koeninger <cody@koeninger.org>

Closes #6846 from koeninger/SPARK-8389 and squashes the following commits:

3f3c57a [cody koeninger] [Streaming][Kafka][SPARK-8389] Example of getting offset ranges out of the existing java direct stream api

Please review this pull request.

Author: Jihong MA <linlin200605@gmail.com>

Closes #5933 from JihongMA/SPARK-7265 and squashes the following commits:

dfaa971 [Jihong MA] SPARK-7265 minor fix of the content
ace454d [Jihong MA] SPARK-7265 take out PySpark on YARN limitation
9ea0832 [Jihong MA] Merge remote-tracking branch 'upstream/master'
d5bf3f5 [Jihong MA] Merge remote-tracking branch 'upstream/master'
7b842e6 [Jihong MA] Merge remote-tracking branch 'upstream/master'
9c84695 [Jihong MA] SPARK-7265 address review comment
a399aa6 [Jihong MA] SPARK-7265 Improving documentation for Spark SQL Hive support

[SPARK-7913] [CORE] Make AppendOnlyMap use the same growth strategy of OpenHashSet and consistent exception message

This is a follow up PR for #6456 to make AppendOnlyMap consistent with OpenHashSet.

/cc srowen andrewor14

Author: zsxwing <zsxwing@gmail.com>

Closes #6879 from zsxwing/append-only-map and squashes the following commits:

912c0ad [zsxwing] Fix the doc
dd4385b [zsxwing] Make AppendOnlyMap use the same growth strategy of OpenHashSet and consistent exception message

This is to follow up #6834 , update the driver log URL as well for consistency.

Author: Carson Wang <carson.wang@intel.com>

Closes #6878 from carsonwang/logUrl and squashes the following commits:

13be948 [Carson Wang] update log URL in YarnClusterSuite
a0004f4 [Carson Wang] Update driver log URL to show only 4096 bytes

Itertools islice requires an integer for the stop argument.  Switching to integer division here prevents a ValueError when vs is evaluated above.

davies

This is my original work, and I license it to the project.

Author: Kevin Conor <kevin@discoverybayconsulting.com>

Closes #6794 from kconor/kconor-patch-1 and squashes the following commits:

da5e700 [Kevin Conor] Integer division for batch size

A Python example similar to the existing one for Scala.

Author: Bryan Cutler <bjcutler@us.ibm.com>

Closes #6884 from BryanCutler/streaming-queueStream-example-8444 and squashes the following commits:

435ba7e [Bryan Cutler] [SPARK-8444] Fixed style checks, increased sleep time to show empty queue
257abb0 [Bryan Cutler] [SPARK-8444] Stop context gracefully, Removed unused import, Added description comment
376ef6e [Bryan Cutler] [SPARK-8444] Fixed bug causing DStream.pprint to append empty parenthesis to output instead of blank line
1ff5f8b [Bryan Cutler] [SPARK-8444] Adding Python streaming example for queue_stream

I have added it for only Scala.

TODO: we should also support `in` operator in Python.

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

Closes #6824 from yu-iskw/SPARK-8348 and squashes the following commits:

e76d02f [Yu ISHIKAWA] Not use infix notation
6f744ac [Yu ISHIKAWA] Fit the test cases because these used the old test data set.
00077d3 [Yu ISHIKAWA] [SPARK-8348][SQL] Add in operator to DataFrame Column

`Path.toUri.getPath` strips scheme part of output path (from `file:///foo` to `/foo`), which causes ORC data source only writes to the file system configured in Hadoop configuration. Should use `Path.toString` instead.

Author: Cheng Lian <lian@databricks.com>

Closes #6892 from liancheng/spark-8458 and squashes the following commits:

87f8199 [Cheng Lian] Don't strip scheme of output path when writing ORC files

tdas  zsxwing this is the new PR for Spark-8080

I have merged https://github.com/apache/spark/pull/6659

Also to mention , for MEMORY_ONLY settings , when Block is not able to unrollSafely to memory if enough space is not there, BlockManager won't try to put the block and ReceivedBlockHandler will throw SparkException as it could not find the block id in PutResult. Thus number of records in block won't be counted if Block failed to unroll in memory. Which is fine.

For MEMORY_DISK settings , if BlockManager not able to unroll block to memory, block will still get deseralized to Disk. Same for WAL based store. So for those cases ( storage level = memory + disk )  number of records will be counted even though the block not able to unroll to memory.

thus I added the isFullyConsumed in the CountingIterator but have not used it as such case will never happen that block not fully consumed and ReceivedBlockHandler still get the block ID.

I have added few test cases to cover those block unrolling scenarios also.

Author: Dibyendu Bhattacharya <dibyendu.bhattacharya1@pearson.com>
Author: U-PEROOT\UBHATD1 <UBHATD1@PIN-L-PI046.PEROOT.com>

Closes #6707 from dibbhatt/master and squashes the following commits:

f6cb6b5 [Dibyendu Bhattacharya] [SPARK-8080][STREAMING] Receiver.store with Iterator does not give correct count at Spark UI
f37cfd8 [Dibyendu Bhattacharya] [SPARK-8080][STREAMING] Receiver.store with Iterator does not give correct count at Spark UI
5a8344a [Dibyendu Bhattacharya] [SPARK-8080][STREAMING] Receiver.store with Iterator does not give correct count at Spark UI Count ByteBufferBlock as 1 count
fceac72 [Dibyendu Bhattacharya] [SPARK-8080][STREAMING] Receiver.store with Iterator does not give correct count at Spark UI
0153e7e [Dibyendu Bhattacharya] [SPARK-8080][STREAMING] Receiver.store with Iterator does not give correct count at Spark UI Fixed comments given by @zsxwing
4c5931d [Dibyendu Bhattacharya] [SPARK-8080][STREAMING] Receiver.store with Iterator does not give correct count at Spark UI
01e6dc8 [U-PEROOT\UBHATD1] A

This fixes various minor documentation issues on the Spark SQL page

Author: Lars Francke <lars.francke@gmail.com>

Closes #6890 from lfrancke/SPARK-8462 and squashes the following commits:

dd7e302 [Lars Francke] Merge branch 'master' into SPARK-8462
34eff2c [Lars Francke] Minor documentation fixes

Author: Sandy Ryza <sandy@cloudera.com>

Closes #6679 from sryza/sandy-spark-8135 and squashes the following commits:

c5554ff [Sandy Ryza] SPARK-8135. In SerializableWritable, don't load defaults when instantiating Configuration

Some minor updates based on after merging #6725.

Author: Reynold Xin <rxin@databricks.com>

Closes #6871 from rxin/log and squashes the following commits:

ab51542 [Reynold Xin] Use JVM log
76fc8de [Reynold Xin] Fixed arg.
a7c1522 [Reynold Xin] [SPARK-8218][SQL] Binary log math function update.

This patch introduces `SparkPlanTest`, a base class for unit tests of SparkPlan physical operators.  This is analogous to Spark SQL's existing `QueryTest`, which does something similar for end-to-end tests with actual queries.

These helper methods provide nicer error output when tests fail and help developers to avoid writing lots of boilerplate in order to execute manually constructed physical plans.

Author: Josh Rosen <joshrosen@databricks.com>
Author: Josh Rosen <rosenville@gmail.com>
Author: Michael Armbrust <michael@databricks.com>

Closes #6885 from JoshRosen/spark-plan-test and squashes the following commits:

f8ce275 [Josh Rosen] Fix some IntelliJ inspections and delete some dead code
84214be [Josh Rosen] Add an extra column which isn't part of the sort
ae1896b [Josh Rosen] Provide implicits automatically
a80f9b0 [Josh Rosen] Merge pull request #4 from marmbrus/pr/6885
d9ab1e4 [Michael Armbrust] Add simple resolver
c60a44d [Josh Rosen] Manually bind references
996332a [Josh Rosen] Add types so that tests compile
a46144a [Josh Rosen] WIP

Commons Lang 3 has been added as one of the dependencies of Spark Flume Sink since #5703. This PR updates the doc for it.

Author: zsxwing <zsxwing@gmail.com>

Closes #6829 from zsxwing/flume-sink-dep and squashes the following commits:

f8617f0 [zsxwing] Add common lang3 to the Spark Flume Sink doc

This patch uses [AnchorJS](https://bryanbraun.github.io/anchorjs/) to show deep anchor links when hovering over headers in the Spark documentation. For example:

![image](https://cloud.githubusercontent.com/assets/50748/8240800/1502f85c-15ba-11e5-819a-97b231370a39.png)

This makes it easier for users to link to specific sections of the documentation.

I also removed some dead Javascript which isn't used in our current docs (it was introduced for the old AMPCamp training, but isn't used anymore).

Author: Josh Rosen <joshrosen@databricks.com>

Closes #6808 from JoshRosen/SPARK-8353 and squashes the following commits:

e59d8a7 [Josh Rosen] Suppress underline on hover
f518b6a [Josh Rosen] Turn on for all headers, since we use H1s in a bunch of places
a9fec01 [Josh Rosen] Add anchor links when hovering over headers; remove some dead JS code

The batch size during external sort will grow up to max 10000, then shrink down to zero, causing infinite loop.
Given the assumption that the items usually have similar size, so we don't need to adjust the batch size after first spill.

cc JoshRosen rxin angelini

Author: Davies Liu <davies@databricks.com>

Closes #6714 from davies/batch_size and squashes the following commits:

b170dfb [Davies Liu] update test
b9be832 [Davies Liu] Merge branch 'batch_size' of github.com:davies/spark into batch_size
6ade745 [Davies Liu] update test
5c21777 [Davies Liu] Update shuffle.py
e746aec [Davies Liu] fix batch size during sort

JIRA: https://issues.apache.org/jira/browse/SPARK-8363

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

Closes #6823 from viirya/move_sqrt and squashes the following commits:

8977e11 [Liang-Chi Hsieh] Remove unnecessary old tests.
d23e79e [Liang-Chi Hsieh] Explicitly indicate sqrt value sequence.
699f48b [Liang-Chi Hsieh] Use correct @since tag.
8dff6d1 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into move_sqrt
bc2ed77 [Liang-Chi Hsieh] Remove/move arithmetic expression test and expression type checking test. Remove unnecessary Sqrt type rule.
d38492f [Liang-Chi Hsieh] Now sqrt accepts boolean because type casting is handled by HiveTypeCoercion.
297cc90 [Liang-Chi Hsieh] Sqrt only accepts double input.
ef4a21a [Liang-Chi Hsieh] Move sqrt to math.

[SPARK-8320] [STREAMING] Add example in streaming programming guide that shows union of multiple input streams

Added python code to https://spark.apache.org/docs/latest/streaming-programming-guide.html
to the Level of Parallelism in Data Receiving section.

Please review and let me know if there are any additional changes that are needed.

Thank you.

Author: Neelesh Srinivas Salian <nsalian@cloudera.com>

Closes #6862 from nssalian/SPARK-8320 and squashes the following commits:

4bfd126 [Neelesh Srinivas Salian] Changed loop structure to be more in line with Python style
e5345de [Neelesh Srinivas Salian] Changes to kafak append, for loop and show to print()
3fc5c6d [Neelesh Srinivas Salian] SPARK-8320

This PR aimed to resolve udf_struct test failure in HiveCompatibilitySuite.

Currently, this is done by loosening CreateStruct's children type from NamedExpression to Expression and automatically generating StructField name for non-NamedExpression children.

The naming convention for unnamed children follows the udf's counterpart in Hive:
`col1, col2, col3, ...`

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

Closes #6828 from yijieshen/SPARK-8283 and squashes the following commits:

6052b73 [Yijie Shen] Doc fix
677e0b7 [Yijie Shen] Resolve udf_struct test failure by automatically generate structField name for non-NamedExpression children

JIRA: https://issues.apache.org/jira/browse/SPARK-8218

Because there is already `log` unary function defined, the binary log function is called `logarithm` for now.

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

Closes #6725 from viirya/expr_binary_log and squashes the following commits:

bf96bd9 [Liang-Chi Hsieh] Compare log result in string.
102070d [Liang-Chi Hsieh] Round log result to better comparing in python test.
fd01863 [Liang-Chi Hsieh] For comments.
beed631 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_binary_log
6089d11 [Liang-Chi Hsieh] Remove unnecessary override.
8cf37b7 [Liang-Chi Hsieh] For comments.
bc89597 [Liang-Chi Hsieh] For comments.
db7dc38 [Liang-Chi Hsieh] Use ctor instead of companion object.
0634ef7 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_binary_log
1750034 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_binary_log
3d75bfc [Liang-Chi Hsieh] Fix scala style.
5b39c02 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_binary_log
23c54a3 [Liang-Chi Hsieh] Fix scala style.
ebc9929 [Liang-Chi Hsieh] Let Logarithm accept one parameter too.
605574d [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_binary_log
21c3bfd [Liang-Chi Hsieh] Fix scala style.
c6c187f [Liang-Chi Hsieh] For comments.
c795342 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into expr_binary_log
f373bac [Liang-Chi Hsieh] Add binary log expression.

1. Add `SQLConfEntry` to store the information about a configuration. For those configurations that cannot be found in `sql-programming-guide.md`, I left the doc as `<TODO>`.
2. Verify the value when setting a configuration if this is in SQLConf.
3. Use `SET -v` to display all public configurations.

Author: zsxwing <zsxwing@gmail.com>

Closes #6747 from zsxwing/sqlconf and squashes the following commits:

7d09bad [zsxwing] Use SQLConfEntry in HiveContext
49f6213 [zsxwing] Add getConf, setConf to SQLContext and HiveContext
e014f53 [zsxwing] Merge branch 'master' into sqlconf
93dad8e [zsxwing] Fix the unit tests
cf950c1 [zsxwing] Fix the code style and tests
3c5f03e [zsxwing] Add unsetConf(SQLConfEntry) and fix the code style
a2f4add [zsxwing] getConf will return the default value if a config is not set
037b1db [zsxwing] Add schema to SetCommand
0520c3c [zsxwing] Merge branch 'master' into sqlconf
7afb0ec [zsxwing] Fix the configurations about HiveThriftServer
7e728e3 [zsxwing] Add doc for SQLConfEntry and fix 'toString'
5e95b10 [zsxwing] Add enumConf
c6ba76d [zsxwing] setRawString => setConfString, getRawString => getConfString
4abd807 [zsxwing] Fix the test for 'set -v'
6e47e56 [zsxwing] Fix the compilation error
8973ced [zsxwing] Remove floatConf
1fc3a8b [zsxwing] Remove the 'conf' command and use 'set -v' instead
99c9c16 [zsxwing] Fix tests that use SQLConfEntry as a string
88a03cc [zsxwing] Add new lines between confs and return types
ce7c6c8 [zsxwing] Remove seqConf
f3c1b33 [zsxwing] Refactor SQLConf to display better error message

reuse-typeConvert when convert Seq[Row] to CatalystType

Author: Lianhui Wang <lianhuiwang09@gmail.com>

Closes #6831 from lianhuiwang/reuse-typeConvert and squashes the following commits:

1fec395 [Lianhui Wang] remove CatalystTypeConverters.convertToCatalyst
714462d [Lianhui Wang] add package[sql]
9d1fbf3 [Lianhui Wang] address JoshRosen's comments
768956f [Lianhui Wang] update scala style
4498c62 [Lianhui Wang] reuse typeConvert

Dependencies of artifacts in the local ivy cache were not being resolved properly. The dependencies were not being picked up. Now they should be.

cc andrewor14

Author: Burak Yavuz <brkyvz@gmail.com>

Closes #6788 from brkyvz/local-ivy-fix and squashes the following commits:

2875bf4 [Burak Yavuz] fix temp dir bug
48cc648 [Burak Yavuz] improve deletion
a69e3e6 [Burak Yavuz] delete cache before test as well
0037197 [Burak Yavuz] fix merge conflicts
f60772c [Burak Yavuz] use different folder for m2 cache during testing
b6ef038 [Burak Yavuz] [SPARK-8095] Resolve dependencies of Spark Packages in local ivy cache

```def getAllNodes: Seq[RDDOperationNode] =
{ _childNodes ++ _childClusters.flatMap(_.childNodes) }```

when the ```_childClusters``` has so many nodes, the process will hang on. I think we can improve the efficiency here.

Author: xutingjun <xutingjun@huawei.com>

Closes #6839 from XuTingjun/DAGImprove and squashes the following commits:

53b03ea [xutingjun] change code to more concise and easier to read
f98728b [xutingjun] fix words: node -> nodes
f87c663 [xutingjun] put the filter inside
81f9fd2 [xutingjun] put the filter inside

Python API for org.apache.spark.mllib.feature.ElementwiseProduct

Author: MechCoder <manojkumarsivaraj334@gmail.com>

Closes #6346 from MechCoder/spark-7605 and squashes the following commits:

79d1ef5 [MechCoder] Consistent and support list / array types
5f81d81 [MechCoder] [SPARK-7605] [MLlib] Python API for ElementwiseProduct

This is a follow-up PR to remove unused `PythonRDD.emptyRDD` added by #6826

Author: zsxwing <zsxwing@gmail.com>

Closes #6867 from zsxwing/remove-PythonRDD-emptyRDD and squashes the following commits:

b66d363 [zsxwing] Remove PythonRDD.emptyRDD

We encourage people to use TestHive in unit tests, because it's
impossible to create more than one HiveContext within one process. The
current implementation locks people into using a local[2] SparkContext
underlying their HiveContext.  We should make it possible to override
this using a system property so that people can test against
local-cluster or remote spark clusters to make their tests more
realistic.

Author: Punya Biswal <pbiswal@palantir.com>

Closes #6844 from punya/feature/SPARK-8397 and squashes the following commits:

97ef394 [Punya Biswal] [SPARK-8397][SQL] Allow custom configuration for TestHive

KafkaStreamSuite, DirectKafkaStreamSuite, JavaKafkaStreamSuite and JavaDirectKafkaStreamSuite use non-thread-safe collections to collect data in one thread and check it in another thread. It may fail the tests.

This PR changes them to thread-safe collections.

Note: I cannot reproduce the test failures in my environment. But at least, this PR should make the tests more reliable.

Author: zsxwing <zsxwing@gmail.com>

Closes #6852 from zsxwing/fix-KafkaStreamSuite and squashes the following commits:

d464211 [zsxwing] Use thread-safe collections to make the tests more reliable

[SPARK-8306] [SQL] AddJar command needs to set the new class loader to the HiveConf inside executionHive.state.

https://issues.apache.org/jira/browse/SPARK-8306

I will try to add a test later.

marmbrus aarondav

Author: Yin Huai <yhuai@databricks.com>

Closes #6758 from yhuai/SPARK-8306 and squashes the following commits:

1292346 [Yin Huai] [SPARK-8306] AddJar command needs to set the new class loader to the HiveConf inside executionHive.state.

This PR is a improvement for https://github.com/apache/spark/pull/5189.

The resolution rule for ORDER BY is: first resolve based on what comes from the select clause and then fall back on its child only when this fails.

There are 2 steps. First, try to resolve `Sort` in `ResolveReferences` based on select clause, and ignore exceptions. Second, try to resolve `Sort` in `ResolveSortReferences` and add missing projection.

However, the way we resolve `SortOrder` is wrong. We just resolve `UnresolvedAttribute` and use the result to indicate if we can resolve `SortOrder`. But `UnresolvedAttribute` is only part of `GetField` chain(broken by `GetItem`), so we need to go through the whole chain to indicate if we can resolve `SortOrder`.

With this change, we can also avoid re-throw GetField exception in `CheckAnalysis` which is little ugly.

Author: Wenchen Fan <cloud0fan@outlook.com>

Closes #5659 from cloud-fan/order-by and squashes the following commits:

cfa79f8 [Wenchen Fan] update test
3245d28 [Wenchen Fan] minor improve
465ee07 [Wenchen Fan] address comment
1fc41a2 [Wenchen Fan] fix SPARK-7067

[SPARK-7913] [CORE] Increase the maximum capacity of PartitionedPairBuffe, PartitionedSerializedPairBuffer and AppendOnlyMap

The previous growing strategy is alway doubling the capacity.

This PR adjusts the growing strategy: doubling the capacity but if overflow, use the maximum capacity as the new capacity. It increases the maximum capacity of PartitionedPairBuffer from `2 ^ 29` to `2 ^ 30 - 1`, the maximum capacity of PartitionedSerializedPairBuffer from `2 ^ 28` to `(2 ^ 29) - 1`, and the maximum capacity of AppendOnlyMap from `0.7 * (2 ^ 29)` to `(2 ^ 29)`.

Author: zsxwing <zsxwing@gmail.com>

Closes #6456 from zsxwing/SPARK-7913 and squashes the following commits:

abcb932 [zsxwing] Address comments
e30b61b [zsxwing] Increase the maximum capacity of AppendOnlyMap
05b6420 [zsxwing] Update the exception message
64fe227 [zsxwing] Increase the maximum capacity of PartitionedPairBuffer and PartitionedSerializedPairBuffer

This PR fixes the sum issue and also adds `emptyRDD` so that it's easy to create a test case.

Author: zsxwing <zsxwing@gmail.com>

Closes #6826 from zsxwing/python-emptyRDD and squashes the following commits:

b36993f [zsxwing] Update the return type to JavaRDD[T]
71df047 [zsxwing] Add emptyRDD to pyspark and fix the issue when calling sum on an empty RDD

The history server may show an incorrect App ID for an incomplete application like <App ID>.inprogress. This app info will never disappear even after the app is completed.
![incorrectappinfo](https://cloud.githubusercontent.com/assets/9278199/8156147/2a10fdbe-137d-11e5-9620-c5b61d93e3c1.png)

The cause of the issue is that a log path name is used as the app id when app id cannot be got during replay.

Author: Carson Wang <carson.wang@intel.com>

Closes #6827 from carsonwang/SPARK-8372 and squashes the following commits:

cdbb089 [Carson Wang] Fix code style
3e46b35 [Carson Wang] Update code style
90f5dde [Carson Wang] Add a unit test
d8c9cd0 [Carson Wang] Replaying events only return information when app is started