## What changes were proposed in this pull request?
Made BinaryClassificationEvaluator, MulticlassClassificationEvaluator and RegressionEvaluator accept all numeric types for label
## How was this patch tested?
Unit tests
Author: BenFradet <benjamin.fradet@gmail.com>
Closes#12500 from BenFradet/SPARK-13962.
## What changes were proposed in this pull request?
In Spark 2.0, `SparkSession` is the new thing. Internally we should stop using `SQLContext` everywhere since that's supposed to be not the main user-facing API anymore.
In this patch I took care to not break any public APIs. The one place that's suspect is `o.a.s.ml.source.libsvm.DefaultSource`, but according to mengxr it's not supposed to be public so it's OK to change the underlying `FileFormat` trait.
**Reviewers**: This is a big patch that may be difficult to review but the changes are actually really straightforward. If you prefer I can break it up into a few smaller patches, but it will delay the progress of this issue a little.
## How was this patch tested?
No change in functionality intended.
Author: Andrew Or <andrew@databricks.com>
Closes#12625 from andrewor14/spark-session-refactor.
## What changes were proposed in this pull request?
This is for users who can't upgrade and need to continue to use HiveContext.
## How was this patch tested?
Added some basic tests for sanity check.
This is based on #12672 and closes#12672.
Author: Andrew Or <andrew@databricks.com>
Author: Reynold Xin <rxin@databricks.com>
Closes#12682 from rxin/add-back-hive-context.
## What changes were proposed in this pull request?
Minor followup to https://github.com/apache/spark/pull/12651
## How was this patch tested?
Test-only change
Author: Sameer Agarwal <sameer@databricks.com>
Closes#12674 from sameeragarwal/tpcds-fix-2.
## What changes were proposed in this pull request?
`RuntimeConfig` is the new user-facing API in 2.0 added in #11378. Until now, however, it's been dead code. This patch uses `RuntimeConfig` in `SessionState` and exposes that through the `SparkSession`.
## How was this patch tested?
New test in `SQLContextSuite`.
Author: Andrew Or <andrew@databricks.com>
Closes#12669 from andrewor14/use-runtime-conf.
## What changes were proposed in this pull request?
This patch changes UnresolvedFunction and UnresolvedGenerator to use a FunctionIdentifier rather than just a String for function name. Also changed SessionCatalog to accept FunctionIdentifier in lookupFunction.
## How was this patch tested?
Updated related unit tests.
Author: Reynold Xin <rxin@databricks.com>
Closes#12659 from rxin/SPARK-14888.
## What changes were proposed in this pull request?
```
Spark context available as 'sc' (master = local[*], app id = local-1461283768192).
Spark session available as 'spark'.
Welcome to
____ __
/ __/__ ___ _____/ /__
_\ \/ _ \/ _ `/ __/ '_/
/___/ .__/\_,_/_/ /_/\_\ version 2.0.0-SNAPSHOT
/_/
Using Scala version 2.11.8 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_51)
Type in expressions to have them evaluated.
Type :help for more information.
scala> sql("SHOW TABLES").collect()
16/04/21 17:09:39 WARN ObjectStore: Version information not found in metastore. hive.metastore.schema.verification is not enabled so recording the schema version 1.2.0
16/04/21 17:09:39 WARN ObjectStore: Failed to get database default, returning NoSuchObjectException
res0: Array[org.apache.spark.sql.Row] = Array([src,false])
scala> sql("SHOW TABLES").collect()
res1: Array[org.apache.spark.sql.Row] = Array([src,false])
scala> spark.createDataFrame(Seq((1, 1), (2, 2), (3, 3)))
res2: org.apache.spark.sql.DataFrame = [_1: int, _2: int]
```
Hive things are loaded lazily.
## How was this patch tested?
Manual.
Author: Andrew Or <andrew@databricks.com>
Closes#12589 from andrewor14/spark-session-repl.
## What changes were proposed in this pull request?
SparkR ```NaiveBayesModel``` supports ```save/load``` by the following API:
```
df <- createDataFrame(sqlContext, infert)
model <- naiveBayes(education ~ ., df, laplace = 0)
ml.save(model, path)
model2 <- ml.load(path)
```
## How was this patch tested?
Add unit tests.
cc mengxr
Author: Yanbo Liang <ybliang8@gmail.com>
Closes#12573 from yanboliang/spark-14312.
#### What changes were proposed in this pull request?
For performance, predicates can be pushed through Window if and only if the following conditions are satisfied:
1. All the expressions are part of window partitioning key. The expressions can be compound.
2. Deterministic
#### How was this patch tested?
TODO:
- [X] DSL needs to be modified for window
- [X] more tests will be added.
Author: gatorsmile <gatorsmile@gmail.com>
Author: xiaoli <lixiao1983@gmail.com>
Author: Xiao Li <xiaoli@Xiaos-MacBook-Pro.local>
Closes#11635 from gatorsmile/pushPredicateThroughWindow.
## What changes were proposed in this pull request?
This removes the class `HiveContext` itself along with all code usages associated with it. The bulk of the work was already done in #12485. This is mainly just code cleanup and actually removing the class.
Note: A couple of things will break after this patch. These will be fixed separately.
- the python HiveContext
- all the documentation / comments referencing HiveContext
- there will be no more HiveContext in the REPL (fixed by #12589)
## How was this patch tested?
No change in functionality.
Author: Andrew Or <andrew@databricks.com>
Closes#12585 from andrewor14/delete-hive-context.
## What changes were proposed in this pull request?
SPARK-12130 make 2.0 shuffle service incompatible with 1.x. So from discussion: [http://apache-spark-developers-list.1001551.n3.nabble.com/YARN-Shuffle-service-and-its-compatibility-td17222.html](url) we should maintain compatibility between Spark 1.x and Spark 2.x's shuffle service.
I put string comparison into executor's register at first avoid string comparison in getBlockData every time.
## How was this patch tested?
N/A
Author: Lianhui Wang <lianhuiwang09@gmail.com>
Closes#12568 from lianhuiwang/SPARK-14731.
## What changes were proposed in this pull request?
As the discussion at [SPARK-10574](https://issues.apache.org/jira/browse/SPARK-10574), ```HashingTF``` should support MurmurHash3 and make it as the default hash algorithm. We should also expose set/get API for ```hashAlgorithm```, then users can choose the hash method.
Note: The problem that ```mllib.feature.HashingTF``` behaves differently between Scala/Java and Python will be resolved in the followup work.
## How was this patch tested?
unit tests.
cc jkbradley MLnick
Author: Yanbo Liang <ybliang8@gmail.com>
Author: Joseph K. Bradley <joseph@databricks.com>
Closes#12498 from yanboliang/spark-10574.
#### What changes were proposed in this pull request?
Disable the test case involving INPUTDRIVER and OUTPUTDRIVER, which are not supported
#### How was this patch tested?
N/A
Author: gatorsmile <gatorsmile@gmail.com>
Closes#12662 from gatorsmile/disableInOutDriver.
## What changes were proposed in this pull request?
Removed instances of JavaMLWriter, JavaMLReader appearing in public Python API docs
## How was this patch tested?
n/a
Author: Joseph K. Bradley <joseph@databricks.com>
Closes#12542 from jkbradley/javamlwriter-doc.
## What changes were proposed in this pull request?
Add Python API in ML for GaussianMixture
## How was this patch tested?
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
Add doctest and test cases are the same as mllib Python tests
./dev/lint-python
PEP8 checks passed.
rm -rf _build/*
pydoc checks passed.
./python/run-tests --python-executables=python2.7 --modules=pyspark-ml
Running PySpark tests. Output is in /Users/mwang/spark_ws_0904/python/unit-tests.log
Will test against the following Python executables: ['python2.7']
Will test the following Python modules: ['pyspark-ml']
Finished test(python2.7): pyspark.ml.evaluation (18s)
Finished test(python2.7): pyspark.ml.clustering (40s)
Finished test(python2.7): pyspark.ml.classification (49s)
Finished test(python2.7): pyspark.ml.recommendation (44s)
Finished test(python2.7): pyspark.ml.feature (64s)
Finished test(python2.7): pyspark.ml.regression (45s)
Finished test(python2.7): pyspark.ml.tuning (30s)
Finished test(python2.7): pyspark.ml.tests (56s)
Tests passed in 106 seconds
Author: wm624@hotmail.com <wm624@hotmail.com>
Closes#12402 from wangmiao1981/gmm.
First, make all dependencies in the examples module provided, and explicitly
list a couple of ones that somehow are promoted to compile by maven. This
means that to run streaming examples, the streaming connector package needs
to be provided to run-examples using --packages or --jars, just like regular
apps.
Also, remove a couple of outdated examples. HBase has had Spark bindings for
a while and is even including them in the HBase distribution in the next
version, making the examples obsolete. The same applies to Cassandra, which
seems to have a proper Spark binding library already.
I just tested the build, which passes, and ran SparkPi. The examples jars
directory now has only two jars:
```
$ ls -1 examples/target/scala-2.11/jars/
scopt_2.11-3.3.0.jar
spark-examples_2.11-2.0.0-SNAPSHOT.jar
```
Author: Marcelo Vanzin <vanzin@cloudera.com>
Closes#12544 from vanzin/SPARK-14744.
## What changes were proposed in this pull request?
Removed expectedType arg from PySpark Param __init__, as suggested by the JIRA.
## How was this patch tested?
Manually looked through all places that use Param. Compiled and ran all ML PySpark test cases before and after the fix.
Author: Jason Lee <cjlee@us.ibm.com>
Closes#12581 from jasoncl/SPARK-14768.
## What changes were proposed in this pull request?
This method was accidentally made `private[sql]` in Spark 2.0. This PR makes it public again, since 3rd party data sources like spark-avro depend on it.
## How was this patch tested?
N/A
Author: Cheng Lian <lian@databricks.com>
Closes#12652 from liancheng/spark-14875.
## What changes were proposed in this pull request?
Implement the same memory size validations for the StaticMemoryManager (Legacy) as the UnifiedMemoryManager has.
## How was this patch tested?
Manual tests were done in CDH cluster.
Test with small executor memory:
`
spark-submit --class org.apache.spark.examples.SparkPi --deploy-mode client --master yarn --executor-memory 15m --conf spark.memory.useLegacyMode=true /opt/cloudera/parcels/CDH/lib/spark/examples/lib/spark-examples*.jar 10
`
Exception thrown:
```
ERROR spark.SparkContext: Error initializing SparkContext.
java.lang.IllegalArgumentException: Executor memory 15728640 must be at least 471859200. Please increase executor memory using the --executor-memory option or spark.executor.memory in Spark configuration.
at org.apache.spark.memory.StaticMemoryManager$.org$apache$spark$memory$StaticMemoryManager$$getMaxExecutionMemory(StaticMemoryManager.scala:127)
at org.apache.spark.memory.StaticMemoryManager.<init>(StaticMemoryManager.scala:46)
at org.apache.spark.SparkEnv$.create(SparkEnv.scala:352)
at org.apache.spark.SparkEnv$.createDriverEnv(SparkEnv.scala:193)
at org.apache.spark.SparkContext.createSparkEnv(SparkContext.scala:289)
at org.apache.spark.SparkContext.<init>(SparkContext.scala:462)
at org.apache.spark.examples.SparkPi$.main(SparkPi.scala:29)
at org.apache.spark.examples.SparkPi.main(SparkPi.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:731)
at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:181)
at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:206)
at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:121)
at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
```
Author: Peter Ableda <peter.ableda@cloudera.com>
Closes#12395 from peterableda/SPARK-14636.
## What changes were proposed in this pull request?
add the checking for StepSize and Tol in sharedParams
## How was this patch tested?
Unit tests
Author: Zheng RuiFeng <ruifengz@foxmail.com>
Closes#12530 from zhengruifeng/ml_args_checking.
## What changes were proposed in this pull request?
Sbt compile and test should also run scalastyle. This makes it less likely you forget to run scalastyle and fail in jenkins. Scalastyle results are cached for efficiency.
This patch was originally written by ahirreddy; I just fixed it up to work with scalastyle 0.8.0.
## How was this patch tested?
Tested manually with `build/sbt package`.
Author: Eric Liang <ekl@databricks.com>
Closes#12555 from ericl/scalastyle.
## What changes were proposed in this pull request?
This PR fixes a bug in `TungstenAggregate` that manifests while aggregating by keys over nullable `BigDecimal` columns. This causes a null pointer exception while executing TPCDS q14a.
## How was this patch tested?
1. Added regression test in `DataFrameAggregateSuite`.
2. Verified that TPCDS q14a works
Author: Sameer Agarwal <sameer@databricks.com>
Closes#12651 from sameeragarwal/tpcds-fix.
## What changes were proposed in this pull request?
Change default logging to WARN for pyspark shell and sparkR shell for a much cleaner environment.
## How was this patch tested?
Manually running pyspark and sparkR shell
Author: felixcheung <felixcheung_m@hotmail.com>
Closes#12648 from felixcheung/pylogging.
## What changes were proposed in this pull request?
This issue aims to fix some errors in R examples and make them up-to-date in docs and example modules.
- Remove the wrong usage of `map`. We need to use `lapply` in `sparkR` if needed. However, `lapply` is private so far. The corrected example will be added later.
- Fix the wrong example in Section `Generic Load/Save Functions` of `docs/sql-programming-guide.md` for consistency
- Fix datatypes in `sparkr.md`.
- Update a data result in `sparkr.md`.
- Replace deprecated functions to remove warnings: jsonFile -> read.json, parquetFile -> read.parquet
- Use up-to-date R-like functions: loadDF -> read.df, saveDF -> write.df, saveAsParquetFile -> write.parquet
- Replace `SparkR DataFrame` with `SparkDataFrame` in `dataframe.R` and `data-manipulation.R`.
- Other minor syntax fixes and a typo.
## How was this patch tested?
Manual.
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#12649 from dongjoon-hyun/SPARK-14883.
## What changes were proposed in this pull request?
Right now, the data type field of a CatalogColumn is using the string representation. When we create this string from a DataType object, there are places where we use simpleString instead of catalogString. Although catalogString is the same as simpleString right now, it is still good to use catalogString. So, we will not silently introduce issues when we change the semantic of simpleString or the implementation of catalogString.
## How was this patch tested?
Existing tests.
Author: Yin Huai <yhuai@databricks.com>
Closes#12654 from yhuai/useCatalogString.
## What changes were proposed in this pull request?
Spark uses `NewLineAtEofChecker` rule in Scala by ScalaStyle. And, most Java code also comply with the rule. This PR aims to enforce the same rule `NewlineAtEndOfFile` by CheckStyle explicitly. Also, this fixes lint-java errors since SPARK-14465. The followings are the items.
- Adds a new line at the end of the files (19 files)
- Fixes 25 lint-java errors (12 RedundantModifier, 6 **ArrayTypeStyle**, 2 LineLength, 2 UnusedImports, 2 RegexpSingleline, 1 ModifierOrder)
## How was this patch tested?
After the Jenkins test succeeds, `dev/lint-java` should pass. (Currently, Jenkins dose not run lint-java.)
```bash
$ dev/lint-java
Using `mvn` from path: /usr/local/bin/mvn
Checkstyle checks passed.
```
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#12632 from dongjoon-hyun/SPARK-14868.
## What changes were proposed in this pull request?
This patch changes SparkSession to be case insensitive by default, in order to match other database systems.
## How was this patch tested?
N/A - I'm sure some tests will fail and I will need to fix those.
Author: Reynold Xin <rxin@databricks.com>
Closes#12643 from rxin/SPARK-14876.
!< means not less than which is equivalent to >=
!> means not greater than which is equivalent to <=
I'd to create a PR to support these two operators.
I've added new test cases in: DataFrameSuite, ExpressionParserSuite, JDBCSuite, PlanParserSuite, SQLQuerySuite
dilipbiswal viirya gatorsmile
Author: jliwork <jiali@us.ibm.com>
Closes#12316 from jliwork/SPARK-14548.
#### What changes were proposed in this pull request?
So far, we are capturing each unsupported Alter Table in separate visit functions. They should be unified and issue the same ParseException instead.
This PR is to refactor the existing implementation and make error message consistent for Alter Table DDL.
#### How was this patch tested?
Updated the existing test cases and also added new test cases to ensure all the unsupported statements are covered.
Author: gatorsmile <gatorsmile@gmail.com>
Author: xiaoli <lixiao1983@gmail.com>
Author: Xiao Li <xiaoli@Xiaos-MacBook-Pro.local>
Closes#12459 from gatorsmile/cleanAlterTable.
## What changes were proposed in this pull request?
Added screenshot + minor fixes to improve reading
## How was this patch tested?
Manual
Author: Jacek Laskowski <jacek@japila.pl>
Closes#12569 from jaceklaskowski/docs-accumulators.
Add to the REST API details on the ? args and examples from the test suite.
I've used the existing table, adding all the fields to the second table.
see [in the pr](https://github.com/steveloughran/spark/blob/history/SPARK-13267-doc-params/docs/monitoring.md).
There's a slightly more sophisticated option: make the table 3 columns wide, and for all existing entries, have the initial `td` span 2 columns. The new entries would then have an empty 1st column, param in 2nd and text in 3rd, with any examples after a `br` entry.
Author: Steve Loughran <stevel@hortonworks.com>
Closes#11152 from steveloughran/history/SPARK-13267-doc-params.
## What changes were proposed in this pull request?
In Python, sqlContext.getConf didn't allow getting the system default (getConf with one parameter).
Now the following are supported:
```
sqlContext.getConf(confName) # System default if not locally set, this is new
sqlContext.getConf(confName, myDefault) # myDefault if not locally set, old behavior
```
I also added doctests to this function. The original behavior does not change.
## How was this patch tested?
Manually, but doctests were added.
Author: mathieu longtin <mathieu.longtin@nuance.com>
Closes#12488 from mathieulongtin/pyfixgetconf3.
## What changes were proposed in this pull request?
CreateMetastoreDataSource and CreateMetastoreDataSourceAsSelect are not Hive-specific. So, this PR moves them from sql/hive to sql/core. Also, I am adding `Command` suffix to these two classes.
## How was this patch tested?
Existing tests.
Author: Yin Huai <yhuai@databricks.com>
Closes#12645 from yhuai/moveCreateDataSource.
## What changes were proposed in this pull request?
Current StreamTest allows testing of a streaming Dataset generated explicitly wraps a source. This is different from the actual production code path where the source object is dynamically created through a DataSource object every time a query is started. So all the fault-tolerance testing in FileSourceSuite and FileSourceStressSuite is not really testing the actual code path as they are just reusing the FileStreamSource object.
This PR fixes StreamTest and the FileSource***Suite to test this correctly. Instead of maintaining a mapping of source --> expected offset in StreamTest (which requires reuse of source object), it now maintains a mapping of source index --> offset, so that it is independent of the source object.
Summary of changes
- StreamTest refactored to keep track of offset by source index instead of source
- AddData, AddTextData and AddParquetData updated to find the FileStreamSource object from an active query, so that it can work with sources generated when query is started.
- Refactored unit tests in FileSource***Suite to test using DataFrame/Dataset generated with public, rather than reusing the same FileStreamSource. This correctly tests fault tolerance.
The refactoring changed a lot of indents in FileSourceSuite, so its recommended to hide whitespace changes with this - https://github.com/apache/spark/pull/12592/files?w=1
## How was this patch tested?
Refactored unit tests.
Author: Tathagata Das <tathagata.das1565@gmail.com>
Closes#12592 from tdas/SPARK-14833.
## What changes were proposed in this pull request?
We have logical plans that produce domain objects which are `ObjectType`. As we can't estimate the size of `ObjectType`, we throw an `UnsupportedOperationException` if trying to do that. We should set a default size for `ObjectType` to avoid this failure.
## How was this patch tested?
`DatasetSuite`.
Author: Liang-Chi Hsieh <simonh@tw.ibm.com>
Closes#12599 from viirya/skip-broadcast-objectproducer.
## What changes were proposed in this pull request?
Fixed inadvertent roxygen2 doc changes, added class name change to programming guide
Follow up of #12621
## How was this patch tested?
manually checked
Author: felixcheung <felixcheung_m@hotmail.com>
Closes#12647 from felixcheung/rdataframe.
## What changes were proposed in this pull request?
There was a typo in the message for second assertion in "returning batch for wide table" test
## How was this patch tested?
Existing tests.
Author: tedyu <yuzhihong@gmail.com>
Closes#12639 from tedyu/master.
## What changes were proposed in this pull request?
TernaryExpressions should thows proper error message for itself.
```scala
protected def nullSafeEval(input1: Any, input2: Any, input3: Any): Any =
- sys.error(s"BinaryExpressions must override either eval or nullSafeEval")
+ sys.error(s"TernaryExpressions must override either eval or nullSafeEval")
```
## How was this patch tested?
Manual.
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#12642 from dongjoon-hyun/minor_fix_error_msg_in_ternaryexpression.
## What changes were proposed in this pull request?
It is unnecessary as DataType.catalogString largely replaces the need for this class.
## How was this patch tested?
Mostly removing dead code and should be covered by existing tests.
Author: Reynold Xin <rxin@databricks.com>
Closes#12644 from rxin/SPARK-14877.
## What changes were proposed in this pull request?
This patch improves error handling in view creation. CreateViewCommand itself will analyze the view SQL query first, and if it cannot successfully analyze it, throw an AnalysisException.
In addition, I also added the following two conservative guards for easier identification of Spark bugs:
1. If there is a bug and the generated view SQL cannot be analyzed, throw an exception at runtime. Note that this is not an AnalysisException because it is not caused by the user and more likely indicate a bug in Spark.
2. SQLBuilder when it gets an unresolved plan, it will also show the plan in the error message.
I also took the chance to simplify the internal implementation of CreateViewCommand, and *removed* a fallback path that would've masked an exception from before.
## How was this patch tested?
1. Added a unit test for the user facing error handling.
2. Manually introduced some bugs in Spark to test the internal defensive error handling.
3. Also added a test case to test nested views (not super relevant).
Author: Reynold Xin <rxin@databricks.com>
Closes#12633 from rxin/SPARK-14865.
## What changes were proposed in this pull request?
In order to support running SQL directly on files, we added some code in ResolveRelations to catch the exception thrown by catalog.lookupRelation and ignore it. This unfortunately masks all the exceptions. This patch changes the logic to simply test the table's existence.
## How was this patch tested?
I manually hacked some bugs into Spark and made sure the exceptions were being propagated up.
Author: Reynold Xin <rxin@databricks.com>
Closes#12634 from rxin/SPARK-14869.
## What changes were proposed in this pull request?
This patch restructures sql.execution.command package to break the commands into multiple files, in some logical organization: databases, tables, views, functions.
I also renamed basicOperators.scala to basicLogicalOperators.scala and basicPhysicalOperators.scala.
## How was this patch tested?
N/A - all I did was moving code around.
Author: Reynold Xin <rxin@databricks.com>
Closes#12636 from rxin/SPARK-14872.
## What changes were proposed in this pull request?
Spark SQL inherited from Shark to use the StatsReportListener. Unfortunately this clutters the spark-sql CLI output and makes it very difficult to read the actual query results.
## How was this patch tested?
Built and tested in spark-sql CLI.
Author: Reynold Xin <rxin@databricks.com>
Closes#12635 from rxin/SPARK-14871.
## What changes were proposed in this pull request?
(Please fill in changes proposed in this fix)
## How was this patch tested?
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)
Author: Reynold Xin <rxin@databricks.com>
Closes#12565 from rxin/test-flaky.
## What changes were proposed in this pull request?
When JVM backend fails without going proper error handling (eg. process crashed), the R error message could be ambiguous.
```
Error in if (returnStatus != 0) { : argument is of length zero
```
This change attempts to make it more clear (however, one would still need to investigate why JVM fails)
## How was this patch tested?
manually
Author: felixcheung <felixcheung_m@hotmail.com>
Closes#12622 from felixcheung/rreturnstatus.
