### What changes were proposed in this pull request?
If `LLL`/`qqq` is used in the datetime pattern string, and the current JDK in use has a bug for the stand-alone form (see https://bugs.openjdk.java.net/browse/JDK-8114833), throw an exception with a clear error message.
### Why are the changes needed?
to keep backward compatibility with Spark 2.4
### Does this PR introduce _any_ user-facing change?
Yes
Spark 2.4
```
scala> sql("select date_format('1990-1-1', 'LLL')").show
+---------------------------------------------+
|date_format(CAST(1990-1-1 AS TIMESTAMP), LLL)|
+---------------------------------------------+
| Jan|
+---------------------------------------------+
```
Spark 3.0 with Java 11
```
scala> sql("select date_format('1990-1-1', 'LLL')").show
+---------------------------------------------+
|date_format(CAST(1990-1-1 AS TIMESTAMP), LLL)|
+---------------------------------------------+
| Jan|
+---------------------------------------------+
```
Spark 3.0 with Java 8
```
// before this PR
+---------------------------------------------+
|date_format(CAST(1990-1-1 AS TIMESTAMP), LLL)|
+---------------------------------------------+
| 1|
+---------------------------------------------+
// after this PR
scala> sql("select date_format('1990-1-1', 'LLL')").show
org.apache.spark.SparkUpgradeException
```
### How was this patch tested?
manual test with java 8 and 11
Closes#28646 from cloud-fan/format.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
This PR adds the structured streaming UI introduction to the Web UI doc.
### Why are the changes needed?
The structured streaming web UI introduced before was missing from the Web UI documentation.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
N.A.
Closes#28609 from xccui/ss-ui-doc.
Authored-by: Xingcan Cui <xccui@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Five continuous pattern characters with 'G/M/L/E/u/Q/q' means Narrow-Text Style while we turn to use `java.time.DateTimeFormatterBuilder` since 3.0.0, which output the leading single letter of the value, e.g. `December` would be `D`. In Spark 2.4 they mean Full-Text Style.
In this PR, we explicitly disable Narrow-Text Style for these pattern characters.
### Why are the changes needed?
Without this change, there will be a silent data change.
### Does this PR introduce _any_ user-facing change?
Yes, queries with datetime operations using datetime patterns, e.g. `G/M/L/E/u` will fail if the pattern length is 5 and other patterns, e,g. 'k', 'm' also can accept a certain number of letters.
1. datetime patterns that are not supported by the new parser but the legacy will get SparkUpgradeException, e.g. "GGGGG", "MMMMM", "LLLLL", "EEEEE", "uuuuu", "aa", "aaa". 2 options are given to end-users, one is to use legacy mode, and the other is to follow the new online doc for correct datetime patterns
2, datetime patterns that are not supported by both the new parser and the legacy, e.g. "QQQQQ", "qqqqq", will get IllegalArgumentException which is captured by Spark internally and results NULL to end-users.
### How was this patch tested?
add unit tests
Closes#28592 from yaooqinn/SPARK-31771.
Authored-by: Kent Yao <yaooqinn@hotmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
add docs for sql migration-guide
### Why are the changes needed?
let user know more about the cast scenarios in which Hive and Spark generate different results
### Does this PR introduce _any_ user-facing change?
no
### How was this patch tested?
no need to test
Closes#28605 from GuoPhilipse/spark-docs.
Lead-authored-by: GuoPhilipse <guofei_ok@126.com>
Co-authored-by: GuoPhilipse <46367746+GuoPhilipse@users.noreply.github.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Added MDC support in all thread pools.
ThreaddUtils create new pools that pass over MDC.
### Why are the changes needed?
In many cases, it is very hard to understand from which actions the logs in the executor come from.
when you are doing multi-thread work in the driver and send actions in parallel.
### Does this PR introduce any user-facing change?
No
### How was this patch tested?
No test added because no new functionality added it is thread pull change and all current tests pass.
Closes#26624 from igreenfield/master.
Authored-by: Izek Greenfield <igreenfield@axiomsl.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
1. Describe standard 'M' and stand-alone 'L' text forms
2. Add examples for all supported number of month letters
<img width="1047" alt="Screenshot 2020-05-18 at 08 57 31" src="https://user-images.githubusercontent.com/1580697/82178856-b16f1000-98e5-11ea-87c0-456ef94dcd43.png">
### Why are the changes needed?
To improve docs and show how to use month patterns.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
By building docs and checking by eyes.
Closes#28558 from MaxGekk/describe-L-M-date-pattern.
Authored-by: Max Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
This patch effectively reverts SPARK-30098 via below changes:
* Removed the config
* Removed the changes done in parser rule
* Removed the usage of config in tests
* Removed tests which depend on the config
* Rolled back some tests to before SPARK-30098 which were affected by SPARK-30098
* Reflect the change into docs (migration doc, create table syntax)
### Why are the changes needed?
SPARK-30098 brought confusion and frustration on using create table DDL query, and we agreed about the bad effect on the change.
Please go through the [discussion thread](http://apache-spark-developers-list.1001551.n3.nabble.com/DISCUSS-Resolve-ambiguous-parser-rule-between-two-quot-create-table-quot-s-td29051i20.html) to see the details.
### Does this PR introduce _any_ user-facing change?
No, compared to Spark 2.4.x. End users tried to experiment with Spark 3.0.0 previews will see the change that the behavior is going back to Spark 2.4.x, but I believe we won't guarantee compatibility in preview releases.
### How was this patch tested?
Existing UTs.
Closes#28517 from HeartSaVioR/revert-SPARK-30098.
Authored-by: Jungtaek Lim (HeartSaVioR) <kabhwan.opensource@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
# What changes were proposed in this pull request?
This PR is a follow-up to fix a version of configuration document.
### Why are the changes needed?
The original PR is backported to branch-3.0.
### Does this PR introduce _any_ user-facing change?
Yes.
### How was this patch tested?
Manual.
Closes#28530 from dongjoon-hyun/SPARK-31696-2.
Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
This PR aims to add `spark.kubernetes.driver.service.annotation` like `spark.kubernetes.driver.service.annotation`.
### Why are the changes needed?
Annotations are used in many ways. One example is that Prometheus monitoring system search metric endpoint via annotation.
- https://github.com/helm/charts/tree/master/stable/prometheus#scraping-pod-metrics-via-annotations
### Does this PR introduce _any_ user-facing change?
Yes. The documentation is added.
### How was this patch tested?
Pass Jenkins with the updated unit tests.
Closes#28518 from dongjoon-hyun/SPARK-31696.
Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
This PR proposes to set the minimum Arrow version as 0.15.1 to be consistent with PySpark side at.
### Why are the changes needed?
It will reduce the maintenance overhead to match the Arrow versions, and minimize the supported range. SparkR Arrow optimization is experimental yet.
### Does this PR introduce _any_ user-facing change?
No, it's the change in unreleased branches only.
### How was this patch tested?
0.15.x was already tested at SPARK-29378, and we're testing the latest version of SparkR currently in AppVeyor. I already manually tested too.
Closes#28520 from HyukjinKwon/SPARK-31701.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
This changes the docs to make it clearer that order preservation is not guaranteed when saving a RDD to disk and reading it back ([SPARK-5300](https://issues.apache.org/jira/browse/SPARK-5300)).
I added two sentences about this in the RDD Programming Guide.
The issue was discussed on the dev mailing list:
http://apache-spark-developers-list.1001551.n3.nabble.com/RDD-order-guarantees-td10142.html
### Why are the changes needed?
Because RDDs are order-aware collections, it is natural to expect that if I use `saveAsTextFile` and then load the resulting file with `sparkContext.textFile`, I obtain a RDD in the same order.
This is unfortunately not the case at the moment and there is no agreed upon way to fix this in Spark itself (see PR #4204 which attempted to fix this). Users should be aware of this.
### Does this PR introduce _any_ user-facing change?
Yes, two new sentences in the documentation.
### How was this patch tested?
By checking that the documentation looks good.
Closes#28465 from wetneb/SPARK-5300-docs.
Authored-by: Antonin Delpeuch <antonin@delpeuch.eu>
Signed-off-by: Sean Owen <srowen@gmail.com>
### What changes were proposed in this pull request?
This PR aims to new Prometheus-format metric endpoints experimental in Apache Spark 3.0.0.
### Why are the changes needed?
Although the new metrics are disabled by default, we had better make it experimental explicitly in Apache Spark 3.0.0 since the output format is still not fixed. We can finalize it in Apache Spark 3.1.0.
### Does this PR introduce _any_ user-facing change?
Only doc-change is visible to the users.
### How was this patch tested?
Manually check the code since this is a documentation and class annotation change.
Closes#28495 from dongjoon-hyun/SPARK-31674.
Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
Remove the unneeded embedded inline HTML markup by using the basic markdown syntax.
Please see #28414
### Why are the changes needed?
Make the doc cleaner and easily editable by MD editors.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Manually build and check
Closes#28451 from huaxingao/html_cleanup.
Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Sean Owen <srowen@gmail.com>
### What changes were proposed in this pull request?
This PR adds `spark.yarn.applicationType` to identify the application type
### Why are the changes needed?
The current application defaults to the SPARK type.
In fact, different types of applications have different characteristics and are suitable for different scenarios.For example: SPAKR-SQL, SPARK-STREAMING.
I recommend distinguishing them by the parameter `spark.yarn.applicationType` so that we can more easily manage and maintain different types of applications.
### How was this patch tested?
1.add UT
2.Tested by verifying Yarn-UI `ApplicationType` in the following cases:
- client and cluster mode
Need additional explanation:
limit cannot exceed 20 characters, can be empty or space
The reasons are as follows:
```
// org.apache.hadoop.yarn.server.resourcemanager.submitApplication.
if (submissionContext.getApplicationType() == null) {
submissionContext
.setApplicationType(YarnConfiguration.DEFAULT_APPLICATION_TYPE);
} else {
// APPLICATION_TYPE_LENGTH = 20
if (submissionContext.getApplicationType().length() > YarnConfiguration.APPLICATION_TYPE_LENGTH) {
submissionContext.setApplicationType(submissionContext
.getApplicationType().substring(0,
YarnConfiguration.APPLICATION_TYPE_LENGTH));
}
}
```
Closes#28009 from wang-zhun/SPARK-31235.
Authored-by: wang-zhun <wangzhun6103@gmail.com>
Signed-off-by: Thomas Graves <tgraves@apache.org>
### What changes were proposed in this pull request?
This reverts commit 43a73e387c. It sets `INT96` as the timestamp type while saving timestamps to parquet files.
### Why are the changes needed?
To be compatible with Hive and Presto that don't support the `TIMESTAMP_MICROS` type in current stable releases.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
By existing test suites.
Closes#28450 from MaxGekk/parquet-int96.
Authored-by: Max Gekk <max.gekk@gmail.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
Fixed typo in `docs` directory and in `project/MimaExcludes.scala`
### Why are the changes needed?
Better readability of documents
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
No test needed
Closes#28447 from kiszk/typo_20200504.
Authored-by: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
The "spark.dynamicAllocation.shuffleTimeout" configuration only takes effect if "spark.dynamicAllocation.shuffleTracking.enabled" is true, so we should re-namespace that configuration so that it's nested under the "shuffleTracking" one.
### How was this patch tested?
Covered by current existing test cases.
Closes#28426 from jiangxb1987/confName.
Authored-by: Xingbo Jiang <xingbo.jiang@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
This PR is to clean up the markdown file in SHOW COLUMNS page.
- remove the unneeded embedded inline HTML markup by using the basic markdown syntax.
- use the ``` sql for highlighting the SQL syntax.
### Why are the changes needed?
Make the doc cleaner and easily editable by MD editors.
### Does this PR introduce _any_ user-facing change?
NO
### How was this patch tested?
**Before**
**After**
Closes#28414 from gatorsmile/cleanupShowColumns.
Lead-authored-by: Xiao Li <gatorsmile@gmail.com>
Co-authored-by: gatorsmile <gatorsmile@gmail.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
### What changes were proposed in this pull request?
- Rephrase the API doc for `Column.as`
- Simplify the UTs
### Why are the changes needed?
Address comments in https://github.com/apache/spark/pull/28326
### Does this PR introduce any user-facing change?
No
### How was this patch tested?
New UT added.
Closes#28390 from xuanyuanking/SPARK-27340-follow.
Authored-by: Yuanjian Li <xyliyuanjian@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
We are adding a new Spark Yarn configuration, `spark.yarn.populateHadoopClasspath` to not populate Hadoop classpath from `yarn.application.classpath` and `mapreduce.application.classpath`.
### Why are the changes needed?
Spark Yarn client populates extra Hadoop classpath from `yarn.application.classpath` and `mapreduce.application.classpath` when a job is submitted to a Yarn Hadoop cluster.
However, for `with-hadoop` Spark build that embeds Hadoop runtime, it can cause jar conflicts because Spark distribution can contain different version of Hadoop jars.
One case we have is when a user uses an Apache Spark distribution with its-own embedded hadoop, and submits a job to Cloudera or Hortonworks Yarn clusters, because of two different incompatible Hadoop jars in the classpath, it runs into errors.
By not populating the Hadoop classpath from the clusters can address this issue.
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
An UT is added, but very hard to add a new integration test since this requires using different incompatible versions of Hadoop.
We also manually tested this PR, and we are able to submit a Spark job using Spark distribution built with Apache Hadoop 2.10 to CDH 5.6 without populating CDH classpath.
Closes#28376 from dbtsai/yarn-classpath.
Authored-by: DB Tsai <d_tsai@apple.com>
Signed-off-by: DB Tsai <d_tsai@apple.com>
### What changes were proposed in this pull request?
This PR addresses two things:
- `SHOW TBLPROPERTIES` should supports view (a regression introduced by #26921)
- `SHOW TBLPROPERTIES` on a temporary view should return empty result (2.4 behavior instead of throwing `AnalysisException`.
### Why are the changes needed?
It's a bug.
### Does this PR introduce any user-facing change?
Yes, now `SHOW TBLPROPERTIES` works on views:
```
scala> sql("CREATE VIEW view TBLPROPERTIES('p1'='v1', 'p2'='v2') AS SELECT 1 AS c1")
scala> sql("SHOW TBLPROPERTIES view").show(truncate=false)
+---------------------------------+-------------+
|key |value |
+---------------------------------+-------------+
|view.catalogAndNamespace.numParts|2 |
|view.query.out.col.0 |c1 |
|view.query.out.numCols |1 |
|p2 |v2 |
|view.catalogAndNamespace.part.0 |spark_catalog|
|p1 |v1 |
|view.catalogAndNamespace.part.1 |default |
+---------------------------------+-------------+
```
And for a temporary view:
```
scala> sql("CREATE TEMPORARY VIEW tview TBLPROPERTIES('p1'='v1', 'p2'='v2') AS SELECT 1 AS c1")
scala> sql("SHOW TBLPROPERTIES tview").show(truncate=false)
+---+-----+
|key|value|
+---+-----+
+---+-----+
```
### How was this patch tested?
Added tests.
Closes#28375 from imback82/show_tblproperties_followup.
Authored-by: Terry Kim <yuminkim@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
This PR adds `-Phive` profile to the pre-build phase to build the hive module to dev classpath.
Then reflect the HiveUtils object to dump all configurations in the class.
### Why are the changes needed?
supply SQL configurations from hive module to doc
### Does this PR introduce any user-facing change?
NO
### How was this patch tested?
passing Jenkins
add verified locally
Closes#28394 from yaooqinn/SPARK-31596.
Authored-by: Kent Yao <yaooqinn@hotmail.com>
Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>
### What changes were proposed in this pull request?
This PR proposes to use a different approach instead of breaking it per Micheal's rubric added at https://spark.apache.org/versioning-policy.html. It deprecates the behaviour for now. It will be gradually removed in the future releases.
After this change,
```python
import warnings
warnings.simplefilter("always")
from pyspark.sql.functions import *
df = spark.range(2)
map_col = create_map(lit(0), lit(100), lit(1), lit(200))
df.withColumn("mapped", map_col.getItem(col('id'))).show()
```
```
/.../python/pyspark/sql/column.py:311: DeprecationWarning: A column as 'key' in getItem is
deprecated as of Spark 3.0, and will not be supported in the future release. Use `column[key]`
or `column.key` syntax instead.
DeprecationWarning)
...
```
```python
import warnings
warnings.simplefilter("always")
from pyspark.sql.functions import *
df = spark.range(2)
struct_col = struct(lit(0), lit(100), lit(1), lit(200))
df.withColumn("struct", struct_col.getField(lit("col1"))).show()
```
```
/.../spark/python/pyspark/sql/column.py:336: DeprecationWarning: A column as 'name'
in getField is deprecated as of Spark 3.0, and will not be supported in the future release. Use
`column[name]` or `column.name` syntax instead.
DeprecationWarning)
```
### Why are the changes needed?
To prevent the radical behaviour change after the amended versioning policy.
### Does this PR introduce any user-facing change?
Yes, it will show the deprecated warning message.
### How was this patch tested?
Manually tested.
Closes#28327 from HyukjinKwon/SPARK-29664.
Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
This PR proposes to remove the non-existed `hiveClientCalls.count` metric documentation of `CodeGenerator` of the Spark metrics system in the monitoring guide.
There is a duplicated `hiveClientCalls.count` metric in both `namespace=HiveExternalCatalog` and `namespace=CodeGenerator` bullet lists, but there is only one defined inside object `HiveCatalogMetrics`.
Closes#28292 from wezhang/monitoringdoc.
Authored-by: Wei Zhang <wezhang@outlook.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
Give more friendly warning message/migration guide of deprecated scala udf to users.
### Why are the changes needed?
User can not distinguish function signature between typed and untyped scala udf. Instead, we shall tell user what to do directly.
### Does this PR introduce any user-facing change?
No, it's newly added in Spark 3.0.
### How was this patch tested?
Pass Jenkins.
Closes#28311 from Ngone51/update_udf_doc.
Authored-by: yi.wu <yi.wu@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
### What changes were proposed in this pull request?
Add migration guide for removed accumulator v1 APIs.
### Why are the changes needed?
Provide better guidance for users' migration.
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
Pass Jenkins.
Closes#28309 from Ngone51/SPARK-16775-migration-guide.
Authored-by: yi.wu <yi.wu@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
Need to address a few more comments
### Why are the changes needed?
Fix a few problems
### Does this PR introduce any user-facing change?
Yes
### How was this patch tested?
Manually build and check
Closes#28306 from huaxingao/literal-folllowup.
Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>
### What changes were proposed in this pull request?
Currently, only the non-static public SQL configurations are dump to public doc, we'd better also add those static public ones as the command `set -v`
This PR force call StaticSQLConf to buildStaticConf.
### Why are the changes needed?
Fix missing SQL configurations in doc
### Does this PR introduce any user-facing change?
NO
### How was this patch tested?
add unit test and verify locally to see if public static SQL conf is in `docs/sql-config.html`
Closes#28274 from yaooqinn/SPARK-31498.
Authored-by: Kent Yao <yaooqinn@hotmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
### What changes were proposed in this pull request?
**Hive 2.3.7** fixed these issues:
- HIVE-21508: ClassCastException when initializing HiveMetaStoreClient on JDK10 or newer
- HIVE-21980:Parsing time can be high in case of deeply nested subqueries
- HIVE-22249: Support Parquet through HCatalog
### Why are the changes needed?
Fix CCE during creating HiveMetaStoreClient in JDK11 environment: [SPARK-29245](https://issues.apache.org/jira/browse/SPARK-29245).
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
- [x] Test Jenkins with Hadoop 2.7 (https://github.com/apache/spark/pull/28148#issuecomment-616757840)
- [x] Test Jenkins with Hadoop 3.2 on JDK11 (https://github.com/apache/spark/pull/28148#issuecomment-616294353)
- [x] Manual test with remote hive metastore.
Hive side:
```
export JAVA_HOME=/usr/lib/jdk1.8.0_221
export PATH=$JAVA_HOME/bin:$PATH
cd /usr/lib/hive-2.3.6 # Start Hive metastore with Hive 2.3.6
bin/schematool -dbType derby -initSchema --verbose
bin/hive --service metastore
```
Spark side:
```
export JAVA_HOME=/usr/lib/jdk-11.0.3
export PATH=$JAVA_HOME/bin:$PATH
build/sbt clean package -Phive -Phadoop-3.2 -Phive-thriftserver
export SPARK_PREPEND_CLASSES=true
bin/spark-sql --conf spark.hadoop.hive.metastore.uris=thrift://localhost:9083
```
Closes#28148 from wangyum/SPARK-31381.
Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
This PR is the follow-up PR of https://github.com/apache/spark/pull/28003
- add a migration guide
- add an end-to-end test case.
### Why are the changes needed?
The original PR made the major behavior change in the user-facing RESET command.
### Does this PR introduce any user-facing change?
No
### How was this patch tested?
Added a new end-to-end test
Closes#28265 from gatorsmile/spark-31234followup.
Authored-by: gatorsmile <gatorsmile@gmail.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
### What changes were proposed in this pull request?
This adds newly supported `nfs` volume type description into the document for Apache Spark 3.1.0.
### Why are the changes needed?
To complete the document.
### Does this PR introduce any user-facing change?
Yes. (Doc)
### How was this patch tested?
Manually generate doc and check it.
```
SKIP_API=1 jekyll build
```
Closes#28236 from dongjoon-hyun/SPARK-NFS-DOC.
Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
### What changes were proposed in this pull request?
Update the document and shell script to warn user about the deprecation of multiple workers on the same host support.
### Why are the changes needed?
This is a sub-task of [SPARK-30978](https://issues.apache.org/jira/browse/SPARK-30978), which plans to totally remove support of multiple workers in Spark 3.1. This PR makes the first step to deprecate it firstly in Spark 3.0.
### Does this PR introduce any user-facing change?
Yeah, user see warning when they run start worker script.
### How was this patch tested?
Tested manually.
Closes#27768 from Ngone51/deprecate_spark_worker_instances.
Authored-by: yi.wu <yi.wu@databricks.com>
Signed-off-by: Xingbo Jiang <xingbo.jiang@databricks.com>
### What changes were proposed in this pull request?
Add a SQL example for UDAF
### Why are the changes needed?
To make SQL Reference complete
### Does this PR introduce any user-facing change?
Yes.
Add the following page, also change ```Sql``` to ```SQL``` in the example tab for all the sql examples.
<img width="1110" alt="Screen Shot 2020-04-13 at 6 09 24 PM" src="https://user-images.githubusercontent.com/13592258/79175240-06cd7400-7db2-11ea-8f3e-af71a591a64b.png">
### How was this patch tested?
Manually build and check
Closes#28209 from huaxingao/udf_followup.
Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
