## What changes were proposed in this pull request?
Add a metric for number of exceptions caught in the `ExternalShuffleBlockHandler`, the idea being that spikes in this metric over some time window (or more desirably, the lack thereof) can be used as an indicator of the health of an external shuffle service. (Where "health" refers to its ability to successfully respond to client requests.)
## How was this patch tested?
Deployed a build of this PR to a YARN cluster, and confirmed that the NodeManagers' JMX metrics include `numCaughtExceptions`.
Closes#24645 from sjrand/SPARK-27773.
Authored-by: Steven Rand <srand@palantir.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
First, there is currently no public documentation for this setting. So it's hard
to even know that it could be a problem if your application starts failing with
weird shuffle errors.
Second, the javadoc attached to the code was incorrect; the default value just uses
the default value from the JRE, which is 50, instead of having an unbounded queue
as the comment implies.
So use a default that is a "rounded" version of the JRE default, and provide
documentation explaining that this value may need to be adjusted. Also added
a log message that was very helpful in debugging an issue caused by this
problem.
Closes#24732 from vanzin/SPARK-27868.
Authored-by: Marcelo Vanzin <vanzin@cloudera.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
`ExecutorClassLoader`'s `findClass` may fail to fetch a class due to transient exceptions. For example, when a task is interrupted, if `ExecutorClassLoader` is fetching a class, you may see `InterruptedException` or `IOException` wrapped by `ClassNotFoundException`, even if this class can be loaded. Then the result of `findClass` will be cached by JVM, and later when the same class is being loaded in the same executor, it will just throw NoClassDefFoundError even if the class can be loaded.
I found JVM only caches `LinkageError` and `ClassNotFoundException`. Hence in this PR, I changed ExecutorClassLoader to throw `RemoteClassLoadedError` if we cannot get a response from driver.
## How was this patch tested?
New unit tests.
Closes#24683 from zsxwing/SPARK-20547-fix.
Authored-by: Shixiong Zhu <zsxwing@gmail.com>
Signed-off-by: Shixiong Zhu <zsxwing@gmail.com>
## What changes were proposed in this pull request?
As the current approach in OneForOneBlockFetcher, we reuse the OpenBlocks protocol to describe the fetch request for shuffle blocks, and it causes the extension work for shuffle fetching like #19788 and #24110 very awkward.
In this PR, we split the fetch request for shuffle blocks from OpenBlocks which named FetchShuffleBlocks. It's a loose bind with ShuffleBlockId and can easily extend by adding new fields in this protocol.
## How was this patch tested?
Existing and new added UT.
Closes#24565 from xuanyuanking/SPARK-27665.
Authored-by: Yuanjian Li <xyliyuanjian@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In the PR the config `spark.shuffle.service.fetch.rdd.enabled` default is changed to **false** to avoid breaking any compatibility with older external shuffle service installations. As external shuffle service is deployed separately and disk persisted RDD block fetching had even introduced new network messages (`RemoveBlocks` and `BlocksRemoved`) and changed the behaviour of the already existing fetching: extended it for RDD blocks.
## How was this patch tested?
With existing unit tests.
Closes#24697 from attilapiros/minor-ext-shuffle-fetch-disabled.
Authored-by: “attilapiros” <piros.attila.zsolt@gmail.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
# What changes were proposed in this pull request?
## Problem statement
An executor which has persisted blocks does not consider to be idle and this way ready to be released by dynamic allocation after the regular timeout `spark.dynamicAllocation.executorIdleTimeout` but there is separate configuration `spark.dynamicAllocation.cachedExecutorIdleTimeout` which defaults to `Integer.MAX_VALUE`. This is because releasing the executor also means losing the persisted blocks (as the metadata for individual blocks called `BlockInfo` are kept in memory) and when the RDD is referenced latter on this lost blocks will be recomputed.
On the other hand keeping the executors too long without any task to work on is also a waste of resources (as executors are reserved for the application by the resource manager).
## Solution
This PR focuses on the first part of SPARK-25888: it extends the external shuffle service with the capability to serve RDD blocks which are persisted on the local disk store by the executors. Moreover when this feature is enabled by setting the `spark.shuffle.service.fetch.rdd.enabled` config to true and a block is reported to be persisted on to disk the external shuffle service instance running on the same host as the executor is also registered (along with the reporting block manager) as a possible location for fetching it.
## Some implementation detail
Some explanation about the decisions made during the development:
- the location list to fetch a block was randomized but the groups (same host, same rack, others) order was kept. In this PR the order of groups are kept and external shuffle service added to the end of the each group.
- `BlockManagerInfo` is not introduced for external shuffle service but only a lightweight solution is taken. A hash map from `BlockId` to `BlockStatus` is introduced. A type alias would make the source more readable but I know it is discouraged. On the other hand a new class wrapping this hash map would introduce unnecessary indirection.
- when this feature is on the cleanup triggered during removing of executors (which is handled in `ExternalShuffleBlockResolver`) is modified to keep the disk persisted RDD blocks. This cleanup is triggered in standalone mode when the `spark.storage.cleanupFilesAfterExecutorExit` config is set.
- the unpersisting of an RDD is extended to use the external shuffle service for disk persisted RDD blocks when the original executor which created the blocks are already released. New block transport messages are introduced to support this: `RemoveBlocks` and `BlocksRemoved`.
# How was this patch tested?
## Unit tests
### ExternalShuffleServiceSuite
Here the complete use case is tested by the "SPARK-25888: using external shuffle service fetching disk persisted blocks" with a tiny difference: here the executor is killed manually, this way the test is a bit faster than waiting for the idle timeout.
### ExternalShuffleBlockHandlerSuite
Tests the fetching of the RDD blocks via the external shuffle service.
### BlockManagerInfoSuite
This a new suite. As the `BlockManagerInfo` behaviour depends very much on whether the external shuffle service enabled or not all the tests are executed with and without it.
### BlockManagerSuite
Tests the sorting of the block locations.
## Manually on YARN
Spark App was:
~~~scala
package com.mycompany
import org.apache.spark.rdd.RDD
import org.apache.spark.{SparkContext, SparkConf}
import org.apache.spark.storage.StorageLevel
object TestAppDiskOnlyLevel {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("test-app")
println("Attila: START")
val sc = new SparkContext(conf)
val rdd = sc.parallelize(0 until 100, 10)
.map { i =>
println(s"Attila: calculate first rdd i=$i")
Thread.sleep(1000)
i
}
rdd.persist(StorageLevel.DISK_ONLY)
rdd.count()
println("Attila: First RDD is processed, waiting for 60 sec")
Thread.sleep(60 * 1000)
println("Attila: Num executors must be 0 as executorIdleTimeout is way over")
val rdd2 = sc.parallelize(0 until 10, 1)
.map(i => (i, 1))
.persist(StorageLevel.DISK_ONLY)
rdd2.count()
println("Attila: Second RDD with one partition (only one executors must be alive)")
// reduce runs as user code to detect the empty seq (empty blocks)
println("Calling collect on the first RDD: " + rdd.collect().reduce(_ + _))
println("Attila: STOP")
}
}
~~~
I have submitted with the following configuration:
~~~bash
spark-submit --master yarn \
--conf spark.dynamicAllocation.enabled=true \
--conf spark.dynamicAllocation.executorIdleTimeout=30 \
--conf spark.dynamicAllocation.cachedExecutorIdleTimeout=90 \
--class com.mycompany.TestAppDiskOnlyLevel dyn_alloc_demo-core_2.11-0.1.0-SNAPSHOT-jar-with-dependencies.jar
~~~
Checked the result by filtering for the side effect of the task calculations:
~~~bash
[userserver ~]$ yarn logs -applicationId application_1556299359453_0001 | grep "Attila: calculate" | wc -l
WARNING: YARN_OPTS has been replaced by HADOOP_OPTS. Using value of YARN_OPTS.
19/04/26 10:31:59 INFO client.RMProxy: Connecting to ResourceManager at apiros-1.gce.company.com/172.31.115.165:8032
100
~~~
So it is only 100 task execution and not 200 (which would be the case for re-computation).
Moreover from the submit/launcher log we can see executors really stopped in between (see the new total is 0 before the last line):
~~~
[userserver ~]$ grep "Attila: Num executors must be 0" -B 2 spark-submit.log
19/04/26 10:24:27 INFO cluster.YarnScheduler: Executor 9 on apiros-3.gce.company.com killed by driver.
19/04/26 10:24:27 INFO spark.ExecutorAllocationManager: Existing executor 9 has been removed (new total is 0)
Attila: Num executors must be 0 as executorIdleTimeout is way over
~~~
[Full spark submit log](https://github.com/attilapiros/spark/files/3122465/spark-submit.log)
I have done a test also after changing the `DISK_ONLY` storage level to `MEMORY_ONLY` for the first RDD. After this change during the 60sec waiting no executor was removed.
Closes#24499 from attilapiros/SPARK-25888-final.
Authored-by: “attilapiros” <piros.attila.zsolt@gmail.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
The details of the PR are explored in-depth in the sub-tasks of the umbrella jira SPARK-27726.
Briefly:
1. Stop issuing asynchronous requests to cleanup elements in the tracking store when a request is already pending
2. Fix a couple of thread-safety issues (mutable state and mis-ordered updates)
3. Move Summary deletion outside of Stage deletion loop like Tasks already are
4. Reimplement multi-delete in a removeAllKeys call which allows InMemoryStore to implement it in a performant manner.
5. Some generic typing and exception handling cleanup
We see about five orders of magnitude improvement in the deletion code, which for us is the difference between a server that needs restarting daily, and one that is stable over weeks.
Unit tests for the fire-once asynchronous code and the removeAll calls in both LevelDB and InMemoryStore are supplied. It was noted that the testing code for the LevelDB and InMemoryStore is highly repetitive, and should probably be merged, but we did not attempt that in this PR.
A version of this code was run in our production 2.3.3 and we were able to sustain higher throughput without going into GC overload (which was happening on a daily basis some weeks ago).
A version of this code was also put under a purpose-built Performance Suite of tests to verify performance under both types of Store implementations for both before and after code streams and for both total and partial delete cases (this code is not included in this PR).
Closes#24616 from davidnavas/PentaBugFix.
Authored-by: David Navas <davidn@clearstorydata.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
## What changes were proposed in this pull request?
This pr removes duplicate declaration of plugin `org.apache.maven.plugins:maven-antrun-plugin`:
```
[WARNING] Some problems were encountered while building the effective model for org.apache.spark:spark-network-yarn_2.12🫙3.0.0-SNAPSHOT
[WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-antrun-plugin line 177, column 15
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
```
https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/105523/consoleFull
## How was this patch tested?
Existing test
Closes#24641 from wangyum/SPARK-27610.
Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
Some APIs in Structured Streaming requires the user to specify an interval. Right now these APIs don't accept upper-case strings.
This PR adds a new method `fromCaseInsensitiveString` to `CalendarInterval` to support paring upper-case strings, and fixes all APIs that need to parse an interval string.
## How was this patch tested?
The new unit test.
Closes#24619 from zsxwing/SPARK-27735.
Authored-by: Shixiong Zhu <zsxwing@gmail.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
If the interval is `0`, it doesn't show both the value `0` and the unit at all. For example, this happens in the explain plans and Spark Web UI on `EventTimeWatermark` diagram.
**BEFORE**
```scala
scala> spark.readStream.schema("ts timestamp").parquet("/tmp/t").withWatermark("ts", "1 microsecond").explain
== Physical Plan ==
EventTimeWatermark ts#0: timestamp, interval 1 microseconds
+- StreamingRelation FileSource[/tmp/t], [ts#0]
scala> spark.readStream.schema("ts timestamp").parquet("/tmp/t").withWatermark("ts", "0 microsecond").explain
== Physical Plan ==
EventTimeWatermark ts#3: timestamp, interval
+- StreamingRelation FileSource[/tmp/t], [ts#3]
```
**AFTER**
```scala
scala> spark.readStream.schema("ts timestamp").parquet("/tmp/t").withWatermark("ts", "1 microsecond").explain
== Physical Plan ==
EventTimeWatermark ts#0: timestamp, interval 1 microseconds
+- StreamingRelation FileSource[/tmp/t], [ts#0]
scala> spark.readStream.schema("ts timestamp").parquet("/tmp/t").withWatermark("ts", "0 microsecond").explain
== Physical Plan ==
EventTimeWatermark ts#3: timestamp, interval 0 microseconds
+- StreamingRelation FileSource[/tmp/t], [ts#3]
```
## How was this patch tested?
Pass the Jenkins with the updated test case.
Closes#24516 from dongjoon-hyun/SPARK-27624.
Authored-by: Dongjoon Hyun <dhyun@apple.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
Fixed the `spark-<version>-yarn-shuffle.jar` artifact packaging to shade the native netty libraries:
- shade the `META-INF/native/libnetty_*` native libraries when packagin
the yarn shuffle service jar. This is required as netty library loader
derives that based on shaded package name.
- updated the `org/spark_project` shade package prefix to `org/sparkproject`
(i.e. removed underscore) as the former breaks the netty native lib loading.
This was causing the yarn external shuffle service to fail
when spark.shuffle.io.mode=EPOLL
## How was this patch tested?
Manual tests
Closes#24502 from amuraru/SPARK-27610_master.
Authored-by: Adi Muraru <amuraru@adobe.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
## What changes were proposed in this pull request?
Fix build warnings -- see some details below.
But mostly, remove use of postfix syntax where it causes warnings without the `scala.language.postfixOps` import. This is mostly in expressions like "120000 milliseconds". Which, I'd like to simplify to things like "2.minutes" anyway.
## How was this patch tested?
Existing tests.
Closes#24314 from srowen/SPARK-27404.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Right now there are several issues in `EncryptedMessage.transferTo`:
- When the underlying buffer has more than `1024 * 32` bytes (this should be rare but it could happen in error messages that send over the wire), it may just send a partial message as `EncryptedMessage.count` becomes less than `transferred`. This will cause the client hang forever (or timeout) as it will wait until receiving expected length of bytes, or weird errors (such as corruption or silent correctness issue) if the channel is reused by other messages.
- When the underlying buffer is full, it's still trying to write out bytes in a busy loop.
This PR fixes the issues in `EncryptedMessage.transferTo` and also makes it follow the contract of `FileRegion`:
- `count` should be a fixed value which is just the length of the whole message.
- It should be non-blocking. When the underlying socket is not ready to write, it should give up and give control back.
- `transferTo` should return the length of written bytes.
## How was this patch tested?
The new added tests.
Closes#24211 from zsxwing/fix-enc.
Authored-by: Shixiong Zhu <zsxwing@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
When a timeout happens we don't know what's the state of the remote end,
so there is no point in doing anything else since it will most probably
fail anyway.
The change also demotes the log message printed when falling back to
SASL, since a warning is too noisy for when the fallback is really
needed (e.g. old shuffle service, or shuffle service with new auth
disabled).
Closes#24160 from vanzin/SPARK-27219.
Authored-by: Marcelo Vanzin <vanzin@cloudera.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
As we all know that spark on Yarn uses DB https://github.com/apache/spark/pull/7943 to record RegisteredExecutors information which can be reloaded and used again when the ExternalShuffleService is restarted .
The RegisteredExecutors information can't be recorded both in the mode of spark's standalone and spark on k8s , which will cause the RegisteredExecutors information to be lost ,when the ExternalShuffleService is restarted.
To solve the problem above, a method is proposed and is committed .
## How was this patch tested?
new unit tests
Closes#23393 from weixiuli/SPARK-26288.
Authored-by: weixiuli <weixiuli@jd.com>
Signed-off-by: Imran Rashid <irashid@cloudera.com>
## What changes were proposed in this pull request?
When TransportChannelHandler processes IdleStateEvent, it first calculates whether the last request time has timed out.
At this time, TransportClient.sendRpc initiates a request.
TransportChannelHandler gets responseHandler.numOutstandingRequests() > 0, causing the normal connection to be closed.
## How was this patch tested?
Closes#23989 from cxzl25/fix_IdleStateEvent_timeout.
Authored-by: sychen <sychen@ctrip.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
## What changes were proposed in this pull request?
Creating an Netty `EventLoopGroup` leads to creating a new Thread pool for handling the events. For stopping the threads of the pool the event loop group should be shut down which is properly done for transport servers and clients by calling for example the `shutdownGracefully()` method (for details see the `close()` method of `TransportClientFactory` and `TransportServer`). But there is a separate event loop group for shuffle chunk fetch requests which is in pipeline for handling fetch request (shared between the client and server) and owned by the `TransportContext` and this was never shut down.
## How was this patch tested?
With existing unittest.
This leak is in the production system too but its effect is spiking in the unittest.
Checking the core unittest logs before the PR:
```
$ grep "LEAK IN SUITE" unit-tests.log | grep -o shuffle-chunk-fetch-handler | wc -l
381
```
And after the PR without whitelisting in thread audit and with an extra `await` after the
` chunkFetchWorkers.shutdownGracefully()`:
```
$ grep "LEAK IN SUITE" unit-tests.log | grep -o shuffle-chunk-fetch-handler | wc -l
0
```
Closes#23930 from attilapiros/SPARK-27021.
Authored-by: “attilapiros” <piros.attila.zsolt@gmail.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
## What changes were proposed in this pull request?
Currently, TransportFrameDecoder will not consolidate the buffers read from network which may cause memory waste. Actually, bytebuf's writtenIndex is far less than it's capacity in most cases, so we can optimize it by doing consolidation.
This PR will do this optimization.
Related codes:
9a30e23211/common/network-common/src/main/java/org/apache/spark/network/util/TransportFrameDecoder.java (L143)
## How was this patch tested?
UT
Please review http://spark.apache.org/contributing.html before opening a pull request.
Closes#23602 from liupc/Reduce-memory-consumption-in-TransportFrameDecoder.
Lead-authored-by: liupengcheng <liupengcheng@xiaomi.com>
Co-authored-by: Liupengcheng <liupengcheng@xiaomi.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
## What changes were proposed in this pull request?
How to reproduce
./build/mvn test -Dtest=org.apache.spark.network.RequestTimeoutIntegrationSuite,org.apache.spark.network.ChunkFetchIntegrationSuite -DwildcardSuites=None test
furtherRequestsDelay Test within RequestTimeoutIntegrationSuite was holding onto buffer references within worker threads. The test does close the server context but since the threads are global and there is sleep of 60 secs to fetch a specific chunk within this test, it grabs on it and waits for the client to consume but however the test is testing for a request timeout and it times out after 10 secs, so the workers are just waiting there for the buffer to be consumed by client as per my understanding.
This tends to happen if you dont have enough IO threads available on the specific system and also the order of the tests being run determines its flakyness like if ChunkFetchIntegrationSuite runs first then there is no issue. For example on mac with 8 threads these tests run fine but on my vm with 4 threads it fails. It matches the number of fetch calls in RequestTimeoutIntegrationSuite.
So do we really need it to be static?
I dont think this requires a global declaration as these threads are only required on the shuffle server end and on the client TransportContext initialization i.e the Client don't initialize these threads. The Shuffle Server initializes one TransportContext object. So, I think this is fine to be an instance variable and I see no harm.
## How was this patch tested?
Integration tests, manual tests
Closes#23700 from redsanket/SPARK-25692.
Authored-by: schintap <schintap@oath.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
In MessageEncoder.java, the header would always be allocated on onheap memory regardless of whether netty was configured to use/prefer onheap or offheap. By default this made netty allocate 16mb of onheap memory for a tiny header message. It would be more practical to use preallocated buffers.
Using a memory monitor tool on a simple spark application, the following services currently allocate 16 mb of onheap memory:
netty-rpc-client
netty-blockTransfer-client
netty-external-shuffle-client
With this change, the memory monitor tool reports all three of these services as using 0 b of onheap memory. The offheap memory allocation does not increase, but more of the already-allocated space is used.
## How was this patch tested?
Manually tested change using spark-memory-tool https://github.com/squito/spark-memoryCloses#22114 from NiharS/nettybuffer.
Lead-authored-by: Nihar Sheth <niharrsheth@gmail.com>
Co-authored-by: Nihar Sheth <nsheth@cloudera.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Now in `TransportRequestHandler.processStreamRequest`, when a stream request is processed, the stream id is not registered with the current channel in stream manager. It should do that so in case of that the channel gets terminated we can remove associated streams of stream requests too.
This also cleans up channel registration in `StreamManager`. Since `StreamManager` doesn't register channel but only `OneForOneStreamManager` does it, this removes `registerChannel` from `StreamManager`. When `OneForOneStreamManager` goes to register stream, it will also register channel for the stream.
## How was this patch tested?
Existing tests.
Closes#23521 from viirya/SPARK-26604.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
Fix typos in comments by replacing "in-heap" with "on-heap".
## How was this patch tested?
Existing Tests.
Closes#23533 from SongYadong/typos_inheap_to_onheap.
Authored-by: SongYadong <song.yadong1@zte.com.cn>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
Make it possible for the master to enable TCP keep alive on the RPC connections with clients.
## How was this patch tested?
Manually tested.
Added the following:
```
spark.rpc.io.enableTcpKeepAlive true
```
to spark-defaults.conf.
Observed the following on the Spark master:
```
$ netstat -town | grep 7077
tcp6 0 0 10.240.3.134:7077 10.240.1.25:42851 ESTABLISHED keepalive (6736.50/0/0)
tcp6 0 0 10.240.3.134:44911 10.240.3.134:7077 ESTABLISHED keepalive (4098.68/0/0)
tcp6 0 0 10.240.3.134:7077 10.240.3.134:44911 ESTABLISHED keepalive (4098.68/0/0)
```
Which proves that the keep alive setting is taking effect.
It's currently possible to enable TCP keep alive on the worker / executor, but is not possible to configure on other RPC connections. It's unclear to me why this could be the case. Keep alive is more important for the master to protect it against suddenly departing workers / executors, thus I think it's very important to have it. Particularly this makes the master resilient in case of using preemptible worker VMs in GCE. GCE has the concept of shutdown scripts, which it doesn't guarantee to execute. So workers often don't get shutdown gracefully and the TCP connections on the master linger as there's nothing to close them. Thus the need of enabling keep alive.
This enables keep-alive on connections besides the master's connections, but that shouldn't cause harm.
Closes#20512 from peshopetrov/master.
Authored-by: Petar Petrov <petar.petrov@leanplum.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Introducing shared polled ByteBuf allocators.
This feature can be enabled via the "spark.network.sharedByteBufAllocators.enabled" configuration.
When it is on then only two pooled ByteBuf allocators are created:
- one for transport servers where caching is allowed and
- one for transport clients where caching is disabled
This way the cache allowance remains as before.
Both shareable pools are created with numCores parameter set to 0 (which defaults to the available processors) as conf.serverThreads() and conf.clientThreads() are module dependant and the lazy creation of this allocators would lead to unpredicted behaviour.
When "spark.network.sharedByteBufAllocators.enabled" is false then a new allocator is created for every transport client and server separately as was before this PR.
## How was this patch tested?
Existing unit tests.
Closes#23278 from attilapiros/SPARK-24920.
Authored-by: “attilapiros” <piros.attila.zsolt@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
This PR upgrades Mockito from 1.10.19 to 2.23.4. The following changes are required.
- Replace `org.mockito.Matchers` with `org.mockito.ArgumentMatchers`
- Replace `anyObject` with `any`
- Replace `getArgumentAt` with `getArgument` and add type annotation.
- Use `isNull` matcher in case of `null` is invoked.
```scala
saslHandler.channelInactive(null);
- verify(handler).channelInactive(any(TransportClient.class));
+ verify(handler).channelInactive(isNull());
```
- Make and use `doReturn` wrapper to avoid [SI-4775](https://issues.scala-lang.org/browse/SI-4775)
```scala
private def doReturn(value: Any) = org.mockito.Mockito.doReturn(value, Seq.empty: _*)
```
## How was this patch tested?
Pass the Jenkins with the existing tests.
Closes#23452 from dongjoon-hyun/SPARK-26536.
Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
## What changes were proposed in this pull request?
In Java 9+ we can't use sun.misc.Cleaner by default anymore, and this was largely handled in https://github.com/apache/spark/pull/22993 However I think the change there left a significant problem.
If a DirectByteBuffer is allocated using the reflective hack in Platform, now, we by default can't set a Cleaner. But I believe this means the memory isn't freed promptly or possibly at all. If a Cleaner can't be set, I think we need to use normal APIs to allocate the direct ByteBuffer.
According to comments in the code, the downside is simply that the normal APIs will check and impose limits on how much off-heap memory can be allocated. Per the original review on https://github.com/apache/spark/pull/22993 this much seems fine, as either way in this case the user would have to add a JVM setting (increase max, or allow the reflective access).
## How was this patch tested?
Existing tests. This resolved an OutOfMemoryError in Java 11 from TimSort tests without increasing test heap size. (See https://github.com/apache/spark/pull/23419#issuecomment-450772125 ) This suggests there is a problem and that this resolves it.
Closes#23424 from srowen/SPARK-24421.2.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
`fireChannelRead` expects `io.netty.buffer.ByteBuf`.I checked that this is the only place which misuse `java.nio.ByteBuffer` in `network` module.
## How was this patch tested?
Pass the Jenkins with the existing tests.
Closes#23442 from dongjoon-hyun/SPARK-NETWORK-COMMON.
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 addresses warning messages in Java files reported at [lgtm.com](https://lgtm.com).
[lgtm.com](https://lgtm.com) provides automated code review of Java/Python/JavaScript files for OSS projects. [Here](https://lgtm.com/projects/g/apache/spark/alerts/?mode=list&severity=warning) are warning messages regarding Apache Spark project.
This PR addresses the following warnings:
- Result of multiplication cast to wider type
- Implicit narrowing conversion in compound assignment
- Boxed variable is never null
- Useless null check
NOTE: `Potential input resource leak` looks false positive for now.
## How was this patch tested?
Existing UTs
Closes#23420 from kiszk/SPARK-26508.
Authored-by: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
Recently, the ability to expose the metrics for YARN Shuffle Service was added as part of [SPARK-18364](https://github.com/apache/spark/pull/22485). We need to add some metrics to be able to determine the number of active connections as well as open connections to the external shuffle service to benchmark network and connection issues on large cluster environments.
Added two more shuffle server metrics for Spark Yarn shuffle service: numRegisteredConnections which indicate the number of registered connections to the shuffle service and numActiveConnections which indicate the number of active connections to the shuffle service at any given point in time.
If these metrics are outputted to a file, we get something like this:
1533674653489 default.shuffleService: Hostname=server1.abc.com, openBlockRequestLatencyMillis_count=729, openBlockRequestLatencyMillis_rate15=0.7110833548897356, openBlockRequestLatencyMillis_rate5=1.657808981793011, openBlockRequestLatencyMillis_rate1=2.2404486061620474, openBlockRequestLatencyMillis_rateMean=0.9242558551196706,
numRegisteredConnections=35,
blockTransferRateBytes_count=2635880512, blockTransferRateBytes_rate15=2578547.6094160094, blockTransferRateBytes_rate5=6048721.726302424, blockTransferRateBytes_rate1=8548922.518223226, blockTransferRateBytes_rateMean=3341878.633637769, registeredExecutorsSize=5, registerExecutorRequestLatencyMillis_count=5, registerExecutorRequestLatencyMillis_rate15=0.0027973949328659836, registerExecutorRequestLatencyMillis_rate5=0.0021278007987206426, registerExecutorRequestLatencyMillis_rate1=2.8270296777387467E-6, registerExecutorRequestLatencyMillis_rateMean=0.006339206380043053, numActiveConnections=35
Closes#22498 from pgandhi999/SPARK-18364.
Authored-by: pgandhi <pgandhi@oath.com>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
## What changes were proposed in this pull request?
A followup of https://github.com/apache/spark/pull/23043
There are 4 places we need to deal with NaN and -0.0:
1. comparison expressions. `-0.0` and `0.0` should be treated as same. Different NaNs should be treated as same.
2. Join keys. `-0.0` and `0.0` should be treated as same. Different NaNs should be treated as same.
3. grouping keys. `-0.0` and `0.0` should be assigned to the same group. Different NaNs should be assigned to the same group.
4. window partition keys. `-0.0` and `0.0` should be treated as same. Different NaNs should be treated as same.
The case 1 is OK. Our comparison already handles NaN and -0.0, and for struct/array/map, we will recursively compare the fields/elements.
Case 2, 3 and 4 are problematic, as they compare `UnsafeRow` binary directly, and different NaNs have different binary representation, and the same thing happens for -0.0 and 0.0.
To fix it, a simple solution is: normalize float/double when building unsafe data (`UnsafeRow`, `UnsafeArrayData`, `UnsafeMapData`). Then we don't need to worry about it anymore.
Following this direction, this PR moves the handling of NaN and -0.0 from `Platform` to `UnsafeWriter`, so that places like `UnsafeRow.setFloat` will not handle them, which reduces the perf overhead. It's also easier to add comments explaining why we do it in `UnsafeWriter`.
## How was this patch tested?
existing tests
Closes#23239 from cloud-fan/minor.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
## What changes were proposed in this pull request?
a followup of https://github.com/apache/spark/pull/23043 . Add a test to show the minor behavior change introduced by #23043 , and add migration guide.
## How was this patch tested?
a new test
Closes#23141 from cloud-fan/follow.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
`org.apache.spark.network.RpcIntegrationSuite.sendRpcWithStreamFailures` is still flaky and here is error message:
```
sbt.ForkMain$ForkError: java.lang.AssertionError: Got a non-empty set [Failed to send RPC RPC 8249697863992194475 to /172.17.0.2:41177: java.io.IOException: Broken pipe]
at org.junit.Assert.fail(Assert.java:88)
at org.junit.Assert.assertTrue(Assert.java:41)
at org.apache.spark.network.RpcIntegrationSuite.assertErrorAndClosed(RpcIntegrationSuite.java:389)
at org.apache.spark.network.RpcIntegrationSuite.sendRpcWithStreamFailures(RpcIntegrationSuite.java:347)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at com.novocode.junit.JUnitRunner$1.execute(JUnitRunner.java:132)
at sbt.ForkMain$Run$2.call(ForkMain.java:296)
at sbt.ForkMain$Run$2.call(ForkMain.java:286)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
```
This happened when the second RPC message was being sent but the connection was closed at the same time.
## How was this patch tested?
Jenkins
Closes#23109 from zsxwing/SPARK-26069-2.
Authored-by: Shixiong Zhu <zsxwing@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
GROUP BY treats -0.0 and 0.0 as different values which is unlike hive's behavior.
In addition current behavior with codegen is unpredictable (see example in JIRA ticket).
## What changes were proposed in this pull request?
In Platform.putDouble/Float() checking if the value is -0.0, and if so replacing with 0.0.
This is used by UnsafeRow so it won't have -0.0 values.
## How was this patch tested?
Added tests
Closes#23043 from adoron/adoron-spark-26021-replace-minus-zero-with-zero.
Authored-by: Alon Doron <adoron@palantir.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
The build has a lot of deprecation warnings. Some are new in Scala 2.12 and Java 11. We've fixed some, but I wanted to take a pass at fixing lots of easy miscellaneous ones here.
They're too numerous and small to list here; see the pull request. Some highlights:
- `BeanInfo` is deprecated in 2.12, and BeanInfo classes are pretty ancient in Java. Instead, case classes can explicitly declare getters
- Eta expansion of zero-arg methods; foo() becomes () => foo() in many cases
- Floating-point Range is inexact and deprecated, like 0.0 to 100.0 by 1.0
- finalize() is finally deprecated (just needs to be suppressed)
- StageInfo.attempId was deprecated and easiest to remove here
I'm not now going to touch some chunks of deprecation warnings:
- Parquet deprecations
- Hive deprecations (particularly serde2 classes)
- Deprecations in generated code (mostly Thriftserver CLI)
- ProcessingTime deprecations (we may need to revive this class as internal)
- many MLlib deprecations because they concern methods that may be removed anyway
- a few Kinesis deprecations I couldn't figure out
- Mesos get/setRole, which I don't know well
- Kafka/ZK deprecations (e.g. poll())
- Kinesis
- a few other ones that will probably resolve by deleting a deprecated method
## How was this patch tested?
Existing tests, including manual testing with the 2.11 build and Java 11.
Closes#23065 from srowen/SPARK-26090.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
This restores scaladoc artifact generation, which got dropped with the Scala 2.12 update. The change looks large, but is almost all due to needing to make the InterfaceStability annotations top-level classes (i.e. `InterfaceStability.Stable` -> `Stable`), unfortunately. A few inner class references had to be qualified too.
Lots of scaladoc warnings now reappear. We can choose to disable generation by default and enable for releases, later.
## How was this patch tested?
N/A; build runs scaladoc now.
Closes#23069 from srowen/SPARK-26026.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
The test failure is because `assertErrorAndClosed` misses one possible error message: `java.nio.channels.ClosedChannelException`. This happens when the second `uploadStream` is called after the channel has been closed. This can be reproduced by adding `Thread.sleep(1000)` below this line: 03306a6df3/common/network-common/src/test/java/org/apache/spark/network/RpcIntegrationSuite.java (L217)
This PR fixes the above issue and also improves the test failure messages of `assertErrorAndClosed`.
## How was this patch tested?
Jenkins
Closes#23041 from zsxwing/SPARK-26069.
Authored-by: Shixiong Zhu <zsxwing@gmail.com>
Signed-off-by: Shixiong Zhu <zsxwing@gmail.com>
## What changes were proposed in this pull request?
It's good to have annotations available at runtime, so that tools like MiMa can detect them and deal with then specially. e.g. we don't want to track compatibility for unstable classes.
This PR makes `InterfaceStability` annotations to be retained at runtime, to be consistent with `Experimental` and `DeveloperApi`
## How was this patch tested?
N/A
Closes#23029 from cloud-fan/annotation.
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 makes Spark's default Scala version as 2.12, and Scala 2.11 will be the alternative version. This implies that Scala 2.12 will be used by our CI builds including pull request builds.
We'll update the Jenkins to include a new compile-only jobs for Scala 2.11 to ensure the code can be still compiled with Scala 2.11.
## How was this patch tested?
existing tests
Closes#22967 from dbtsai/scala2.12.
Authored-by: DB Tsai <d_tsai@apple.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
## What changes were proposed in this pull request?
Add scala and java lint check rules to ban the usage of `throw new xxxErrors` and fix up all exists instance followed by https://github.com/apache/spark/pull/22989#issuecomment-437939830. See more details in https://github.com/apache/spark/pull/22969.
## How was this patch tested?
Local test with lint-scala and lint-java.
Closes#22989 from xuanyuanking/SPARK-25986.
Authored-by: Yuanjian Li <xyliyuanjian@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
…. Other related changes to get JDK 11 working, to test
## What changes were proposed in this pull request?
- Access `sun.misc.Cleaner` (Java 8) and `jdk.internal.ref.Cleaner` (JDK 9+) by reflection (note: the latter only works if illegal reflective access is allowed)
- Access `sun.misc.Unsafe.invokeCleaner` in Java 9+ instead of `sun.misc.Cleaner` (Java 8)
In order to test anything on JDK 11, I also fixed a few small things, which I include here:
- Fix minor JDK 11 compile issues
- Update scala plugin, Jetty for JDK 11, to facilitate tests too
This doesn't mean JDK 11 tests all pass now, but lots do. Note also that the JDK 9+ solution for the Cleaner has a big caveat.
## How was this patch tested?
Existing tests. Manually tested JDK 11 build and tests, and tests covering this change appear to pass. All Java 8 tests should still pass, but this change alone does not achieve full JDK 11 compatibility.
Closes#22993 from srowen/SPARK-24421.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
The commons-crypto library does some questionable error handling internally,
which can lead to JVM crashes if some call into native code fails and cleans
up state it should not.
While the library is not fixed, this change adds some workarounds in Spark code
so that when an error is detected in the commons-crypto side, Spark avoids
calling into the library further.
Tested with existing and added unit tests.
Closes#22557 from vanzin/SPARK-25535.
Authored-by: Marcelo Vanzin <vanzin@cloudera.com>
Signed-off-by: Imran Rashid <irashid@cloudera.com>
## What changes were proposed in this pull request?
We want to change the default percentage to 100 for spark.shuffle.server.chunkFetchHandlerThreadsPercent. The reason being
currently this is set to 0. Which means currently if server.ioThreads > 0, the default number of threads would be 2 * #cores instead of server.io.Threads. We want the default to server.io.Threads in case this is not set at all. Also here a default of 0 would also mean 2 * #cores
## How was this patch tested?
Manual
(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)
Please review http://spark.apache.org/contributing.html before opening a pull request.
Closes#22628 from redsanket/SPARK-25641.
Lead-authored-by: Sanket Chintapalli <schintap@yahoo-inc.com>
Co-authored-by: Sanket Chintapalli <chintapalli.sanketreddy@gmail.com>
Signed-off-by: Thomas Graves <tgraves@apache.org>
While working on another PR, I noticed that there is quite some legacy Java in there that can be beautified. For example the use of features from Java8, such as:
- Collection libraries
- Try-with-resource blocks
No logic has been changed. I think it is important to have a solid codebase with examples that will inspire next PR's to follow up on the best practices.
What are your thoughts on this?
This makes code easier to read, and using try-with-resource makes is less likely to forget to close something.
## What changes were proposed in this pull request?
No changes in the logic of Spark, but more in the aesthetics of the code.
## How was this patch tested?
Using the existing unit tests. Since no logic is changed, the existing unit tests should pass.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Closes#22637 from Fokko/SPARK-25408.
Authored-by: Fokko Driesprong <fokkodriesprong@godatadriven.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Adds support for the setting limit in the sql split function
## How was this patch tested?
1. Updated unit tests
2. Tested using Scala spark shell
Please review http://spark.apache.org/contributing.html before opening a pull request.
Closes#22227 from phegstrom/master.
Authored-by: Parker Hegstrom <phegstrom@palantir.com>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>
While working on another PR, I noticed that there is quite some legacy Java in there that can be beautified. For example the use og features from Java8, such as:
- Collection libraries
- Try-with-resource blocks
No code has been changed
What are your thoughts on this?
This makes code easier to read, and using try-with-resource makes is less likely to forget to close something.
## 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)
Please review http://spark.apache.org/contributing.html before opening a pull request.
Closes#22399 from Fokko/SPARK-25408.
Authored-by: Fokko Driesprong <fokkodriesprong@godatadriven.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
This patch is to bump the master branch version to 3.0.0-SNAPSHOT.
## How was this patch tested?
N/A
Closes#22606 from gatorsmile/bump3.0.
Authored-by: gatorsmile <gatorsmile@gmail.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
## What changes were proposed in this pull request?
This PR is follow-up of closed https://github.com/apache/spark/pull/17401 which only ended due to of inactivity, but its still nice feature to have.
Given review by jerryshao taken in consideration and edited:
- VisibleForTesting deleted because of dependency conflicts
- removed unnecessary reflection for `MetricsSystemImpl`
- added more available types for gauge
## How was this patch tested?
Manual deploy of new yarn-shuffle jar into a Node Manager and verifying that the metrics appear in the Node Manager-standard location. This is JMX with an query endpoint running on `hostname:port`
Resulting metrics look like this:
```
curl -sk -XGET hostname:port | grep -v '#' | grep 'shuffleService'
hadoop_nodemanager_openblockrequestlatencymillis_rate15{name="shuffleService",} 0.31428910657834713
hadoop_nodemanager_blocktransferratebytes_rate15{name="shuffleService",} 566144.9983653595
hadoop_nodemanager_blocktransferratebytes_ratemean{name="shuffleService",} 2464409.9678099006
hadoop_nodemanager_openblockrequestlatencymillis_rate1{name="shuffleService",} 1.2893844732240272
hadoop_nodemanager_registeredexecutorssize{name="shuffleService",} 2.0
hadoop_nodemanager_openblockrequestlatencymillis_ratemean{name="shuffleService",} 1.255574678369966
hadoop_nodemanager_openblockrequestlatencymillis_count{name="shuffleService",} 315.0
hadoop_nodemanager_openblockrequestlatencymillis_rate5{name="shuffleService",} 0.7661929192569739
hadoop_nodemanager_registerexecutorrequestlatencymillis_ratemean{name="shuffleService",} 0.0
hadoop_nodemanager_registerexecutorrequestlatencymillis_count{name="shuffleService",} 0.0
hadoop_nodemanager_registerexecutorrequestlatencymillis_rate1{name="shuffleService",} 0.0
hadoop_nodemanager_registerexecutorrequestlatencymillis_rate5{name="shuffleService",} 0.0
hadoop_nodemanager_blocktransferratebytes_count{name="shuffleService",} 6.18271213E8
hadoop_nodemanager_registerexecutorrequestlatencymillis_rate15{name="shuffleService",} 0.0
hadoop_nodemanager_blocktransferratebytes_rate5{name="shuffleService",} 1154114.4881816586
hadoop_nodemanager_blocktransferratebytes_rate1{name="shuffleService",} 574745.0749848988
```
Closes#22485 from mareksimunek/SPARK-18364.
Lead-authored-by: marek.simunek <marek.simunek@firma.seznam.cz>
Co-authored-by: Andrew Ash <andrew@andrewash.com>
Signed-off-by: Thomas Graves <tgraves@apache.org>
## What changes were proposed in this pull request?
This PR adds a rule to force `.toLowerCase(Locale.ROOT)` or `toUpperCase(Locale.ROOT)`.
It produces an error as below:
```
[error] Are you sure that you want to use toUpperCase or toLowerCase without the root locale? In most cases, you
[error] should use toUpperCase(Locale.ROOT) or toLowerCase(Locale.ROOT) instead.
[error] If you must use toUpperCase or toLowerCase without the root locale, wrap the code block with
[error] // scalastyle:off caselocale
[error] .toUpperCase
[error] .toLowerCase
[error] // scalastyle:on caselocale
```
This PR excludes the cases above for SQL code path for external calls like table name, column name and etc.
For test suites, or when it's clear there's no locale problem like Turkish locale problem, it uses `Locale.ROOT`.
One minor problem is, `UTF8String` has both methods, `toLowerCase` and `toUpperCase`, and the new rule detects them as well. They are ignored.
## How was this patch tested?
Manually tested, and Jenkins tests.
Closes#22581 from HyukjinKwon/SPARK-25565.
Authored-by: hyukjinkwon <gurwls223@apache.org>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>
