[SPARK-3121] Wrong implementation of implicit bytesWritableConverter

val path = ... //path to seq file with BytesWritable as type of both key and value
val file = sc.sequenceFile[Array[Byte],Array[Byte]](path)
file.take(1)(0)._1

This prints incorrect content of byte array. Actual content starts with correct one and some "random" bytes and zeros are appended. BytesWritable has two methods:

getBytes() - return content of all internal array which is often longer then actual value stored. It usually contains the rest of previous longer values

copyBytes() - return just begining of internal array determined by internal length property

It looks like in implicit conversion between BytesWritable and Array[byte] getBytes is used instead of correct copyBytes.

dbtsai

Author: Jakub Dubovský <james64@inMail.sk>
Author: Dubovsky Jakub <dubovsky@avast.com>

Closes #2712 from james64/3121-bugfix and squashes the following commits:

f85d24c [Jakub Dubovský] Test name changed, comments added
1b20d51 [Jakub Dubovský] Import placed correctly
406e26c [Jakub Dubovský] Scala style fixed
f92ffa6 [Dubovsky Jakub] performance tuning
480f9cd [Dubovsky Jakub] Bug 3121 fixed
[SPARK-3905][Web UI]The keys for sorting the columns of Executor page ,Stage page Storage page are incorrect

Author: GuoQiang Li <witgo@qq.com>

Closes #2763 from witgo/SPARK-3905 and squashes the following commits:

17d7990 [GuoQiang Li] The keys for sorting the columns of Executor page ,Stage page Storage page are incorrect
Add echo "Run streaming tests ..."

Author: Ken Takagiwa <ugw.gi.world@gmail.com>

Closes #2778 from giwa/patch-2 and squashes the following commits:

a59f9a1 [Ken Takagiwa] Add echo "Run streaming tests ..."
[SPARK-3899][Doc]fix wrong links in streaming doc

There are three  [Custom Receiver Guide] links in streaming doc, the first is wrong.

Author: w00228970 <wangfei1@huawei.com>
Author: wangfei <wangfei1@huawei.com>

Closes #2749 from scwf/streaming-doc and squashes the following commits:

0cd76b7 [wangfei] update link tojump to the Akka-specific section
45b0646 [w00228970] wrong link in streaming doc