HADOOP-19056. Highlight RBF features and improvements targeting version 3.4.

[tasanuma]

Description of PR

JIRA: HADOOP-19056

A large number of developers from various companies have contributed to RBF, and I want to highlight recent RBF features and improvements.

• Support observer node from Router-Based Federation
• Enhanced IPC throughput between Router and NameNode
• Improved isolation for downstream name nodes.

How was this patch tested?

For code changes:

• Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')?

[tasanuma]

@slfan1989 I'm really sorry for being late, but if there is a chance to incorporate changes into 3.4.0, could you consider including this PR? If RC1 has already been created, perhaps it would be best for us to simply merge this into the trunk.

[hadoop-yetus]

🎊 +1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 33s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 0s		No case conflicting files found.
+0 🆗	codespell	0m 0s		codespell was not available.
+0 🆗	detsecrets	0m 0s		detect-secrets was not available.
+1 💚	@author	0m 0s		The patch does not contain any @author tags.
			_ trunk Compile Tests _
+1 💚	mvninstall	42m 56s		trunk passed
+1 💚	mvnsite	0m 25s		trunk passed
+1 💚	shadedclient	76m 17s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 13s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	mvnsite	0m 15s		the patch passed
+1 💚	shadedclient	32m 25s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	asflicense	0m 36s		The patch does not generate ASF License warnings.
		114m 14s

Subsystem	Report/Notes
Docker	ClientAPI=1.44 ServerAPI=1.44 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-6512/1/artifact/out/Dockerfile
GITHUB PR	#6512
Optional Tests	dupname asflicense mvnsite codespell detsecrets
uname	Linux 7409fb68ea70 5.15.0-88-generic #98-Ubuntu SMP Mon Oct 2 15:18:56 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 62806a9
Max. process+thread count	718 (vs. ulimit of 5500)
modules	C: hadoop-project U: hadoop-project
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-6512/1/console
versions	git=2.25.1 maven=3.6.3
Powered by	Apache Yetus 0.14.0 https://yetus.apache.org

This message was automatically generated.

[slfan1989]

@slfan1989 I'm really sorry for being late, but if there is a chance to incorporate changes into 3.4.0, could you consider including this PR? If RC1 has already been created, perhaps it would be best for us to simply merge this into the trunk.

@tasanuma Thank you very much for providing the RBF Highlight. We can add this part of the content to Hadoop-3.4.0 RC2. Hadoop-3.4.0-RC1 has been packaged and voting will begin soon.

cc: @Hexiaoqiao

[tasanuma]

@slfan1989 I understand. Thank you!

[brahmareddybattula]

@tasanuma thanks for reporting this and collecting all these jira's.
are these part of hadoop-3.3 itself..?

[tasanuma]

@brahmareddybattula Thanks for your review.
In the JIRA issues I highlighted, only HADOOP-13144 has been released in 3.3.5. However, I included it because HADOOP-13144, along with HDFS-13274 and HDFS-15757, are a set that enhances the IPC throughput for RBF.

[slfan1989]

@tasanuma Thanks for the contribution! merged into trunk.

[tasanuma]

Thanks for merging it, @slfan1989.

[slfan1989]

@tasanuma Hadoop-3.4.0-RC1 and Hadoop-Thirdparty-1.2.0-RC0 voting has started. I kindly request your assistance in reviewing and providing some suggestions. Thank you very much!

[VOTE] Release Apache Hadoop 3.4.0 (RC1)
https://lists.apache.org/thread/gzx1tr0x57oh7q88fh8hd0917jl00mf6

[VOTE] Release Apache Hadoop Thirdparty 1.2.0 (RC0)
https://lists.apache.org/thread/s5n58oqgnjkljo2xj8tsdm1h5jw59w06

cc: @Hexiaoqiao