HADOOP-17861. improve YARN Registry DNS Server qps

[eubnara]

Description of PR

There are some points to improve the performance of YARN Registry DNS Server.

• Do not print unnecessary logs (It just needs change log4j.properties)
  • log4j.logger.org.apache.hadoop.registry.server.dns=WARN
• Change some loglevels at points which can affect performance degradation.
• Use "newFixedThreadPool" instead of "newCachedThreadPool" to prevent OOM
• Use Blocking on TCP handler. Using non-blocking and sleeping some time("Thread.sleep(500)") is meaningless.

In our environment, QPS of original yarn dns server is about 5000 (UDP), 100 (TCP).
Now, QPS of our improved yarn dns server is about 47000 (UDP), 500 (TCP).

I will make a pull request at https://github.com/apache/hadoop soon.

How was this patch tested?

Our team members have tested this manually in our cluster.

For code changes:

• Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')?
• Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE, LICENSE-binary, NOTICE-binary files?

[eubnara]

@edwardcapriolo
I addressed your PR comment. (#8106 (comment))
Could you review it please?

@jian-he
I found it your previous commit. Could you review it, please?

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	7m 15s		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.
-1 ❌	test4tests	0m 0s		The patch doesn't appear to include any new or modified tests. Please justify why no new tests are needed for this patch. Also please list what manual steps were performed to verify this patch.
			_ trunk Compile Tests _
+1 💚	mvninstall	26m 27s		trunk passed
+1 💚	compile	8m 46s		trunk passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	compile	8m 55s		trunk passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	checkstyle	0m 36s		trunk passed
+1 💚	mvnsite	0m 38s		trunk passed
+1 💚	javadoc	0m 35s		trunk passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javadoc	0m 34s		trunk passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	spotbugs	0m 51s		trunk passed
+1 💚	shadedclient	15m 59s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 14s		the patch passed
+1 💚	compile	8m 13s		the patch passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javac	8m 13s		the patch passed
+1 💚	compile	8m 55s		the patch passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	javac	8m 55s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	0m 31s		the patch passed
+1 💚	mvnsite	0m 36s		the patch passed
-1 ❌	javadoc	0m 36s	/results-javadoc-javadoc-hadoop-common-project_hadoop-registry-jdkUbuntu-21.0.10+7-Ubuntu-124.04.txt	hadoop-common-project_hadoop-registry-jdkUbuntu-21.0.10+7-Ubuntu-124.04 with JDK Ubuntu-21.0.10+7-Ubuntu-124.04 generated 1 new + 136 unchanged - 0 fixed = 137 total (was 136)
-1 ❌	javadoc	0m 33s	/results-javadoc-javadoc-hadoop-common-project_hadoop-registry-jdkUbuntu-17.0.18+8-Ubuntu-124.04.1.txt	hadoop-common-project_hadoop-registry-jdkUbuntu-17.0.18+8-Ubuntu-124.04.1 with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1 generated 1 new + 129 unchanged - 0 fixed = 130 total (was 129)
-1 ❌	spotbugs	0m 57s	/new-spotbugs-hadoop-common-project_hadoop-registry.html	hadoop-common-project/hadoop-registry generated 1 new + 0 unchanged - 0 fixed = 1 total (was 0)
+1 💚	shadedclient	16m 1s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	1m 9s		hadoop-registry in the patch passed.
+1 💚	asflicense	0m 49s		The patch does not generate ASF License warnings.
		112m 29s

Reason	Tests
SpotBugs	module:hadoop-common-project/hadoop-registry
	Exceptional return value of java.util.concurrent.ExecutorService.submit(Callable) ignored in org.apache.hadoop.registry.server.dns.RegistryDNS.serveNIOUDP(DatagramChannel) At RegistryDNS.java:ignored in org.apache.hadoop.registry.server.dns.RegistryDNS.serveNIOUDP(DatagramChannel) At RegistryDNS.java:[line 1053]

Subsystem	Report/Notes
Docker	ClientAPI=1.54 ServerAPI=1.54 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8458/1/artifact/out/Dockerfile
GITHUB PR	#8458
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell detsecrets
uname	Linux 2d8e4e4a5f72 5.15.0-173-generic #183-Ubuntu SMP Fri Mar 6 13:29:34 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 633004e
Default Java	Ubuntu-17.0.18+8-Ubuntu-124.04.1
Multi-JDK versions	/usr/lib/jvm/java-21-openjdk-amd64:Ubuntu-21.0.10+7-Ubuntu-124.04 /usr/lib/jvm/java-17-openjdk-amd64:Ubuntu-17.0.18+8-Ubuntu-124.04.1
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8458/1/testReport/
Max. process+thread count	635 (vs. ulimit of 10000)
modules	C: hadoop-common-project/hadoop-registry U: hadoop-common-project/hadoop-registry
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8458/1/console
versions	git=2.43.0 maven=3.9.11 spotbugs=4.9.7
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