HADOOP-19319. configurationChangeMonitor is not properly set on HttpServer2

[eubnara]

Description of PR

When I'm trying to mimic HADOOP-16524 and make a contribution to HBASE-28911, I found that configurationChangeMonitor is not properly set on HttpServer2.java and it is not gracefully cancelled on HttpServer2#stop().

How was this patch tested?

Manual test.

For code changes:

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

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	7m 29s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 0s		No case conflicting files found.
+0 🆗	codespell	0m 1s		codespell was not available.
+0 🆗	detsecrets	0m 1s		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	34m 31s		trunk passed
-1 ❌	compile	0m 16s	/branch-compile-root-jdkUbuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04.txt	root in trunk failed with JDK Ubuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04.
+1 💚	compile	9m 34s		trunk passed with JDK Private Build-1.8.0_422-8u422-b05-1~20.04-b05
+1 💚	checkstyle	0m 43s		trunk passed
+1 💚	mvnsite	1m 0s		trunk passed
+1 💚	javadoc	0m 48s		trunk passed with JDK Ubuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04
+1 💚	javadoc	0m 32s		trunk passed with JDK Private Build-1.8.0_422-8u422-b05-1~20.04-b05
+1 💚	spotbugs	1m 35s		trunk passed
+1 💚	shadedclient	24m 9s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 36s		the patch passed
-1 ❌	compile	0m 12s	/patch-compile-root-jdkUbuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04.txt	root in the patch failed with JDK Ubuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04.
-1 ❌	javac	0m 12s	/patch-compile-root-jdkUbuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04.txt	root in the patch failed with JDK Ubuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04.
+1 💚	compile	8m 59s		the patch passed with JDK Private Build-1.8.0_422-8u422-b05-1~20.04-b05
+1 💚	javac	8m 59s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	0m 38s		the patch passed
+1 💚	mvnsite	1m 2s		the patch passed
+1 💚	javadoc	0m 42s		the patch passed with JDK Ubuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04
+1 💚	javadoc	0m 33s		the patch passed with JDK Private Build-1.8.0_422-8u422-b05-1~20.04-b05
+1 💚	spotbugs	1m 38s		the patch passed
+1 💚	shadedclient	24m 32s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	16m 49s		hadoop-common in the patch passed.
+1 💚	asflicense	0m 38s		The patch does not generate ASF License warnings.
		137m 34s

Subsystem	Report/Notes
Docker	ClientAPI=1.47 ServerAPI=1.47 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7131/1/artifact/out/Dockerfile
GITHUB PR	#7131
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell detsecrets
uname	Linux c03a39a6dc2e 5.15.0-124-generic #134-Ubuntu SMP Fri Sep 27 20:20:17 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 08e3da7
Default Java	Private Build-1.8.0_422-8u422-b05-1~20.04-b05
Multi-JDK versions	/usr/lib/jvm/java-11-openjdk-amd64:Ubuntu-11.0.24+8-post-Ubuntu-1ubuntu320.04 /usr/lib/jvm/java-8-openjdk-amd64:Private Build-1.8.0_422-8u422-b05-1~20.04-b05
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7131/1/testReport/
Max. process+thread count	1275 (vs. ulimit of 5500)
modules	C: hadoop-common-project/hadoop-common U: hadoop-common-project/hadoop-common
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-7131/1/console
versions	git=2.25.1 maven=3.6.3 spotbugs=4.2.2
Powered by	Apache Yetus 0.14.0 https://yetus.apache.org

This message was automatically generated.