YARN-11334. [Federation] Improve SubClusterState#fromString parameter and LogMessage.

[slfan1989]

JIRA: YARN-11334. [Federation] Improve SubClusterState#fromString parameter and LogMessage.

The SubClusterState object has a fromString method, which can be improved in the following 2 places

/**
 * Convert a string into {@code SubClusterState}.
 *
 * @param x the string to convert in SubClusterState
 * @return the respective {@code SubClusterState}
 */
public static SubClusterState fromString(String x) {
  try {
    return SubClusterState.valueOf(x);
  } catch (Exception e) {
    LOG.error("Invalid SubCluster State value in the StateStore does not"
        + " match with the YARN Federation standard.");
    return null;
  }
} 

• The parameter is named x, which cannot well express the meaning of the input parameter.
• The error log does not print the error value.

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 54s		Docker mode activated.
			_ Prechecks _
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+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	42m 17s		trunk passed
+1 💚	compile	0m 54s		trunk passed with JDK Ubuntu-11.0.16+8-post-Ubuntu-0ubuntu120.04
+1 💚	compile	0m 46s		trunk passed with JDK Private Build-1.8.0_342-8u342-b07-0ubuntu1~20.04-b07
+1 💚	checkstyle	0m 38s		trunk passed
+1 💚	mvnsite	0m 53s		trunk passed
+1 💚	javadoc	0m 55s		trunk passed with JDK Ubuntu-11.0.16+8-post-Ubuntu-0ubuntu120.04
+1 💚	javadoc	0m 41s		trunk passed with JDK Private Build-1.8.0_342-8u342-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	1m 50s		trunk passed
+1 💚	shadedclient	24m 28s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 37s		the patch passed
+1 💚	compile	0m 39s		the patch passed with JDK Ubuntu-11.0.16+8-post-Ubuntu-0ubuntu120.04
+1 💚	javac	0m 39s		the patch passed
+1 💚	compile	0m 34s		the patch passed with JDK Private Build-1.8.0_342-8u342-b07-0ubuntu1~20.04-b07
+1 💚	javac	0m 34s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	0m 19s		the patch passed
+1 💚	mvnsite	0m 38s		the patch passed
+1 💚	javadoc	0m 32s		the patch passed with JDK Ubuntu-11.0.16+8-post-Ubuntu-0ubuntu120.04
+1 💚	javadoc	0m 29s		the patch passed with JDK Private Build-1.8.0_342-8u342-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	1m 30s		the patch passed
+1 💚	shadedclient	23m 50s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	3m 0s		hadoop-yarn-server-common in the patch passed.
+1 💚	asflicense	0m 39s		The patch does not generate ASF License warnings.
		107m 19s

Subsystem	Report/Notes
Docker	ClientAPI=1.41 ServerAPI=1.41 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-4988/1/artifact/out/Dockerfile
GITHUB PR	#4988
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell detsecrets
uname	Linux 768b49558c09 4.15.0-191-generic #202-Ubuntu SMP Thu Aug 4 01:49:29 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 074a99b
Default Java	Private Build-1.8.0_342-8u342-b07-0ubuntu1~20.04-b07
Multi-JDK versions	/usr/lib/jvm/java-11-openjdk-amd64:Ubuntu-11.0.16+8-post-Ubuntu-0ubuntu120.04 /usr/lib/jvm/java-8-openjdk-amd64:Private Build-1.8.0_342-8u342-b07-0ubuntu1~20.04-b07
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-4988/1/testReport/
Max. process+thread count	582 (vs. ulimit of 5500)
modules	C: hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common U: hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common
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[slfan1989]

@goiri @ayushtkn Can you help review this PR? Thank you very much! From my personal point of view, there should be no need for unit test.

[ayushtkn]

LGTM

[slfan1989]

@ayushtkn Thank you very much for helping to review the code!

[slfan1989]

@ayushtkn Thank you very much for your help reviewing the code and merging the code!