HDFS-4277. SocketTimeoutExceptions over the DataXceiver service of a DN should print the DFSClient ID

[balodesecurity]

Summary

• When a SocketTimeoutException (or other error) occurs in the DataXceiver service, the log messages did not include the DFSClient ID, making it impossible to trace which client caused the error.
• Added previousOpClientName (the DFSClient ID) to the shared error string in run()'s catch block, which covers all error paths including SocketTimeoutException during READ_BLOCK.
• Also added clientName to exception log messages directly in readBlock(), writeBlock(), and transferBlock() for completeness.

Changes

• DataXceiver.run(): include previousOpClientName in the error string used across all exception branches
• DataXceiver.readBlock(): add clientName to SocketException (TRACE) and IOException (WARN) log messages
• DataXceiver.writeBlock(): add clientname to the IOException log message
• DataXceiver.transferBlock(): add clientName to the IOException log message

Test plan

• Existing TestDataXceiverBackwardsCompat passes
• Existing TestDataXceiverLazyPersistHint passes
• CI (Yetus) build passes on trunk

🤖 Generated with Claude Code

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 21s		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	28m 17s		trunk passed
+1 💚	compile	0m 53s		trunk passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	compile	0m 57s		trunk passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	checkstyle	1m 1s		trunk passed
+1 💚	mvnsite	0m 59s		trunk passed
+1 💚	javadoc	0m 52s		trunk passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javadoc	0m 56s		trunk passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	spotbugs	2m 11s		trunk passed
+1 💚	shadedclient	16m 39s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 43s		the patch passed
+1 💚	compile	0m 37s		the patch passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javac	0m 37s		the patch passed
+1 💚	compile	0m 44s		the patch passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	javac	0m 44s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	0m 42s		the patch passed
+1 💚	mvnsite	0m 44s		the patch passed
+1 💚	javadoc	0m 33s		the patch passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javadoc	0m 34s		the patch passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	spotbugs	1m 59s		the patch passed
+1 💚	shadedclient	16m 17s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
-1 ❌	unit	175m 54s	/patch-unit-hadoop-hdfs-project_hadoop-hdfs.txt	hadoop-hdfs in the patch passed.
+1 💚	asflicense	0m 25s		The patch does not generate ASF License warnings.
		251m 56s

Reason	Tests
Failed junit tests	hadoop.hdfs.tools.TestDFSAdmin

Subsystem	Report/Notes
Docker	ClientAPI=1.53 ServerAPI=1.53 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8271/1/artifact/out/Dockerfile
GITHUB PR	#8271
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell detsecrets
uname	Linux efcb0d9e0f13 5.15.0-164-generic #174-Ubuntu SMP Fri Nov 14 20:25:16 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / e80c2ca
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-8271/1/testReport/
Max. process+thread count	4204 (vs. ulimit of 5500)
modules	C: hadoop-hdfs-project/hadoop-hdfs U: hadoop-hdfs-project/hadoop-hdfs
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8271/1/console
versions	git=2.43.0 maven=3.9.11 spotbugs=4.9.7
Powered by	Apache Yetus 0.14.1 https://yetus.apache.org

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[balodesecurity]

This change is purely additive to logging — it only includes the DFSClient ID in existing error log messages in DataXceiver.java. No functional behavior, control flow, or data handling is modified. The existing test suite fully validates the unchanged logic. Adding new unit tests for a log message change would not provide meaningful coverage beyond what is already present.

[balodesecurity]

The TestDFSAdmin failure in the CI run is a pre-existing flaky test unrelated to this patch, fixed by HDFS-17885 (PR #8269, merged Feb 23).

[balodesecurity]

CC @cnauroth @aajisaka — would appreciate a review when you have a chance. This is a small logging improvement that adds the DFSClient ID to error messages in DataXceiver.java to make debugging client-specific failures easier.

[balodesecurity]

retest this please