HDFS-17918. WebHDFS client-side failover fails during NameNode fsimage loading in HA

[magnuma3]

Description of PR

When NameNode is configured with HA and NameNode 1 is restarting and loading fsimage, accessing WebHDFS does not trigger client-side failover.

During fsimage loading after NameNode restart in HA configuration, WebHDFS returns RetriableException instead of StandbyException. Because of this, the client-side failover does not work and the client keeps retrying the same NameNode. Eventually the client fails because it cannot find the active NameNode.

$ hdfs dfs -ls swebhdfs://blue
2023-07-14 12:23:55,890 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 0 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 0ms.
2023-07-14 12:23:55,929 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 1 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 731ms.
2023-07-14 12:23:56,697 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 2 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 1475ms.
2023-07-14 12:23:58,207 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 3 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 5061ms.
2023-07-14 12:24:03,304 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 4 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 7898ms.
2023-07-14 12:24:11,235 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 5 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 18847ms.
2023-07-14 12:24:30,117 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 6 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 20826ms.
2023-07-14 12:24:50,979 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 7 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 10374ms.
2023-07-14 12:25:01,385 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 8 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 16640ms.
2023-07-14 12:25:18,059 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 9 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 15514ms.
2023-07-14 12:25:33,610 INFO web.WebHdfsFileSystem: Retrying connect to namenode: blue-nn1.host/10.10.10.10:9470. Already retried 10 time(s); retry policy is org.apache.hadoop.io.retry.RetryPolicies$FailoverOnNetworkExceptionRetry@95e33cc, delay 10745ms.
ls: Namenode is in startup mode

How was this patch tested?

Added unit test. Also verified on a real HA cluster that client-side failover works correctly after the fix.

For code changes:

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• If applicable, have you updated the LICENSE, LICENSE-binary, NOTICE-binary files?

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[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 22s		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 appears to include 1 new or modified test files.
			_ trunk Compile Tests _
+1 💚	mvninstall	26m 22s		trunk passed
+1 💚	compile	0m 55s		trunk passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	compile	0m 53s		trunk passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	checkstyle	0m 59s		trunk passed
+1 💚	mvnsite	1m 1s		trunk passed
+1 💚	javadoc	0m 53s		trunk passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javadoc	0m 49s		trunk passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	spotbugs	2m 10s		trunk passed
+1 💚	shadedclient	17m 59s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 47s		the patch passed
+1 💚	compile	0m 40s		the patch passed with JDK Ubuntu-21.0.10+7-Ubuntu-124.04
+1 💚	javac	0m 40s		the patch passed
+1 💚	compile	0m 40s		the patch passed with JDK Ubuntu-17.0.18+8-Ubuntu-124.04.1
+1 💚	javac	0m 40s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
-0 ⚠️	checkstyle	0m 45s	/results-checkstyle-hadoop-hdfs-project_hadoop-hdfs.txt	hadoop-hdfs-project/hadoop-hdfs: The patch generated 3 new + 130 unchanged - 1 fixed = 133 total (was 131)
+1 💚	mvnsite	0m 46s		the patch passed
+1 💚	javadoc	0m 32s		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	2m 3s		the patch passed
+1 💚	shadedclient	17m 3s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
-1 ❌	unit	185m 40s	/patch-unit-hadoop-hdfs-project_hadoop-hdfs.txt	hadoop-hdfs in the patch passed.
+1 💚	asflicense	0m 28s		The patch does not generate ASF License warnings.
		261m 50s

Reason	Tests
Failed junit tests	hadoop.hdfs.server.balancer.TestBalancerWithHANameNodes

Subsystem	Report/Notes
Docker	ClientAPI=1.54 ServerAPI=1.54 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8487/1/artifact/out/Dockerfile
GITHUB PR	#8487
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell detsecrets
uname	Linux bba5b49fb61b 5.15.0-141-generic #151-Ubuntu SMP Sun May 18 21:35:19 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / a076f8b
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-8487/1/testReport/
Max. process+thread count	4179 (vs. ulimit of 10000)
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-8487/1/console
versions	git=2.43.0 maven=3.9.15 spotbugs=4.9.7
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