[
https://issues.apache.org/jira/browse/YARN-11924?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18055559#comment-18055559
]
ASF GitHub Bot commented on YARN-11924:
---------------------------------------
ferdelyi commented on code in PR #8222:
URL: https://github.com/apache/hadoop/pull/8222#discussion_r2748271721
##########
hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/ZKConfigurationStore.java:
##########
@@ -263,10 +264,46 @@ private boolean createNewZkPath(String path) throws
Exception {
}
}
+ /*
@VisibleForTesting
protected byte[] getZkData(String path) throws Exception {
return zkManager.getData(path);
}
+*/
+
+ @VisibleForTesting
+ protected byte[] getZkData(String path) throws Exception {
+ // Should a 'yarn resourcemanager -format-state-store' command is issued
+ // while one of the RM is in a starting state, there is a time period
+ // when the /confstore/CONF_STORE path does not exist, hence the
+ // getZkData method returns a null value causing the RM to fail.
+ // To prevent this, added a re-try mechanism before giving up.
+ int maxRetries = 6;
+ int attempt = 1;
+ int sleepBetweenRetries = conf.getInt(
+ YarnConfiguration.RM_SCHEDCONF_STORE_ZK_READ_RETRY_SECS,
+ YarnConfiguration.DEFAULT_RM_SCHEDCONF_STORE_ZK_READ_RETRY_SECS);
+
+ while (attempt < maxRetries) {
+
+ if(zkManager.exists(path)) {
+ LOG.debug("zkManager.exists(path) {} exists.", path);
+ byte[] zkData = zkManager.getData(path);
+ // If we found data, return immediately
Review Comment:
You are right, thank you!
> Add zkManager.exists(path) check to ZKConfigurationStore:getZkData() and
> retry mechanism
> ----------------------------------------------------------------------------------------
>
> Key: YARN-11924
> URL: https://issues.apache.org/jira/browse/YARN-11924
> Project: Hadoop YARN
> Issue Type: Bug
> Reporter: Ferenc Erdelyi
> Assignee: Ferenc Erdelyi
> Priority: Major
> Labels: pull-request-available
>
> Should a "yarn resourcemanager -format-state-store" command be issued while
> one of the RM is starting and in the INIT state (because of YARN-11551),
> there is a time period when the /confstore/CONF_STORE path does not exist,
> hence the getZkData method returns a null value, causing the RM to fail. To
> prevent this, add a check and re-try mechanism before giving up.
>
> {code:java}
> FATAL org.apache.hadoop.yarn.server.resourcemanager.ResourceManager: Error
> starting ResourceManagerorg.apache.hadoop.service.ServiceStateException:
> org.apache.hadoop.yarn.exceptions.YarnException: Failed to initialize queues
> at
> org.apache.hadoop.service.ServiceStateException.convert(ServiceStateException.java:105)
> at
> org.apache.hadoop.service.AbstractService.init(AbstractService.java:173)
> at
> org.apache.hadoop.service.CompositeService.serviceInit(CompositeService.java:108)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager$RMActiveServices.serviceInit(ResourceManager.java:875)
> at org.apache.hadoop.service.AbstractService.init(AbstractService.java:164)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.createAndInitActiveServices(ResourceManager.java:1293)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.serviceInit(ResourceManager.java:334)
> at org.apache.hadoop.service.AbstractService.init(AbstractService.java:164)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.main(ResourceManager.java:1580)Caused
> by: org.apache.hadoop.yarn.exceptions.YarnException: Failed to initialize
> queues at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.initializeQueues(CapacityScheduler.java:738)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.initScheduler(CapacityScheduler.java:312)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.serviceInit(CapacityScheduler.java:403)
> at
> org.apache.hadoop.service.AbstractService.init(AbstractService.java:164)
> ... 7 moreCaused by: java.lang.IllegalStateException: Queue configuration
> missing child queue names for root at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerQueueManager.validateParent(CapacitySchedulerQueueManager.java:741)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerQueueManager.parseQueue(CapacitySchedulerQueueManager.java:255)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerQueueManager.initializeQueues(CapacitySchedulerQueueManager.java:177)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.initializeQueues(CapacityScheduler.java:729)
> ... 10 more {code}
>
> As a troubleshooting step, I've added locks, and this is the point when
> noticed that the underlying issue is an NPE:
>
> {code:java}
> 2026-01-26 16:19:54,961 INFO
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf.ZKConfigurationStore:
> ZK confstore is locked for reading. Readers can access it.2026-01-26
> 16:19:54,962 ERROR
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf.ZKConfigurationStore:
> Failed to retrieve configuration from zookeeper
> storeorg.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode =
> NoNode for /confstore/CONF_STORE at
> org.apache.zookeeper.KeeperException.create(KeeperException.java:118)
> at org.apache.zookeeper.KeeperException.create(KeeperException.java:54) at
> org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:1972) at
> org.apache.curator.framework.imps.GetDataBuilderImpl$4.call(GetDataBuilderImpl.java:327)
> at
> org.apache.curator.framework.imps.GetDataBuilderImpl$4.call(GetDataBuilderImpl.java:316)
> at org.apache.curator.RetryLoop.callWithRetry(RetryLoop.java:93)
> at
> org.apache.curator.framework.imps.GetDataBuilderImpl.pathInForeground(GetDataBuilderImpl.java:313)
> at
> org.apache.curator.framework.imps.GetDataBuilderImpl.forPath(GetDataBuilderImpl.java:304)
> at
> org.apache.curator.framework.imps.GetDataBuilderImpl.forPath(GetDataBuilderImpl.java:35)
> at
> org.apache.hadoop.util.curator.ZKCuratorManager.getData(ZKCuratorManager.java:240)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf.ZKConfigurationStore.getZkData(ZKConfigurationStore.java:334)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf.ZKConfigurationStore.retrieve(ZKConfigurationStore.java:272)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf.MutableCSConfigurationProvider.init(MutableCSConfigurationProvider.java:83)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.initScheduler(CapacityScheduler.java:302)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.serviceInit(CapacityScheduler.java:413)
> at
> org.apache.hadoop.service.AbstractService.init(AbstractService.java:165)
> at
> org.apache.hadoop.service.CompositeService.serviceInit(CompositeService.java:110)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager$RMActiveServices.serviceInit(ResourceManager.java:995)
> at org.apache.hadoop.service.AbstractService.init(AbstractService.java:165)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.createAndInitActiveServices(ResourceManager.java:1508)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.serviceInit(ResourceManager.java:351)
> at org.apache.hadoop.service.AbstractService.init(AbstractService.java:165)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.main(ResourceManager.java:1797)2026-01-26
> 16:19:54,966 INFO
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.ConfigurationMutationACLPolicyFactory:
> Using ConfigurationMutationACLPolicy implementation - class
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.DefaultConfigurationMutationACLPolicy2026-01-26
> 16:19:54,966 INFO org.apache.hadoop.service.AbstractService: Service
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler
> failed in state INITEDjava.lang.NullPointerException: Cannot enter
> synchronized block because "other" is null at
> org.apache.hadoop.conf.Configuration.<init>(Configuration.java:845) at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.conf.MutableCSConfigurationProvider.loadConfiguration(MutableCSConfigurationProvider.java:102)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.initScheduler(CapacityScheduler.java:303)
> at
> org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler.serviceInit(CapacityScheduler.java:413)
> at
> org.apache.hadoop.service.AbstractService.init(AbstractService.java:165)
> at
> org.apache.hadoop.service.CompositeService.serviceInit(CompositeService.java:110)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager$RMActiveServices.serviceInit(ResourceManager.java:995)
> at org.apache.hadoop.service.AbstractService.init(AbstractService.java:165)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.createAndInitActiveServices(ResourceManager.java:1508)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.serviceInit(ResourceManager.java:351)
> at org.apache.hadoop.service.AbstractService.init(AbstractService.java:165)
> at
> org.apache.hadoop.yarn.server.resourcemanager.ResourceManager.main(ResourceManager.java:1797)
> {code}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
