Hello,   Ambari on HDP cluster (v. 3.1.0.0 - 78) shows the following alert for the service YARN TIMELINE SERVICE V2.0 READER:   The alert is still showing even after performing all the step described here:  https://community.cloudera.com/t5/Support-Questions/ATS-hbase-does-not-seem-to-start/td-p/235155 https://thisdataguy.com/2019/01/11/ats-server-does-not-start/   Furthermore: - Oozie jobs get unsuccessful response from TimelineServer v2, as follows:   2020-05-20 10:46:08,871 ERROR [pool-10-thread-1] org.apache.hadoop.yarn.client.api.impl.TimelineV2ClientImpl: Response from the timeline server is not successful, HTTP error code: 500, Server response: {"exception":"WebApplicationException","message":"org.apache.hadoop.hbase.client.RetriesExhaustedWithDetailsException: Failed 201 actions: NotServingRegionException: 201 times, servers with issues: xxx.xxx.local,61320,1576513062105","javaClassName":"javax.ws.rs.WebApplicationException"} 2020-05-20 10:46:08,872 ERROR [Job ATS Event Dispatcher] org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler: Exception while publishing configs on JOB_SUBMITTED Event for the job : job_1589797714740_0025 org.apache.hadoop.yarn.exceptions.YarnException: Failed while publishing entity at org.apache.hadoop.yarn.client.api.impl.TimelineV2ClientImpl$TimelineEntityDispatcher.dispatchEntities(TimelineV2ClientImpl.java:548) at org.apache.hadoop.yarn.client.api.impl.TimelineV2ClientImpl.putEntities(TimelineV2ClientImpl.java:149) at org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler.publishConfigsOnJobSubmittedEvent(JobHistoryEventHandler.java:1255) at org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler.processEventForNewTimelineService(JobHistoryEventHandler.java:1414) at org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler.handleTimelineEvent(JobHistoryEventHandler.java:742) at org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler.access$1200(JobHistoryEventHandler.java:93) at org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler$ForwardingEventHandler.handle(JobHistoryEventHandler.java:1795) at org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler$ForwardingEventHandler.handle(JobHistoryEventHandler.java:1791) at org.apache.hadoop.yarn.event.AsyncDispatcher.dispatch(AsyncDispatcher.java:197) at org.apache.hadoop.yarn.event.AsyncDispatcher$1.run(AsyncDispatcher.java:126) at java.lang.Thread.run(Thread.java:745) Caused by: org.apache.hadoop.yarn.exceptions.YarnException: Response from the timeline server is not successful, HTTP error code: 500, Server response: {"exception":"WebApplicationException","message":"org.apache.hadoop.hbase.client.RetriesExhaustedWithDetailsException: Failed 201 actions: NotServingRegionException: 201 times, servers with issues: xxx.xxx.local,61320,1576513062105","javaClassName":"javax.ws.rs.WebApplicationException"} at org.apache.hadoop.yarn.client.api.impl.TimelineV2ClientImpl.putObjects(TimelineV2ClientImpl.java:322) at org.apache.hadoop.yarn.client.api.impl.TimelineV2ClientImpl.putObjects(TimelineV2ClientImpl.java:251)   - In HBase (v. 2.0.2) there are many regions in transitions and the hbase hbck –details command shows the following errors:   ... Number of regions in transition: 64 ... prod.timelineservice.entity,an,1576512763369.ca2577830eb1ec2858fecb3a182bb7ec. state=OPENING, ts=Thu May 21 08:50:49 CEST 2020 (PT29M32.253S ago), server=nul ... prod.timelineservice.application,,1576512767939.d87a0e7a2f479d6f73e697bfcac9d415. state=OPENING, ts=Thu May 21 08:50:49 CEST 2020 (PT29M32.262S ago), server=null ... ---- Table 'prod.timelineservice.application': overlap groups There are 0 overlap groups with 0 overlapping regions ERROR: Found inconsistency in table prod.timelineservice.application ... ERROR: There is a hole in the region chain between ad and an. You need to create a new .regioninfo and region dir in hdfs to plug the hole ... Status: INCONSISTENT   - HBase prod.timelineservice.* tables are not online, as shows below in HBase shell:   Any help would be really appreciated. Thanks ... View more