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Karthik Kambatla commented on YARN-1867: ---------------------------------------- It appears the RM doesn't have the ACLs corresponding to an application from {{RMContext#getRMApps()}}. We couldn't reproduce this. The cluster had RM failover with app recovery. Couldn't identify the source of this through visual inspection. This can happen when the RM goes down (or restarted, or failed over) between adding the app and adding the ACLs for the app. If that were the case, I see the following solutions: # If ACLs are not available, use the default value. # Reverse the order of adding an app to ACLsManager and RMContext. > NPE while fetching apps via the REST API > ---------------------------------------- > > Key: YARN-1867 > URL: https://issues.apache.org/jira/browse/YARN-1867 > Project: Hadoop YARN > Issue Type: Bug > Components: resourcemanager > Affects Versions: 2.4.0 > Reporter: Karthik Kambatla > Assignee: Karthik Kambatla > Priority: Blocker > Labels: rest_api > > We ran into the following NPE when fetching applications using the REST API: > {noformat} > INTERNAL_SERVER_ERROR > java.lang.NullPointerException > at > org.apache.hadoop.yarn.server.security.ApplicationACLsManager.checkAccess(ApplicationACLsManager.java:104) > at > org.apache.hadoop.yarn.server.resourcemanager.webapp.RMWebServices.hasAccess(RMWebServices.java:123) > at > org.apache.hadoop.yarn.server.resourcemanager.webapp.RMWebServices.getApps(RMWebServices.java:418) > {noformat} -- This message was sent by Atlassian JIRA (v6.2#6252)