[ https://issues.apache.org/jira/browse/HADOOP-17866?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Prabhu Joseph moved YARN-10857 to HADOOP-17866: ----------------------------------------------- Component/s: (was: yarn) (was: client) Key: HADOOP-17866 (was: YARN-10857) Project: Hadoop Common (was: Hadoop YARN) > YarnClient Caching Addresses > ---------------------------- > > Key: HADOOP-17866 > URL: https://issues.apache.org/jira/browse/HADOOP-17866 > Project: Hadoop Common > Issue Type: Improvement > Reporter: Steve Suh > Assignee: Prabhu Joseph > Priority: Minor > > We have noticed that when the YarnClient is initialized and used, it is not > very resilient when dns or /etc/hosts is modified in the following scenario: > Take for instance the following (and reproducable) sequence of events that > can occur on a service that instantiates and uses YarnClient. > - Yarn has rm HA enabled (*yarn.resourcemanager.ha.enabled* is *true*) and > there are two rms (rm1 and rm2). > - *yarn.client.failover-proxy-provider* is set to > *org.apache.hadoop.yarn.client.RequestHedgingRMFailoverProxyProvider* > 1) rm2 is currently the active rm > 2) /etc/hosts (or dns) is missing host information for rm2 > 3) A service is started and it initializes the YarnClient at startup. > 4) At some point in time after YarnClient is done initializing, /etc/hosts > is updated and contains host information for rm2 > 5) Yarn is queried, for instance calling *yarnclient.getApplications()* > 6) All YarnClient attempts to communicate with rm2 fail with > UnknownHostExceptions, even though /etc/hosts now contains host information > for it. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org