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Allen Wittenauer commented on HDFS-779: --------------------------------------- bq. I don't want to ever have to explain to Allen that the system is operating in "catastrophic mode." ... and, given this JIRA is still open, you haven't had to Rob. But should this JIRA still be open? That's the question I have for all of you. > Automatic move to safe-mode when cluster size drops > --------------------------------------------------- > > Key: HDFS-779 > URL: https://issues.apache.org/jira/browse/HDFS-779 > Project: Hadoop HDFS > Issue Type: New Feature > Components: namenode > Reporter: Owen O'Malley > Assignee: dhruba borthakur > > As part of looking at using Kerberos, we want to avoid the case where both > the primary (and optional secondary) KDC go offline causing a replication > storm as the DataNodes' service tickets time out and they lose the ability to > connect to the NameNode. However, this is a specific case of a more general > problem of loosing too many nodes too quickly. I think we should have an > option to go into safe mode if the cluster size goes down more than N% in > terms of DataNodes. -- This message was sent by Atlassian JIRA (v6.2#6252)