https://community.cloudera.com/t5/Support-Questions/Namenode-service-failure-in-Active-and-standby-server/m-p/302371#M221091 <P>Hello&nbsp;<a href="https://community.cloudera.com/t5/user/viewprofilepage/user-id/78129">@Atradius</a>&nbsp;,</P><P>&nbsp;</P><P>thank you for reaching out to the Community with your issue of having both NameNodes down.</P><P>&nbsp;</P><P>Do you see in your NN log entries like&nbsp;JvmPauseMonitor saying "Detected pause in JVM or host machine" and a value larger than 1000ms, please? It can be an indication that your service is running out of heap. If it is the NameNode, the short-term solution is to increase the heap and restart the service. A long term solution is to identify why did you run out of heap? E.g. do you face with small files issue? Please read article [1] about how to tackle this.</P><P>&nbsp;</P><P>Losing quorum might be caused by ZK service issue, when the ZK is not in quorum. Please check the ZK logs as well.</P><P>&nbsp;</P><P>Please let us know if you need more input to progress with your investigation.</P><P>&nbsp;</P><P>Best regards:</P><P>Ferenc</P><P>&nbsp;</P><P>[1] <A href="https://blog.cloudera.com/small-files-big-foils-addressing-the-associated-metadata-and-application-challenges/" target="_blank">https://blog.cloudera.com/small-files-big-foils-addressing-the-associated-metadata-and-application-challenges/</A></P> Fri, 04 Sep 2020 10:37:05 GMT Bender 2020-09-04T10:37:05Z