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Kihwal Lee commented on HDFS-13775: ----------------------------------- It could be meaningless if the host is running a caching daemon (e.g. nscd) and its is doing negative caching. > Add a conf property to retry dns reverse lookups during datanode registration > ----------------------------------------------------------------------------- > > Key: HDFS-13775 > URL: https://issues.apache.org/jira/browse/HDFS-13775 > Project: Hadoop HDFS > Issue Type: Bug > Components: namenode > Reporter: Aniket Mokashi > Priority: Major > > During DN registration, if the ip and the hostname in the DN InetAddress are > the same (i.e. reverse name lookup falied; see [the > javadoc|http://docs.oracle.com/javase/6/docs/api/java/net/InetAddress.html#getHostName%28%29]), > the DN will be disallowed to register, where the DN InetAddress was obtained > from the socket. It is a performance improvement added by HDFS-3990 to avoid > unnecessary DNS resolutions. However, in an environment where DNS lookups can > be flaky this can cause datanode registration to fail permanently. > We propose to add a conf property to retry DNS reverse lookup during DN > registration. Otherwise, clusters with flaky reverse DNS lookup will fail > permanently. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org