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ASF GitHub Bot commented on HDFS-4043: -------------------------------------- ndimiduk commented on code in PR #4693: URL: https://github.com/apache/hadoop/pull/4693#discussion_r945852367 ########## hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/DNSDomainNameResolver.java: ########## @@ -40,6 +48,16 @@ public String getHostnameByIP(InetAddress address) { && host.charAt(host.length()-1) == '.') { host = host.substring(0, host.length()-1); } + // Protect against the Java behaviour of returning the IP address as a string from a cache + // instead of performing a reverse lookup. + if (host.equals(address.getHostAddress())) { Review Comment: What's the expected behavior here? does the called expect us to throw or is it acceptable to return `null` ? > Namenode Kerberos Login does not use proper hostname for host qualified hdfs > principal name. > -------------------------------------------------------------------------------------------- > > Key: HDFS-4043 > URL: https://issues.apache.org/jira/browse/HDFS-4043 > Project: Hadoop HDFS > Issue Type: Bug > Components: security > Affects Versions: 2.0.0-alpha, 2.0.1-alpha, 2.0.2-alpha, 2.0.3-alpha, > 3.4.0, 3.3.9 > Environment: CDH4U1 on Ubuntu 12.04 > Reporter: Ahad Rana > Priority: Major > Labels: pull-request-available > Original Estimate: 24h > Time Spent: 50m > Remaining Estimate: 23h 10m > > The Namenode uses the loginAsNameNodeUser method in NameNode.java to login > using the hdfs principal. This method in turn invokes SecurityUtil.login with > a hostname (last parameter) obtained via a call to InetAddress.getHostName. > This call does not always return the fully qualified host name, and thus > causes the namenode to login to fail due to kerberos's inability to find a > matching hdfs principal in the hdfs.keytab file. Instead it should use > InetAddress.getCanonicalHostName. This is consistent with what is used > internally by SecurityUtil.java to login in other services, such as the > DataNode. -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org