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Hanisha Koneru commented on HDFS-12621: --------------------------------------- Hi [~kamrul], are you working on this Jira? If not, I would like to take it up. > Inconsistency/confusion around ViewFileSystem.getDelagation > ------------------------------------------------------------ > > Key: HDFS-12621 > URL: https://issues.apache.org/jira/browse/HDFS-12621 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 2.7.3 > Reporter: Mohammad Kamrul Islam > Assignee: Mohammad Kamrul Islam > > *Symptom*: > When a user invokes ViewFileSystem.getDelegationToken(String renewer), she > gets a "null". However, for any other file system, it returns a valid > delegation token. For a normal user, it is very confusing and it takes > substantial time to debug/find out an alternative. > *Root Cause:* > ViewFileSystem inherits the basic implementation from > FileSystem.getDelegationToken() that returns "_null_". The comments in the > source code indicates not to use it and instead use addDelegationTokens(). > However, it works fine DistributedFileSystem. > In short, the same client call is working for hdfs:// but not for viewfs://. > And there is no way of end-user to identify the root cause. This also creates > a lot of confusion for any service that are supposed to work for both viewfs > and hdfs. > *Possible Solution*: > _Option 1:_ Add a LOG.warn() with reasons/alternative before returning > "null" in the base class. > _Option 2:_ As done for other FS, ViewFileSystem can override the method with > a implementation by returning the token related to fs.defaultFS. In this > case, the defaultFS is something like "viewfs://..". We need to find out the > actual namenode and uses that to retrieve the delegation token. > _Option 3:_ Open for suggestion ? > *Last note:* My hunch is : there are very few users who may be using > viewfs:// with Kerberos. Therefore, it was not being exposed earlier. > I'm working on a good solution. Please add your suggestion. > -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org