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Brandon Li commented on HDFS-6549: ---------------------------------- This sometimes happens with some traditional NFS server/client implementations: when the NFS client does READDIR/READDIRPLUS with a huge directory which keeps changing, the READDIR/READDIRPLUS can never finish because the verifier changes and NFS client has to restart the listing request before it finishes. But based on what you described, the AIX client is a different case. Large directory may need multiple READDIR/READDIRPLUS requests. Many NFS client implementations send 0 as the verifier for the first READDIR/READDIRPLUS RPC request. In the AIX case, after it grabs a verifier from server it will always use the same verifier even in the initial READDIR/READIRPLUS request when it accesses the same directory again. Is my understanding correct? > Add support for accessing the NFS gateway from the AIX NFS client > ----------------------------------------------------------------- > > Key: HDFS-6549 > URL: https://issues.apache.org/jira/browse/HDFS-6549 > Project: Hadoop HDFS > Issue Type: Bug > Components: nfs > Affects Versions: 2.4.0 > Reporter: Aaron T. Myers > Assignee: Aaron T. Myers > Attachments: HDFS-6549.patch > > > We've identified two issues when trying to access the HDFS NFS Gateway from > an AIX NFS client: > # In the case of COMMITs, the AIX NFS client will always send 4096, or a > multiple of the page size, for the offset to be committed, even if fewer > bytes than this have ever, or will ever, be written to the file. This will > cause a write to a file from the AIX NFS client to hang on close unless the > size of that file is a multiple of 4096. > # In the case of READDIR and READDIRPLUS, the AIX NFS client will send the > same cookie verifier for a given directory seemingly forever after that > directory is first accessed over NFS, instead of getting a new cookie > verifier for every set of incremental readdir calls. This means that if a > directory's mtime ever changes, the FS must be unmounted/remounted before > readdir calls on that dir from AIX will ever succeed again. > From my interpretation of RFC-1813, the NFS Gateway is in fact doing the > correct thing in both cases, but we can introduce simple changes on the NFS > Gateway side to be able to optionally work around these incompatibilities. -- This message was sent by Atlassian JIRA (v6.2#6252)