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https://issues.apache.org/jira/browse/HDFS-6549?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14036446#comment-14036446
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Aaron T. Myers commented on HDFS-6549:
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bq. 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?
Correct, this is exactly what I've observed.
> 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.
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