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https://issues.apache.org/jira/browse/HDFS-10843?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15478335#comment-15478335
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Konstantin Shvachko commented on HDFS-10843:
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You are right {{completeBlock()}} calls are too deep inside {{BlockManager}}.
How about we add a new {{getFSDirectory{}}} method to {{Namesystem}}. This
should be sufficient to resolve this case.
Historically {{Namesystem}} interface was added in HDFS-2266. Not much
motivation is given there, but the idea was a better separation between
{{FSNamesystem}} and {{BlockManager}}. Initially {{Namesystem}} was very basic
essentially accessing FSNamesystem's locks and SafeMode. But since then people
were adding rather random methods into it. Mostly in order to allow access to
{{FSDirectory}}, like {{getBlockCollection()}}. So may be we should just add
{{Namesystem.getFSDirectory{}}} so that later we could eliminate
{{getBlockCollection()}} and {{isInSnapshot()}} from {{Namesystem}}.
For the tests you should probably combine new test cases into one or even
integrate with the existing cases. Starting mini-cluster is time consuming,
increases test running time. So optimally we should start the cluster once in
{{@BeforeClass}}.
> Quota Feature Cached Size != Computed Size When Block Committed But Not
> Completed
> ---------------------------------------------------------------------------------
>
> Key: HDFS-10843
> URL: https://issues.apache.org/jira/browse/HDFS-10843
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: hdfs, namenode
> Affects Versions: 2.6.0
> Reporter: Erik Krogen
> Assignee: Erik Krogen
> Attachments: HDFS-10843.000.patch, HDFS-10843.001.patch
>
>
> Currently when a block has been committed but has not yet been completed, the
> cached size (used for the quota feature) of the directory containing that
> block differs from the computed size. This results in log messages of the
> following form:
> bq. ERROR namenode.NameNode
> (DirectoryWithQuotaFeature.java:checkStoragespace(141)) - BUG: Inconsistent
> storagespace for directory /TestQuotaUpdate. Cached = 512 != Computed = 8192
> When a block is initially started under construction, the used space is
> conservatively set to a full block. When the block is committed, the cached
> size is updated to the final size of the block. However, the calculation of
> the computed size uses the full block size until the block is completed, so
> in the period where the block is committed but not completed they disagree.
> To fix this we need to decide which is correct and fix the other to match. It
> seems to me that the cached size is correct since once the block is committed
> its size will not change.
> This can be reproduced using the following steps:
> - Create a directory with a quota
> - Start writing to a file within this directory
> - Prevent all datanodes to which the file is written from communicating the
> corresponding BlockReceivedAndDeletedRequestProto to the NN temporarily (i.e.
> simulate a transient network partition/delay)
> - During this time, call DistributedFileSystem.getContentSummary() on the
> directory with the quota
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