[jira] [Commented] (HDFS-8580) Erasure coding: Persist cellSize in BlockInfoStriped and StripedBlockProto

["Jing Zhao (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HDFS-8580?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14584164#comment-14584164 ] 

Jing Zhao commented on HDFS-8580:
---------------------------------

actually StripedBlockProto is only used in fsimage before and what I meant is that we might want to include the cellSize in LocatedBlockProto. For fsimage part, since HDFS-8585 just removes StripedBlockProto, I guess what we can do here is to either 1) add the cellSize information into {{StripedBlocksFeature}} in fsimage.proto, or 2) bring StripedBlockProto back and put block info and cell size there.

> Erasure coding: Persist cellSize in BlockInfoStriped and StripedBlockProto
> --------------------------------------------------------------------------
>
>                 Key: HDFS-8580
>                 URL: https://issues.apache.org/jira/browse/HDFS-8580
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>            Reporter: Walter Su
>            Assignee: Walter Su
>         Attachments: HDFS-8580.00.patch
>
>
> Zhe Zhang, Kai Zheng and I had a offline discussion. Here is what we thought:  Add a cellSize field in BlockInfoStriped as a workaround, and deal with memory usage in follow-on.(HDFS-8059)
> discussion in HDFS-8494:
> from Walter Su:
> {quote}
> I think BlockInfoStriped needs to keep cellSize.
> {quote}
> from [~vinayrpet]:
> {quote}
> I too was thinking the same when the FSImageLoader problem has came up. This will increase the memory usage by ~4bytes for each block though.
> {quote}
> from [~jingzhao]
> {quote}
> Also, we should consider adding a chunk size field to StripedBlockProto and removing the cell size field from HdfsFileStatus. In this way we can access the chunk size information in the storage layer.
> {quote}



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