[
https://issues.apache.org/jira/browse/HBASE-8109?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13603814#comment-13603814
]
Andrew Purtell commented on HBASE-8109:
---------------------------------------
bq. Today HBCK is using a lot of files/dirs names checks to find lost regions
and things like that. Will we be able to do almost the same thing with blocks?
I think the short answer is that HBCK might come to look a lot like a fsck for
a filesystem.
However going below the filesystem to the block pool directly presents
difficulties. Not sure how HBase would get block reports from DataNodes to know
where blocks are located, would guess this amounts to "embedding NN inside
master" as Enis mentioned.
If we had a couple of additional APIs to manipulate the block lists of files,
then we can do block based optimizations and still retain the namespace view
where it is useful, like for HBCK.
> HBase can manage blocks instead of (or inside) files in HDFS
> ------------------------------------------------------------
>
> Key: HBASE-8109
> URL: https://issues.apache.org/jira/browse/HBASE-8109
> Project: HBase
> Issue Type: Brainstorming
> Reporter: Sergey Shelukhin
>
> Prompted by previous non-Hadoop experience and some dev list discussions, and
> after talking to some HDFS people about blocks.
> HBase could improve a lot by managing HDFS blocks instead of files, and
> reusing the blocks among other things. Some areas that could improve are
> splits, compactions, management of large blobs, locality enforcement.
> I was told that block APIs in Hadoop 2 are well-isolated, but not exposed
> yet. They can easily be exposed, and as one of the first potential users we
> could get to help shape them. Two areas that from my limited understanding is
> currently fuzzy are namespaces for blocks, and ref-counting.
> We should come up with list of initial scenarios to figure out what we need
> from block API (locality, detecting/enforcing block boundary/variable size
> blocks, reusing one block, ...).
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
