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https://issues.apache.org/jira/browse/HBASE-22567?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16883529#comment-16883529
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stack commented on HBASE-22567:
-------------------------------
[~wchevreuil] I added an OfflineMetaRepair to hbck over in HBASE-22680. It is
based on hbck1 implementation trying to exploit already-written code being
selective about what is revealed from hbck1 in hbck2. I see the extant hbck1
tooling as useful implementing not only OfflineMetaRepair but also other items
listed up in HBASE-21745: e.g. 'enumerate store files to determine file level
corruption and sideline corrupt files' and `fix hfile link problems (dangling /
broken)`.
[~busbey] asks in review of HBASE-22680 if overlap with the work here. Let me
review your latest but I don't think so (correct me if I'm wrong). The patch
here works against an online meta selectively posing as a "a lighter version of
'OfflineMetaRepair'". HBASE-22680 does a wholesale rewrite of meta w/ the
cluster offline.
When I asked above, you said this patch could perhaps evolve to subsume
OfflineMetaRepair. When that is the case, we could remove HBASE-22680. What you
reckon?
On [~daisuke.kobayashi]'s note, that table state is migrated from zk on
startup, my comments above were backed by a misunderstanding on my part (only
table 'state' is repopulated; I thought it more than this). My comments above
probably confuse because of this. Having been in the code recently, I was
reminded that the mirroring of table state to zk was supposed to be turned off;
the zk table state mirroring is so hbase1 clients can work against hbase2.
> HBCK2 addMissingRegionsToMeta
> -----------------------------
>
> Key: HBASE-22567
> URL: https://issues.apache.org/jira/browse/HBASE-22567
> Project: HBase
> Issue Type: New Feature
> Reporter: Wellington Chevreuil
> Assignee: Wellington Chevreuil
> Priority: Major
>
> Following latest discussion on HBASE-21745, this proposes an hbck2 command
> that allows for inserting back regions missing in META that still have
> *regioninfo* available in HDFS. Although this is still an interactive and
> simpler version than the old _OfflineMetaRepair_, it still relies on hdfs
> state as the source of truth, and performs META updates mostly independently
> from Master (apart from requiring Meta table been online).
> For a more detailed explanation on this command behaviour, pasting _command
> usage_ text:
> {noformat}
> To be used for scenarios where some regions may be missing in META,
> but there's still a valid 'regioninfo' metadata file on HDFS.
> This is a lighter version of 'OfflineMetaRepair' tool commonly used for
> similar issues on 1.x release line.
> This command needs META to be online. For each table name passed as
> parameter, it performs a diff between regions available in META,
> against existing regions dirs on HDFS. Then, for region dirs with
> no matches in META, it reads regioninfo metadata file and
> re-creates given region in META. Regions are re-created in 'CLOSED'
> state at META table only, but not in Masters' cache, and are not
> assigned either. A rolling Masters restart, followed by a
> hbck2 'assigns' command with all re-inserted regions is required.
> This hbck2 'assigns' command is printed for user convenience.
> WARNING: To avoid potential region overlapping problems due to ongoing
> splits, this command disables given tables while re-inserting regions.
> An example adding missing regions for tables 'table_1' and 'table_2':
> $ HBCK2 addMissingRegionsInMeta table_1 table_2
> Returns hbck2 'assigns' command with all re-inserted regions.{noformat}
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