[jira] [Comment Edited] (HBASE-22938) Fold all the system tables to hbase:meta

["Sean Busbey (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-22938?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16917749#comment-16917749 ] 

Sean Busbey edited comment on HBASE-22938 at 8/28/19 12:53 PM:
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{quote} **Would this make recovery more difficult? (specifically the case where the meta table is out of wack)
{quote}
 

oh man. yeah. having recently dealt with a spat of clusters with meta truncated by an errant hbase 1.z OfflineMetaRepair, how do we rebuild e.g. the ACL information or the visibility label information if we lose meta.

 

I guess ACL we just have meta repair write whatever is needed to have a valid set up that's only accessible to the super user. Visibility labels requires a walk of the hfiles? I hope we keep a dictionary per hfile, but I don't think we do.

 

maybe automated TTL snapshots of hbase:meta is the way meta recoveries happen rather than trying to go from HDFS contents?


was (Author: busbey):
bq. **Would this make recovery more difficult? (specifically the case where the meta table is out of wack)

 

oh man. yeah. having recently dealt with a spat of clusters with meta truncated by an errant hbase 1.z OfflineMetaRepair, how do we rebuild e.g. the ACL information or the visibility label information if we lose meta.

 

I guess ACL we just have meta repair write whatever is needed to have a valid set up that's only accessible to the super user. Visibility labels requires a walk of the hfiles? I hope we keep a dictionary per hfile, but I don't think we do.

 

maybe we automated TTL snapshots of hbase:meta is the way meta recoveries happen rather than trying to go from HDFS contents?

> Fold all the system tables to hbase:meta
> ----------------------------------------
>
>                 Key: HBASE-22938
>                 URL: https://issues.apache.org/jira/browse/HBASE-22938
>             Project: HBase
>          Issue Type: Brainstorming
>            Reporter: Duo Zhang
>            Priority: Major
>
> Quote my post on HBASE-15867 here, on how to deal with the dead lock when we want to store replication queues to hbase:replication table.
> {quote}
> We could add a special prefix in the row key for different system tables, and make a special family for it. For example, for all the records in hbase:acl, we could introduce a prefix like ':::acl:::', since we do not allow ':' in either namespace or table name, so it will not conflict with the existing table related records. And the family could be namd as 'acl'.
> And we could make a special split policy that only splits at these special prefixs, so it will not break any assumptions so far, as all the records for the 'system table' are in the same region.
> {quote}
> And I think there are also other advantages, for example the start up logic can be greatly simplified.



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