[
https://issues.apache.org/jira/browse/HBASE-8348?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13723834#comment-13723834
]
rajeshbabu commented on HBASE-8348:
-----------------------------------
[[email protected]]
bq. ROOT? Or you mean FIRST_META_REGIONINFO?
Its ROOT only.Before migrating to 0.95.x, root table files will be left out in
file system, from that scanning .META. server address to create META server
znode. This will be helpful during master initialization to identify .META.
server is dead or not. Ideally it should help in splitting META logs but in
0.95.x meta hlog files are suffixed with "meta", so cannot find them in older
versions hlogs. If we dont flush .META. and -ROOT- tables before stopping the
existing cluter, there may be chance of loosing recently created tables.
bq. I wonder the utility of migrating the existing znodes / or creating meta
server znodes while doing the migration to 0.95. Why not let HBase create them
out of the box?
zookeeper.znode.tableEnableDisable znode helps to find the exact state of the
table, It will be better to migrate table states to PB instead of deleting
them. Otherwise even if tables are disabled, they will be enabled during master
initialization.
bq. What if we fail in the middle of this znode upgrade?
User can retry, otherwise master initialization may fail. Ex: HBASE-7766
> Polish the migration to 0.96
> ----------------------------
>
> Key: HBASE-8348
> URL: https://issues.apache.org/jira/browse/HBASE-8348
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.95.0
> Reporter: Jean-Daniel Cryans
> Assignee: rajeshbabu
> Priority: Critical
> Fix For: 0.95.2
>
> Attachments: HBASE-8348_trunk.patch, HBASE-8348_trunk_v2.patch
>
>
> Currently, migration works but there's still a couple of rough edges:
> - HBASE-8045 finished the .META. migration but didn't remove ROOT, so it's
> still on the filesystem.
> - Data in ZK needs to be removed manually. Either we fix up the data in ZK
> or we delete it ourselves.
> - TestMetaMigrationRemovingHTD has a testMetaUpdatedFlagInROOT method, but
> ROOT is gone now.
> Elliott was also mentioning that we could have "hbase migrate" do the HFileV1
> checks, clear ZK, remove ROOT, etc.
--
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
