Hi Stack,
the scan of META does not contain any 'offline' or 'split' attributes. Still
parent reqion is present in META. I tried to merge the parent with one child
but received the following error: (on 0.90.3)
11/07/06 11:59:35 FATAL util.Merge: Merge failed
java.lang.NullPointerException
at org.apache.hadoop.hbase.util.Writables.getWritable(Writables.java:75)
at
org.apache.hadoop.hbase.util.Writables.getHRegionInfo(Writables.java:119)
at org.apache.hadoop.hbase.util.Merge.mergeTwoRegions(Merge.java:219)
at org.apache.hadoop.hbase.util.Merge.run(Merge.java:110)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.hbase.util.Merge.main(Merge.java:379)
After executing add_table I restart hbase. Have not used disable/enable.
What actually happens when I copy the META from old cluster to new cluster?
META table contains references to old cluster machines. Because of that we
are using add_table. Is there another way to reuse the META table between
the two clusters?
Thanks for your help
Matthias
On Thu, Jul 7, 2011 at 6:28 PM, Stack <[email protected]> wrote:
> On Thu, Jul 7, 2011 at 2:39 AM, Mat Hofschen <[email protected]> wrote:
> > looking at the old 0.20.4 cluster the parent region is not written to any
> > more. (no data on filesystem) In META table I can not identify that this
> > parent region is offlined though. Where can I find that key? Why is the
> > region not being written to any more if there is no offline flag set?
> >
>
> Dump the meta region:
>
> echo 'scan ".META."' | ./bin/hbase shell &> /tmp/meta.txt
>
> Then look in the outputted file for the parent region (has same start
> key as the first daughter and same end key as second daughter). Look
> through the output for the 'offline' and 'split' attributes.
>
> > So by copying over the data to new cloud and using add_table script the
> > information that the region was offlined is lost. I guess this is one of
> the
> > problems of using copy on dfs level.
> > The new cluster is therefore inconsitent at this point with data written
> to
> > the parent region and not the child regions.
> >
>
> When you do add_table.rb, you then disable and then enable the table
> to get it online? Or how do you get the regions assigned? Restart?
> Maybe this is the issue (enable/disable changed in how it works
> between 0.20 and 0.90 -- the offline attribute is not relied on as
> much).
>
> Its odd that your parent region over in 0.20.4 has no data. It should
> have a bunch (daughters reference the data up in parent until they are
> done with it... the data in parent is not deleted until the parent
> itself if deleted).
>
> Is there data under the daughters in the filesystem?
>
> You tried merging the daughter regions and then merging the resultant
> region with the parent region?
>
> > Is there a way to reuse the META table from old cloud and avoid using the
> > add_table script?
> >
>
> You could copy the .META. from old cluster.
>
> St.Ack
>
