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https://issues.apache.org/jira/browse/HBASE-4358?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13102369#comment-13102369
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Ted Yu commented on HBASE-4358:
-------------------------------
A variant of HTableDescriptor ctor should be created. The storage for the new
HTableDescriptor is under /hbase/tmp on hdfs.
A new method, possibly called copyAndRename() should be added to
HTableDescriptor:
{code}
public void copyAndRename(final HTableDescriptor htd) {
{code}
This method copies the contents of htd to this HTableDescriptor and renames the
.tableinfo of htd to .tableinfo of this HTableDescriptor.
The following should be done to make multi-family modifications atomic:
1. Create new HTableDescriptor, htd1, whose storage is under /hbase/tmp on hdfs
and is a clone of original HTableDescriptor, htd
2. Perform series of modifications on htd1
3. Assuming there is no error, copy contents of htd1 onto htd and rename the
.tableinfo file under /hbase/tmp using htd.copyAndRename(htd1).
4. If there was error, report back the exception and skip step 3 above
> Batch Table Alter Operations
> ----------------------------
>
> Key: HBASE-4358
> URL: https://issues.apache.org/jira/browse/HBASE-4358
> Project: HBase
> Issue Type: Improvement
> Components: ipc, master, shell
> Affects Versions: 0.92.0
> Reporter: Riley Patterson
> Assignee: Riley Patterson
> Priority: Minor
> Attachments: 4358-v3.txt, HBASE-4358-v2.patch, HBASE-4358.patch
>
>
> Currently, the RPC provides no way of asking for several table alterations at
> once, and the master has no way of batch handling alter requests. Thus, when
> the user requests several changes at the same time (i.e. add these I columns,
> delete these J columns, and modify these K columns), each region is brought
> down (I+J+K) times so that it can reflect the new schema. Additionally,
> multiple writes are made to META, and multiple RPC calls must be made.
> This patch provides batching for these operations, both at the RPC level and
> within the Master's TableEventHandlers. This involves a bit of reorganization
> in the TableEventHandler class hierarchy, and a new TableEventHandler,
> TableMultiFamilyHandler. The net effect ends up being the difference seen
> here:
> Before patch:
> hbase(main):001:0> alter 'peeps', {NAME => 'rawr'}, {METHOD => 'delete', NAME
> => 'name'}
> Updating all regions with the new schema...
> 1/1 regions updated.
> Done.
> Updating all regions with the new schema...
> 1/1 regions updated.
> Done.
> 0 row(s) in 2.6450 seconds
> After patch:
> hbase(main):002:0> alter 'peeps', {NAME => 'rawr'}, {METHOD => 'delete', NAME
> => 'name'}
> Updating all regions with the new schema...
> 1/1 regions updated.
> Done.
> 0 row(s) in 1.1930 seconds
> Regions are only brought down once, and the duration is cut 1/N.
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