HPE Ezmeral Data Fabric Database Binary CopyTable
Copies data from one HPE Ezmeral Data Fabric Database binary table to another HPE Ezmeral Data Fabric Database binary table.
CopyTable
utility is different from Apache HBase's
CopyTable
utility. This utility has the
following capability: - If the destination table does not exist,
CopyTable
creates the target table with the same metadata (column families and access control expressions) as the source table, and then copies data. - If the destination table exists,
CopyTable
copies data only. - If you manually set up replication to a HPE Ezmeral Data Fabric Database table,
CopyTable
can be used to perform an initial load of source data to the replica before table replication begins.
CopyTable
.Required Permissions
The user that runs theCopyTable
utility must have the following permissions: - The permission
readAce
on the volume where the source table is located, and the permissionwriteAce
on the volume where the destination table is or will be located. - The permission
adminperm
on the source table. - The permission for column-family and column reads (
readperm
) on the data in the source table that you want to copy. - When bulkload =
false
, the permission for column writes (writeperm
) on the destination table. - When bulkload =
true
(default), the permission to load the destination table with bulk loads (bulkloadperm
). - If the destination table does not yet exist:
createrenamefamily
on the source table.
mapr
user is not treated as a
superuser. HPE Ezmeral Data Fabric Database does not allow the mapr
user to run this utility unless that user is given the relevant permission or permissions
with access-control expressions.If
CopyTable
is run between tables on different clusters, the user that runs
the command must have the required permissions on each cluster.
For information about how to set permissions on volumes, see Setting Whole Volume ACEs.
For information about how to set permissions on tables, see Enabling Table and Stream Authorizations with ACEs.
Syntax
hbase com.mapr.fs.hbase.tools.mapreduce.CopyTable
-src <source table path> -dst <destination table path>
[-columns cf1[:col1],...] [-maxversions <max number of versions to copy>]
[-starttime <time>]
[-endtime <time>]
[-mapreduce <true|false> (default: true)]
[-bulkload <true|false> (default: true)]
[-numthreads <numThreads> (default:16, valid only when -mapreduce is false)]
Parameters
Parameters | Description |
---|---|
src |
The path to the source table that you want to replicate.
|
dst |
The path to the replica.
|
columns | By default, all columns in the source table are copied. If you do not want to
copy all columns in the table, you can specify columns to copy. Provide a
comma-separated list of column families or columns from a certain column family
(column family:qualifier). For example, use the following syntax to copy only the
purchases column family and the stars column in the reviews column family:
|
maxversions | By default, all versions from the source table are copied. If you do not want to copy all versions, use this parameter to specify the number of versions to copy. |
starttime | By default, all table values regardless of their associated timestamp are copied. You can specify a timestamp to indicate the table cell version at which to start the copy. The timestamp is a long integer value that is either user-defined or system-defined (epoch in milliseconds). Values with timestamps lower than the specified timestamp will not be copied to the destination. |
endtime | By default, all table values regardless of their associated timestamp are copied. You can specify a timestamp to indicate the table cell version at which to end the copy. The timestamp is a long integer value that is either user-defined or system-defined (epoch in milliseconds). Values with timestamps greater than or equal to the specified timestamp will not be copied to the destination. |
mapreduce |
A Boolean value that specifies whether or not to use a
MapReduce program to perform the copying operation. The default, preferred method
is to use a MapReduce program ( When this parameter is set to |
bulkload | A Boolean value that specifies whether or not to perform a full bulk load of
the table. The default is to use bulk loading (true ). When you use
bulk loading, the utility automatically unsets the bulk load mode on the table to
restore normal client operations at the end of the table copy operation. For more
information, see Bulk Loading and HPE Ezmeral Data Fabric Database Tables. |
numthreads |
When -mapreduce is
false , this parameter specifies the number of threads allocated
to perform the copying of data. The default is 16. If additional CPU resources are
available, you might want to increase the number of threads to achieve better
performance. |
Monitoring the CopyTable Operation
- If the copy table operation runs as a MapReduce v2 application, monitor the application using the ResourceManager UI.
- If the copy table operation runs as a client process, go to the Tables view of the destination table in the Control System. Then, on the Region tab, monitor the pace at which the number of rows increases.
Example
Copies table data with timestamp greater than 1423226300000 (Fri, 06 Feb 2015 12:38:20 GMT) from one HPE Ezmeral Data Fabric Database table to another HPE Ezmeral Data Fabric Database table:[user@hostname ~]$ hbase com.mapr.fs.hbase.tools.mapreduce.CopyTable -src /t1 -dst /t1_copy7 -starttime 1423226300000