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HBase >> mail # user >> Customizing hbase shell's table formatting

Adam Phelps 2012-12-19, 19:05
Michael Segel 2012-12-19, 19:17
Adam Phelps 2012-12-19, 20:56
Michael Segel 2012-12-19, 21:04
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Re: Customizing hbase shell's table formatting
In trunk, scan and get have formatting options.  If you do help 'scan', in
the middle you should see:

"...Besides the default 'toStringBinary' format, 'scan' supports custom
by column.  A user can define a FORMATTER by adding it to the column name in
the scan specification.  The FORMATTER can be stipulated:

 1. either as a org.apache.hadoop.hbase.util.Bytes method name (e.g, toInt,
 2. or as a custom class followed by method name: e.g.

Example formatting cf:qualifier1 and cf:qualifier2 both as Integers:
  hbase> scan 't1', {COLUMNS => ['cf:qualifier1:toInt',
    'cf:qualifier2:c(org.apache.hadoop.hbase.util.Bytes).toInt'] }

Note that you can specify a FORMATTER by column only (cf:qualifer).  You
specify a FORMATTER for all columns of a column family...."

Also, if you look in src, you fill
find hbase-server/src/main/ruby/shell/formatter.rb.

Check it out.  See how there are a few formatters therein.  Formatters are
responsible for outputting results.

There is a the base abstract class and then a Console and unimplemented
xhtml and json formatters.

You used to be able to specify an alternate 'formatter' to use on the
commmand line.

durruti:hbase stack$ ./bin/hbase shell --help

 --format=OPTION                Formatter for outputting results.
                                Valid options are: console, html.
                                (Default: console)

 -d | --debug                   Set DEBUG log levels.
 -h | --help                    This help.

My guess is this facility has rotted from lack of use but if you wanted to
hook it all up again, the ghosts of an alternate formatter might guide you

Good luck,
On Wed, Dec 19, 2012 at 11:05 AM, Adam Phelps <[EMAIL PROTECTED]> wrote:

> Is there a reasonably straight forward way to customize the shell's
> output for a given table?  While many of our tables use string based
> data, we have some that use serialized data which is useless to view
> directly in the shell on the occasions where it'd be useful for
> debugging the output of a M/R job.
> I'd think there'd be a way to write a object to serialize and
> deserialize the keys and values that could be plugged into the shell,
> but I'm not quickly finding how I'd do that.
> (Note - I know almost nothing about ruby so I could easily be
> overlooking something).
> - Adam
Adam Phelps 2012-12-20, 20:07