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Date: Thu, 31 Mar 2011 21:18:20 -0700
Message-ID: <AANLkTim27Xctv3jaYmmwcANX3-xM+0e1AkGnkvVF+ax4@mail.gmail.com>
Subject: Re: ColumnInterpreter and HbaseObjectWritable Was:
 HbaseObjectWritable and UnsupportedOperationException
From: Ted Yu <yuzhihong@gmail.com>
To: dev@hbase.apache.org
Cc: Himanshu Vashishtha <hvashish@cs.ualberta.ca>
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I found the one more benefit of using (enhanced) interpreter.
We load AggregateProtocolImpl.class into CoprocessorHost. Interpreter feeds
various values (such as Long.MIN_VALUE) of concrete type (Long) into
AggregateProtocolImpl. This simplifies class loading for CoprocessorHost

Cheers

On Thu, Mar 31, 2011 at 11:37 AM, Ted Yu <yuzhihong@gmail.com> wrote:

> Renaming the subject to better reflect the nature of further discussion.
>
> There're two considerations for my current implementation attached to
> HBASE-1512.
> 1. User shouldn't modify HbaseObjectWritable directly for the new class
> which is to be executed on region server.
> 2. The reason for introducing interpreter is that we (plan to) store
> objects of MeasureWritable, a relatively complex class, in hbase. Using
> interpreter would give us flexibility in computing aggregates.
>
> Cheers
>
> On Thu, Mar 31, 2011 at 10:01 AM, Himanshu Vashishtha <
> hvashish@cs.ualberta.ca> wrote:
>
>> Hello Ted,
>> Did you add a new class: LongColumnInterpreter. Is this the new argument
>> type you want to define to pass along rpcs. For all such "new" argument
>> types, they should be supported/backed up with in the HbaseObjectWritable
>> class to read/write it on wire. Do we really need it, just wondering.
>>
>> Himanshu
>>
>> On Thu, Mar 31, 2011 at 10:52 AM, Ted Yu <yuzhihong@gmail.com> wrote:
>>
>> > Hi,
>> > When I experimented with HBASE-1512, I got the following from
>> > HbaseObjectWritable:
>> > java.lang.UnsupportedOperationException: No code for unexpected class
>> >
>> >
>> org.apache.hadoop.hbase.client.coprocessor.AggregationClient$1LongColumnInterpreter
>> >
>> > I think there was initiative to support dynamic class registration in
>> > HbaseObjectWritable
>> >
>> > If someone can enlighten me on the above, that would be great.
>> >
>>
>
>

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