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From Dylan Hutchison <dyhutchi...@gmail.com>
Subject Re: LocalityGroupDeleter
Date Sat, 16 Jul 2016 00:24:17 GMT
Ah, sorry Russ.  Now that I returned to my laptop and looked at your code,
I see you did pass the locality group column families via IteratorOptions.
Nice!

On Fri, Jul 15, 2016 at 2:21 PM, Dylan Hutchison <dyhutchison@gmail.com>
wrote:

> I see. Pass table name via IteratorOptions? Or just pass locality group
> column families?
>
> On Jul 15, 2016 3:03 PM, "Russ Weeks" <rweeks@newbrightidea.com> wrote:
>
>> Hey, Dylan,
>>
>> Yeah, I thought about that but locality group info is kept at the table
>> level (makes sense) and I don't see any way for an iterator to know what
>> table it's operating on (which seems weird but...)
>>
>> On Fri, Jul 15, 2016 at 2:01 PM Dylan Hutchison <
>> dhutchis@cs.washington.edu>
>> wrote:
>>
>> > For accessing locality group column family information inside an
>> Accumulo
>> > iterator, what about querying the Accumulo table property table.group.*
>> > <
>> >
>> https://accumulo.apache.org/1.7/accumulo_user_manual#TABLE_LOCALITY_GROUP_PREFIX
>> > >
>> > from IteratorEnvironment.getConfig() in the iterator's init()?  I
>> haven't
>> > tested this, but it seems like it would work.
>> >
>> > On Fri, Jul 15, 2016 at 1:54 PM, Russ Weeks <rweeks@newbrightidea.com>
>> > wrote:
>> >
>> > > Hey, folks,
>> > >
>> > > Yesterday I asked on IRC about whether there was an optimized way to
>> > delete
>> > > all key/value pairs in a locality group. Keith had the great
>> suggestion
>> > > that, since compactions are done separately for each locality group, I
>> > > could write a custom iterator that returned false from hasTop if the
>> > > iterator was seeked with the right column families.
>> > >
>> > > If it's useful to anyone else, the code is in this gist:
>> > > https://gist.github.com/rweeks/bedb96e20fcb8d2d2f27c555494181c5 and
>> it
>> > > works pretty well, thanks Keith!
>> > >
>> > > It would be more convenient for the end-user to configure the iterator
>> > with
>> > > a specific locality group, instead of a set of column families that
>> must
>> > > match a locality group for the iterator to work correctly.
>> Unfortunately
>> > > the iterator doesn't have the necessary context to map a locality
>> group
>> > > name to the CFs in that group (as far as I can tell).
>> > >
>> > > -Russ
>> > >
>> >
>>
>


-- 
www.cs.stevens.edu/~dhutchis

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