Old tables still exist

[Batranut Bogdan <ba...@yahoo.com>]

Hello all,

I have a question.

I looked in the keyspace directory and saw that old dirs still exist after dropping the corresponding table.

eg drop table t1 and in /data/keyspace I still see the t1 dir. 

Is there a way to get cassandra to remove these old and unused tables?

Re: Old tables still exist

[Robert Coli <rc...@eventbrite.com>]

On Wed, Apr 30, 2014 at 5:36 PM, Michael Shuler <mi...@pbandjelly.org>wrote:

> For the benefit of the ML, CASSANDRA-7127 was opened, and snapshots will
> not be taken, if conf/cassandra.yaml has:
>
> auto_snapshot: false
>

Didn't this already exist as a (not-in-the-default-conf-file) option? I was
aware of it (something like it?) but actually didn't mention because I
don't think I want to encourage people to disable auto_snapshotting as a
general principle.. :)

=Rob

Re: Old tables still exist

[Michael Shuler <mi...@pbandjelly.org>]

On 04/30/2014 05:29 PM, Robert Coli wrote:
> On Wed, Apr 30, 2014 at 3:25 PM, Batranut Bogdan <batranub@yahoo.com
> <ma...@yahoo.com>> wrote:
>
>     During the development of our entire system we generated huge tables
>     (GB or TB) then had to drop them since we changed the definition.
>     This takes up space. There is a constant write on the system so we
>     want to optimize our cluster. Basicaly not expanding untill the real
>     need is there.
>
>
> Yep, DROP not actually DROPping is weird alright. I personally think
> that more people are likely to win from this behavior than lose, but it
> is certainly unexpected.

For the benefit of the ML, CASSANDRA-7127 was opened, and snapshots will 
not be taken, if conf/cassandra.yaml has:

auto_snapshot: false

rm -r also works after the fact  ;)

-- 
Michael

Re: Old tables still exist

[Robert Coli <rc...@eventbrite.com>]

On Wed, Apr 30, 2014 at 3:25 PM, Batranut Bogdan <ba...@yahoo.com> wrote:

> During the development of our entire system we generated huge tables (GB
> or TB) then had to drop them since we changed the definition. This takes up
> space. There is a constant write on the system so we want to optimize our
> cluster. Basicaly not expanding untill the real need is there.
>

Yep, DROP not actually DROPping is weird alright. I personally think that
more people are likely to win from this behavior than lose, but it is
certainly unexpected.

=Rob

Re: Old tables still exist

[Batranut Bogdan <ba...@yahoo.com>]

Well this is not good at all...

During the development of our entire system we generated huge tables (GB or TB) then had to drop them since we changed the definition. This takes up space. There is a constant write on the system so we want to optimize our cluster. Basicaly not expanding untill the real need is there.

Thanks for the answer.
On Thursday, May 1, 2014 1:06 AM, Robert Coli <rc...@eventbrite.com> wrote:
 
On Wed, Apr 30, 2014 at 3:00 PM, Batranut Bogdan <ba...@yahoo.com> wrote:

Is there a way to get cassandra to remove these old and unused tables?

Those directories have to exist after DROP because snapshots taken when you drop, and the snapshots are in a subdirectory of those directories.

nodetool clearsnapshot

Will clear the snapshots; I don't believe there is any way to make cassandra actually clean up the directories. If I were you I might file a trivial feature request in the Cassandra project JIRA.

=Rob

Re: Old tables still exist

[Robert Coli <rc...@eventbrite.com>]

On Wed, Apr 30, 2014 at 3:00 PM, Batranut Bogdan <ba...@yahoo.com> wrote:

> Is there a way to get cassandra to remove these old and unused tables?
>

Those directories have to exist after DROP because snapshots taken when you
drop, and the snapshots are in a subdirectory of those directories.

nodetool clearsnapshot

Will clear the snapshots; I don't believe there is any way to make
cassandra actually clean up the directories. If I were you I might file a
trivial feature request in the Cassandra project JIRA.

=Rob