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From Daniel Chia <danc...@coursera.org>
Subject Re: Question about how to remove data
Date Thu, 20 Aug 2015 20:13:18 GMT
The TTL shouldn't matter if you deleted the data, since to my understanding
the delete should shadow the data signaling to C* that the data is a
candidate for removal on compaction.

Others might know better, but it could very well be the fact that
gc_grace_seconds is 0 that is causing your problems. Others might have
other suggestions, but you could potentially use sstable2json to see the
raw contents of the sstable on disk and see why data is still there.

Thanks,
Daniel

On Thu, Aug 20, 2015 at 12:55 PM, Analia Lorenzatto <
analialorenzatto@gmail.com> wrote:

> Hello,
>
> Daniel, I am using Size Tiered compaction.
>
> My concern is that as I do not have a TTL defined on the Column family,
> and I do not have the possibility to create it.   Perhaps, the "deleted
> data" is never actually going to be removed?
>
> Thanks a lot!
>
>
> On Thu, Aug 20, 2015 at 4:24 AM, Daniel Chia <danchia@coursera.org> wrote:
>
>> Is this a LCS family, or Size Tiered? Manually running compaction on LCS
>> doesn't do anything until C* 2.2 (
>> https://issues.apache.org/jira/browse/CASSANDRA-7272)
>>
>> Thanks,
>> Daniel
>>
>> On Wed, Aug 19, 2015 at 6:56 PM, Analia Lorenzatto <
>> analialorenzatto@gmail.com> wrote:
>>
>>> Hello Michael,
>>>
>>> Thanks for responding!
>>>
>>> I do not have snapshots on any node of the cluster.
>>>
>>> Saludos / Regards.
>>>
>>> Analía Lorenzatto.
>>>
>>> "Hapiness is not something really made. It comes from your own actions"
>>> by Dalai Lama
>>>
>>>
>>> On 19 Aug 2015 6:19 pm, "Laing, Michael" <michael.laing@nytimes.com>
>>> wrote:
>>>
>>>> Possibly you have snapshots? If so, use nodetool to clear them.
>>>>
>>>> On Wed, Aug 19, 2015 at 4:54 PM, Analia Lorenzatto <
>>>> analialorenzatto@gmail.com> wrote:
>>>>
>>>>> Hello guys,
>>>>>
>>>>> I have a cassandra cluster 2.1 comprised of 4 nodes.
>>>>>
>>>>> I removed a lot of data in a Column Family, then I ran manually a
>>>>> compaction on this Column family on every node.   After doing that, If
I
>>>>> query that data, cassandra correctly says this data is not there.  But
the
>>>>> space on disk is exactly the same before removing that data.
>>>>>
>>>>> Also, I realized that  gc_grace_seconds = 0.  Some people on the
>>>>> internet say that it could produce zombie data, what do you think?
>>>>>
>>>>> I do not have a TTL defined on the Column family, and I do not have
>>>>> the possibility to create it.   So my questions is, given that I do not
>>>>> have a TTL defined is data going to be removed?  or the deleted data
is
>>>>> never actually going to be deleted due to I do not have a TTL?
>>>>>
>>>>>
>>>>> Thanks in advance!
>>>>>
>>>>> --
>>>>> Saludos / Regards.
>>>>>
>>>>> Analía Lorenzatto.
>>>>>
>>>>> “It's possible to commit no errors and still lose. That is not
>>>>> weakness.  That is life".  By Captain Jean-Luc Picard.
>>>>>
>>>>
>>>>
>>
>
>
> --
> Saludos / Regards.
>
> Analía Lorenzatto.
>
> “It's possible to commit no errors and still lose. That is not weakness.
> That is life".  By Captain Jean-Luc Picard.
>

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