Switching to TWCS

[Pranay akula <pr...@gmail.com>]

Hi,

Testing to switch from sizetiered to Timewindow, did changed compaction
strategy on a table with a buckets of 3 days

After switching when I checked min and max timestamps on sstables I did see
data older than 3 days range in my case 30-60 days

So when we switch from sizetired to Timewindow, will the existing data will
be rebucketed ??

Thanks
Pranay

Re: Switching to TWCS

[Jonathan Haddad <jo...@jonhaddad.com>]

TWCS uses the max timestamp in an sstable to determine what to compact
together, it won't anti-compact your data.  The goal is to minimize I/O.

You'll have to wait for all your mixed-timestamp sstable data to TTL out
before TWCS's windowing kicks in optimally.

http://thelastpickle.com/blog/2016/12/08/TWCS-part1.html

On Fri, Apr 27, 2018 at 11:23 AM Pranay akula <pr...@gmail.com>
wrote:

> Yes the data is TTLed, but I don't think that's the criteria for the TWCS.
> My understanding is the data is divided into buckets based on written
> timestamp.
>
> Thanks
> Pranay
>
> On Fri, Apr 27, 2018, 1:17 PM Nitan Kainth <ni...@gmail.com> wrote:
>
>> Is old data TTLed already? If not, then I don't think TWCS will know when
>> to delete data.
>>
>> My understanding about TWCS is, data has to be written with TTL. (Please
>> correct me, if wrong)
>>
>>
>> Regards,
>> Nitan K.
>> Cassandra and Oracle Architect/SME
>> Datastax Certified Cassandra expert
>> Oracle 10g Certified
>>
>> On Fri, Apr 27, 2018 at 1:15 PM, Pranay akula <pranay.akula2323@gmail.com
>> > wrote:
>>
>>> Hi,
>>>
>>> Testing to switch from sizetiered to Timewindow, did changed compaction
>>> strategy on a table with a buckets of 3 days
>>>
>>> After switching when I checked min and max timestamps on sstables I did
>>> see data older than 3 days range in my case 30-60 days
>>>
>>> So when we switch from sizetired to Timewindow, will the existing data
>>> will be rebucketed ??
>>>
>>> Thanks
>>> Pranay
>>>
>>
>>

Re: Switching to TWCS

[Pranay akula <pr...@gmail.com>]

Yes the data is TTLed, but I don't think that's the criteria for the TWCS.
My understanding is the data is divided into buckets based on written
timestamp.

Thanks
Pranay

On Fri, Apr 27, 2018, 1:17 PM Nitan Kainth <ni...@gmail.com> wrote:

> Is old data TTLed already? If not, then I don't think TWCS will know when
> to delete data.
>
> My understanding about TWCS is, data has to be written with TTL. (Please
> correct me, if wrong)
>
>
> Regards,
> Nitan K.
> Cassandra and Oracle Architect/SME
> Datastax Certified Cassandra expert
> Oracle 10g Certified
>
> On Fri, Apr 27, 2018 at 1:15 PM, Pranay akula <pr...@gmail.com>
> wrote:
>
>> Hi,
>>
>> Testing to switch from sizetiered to Timewindow, did changed compaction
>> strategy on a table with a buckets of 3 days
>>
>> After switching when I checked min and max timestamps on sstables I did
>> see data older than 3 days range in my case 30-60 days
>>
>> So when we switch from sizetired to Timewindow, will the existing data
>> will be rebucketed ??
>>
>> Thanks
>> Pranay
>>
>
>

Re: Switching to TWCS

[Nitan Kainth <ni...@gmail.com>]

Is old data TTLed already? If not, then I don't think TWCS will know when
to delete data.

My understanding about TWCS is, data has to be written with TTL. (Please
correct me, if wrong)


Regards,
Nitan K.
Cassandra and Oracle Architect/SME
Datastax Certified Cassandra expert
Oracle 10g Certified

On Fri, Apr 27, 2018 at 1:15 PM, Pranay akula <pr...@gmail.com>
wrote:

> Hi,
>
> Testing to switch from sizetiered to Timewindow, did changed compaction
> strategy on a table with a buckets of 3 days
>
> After switching when I checked min and max timestamps on sstables I did
> see data older than 3 days range in my case 30-60 days
>
> So when we switch from sizetired to Timewindow, will the existing data
> will be rebucketed ??
>
> Thanks
> Pranay
>