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Posted to user@cassandra.apache.org by rash aroskar <ra...@gmail.com> on 2013/09/19 17:58:32 UTC
1.2 leveled compactions can affect big bunch of writes? how to
stop/restart them?
Hi,
In general leveled compaction are I/O heavy so when there are bunch of
writes do we need to stop leveled compactions at all?
I found the nodetool stop COMPACTION, which states it stops compaction
happening, does this work for any type of compaction? Also it states in
documents 'eventually cassandra restarts the compaction', isn't there a way
to control when to start the compaction again manually ?
If this is not applicable for leveled compactions in 1.2, then what can be
used for stopping/restating those?
Thanks,
Rashmi
Re: 1.2 leveled compactions can affect big bunch of writes? how to
stop/restart them?
Posted by Juan Manuel Formoso <jf...@gmail.com>.
concurrent_compactors is ignored when using leveled compactions
On Thu, Sep 19, 2013 at 1:19 PM, Nate McCall <na...@thelastpickle.com> wrote:
> As opposed to stopping compaction altogether, have you experimented with
> turning down compaction_throughput_mb_per_sec (16mb default) and/or
> explicitly setting concurrent_compactors (defaults to the number of cores,
> iirc).
>
>
> On Thu, Sep 19, 2013 at 10:58 AM, rash aroskar <ra...@gmail.com>wrote:
>
>> Hi,
>> In general leveled compaction are I/O heavy so when there are bunch of
>> writes do we need to stop leveled compactions at all?
>> I found the nodetool stop COMPACTION, which states it stops compaction
>> happening, does this work for any type of compaction? Also it states in
>> documents 'eventually cassandra restarts the compaction', isn't there a way
>> to control when to start the compaction again manually ?
>> If this is not applicable for leveled compactions in 1.2, then what can
>> be used for stopping/restating those?
>>
>>
>>
>> Thanks,
>> Rashmi
>>
>
>
--
*Juan Manuel Formoso
*Senior Geek
http://twitter.com/juanformoso
http://seniorgeek.com.ar
LLAP
Re: 1.2 leveled compactions can affect big bunch of writes? how to
stop/restart them?
Posted by rash aroskar <ra...@gmail.com>.
Thanks for responses.
Nate - I haven't tried changing compaction_throughput_mb_per_sec. In my
cassandra.yaml I had set it to 32 to begin with. Do you think 32 can be too
much if the cassandra get once in a while writes but when it gets writes
its a big chunk together?
On Thu, Sep 19, 2013 at 12:33 PM, sankalp kohli <ko...@gmail.com>wrote:
> You cannot start level compaction. It will run based on data in each
> level.
>
>
> On Thu, Sep 19, 2013 at 9:19 AM, Nate McCall <na...@thelastpickle.com>wrote:
>
>> As opposed to stopping compaction altogether, have you experimented with
>> turning down compaction_throughput_mb_per_sec (16mb default) and/or
>> explicitly setting concurrent_compactors (defaults to the number of cores,
>> iirc).
>>
>>
>> On Thu, Sep 19, 2013 at 10:58 AM, rash aroskar <ra...@gmail.com>wrote:
>>
>>> Hi,
>>> In general leveled compaction are I/O heavy so when there are bunch of
>>> writes do we need to stop leveled compactions at all?
>>> I found the nodetool stop COMPACTION, which states it stops compaction
>>> happening, does this work for any type of compaction? Also it states in
>>> documents 'eventually cassandra restarts the compaction', isn't there a way
>>> to control when to start the compaction again manually ?
>>> If this is not applicable for leveled compactions in 1.2, then what can
>>> be used for stopping/restating those?
>>>
>>>
>>>
>>> Thanks,
>>> Rashmi
>>>
>>
>>
>
Re: 1.2 leveled compactions can affect big bunch of writes? how to
stop/restart them?
Posted by sankalp kohli <ko...@gmail.com>.
You cannot start level compaction. It will run based on data in each level.
On Thu, Sep 19, 2013 at 9:19 AM, Nate McCall <na...@thelastpickle.com> wrote:
> As opposed to stopping compaction altogether, have you experimented with
> turning down compaction_throughput_mb_per_sec (16mb default) and/or
> explicitly setting concurrent_compactors (defaults to the number of cores,
> iirc).
>
>
> On Thu, Sep 19, 2013 at 10:58 AM, rash aroskar <ra...@gmail.com>wrote:
>
>> Hi,
>> In general leveled compaction are I/O heavy so when there are bunch of
>> writes do we need to stop leveled compactions at all?
>> I found the nodetool stop COMPACTION, which states it stops compaction
>> happening, does this work for any type of compaction? Also it states in
>> documents 'eventually cassandra restarts the compaction', isn't there a way
>> to control when to start the compaction again manually ?
>> If this is not applicable for leveled compactions in 1.2, then what can
>> be used for stopping/restating those?
>>
>>
>>
>> Thanks,
>> Rashmi
>>
>
>
Re: 1.2 leveled compactions can affect big bunch of writes? how to
stop/restart them?
Posted by Nate McCall <na...@thelastpickle.com>.
As opposed to stopping compaction altogether, have you experimented with
turning down compaction_throughput_mb_per_sec (16mb default) and/or
explicitly setting concurrent_compactors (defaults to the number of cores,
iirc).
On Thu, Sep 19, 2013 at 10:58 AM, rash aroskar <ra...@gmail.com>wrote:
> Hi,
> In general leveled compaction are I/O heavy so when there are bunch of
> writes do we need to stop leveled compactions at all?
> I found the nodetool stop COMPACTION, which states it stops compaction
> happening, does this work for any type of compaction? Also it states in
> documents 'eventually cassandra restarts the compaction', isn't there a way
> to control when to start the compaction again manually ?
> If this is not applicable for leveled compactions in 1.2, then what can be
> used for stopping/restating those?
>
>
>
> Thanks,
> Rashmi
>