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HBase >> mail # user >> the occasion of the major compact?


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Re: the occasion of the major compact?
As an aside,

If you can't wait for HBASE-4536 and trunk to get RC'd, you can just add a
'Delete' column to logically serve as a client-side delete marker instead
of issuing the actual delete and have an MR job both extract the delete
data & handle the actual server-side delete.

On 1/26/12 4:11 PM, "lars hofhansl" <[EMAIL PROTECTED]> wrote:

>Unless you have HBASE-4536 (only in trunk, though) or are parsing the
>HFiles yourself you have no way of actuallygettingto the deleted data.
>
>-- Lars
>
>
>
>----- Original Message -----
>From: yonghu <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Cc:
>Sent: Thursday, January 26, 2012 1:00 PM
>Subject: Re: the occasion of the major compact?
>
>Nicolas,
>
>In my use case, I want to extract the deleted data. Hence, if I
>disable the major compaction, I can prevent the hbase to actually
>delete the data. After extracting the deleted data, I can issue major
>compact by myself.
>
>Regards
>
>Yong
>
>On Thu, Jan 26, 2012 at 8:02 PM, Nicolas Spiegelberg
><[EMAIL PROTECTED]> wrote:
>> Yong,
>>
>> Can you please explain why you want to disable major compactions?  What
>> are the problems that you're currently seeing or what are you worried
>>will
>> happen if a major compaction is allowed to occur?  Right now, there are
>> only an extremely small subset of cases where you must explicitly
>>disable
>> compactions.  These use cases I know of are very complicated and require
>> building StoreFile analysis tools underneath HBase, that I'm pretty sure
>> you're not needing this.
>>
>> Please also read my follow up commentary to explaining major compaction
>> logic:
>> http://search-hadoop.com/m/JR9sK1xnbj21
>> http://search-hadoop.com/m/X7W7q1xnbj21
>>
>>
>> The vast majority of users need features completely unrelated to
>> compactions.  The compaction algorithm is an easy target to worry about.
>>
>>
>> On 1/26/12 7:06 AM, "yonghu" <[EMAIL PROTECTED]> wrote:
>>
>>>Hello Mikael,
>>>
>>>I think disabling the major compaction in the timed and client-issued
>>>situation is not a problem. The problem is the size-based. From the
>>>mailing list, it only talks about the situation of minor compaction
>>>not major compaction, if I understand right. So, I want to know if
>>>someone can tell me how to close the major compaction in size-based
>>>situation.
>>>
>>>Thanks
>>>
>>>Yong
>>>I saw the description which indicating the size of store file can also
>>>trigger major compaction.
>>>
>>>On Thu, Jan 26, 2012 at 3:54 PM, Mikael Sitruk <[EMAIL PROTECTED]>
>>>wrote:
>>>> Yong hi
>>>>
>>>> As far as i know setting  hbase.hregion.majorcompaction to 0 will
>>>>disable
>>>> the time based trigger only.
>>>> Client are always able to invoke the major compact, no matter what is
>>>>the
>>>> value of the hbase.hregion.majorcompaction.
>>>>
>>>> Perhaps client invocation of compaction can me disabled with the
>>>>security
>>>> package.
>>>>
>>>> Anyway i'm digging into 0.92, I hope to get those insight soon.
>>>>
>>>> Mikael.S
>>>>
>>>> On Thu, Jan 26, 2012 at 4:39 PM, yonghu <[EMAIL PROTECTED]> wrote:
>>>>
>>>>> Thanks for your response.
>>>>>
>>>>> I knew that major compact can be triggered based on client, time and
>>>>> size. In my situation, I have to close the functionality of major
>>>>> compact. So, if I set the Œhbase.hregion.majorcompaction¹ into 0, it
>>>>> will close all the three situations or I have to set it separately
>>>>>for
>>>>> each case. BTW, my hbase version is 0.92.
>>>>>
>>>>> Thanks!
>>>>>
>>>>> Yong
>>>>>
>>>>> On Thu, Jan 26, 2012 at 3:09 PM, Mikael Sitruk
>>>>><[EMAIL PROTECTED]>
>>>>> wrote:
>>>>> > look at the thread http://search-hadoop.com/m/GHUWQ1xnbj21, it
>>>>>explain a
>>>>> > lot on major compaction and enhancement over versions
>>>>> >
>>>>> > Mikael.S
>>>>> >
>>>>> >
>>>>> > On Thu, Jan 26, 2012 at 3:51 PM, Damien Hardy <[EMAIL PROTECTED]>
>>>>> wrote:
>>>>> >
>>>>> >> Le 26/01/2012 14:43, yonghu a écrit :
>>>>> >> > Hello,
>>>>> >> >
>>>>> >> > I read this blog http://outerthought.org/blog/465-ot.html. It