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From "Hiller, Dean" <Dean.Hil...@nrel.gov>
Subject Re: read-repair and deletes / forgotten deletes
Date Mon, 01 Oct 2012 18:49:40 GMT
Oh, and I have been reading Aaron Mortan's article here

http://thelastpickle.com/2011/05/15/Deletes-and-Tombstones/


On 10/1/12 12:46 PM, "Hiller, Dean" <Dean.Hiller@nrel.gov> wrote:

>Thanks, (actually new it was configurable) BUT what I don't get is why I
>have to run a repair.  IF all nodes became consistent on the delete, it
>should not be possible to get a forgotten delete, correct.  The forgotten
>delete will only occur if I have a node down and out for 10 days and it
>comes back online because by then the nodes no longer have the delete
>anymore and the new node has data so getting to a consistent state the
>node with data would win.
>
>Soooo, if I run repair say every 20 days, isn't it true, I would have no
>problems as long as I did not have a node outage?
>
>And most importantly, does anyone know of an automated tool for running
>repairs every X days(this should really be an automated/schedulable
>thing)???
>
>Thanks,
>Dean
>
>On 10/1/12 11:57 AM, "Aaron Turner" <synfinatic@gmail.com> wrote:
>
>>the 10 days is actually configurable... look into gc_grace.
>>
>>Basically, you always need to run repair once per/gc_grace period.
>>You won't see empty/deleted rows go away until they're compacted away.
>>
>>On Mon, Oct 1, 2012 at 6:32 PM, Hiller, Dean <Dean.Hiller@nrel.gov>
>>wrote:
>>> I know there is a 10 day limit if you have a node out of the cluster
>>>where you better be running read-repair or you end up with forgotten
>>>deletes, but what about on a clean cluster with all nodes always
>>>available?  Shouldn't the deletes eventually take place or does one have
>>>to keep running read-repair manually all the time(god, I hope not as
>>>that should be automated for deletes).
>>>
>>> I am seeing the empty rows in the CLI right now like soŠ(and would
>>>prefer they go away on their own)Š
>>>
>>> RowKey: post:10079376916:b2:4045302966737879216
>>> -------------------
>>> RowKey: post:10079386137:b2:3120637961487430473
>>> -------------------
>>> RowKey: post:10079377944:b2:5118918738052923761
>>> -------------------
>>> RowKey: post:10079378212:b2:1449128414219430571
>>> -------------------
>>> RowKey: post:10079386010:b2:8567843818586569179
>>>
>>> If not, someone has to already have an automated project for this,
>>>anyone know of one??
>>>
>>> Thanks,
>>> Dean
>>>
>>
>>
>>
>>-- 
>>Aaron Turner
>>http://synfin.net/         Twitter: @synfinatic
>>http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix &
>>Windows
>>Those who would give up essential Liberty, to purchase a little temporary
>>Safety, deserve neither Liberty nor Safety.
>>    -- Benjamin Franklin
>>"carpe diem quam minimum credula postero"
>


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