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From Frederick Haebin Na <haebin...@gmail.com>
Subject Re: Paxos table gets larger when using 'IF NOT EXISTS'
Date Tue, 03 Jun 2014 05:21:02 GMT
Really sorry, all.

I should have thoroughly investigated before I post email to the thread.
Okay, paxos rows are set with paxosTtl which defaults to max(3 * 3600,
GC_GRACE_SECONDS).

So, I have to wait 10 days to see the data removal with default
configuration.

Thank you.

Haebin



2014-06-03 12:51 GMT+09:00 Frederick Haebin Na <haebin.na@gmail.com>:

> Again, sorry for spamming.
>
> I found out that there is no delete query for system.paxos. (2.0.6 code
> base, I'm using 2.0.7, tho.)
>
> Holy cow.
> So, It does not get deleted?
> Is this correct?
>
> Thanks.
>
> Haebin
>
>
> 2014-06-03 12:07 GMT+09:00 Frederick Haebin Na <haebin.na@gmail.com>:
>
> Sorry for spamming, folks.
>>
>> Okay, I found out why it is growing.
>>
>> system.paxos row count is actually 3% greater than the data table.
>> It may be caused by re-insertion of some data range.
>>
>> My ultimate question now would be why the paxos rows are not getting
>> removed after the transaction.
>>
>> There is high disk IO on the directory of the server where there are
>> paxos table files.
>> And the insertion gets slower and slower.
>>
>> (Yes, it seems to be somewhat anti-pattern since we are using 'IF NOT
>> EXISTS' massively, yet, still, I don't understand why it is getting slower
>> like this.)
>>
>> Thanks.
>>
>> Haebin
>>
>>
>>
>>
>>
>>
>> 2014-06-03 11:20 GMT+09:00 Frederick Haebin Na <haebin.na@gmail.com>:
>>
>> Sorry, I found out what are in the system.paxos.
>>>
>>> select * from system.paxos limit 1;
>>>
>>> | row_key | cf_id | in_porgress_ballot | most_recent_commit |
>>> most_recent_commit_at | proposal | proposal_ballot |
>>>
>>> I will investigate more on why it is growing continuously.
>>> If anyone have an idea why it is like this, please, share your
>>> experiences.
>>>
>>> Thank you.
>>>
>>> Haebin
>>>
>>>
>>>
>>> 2014-06-03 11:00 GMT+09:00 Frederick Haebin Na <haebin.na@gmail.com>:
>>>
>>> Hello all,
>>>>
>>>> We are trying to migrate data with 'INSERT IF NOT EXISTS' clause.
>>>> Yet, strange thing is that the system.paxos table gets larger like
>>>> 100GB which is equal to the size of the data table.
>>>>
>>>> Does anyone know what is happening here?
>>>> What does system.paxos table store?
>>>>
>>>> Thank you.
>>>>
>>>> Haebin
>>>>
>>>
>>>
>>
>

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