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From Héctor Izquierdo Seliva <izquie...@strands.com>
Subject Re: Tombstones and memtable_operations
Date Tue, 19 Apr 2011 20:39:43 GMT
El mar, 19-04-2011 a las 23:33 +0300, shimi escribió:
> You can use memtable_flush_after_mins instead of the cron
> 
> 
> Shimi
> 

Good point! I'll try that.

Wouldn't it be better to count a delete as a one column operation so it
contributes to flush by operations?

> 2011/4/19 Héctor Izquierdo Seliva <izquierdo@strands.com>
>         
>         El mié, 20-04-2011 a las 08:16 +1200, aaron morton escribió:
>         > I think their may be an issue here, we are counting the
>         number of columns in the operation. When deleting an entire
>         row we do not have a column count.
>         >
>         > Can you let us know what version you are using and how you
>         are doing the delete ?
>         >
>         > Thanks
>         > Aaron
>         >
>         
>         
>         I'm using 0.7.4. I have a file with all the row keys I have to
>         delete
>         (around 100 million) and I just go through the file and issue
>         deletes
>         through pelops.
>         
>         Should I manually issue flushes with a cron every x time?
>         
>         
>         > On 20 Apr 2011, at 04:21, Héctor Izquierdo Seliva wrote:
>         >
>         > > Ok, I've read about gc grace seconds, but i'm not sure I
>         understand it
>         > > fully. Untill gc grace seconds have passed, and there is a
>         compaction,
>         > > the tombstones live in memory? I have to delete 100
>         million rows and my
>         > > insert rate is very low, so I don't have a lot of
>         compactions. What
>         > > should I do in this case? Lower the major compaction
>         threshold and
>         > > memtable_operations to some very low number?
>         > >
>         > > Thanks
>         > >
>         > > El mar, 19-04-2011 a las 17:36 +0200, Héctor Izquierdo
>         Seliva escribió:
>         > >> Hi everyone. I've configured in one of my column families
>         > >> memtable_operations = 0.02 and started deleting keys. I
>         have already
>         > >> deleted 54k, but there hasn't been any flush of the
>         memtable. Memory
>         > >> keeps pilling up and eventually nodes start to do
>         stop-the-world GCs. Is
>         > >> this the way this is supposed to work or have I done
>         something wrong?
>         > >>
>         > >> Thanks!
>         > >>
>         > >
>         > >
>         >
>         
>         
>         
> 
> 



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