cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Robert Wille <rwi...@fold3.com>
Subject Re: Gotchas when creating a lot of tombstones
Date Sat, 11 Jan 2014 03:31:57 GMT
I essentially am using a time-based data model. But, if I don¹t delete
obsolete data, my database will quickly become many times larger than
necessary. After a year, it would probably be 20x the size it would be if I
cleaned out obsolete data.

Based on an analysis of my schema and access patterns, I¹m pretty confident
that things will go well. I just wish that confidence were backed up by
experience rather than conjecture.

Robert

From:  Anthony Grasso <anthony.grasso@gmail.com>
Reply-To:  <user@cassandra.apache.org>
Date:  Friday, January 10, 2014 at 7:12 PM
To:  <user@cassandra.apache.org>
Subject:  Re: Gotchas when creating a lot of tombstones

Hi Robert, 

It sounds like you have done a fair bit investigating and testing already.
Have you considered using a time based data model to avoid doing deletions
in the database?

Regards,
Anthony


On Thu, Jan 9, 2014 at 1:26 PM, sankalp kohli <kohlisankalp@gmail.com>
wrote:
> With Level compaction, you will have some data which could not be reclaimed
> with gc grace=0 because it has not compacted yet. For this you might want to
> look at tombstone_threshold
> 
> 
> On Wed, Jan 8, 2014 at 10:31 AM, Tyler Hobbs <tyler@datastax.com> wrote:
>> 
>> On Wed, Jan 1, 2014 at 7:53 AM, Robert Wille <rwille@fold3.com> wrote:
>>> 
>>> Also, for this application, it would be quite reasonable to set gc grace
>>> seconds to 0 for these tables. Zombie data wouldn¹t really be a problem. The
>>> background process that cleans up orphaned browse structures would simply
>>> re-delete any deleted data that reappeared.
>> 
>> If you can set gc grace to 0, that will basically eliminate your tombstone
>> concerns entirely, so I would suggest that.
>> 
>> 
>> -- 
>> Tyler Hobbs
>> DataStax <http://datastax.com/>
> 




Mime
View raw message