If you're on 3.0 (3.0.6 or 3.0.8 or newer I don't remember which), TWCS was
designed for ttl-only time series use cases
Alternatively, if you have IO to spare, you may find LCS works as well (it'll
cause quite a bit more compaction, but a much higher chance to compact away
tombstones)
There are also tombstone focused sub properties to more aggressively compact
sstables that have a lot of tombstones - check the docs for "unchecked
tombstone compaction" and "tombstone threshold" - enabling those will enable
more aggressive automatic single-sstable compactions
--
Jeff Jirsa
> On Sep 2, 2017, at 7:10 AM, qf zhou <zhouqf2...@gmail.com> wrote:
>
>
> Yes, your are right. I am using STCS compaction strategy with some kind of
> timeseries model. Too much disk space has been occupied.
>
> What should I do to stop the disk full ?
>
> I only want to keep 100 days data most recently, so I set
> default_time_to_live = 8640000(100 days ).
>
> I know I need to do something to stop the disk space cost, but I really don’t
> know how to do it.
>
>
> Here is the strategy of the big data table :
>
> AND compaction = {'class':
> 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy',
> 'max_threshold': '32', 'min_threshold': '12', 'tombstone_threshold': '0.1',
> 'unchecked_tombstone_compaction': 'true'}
> AND compression = {'chunk_length_in_kb': '64', 'class':
> 'org.apache.cassandra.io.compress.LZ4Compressor'}
> AND crc_check_chance = 1.0
> AND dclocal_read_repair_chance = 0.1
> AND default_time_to_live = 8640000
> AND gc_grace_seconds = 432000
>
>
>
>> 在 2017年9月2日，下午7:34，Nicolas Guyomar <nicolas.guyo...@gmail.com> 写道：
>>
>> your are using STCS compaction strategy with some kind of timeseries model,
>> and you are going to end up with yor disk full!
>
