cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Octavian Rinciog <octavian.rinc...@gmail.com>
Subject Re: Best compaction strategy for counters tables
Date Thu, 18 Jan 2018 11:44:16 GMT
Hi Alain,

Thank you for your response.
In my case, counter is the main table, having almost 40% of all data.

Thank you for the recommendation about testing on one node.

2018-01-18 13:02 GMT+02:00 Alain RODRIGUEZ <arodrime@gmail.com>:
> Hello,
>
> I believe there is not a really specifically good strategy for counters.
> Often counter tables size is relatively low (compared to events / raw data).
> So depending on the workload you might want to pick one or the other. Given
> the high number of reads the table will have to face (during reads +
> writes), LCS might be a good choice if there is no better reason to pick
> another strategy. Be aware that LCS have the highest write amplification
> (Data will be written about 8 times on disk through compaction process) but
> should be in a very nice spot for reads, mostly touching one or a few
> SSTables.
>
> In the past I did not care much about the compaction strategy for counters
> as I considered it to be negligible in my case (counters were MB big tables
> out of a few TB for the entire dataset).
>
> You can always pick a strategy you think would work better, and test the
> change on a canary node (use JMX to apply on 1 node only), see how it goes.
> I found the doc for this on Datastax website. I hope this will help:
> https://support.datastax.com/hc/en-us/articles/213370546-Change-CompactionStrategy-and-sub-properties-via-JMX
>
> C*heers,
> -----------------------
> Alain Rodriguez - @arodream - alain@thelastpickle.com
> France / Spain
>
> The Last Pickle - Apache Cassandra Consulting
> http://www.thelastpickle.com
>
> 2018-01-17 16:14 GMT+00:00 Octavian Rinciog <octavian.rinciog@gmail.com>:
>>
>> Hello!
>> I am using Cassandra 3.10.
>> I have a counter table, with the following schema and RF=1
>>
>> CREATE TABLE edges (
>>     src_id text,
>>     src_type text,
>>     source text
>>     weight counter,
>>     PRIMARY KEY ((src_id, src_type), source)
>> );
>>
>> SELECT vs UPDATE requests ratio for this table is 0.1
>> READ vs WRITE rate, given by iostat is 100:1.
>> Counter cache hit rate is 80%, so only for 20% UPDATE requests, the
>> hard-disk is touched.
>>
>> I want to ask you which compation strategy is best for this table
>> (SizeTieredCompactionStrategy or
>> LeveledCompactionStrategy).
>>
>> Thank you,
>> --
>> Octavian Rinciog
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: user-unsubscribe@cassandra.apache.org
>> For additional commands, e-mail: user-help@cassandra.apache.org
>>
>



-- 
Octavian Rinciog

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@cassandra.apache.org
For additional commands, e-mail: user-help@cassandra.apache.org


Mime
View raw message