Hi Jeff, We are running repair with -pr option. You are right it would have no or very minimal impact on read (considering the fact now data has to be read from 2 levels instead of 3). But my guess there is no negative impact of this model2.
On Thu, Jun 30, 2022, 7:41 PM Jeff Jirsa <jji...@gmail.com> wrote: > How are you running repair? -pr? Or -st/-et? > > 4.0 gives you real incremental repair which helps. Splitting the table > won’t make reads faster. It will increase the potential parallelization of > compaction. > > On Jun 30, 2022, at 7:04 AM, MyWorld <timeplus.1...@gmail.com> wrote: > > > Hi all, > > Another query around data Modelling. > > We have a existing table with below structure: > Table(PK,CK, col1,col2, col3, col4,col5) > > Now each Pk here have 1k - 10k Clustering keys. Each PK has size from 10MB > to 80MB. We have overall 100+ millions partitions. Also we have set > levelled compactions in place so as to get better read response time. > > We are currently on 3.11.x version of Cassandra. On running a weekly > repair and compaction job, this model because of levelled compaction > (occupied till Level 3) consume heavy cpu resource and impact db > performance. > > Now what if we divide this table in 10 with each table containing 1/10 > partitions. So now each table will be limited to levelled compaction upto > level-2. I think this would ease down read as well as compaction task. > > What is your opinion on this? > Even if we upgrade to ver 4.0, is the second model ok? > >
