On Wed, May 23, 2012 at 7:42 AM, aaron morton <aa...@thelastpickle.com>wrote:
> 1 KS with 24 CF's will use roughly the same resources as 24 KS's with 1 > CF. Each CF: > > * loads the bloom filter for each SSTable > * samples the index for each sstable > * uses row and key cache > * has a current memtable and potentially memtables waiting to flush. > * had secondary index CF's > > I would generally avoid a data model that calls for CF's to be added in > response to new entities or new data. Older data will move moved to larger > files, and not included in compaction for newer data. > We were thinking of doing a major compaction after each year is 'closed off'. This would mean that compactions for the current year were dealing with a smaller amount of data and hence be faster and have less impact on a day-to-day basis. Our query patterns will only infrequently cross year boundaries. Are we being naive ? cheers > > Hope that helps. > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 23/05/2012, at 3:31 AM, Luís Ferreira wrote: > > I have 24 keyspaces, each with a columns family and am considering > changing it to 1 keyspace with 24 CFs. Would this be beneficial? > On May 22, 2012, at 12:56 PM, samal wrote: > > Not ideally, now cass has global memtable tuning. Each cf correspond to > memory in ram. Year wise cf means it will be in read only state for next > year, memtable will still consume ram. > On 22-May-2012 5:01 PM, "Franc Carter" <franc.car...@sirca.org.au> wrote: > >> On Tue, May 22, 2012 at 9:19 PM, aaron morton <aa...@thelastpickle.com>wrote: >> >>> It's more the number of CF's than keyspaces. >>> >> >> Oh - does increasing the number of Column Families affect performance ? >> >> The design we are working on at the moment is considering using a Column >> Family per year. We were thinking this would isolate compactions to a more >> manageable size as we don't update previous years. >> >> cheers >> >> >>> >>> Cheers >>> >>> ----------------- >>> Aaron Morton >>> Freelance Developer >>> @aaronmorton >>> http://www.thelastpickle.com >>> >>> On 22/05/2012, at 6:58 PM, R. Verlangen wrote: >>> >>> Yes, it does. However there's no real answer what's the limit: it >>> depends on your hardware and cluster configuration. >>> >>> You might even want to search the archives of this mailinglist, I >>> remember this has been asked before. >>> >>> Cheers! >>> >>> 2012/5/21 Luís Ferreira <zamith...@gmail.com> >>> >>>> Hi, >>>> >>>> Does the number of keyspaces affect the overall cassandra performance? >>>> >>>> >>>> Cumprimentos, >>>> Luís Ferreira >>>> >>>> >>>> >>>> >>> >>> >>> -- >>> With kind regards, >>> >>> Robin Verlangen >>> www.robinverlangen.nl >>> >>> >>> >> >> >> -- >> *Franc Carter* | Systems architect | Sirca Ltd >> <marc.zianideferra...@sirca.org.au> >> franc.car...@sirca.org.au | www.sirca.org.au >> Tel: +61 2 9236 9118 >> Level 9, 80 Clarence St, Sydney NSW 2000 >> PO Box H58, Australia Square, Sydney NSW 1215 >> >> > Cumprimentos, > Luís Ferreira > > > > > -- *Franc Carter* | Systems architect | Sirca Ltd <marc.zianideferra...@sirca.org.au> franc.car...@sirca.org.au | www.sirca.org.au Tel: +61 2 9236 9118 Level 9, 80 Clarence St, Sydney NSW 2000 PO Box H58, Australia Square, Sydney NSW 1215
