If you are that write-heavy you should definitely go with STCS, LCS optimizes for reads by doing more compactions
/Marcus On Tue, Nov 25, 2014 at 11:22 AM, Andrei Ivanov <aiva...@iponweb.net> wrote: > Hi Jean-Armel, Nikolai, > > 1. Increasing sstable size doesn't work (well, I think, unless we > "overscale" - add more nodes than really necessary, which is > prohibitive for us in a way). Essentially there is no change. I gave > up and will go for STCS;-( > 2. We use 2.0.11 as of now > 3. We are running on EC2 c3.8xlarge instances with EBS volumes for data > (GP SSD) > > Jean-Armel, I believe that what you say about many small instances is > absolutely true. But, is not good in our case - we write a lot and > almost never read what we've written. That is, we want to be able to > read everything, but in reality we hardly read 1%, I think. This > implies that smaller instances are of no use in terms of read > performance for us. And generally nstances/cpu/ram is more expensive > than storage. So, we really would like to have instances with large > storage. > > Andrei. > > > > > > On Tue, Nov 25, 2014 at 11:23 AM, Jean-Armel Luce <jaluc...@gmail.com> > wrote: > > Hi Andrei, Hi Nicolai, > > > > Which version of C* are you using ? > > > > There are some recommendations about the max storage per node : > > > http://www.datastax.com/dev/blog/performance-improvements-in-cassandra-1-2 > > > > "For 1.0 we recommend 300-500GB. For 1.2 we are looking to be able to > handle > > 10x > > (3-5TB)". > > > > I have the feeling that those recommendations are sensitive according > many > > criteria such as : > > - your hardware > > - the compaction strategy > > - ... > > > > It looks that LCS lower those limitations. > > > > Increasing the size of sstables might help if you have enough CPU and you > > can put more load on your I/O system (@Andrei, I am interested by the > > results of your experimentation about large sstable files) > > > > From my point of view, there are some usage patterns where it is better > to > > have many small servers than a few large servers. Probably, it is better > to > > have many small servers if you need LCS for large tables. > > > > Just my 2 cents. > > > > Jean-Armel > > > > 2014-11-24 19:56 GMT+01:00 Robert Coli <rc...@eventbrite.com>: > >> > >> On Mon, Nov 24, 2014 at 6:48 AM, Nikolai Grigoriev < > ngrigor...@gmail.com> > >> wrote: > >>> > >>> One of the obvious recommendations I have received was to run more than > >>> one instance of C* per host. Makes sense - it will reduce the amount > of data > >>> per node and will make better use of the resources. > >> > >> > >> This is usually a Bad Idea to do in production. > >> > >> =Rob > >> > > > > >
