Yep, Marcus, I know. It's mainly a question of cost of those extra x2 disks, you know. Our "final" setup will be more like 30TB, so doubling it is still some cost. But i guess, we will have to live with it
On Tue, Nov 25, 2014 at 1:26 PM, Marcus Eriksson <krum...@gmail.com> wrote: > 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 >> >> >> > >> > > >
