Aaron, Thanks a lot for your answer, I had in mind something more generic that I am currently working on. The idea is to have a tool with GUI screens where you can feed-in the various column families you are using with column (names and values) sizes. Then it will have anotehr screen withh application-aware fields names associated with their value - all defined by the user. Using these parameters, this (modeling) tool should be able to calculate disk usage and hopefully ram usage... Anyway I am trying to do that for our own case using a simple excel spreadsheet, let you know when it will be ready, Thanks, Miriam
On Thu, Jan 20, 2011 at 11:49 PM, Aaron Morton <aa...@thelastpickle.com>wrote: > Not that I know of, do you have an existing test system you can use as a > baseline ? > > For memory have a read of the JVM Heap Size section here > http://wiki.apache.org/cassandra/MemtableThresholds > You will also want to have some memory for disk caching and the os. 8 or > 12gb feels like a good start. > > For disk capacity I just did some regular old guess work, and multipled my > number by 1.25 to > cover the on disk overhead. You also want to avoid using more than 50% of > the local disk space, due to > compaction and the way the disk performance falls away. There is more info > available here > http://wiki.apache.org/cassandra/CassandraHardware > > How much throughout do you need? How much redundancy do you need? How much > data do you > plan to store? > > Hope that helps > Aaron > > On 21 Jan, 2011,at 05:04 AM, Mimi Aluminium <mimi.alumin...@gmail.com> > wrote: > > Hi, > > We are implementing a 'middlewear' layer to an underneath storage and > need to estimate costs for various system configurations. > Specifically, I want to estimate the resources (memory, disk) for our > data model. > > Is there a tool that given certain storage configuration parameters, > column family fields number and sizes and other details, and then > workload-dependant parameters such as read/write average rates etc. can > predict the > resource consumption (i.e, memory, disk) in an offline mode? > > Thanks, > Miriam > >
