Cassandra disk usage

2014-04-13 Thread Yulian Oifa
I have column family with 2 raws. 2 raws have overall 100 million columns. Each columns have name of 15 chars ( digits ) and same 15 chars in value ( also digits ). Each column should have 30 bytes. Therefore all data should contain approximately 3GB. Cassandra cluster has 3 servers , and data is

Re: Cassandra disk usage

2014-04-13 Thread Mark Reddy
What are you storing these 15 chars as; string, int, double, etc.? 15 chars does not translate to 15 bytes. You may be mixing up replication factor and quorum when you say Cassandra cluster has 3 servers, and data is stored in quorum ( 2 servers ). You read and write at quorum (N/2)+1 where

Re: Cassandra disk usage

2014-04-13 Thread Yulian Oifa
Hello Mark and thanks for you reply. 1) i store is as UTF8String.All digits are from 0x30 to 0x39 and should take 1 byte each digit. Since all characters are digits it should have 15 bytes. 2) I will change the data i am storing to decrease the usage , in value i will find some small value to

Re: Cassandra disk usage

2014-04-13 Thread Michal Michalski
Each columns have name of 15 chars ( digits ) and same 15 chars in value ( also digits ). Each column should have 30 bytes. Remember about the standard Cassandra's column overhead which is, as far as I remember, 15 bytes, so it's 45 bytes in total - 50% more than you estimated, which kind of

Re: Cassandra disk usage

2014-04-13 Thread Mark Reddy
i I will change the data i am storing to decrease the usage , in value i will find some small value to store.Previously i used same value since this table is index only for search purposed and does not really has value. If you don't need a value, you don't have to store anything. You can