Re: Disc size for cluster

2017-01-26 Thread Anuj Wadehra
Adding to what Benjamin said.. It is hard to estimate disk space if you are using STCS for a table where rows are updated frequently leading to lot of fragmentation. STCS may also lead to scenarios where tombstones are not evicted for long times. You may go live and everything goes well for mont

Re: Disc size for cluster

2017-01-26 Thread Benjamin Roth
Hi! This is basically right, but: 1. How do you know the 3TB storage will be 3TB on cassandra? This depends how the data is serialized, compressed and how often it changes and it depends on your compaction settings 2. 50% free space on STCS is only required if you do a full compaction of a single

Disc size for cluster

2017-01-26 Thread Raphael Vogel
Hi Just want to validate my estimation for a C* cluster which should have around 3 TB of usable storage. Assuming a RF of 3 and SizeTiered Compaction Strategy. Is it correct, that SizeTiered Compaction Strategy needs (in the worst case) 50% free disc space during compaction?   So this would