Ok.. Cassandra default block size is 256k ? Now say my data in the column is 4 MB. And the disk is giving me 4k block size random reads @ 100 IOPS. I can read max 400k in one seek ? does that mean I would need multiple seeks to get the complete data ?
-----Original Message----- From: sc...@scode.org [mailto:sc...@scode.org] On Behalf Of Peter Schuller Sent: 21 February 2013 00:05 To: user@cassandra.apache.org Subject: Re: Read IO > Is this correct ? Yes, at least under optimal conditions and assuming a reasonably sized row. Things like read-ahead (at the kernel level) will play into it; and if your read (even if assumed to be small) straddles two pages you might or might not take another read depending on your kernel settings (typically trading pollution of page cache vs. number of I/O:s). -- / Peter Schuller (@scode, http://worldmodscode.wordpress.com)
