High read latency

[Jaydeep Chovatia]

Hi,

My application issues more read requests than write, I do see that under
load cfstats for one of the table is quite high around 43ms

                Local read count: 114479357
                Local read latency: 43.442 ms
                Local write count: 22288868
                Local write latency: 0.609 ms


Here is my node configuration:
RF=3, Read/Write with QUORUM, 64GB RAM, 48 CPU core. I have only 5 GB of
data on each node (and for experiment purpose I stored data in tmpfs)

I've tried increasing concurrent_read count upto 512 but no help in read
latency. CPU/Memory/IO looks fine on system.

Any idea what should I tune?

Jaydeep