Poor key cache hit rate

[Keith <kw...@nanigans.com>]

Hi all,

I am running 1.1.9 with 2 data centers and 3 nodes each.  Recently I have been seeing a terrible key cache hit rate (around 1-3%) with a 98% row cache hit rate.  The seed node appears to take higher traffic than the other nodes (approximately twice) but I believe I have astyanax configured properly with ring describe and token aware.  Any ideas or steps on how to debug?  I also see high GC load.  Perhaps I need more nodes?

Re: Poor key cache hit rate

[Edward Capriolo <ed...@gmail.com>]

You should not use the row cache and the key vacumed on the same cf. If
that is what you are doing it explains your numbers. Some docs suggest you
can use them together but in practice I have seen when this is done the key
cache rate drops to near 0.

On Tuesday, January 29, 2013, Keith <kw...@nanigans.com> wrote:
> Hi all,
>
> I am running 1.1.9 with 2 data centers and 3 nodes each.  Recently I have
been seeing a terrible key cache hit rate (around 1-3%) with a 98% row
cache hit rate.  The seed node appears to take higher traffic than the
other nodes (approximately twice) but I believe I have astyanax configured
properly with ring describe and token aware.  Any ideas or steps on how to
debug?  I also see high GC load.  Perhaps I need more nodes?