To answer my own question, directly from the docs: http://www.datastax.com/docs/1.0/configuration/storage_configuration#replicate-on-write. It appears the answer to this is: "Yes, CL.QUORUM isn't necessary for reads." Essentially, replicate_on_write sets the CL to ALL regardless of what you actually set it to (and for good reason).
On Wed, May 29, 2013 at 9:47 AM, Andrew Bialecki <andrew.biale...@gmail.com>wrote: > Quick question about counter columns. In looking at the replicate_on_write > setting, assuming you go with the default of "true", my understanding is it > writes the increment to all replicas on any increment. > > If that's the case, doesn't that mean there's no point in using CL.QUORUM > for reads because all replicas have the same values? > > Similarly, what effect does the read_repair_chance have on counter columns > since they should need to read repair on write. > > In anticipation a possible answer, that both CL.QUORUM for reads and > read_repair_chance only end up mattering for counter deletions, it's safe > to only use CL.ONE and disable the read repair if we're never deleting > counters. (And, of course, if we did start deleting counters, we'd need to > revert those client and column family changes.) >
