Hi Benjamin, as far as I know both memcache and redis does not support range queries on keys. So it would be really hard to update the cassandra columns reading from these and then updating them to cassandra.

On Thu, Jul 1, 2010 at 3:57 AM, Benjamin Black <b@b3k.us> wrote:
ZK is way overkill for counters.  memcache and redis are much better at the job.

On Tue, Jun 29, 2010 at 12:32 PM, Jonathan Shook <jshook@gmail.com> wrote:
> Until then, a pragmatic solution, however undesirable, would be to
> only have a single logical thread/task/actor that is allowed to
> read,modify,update. If this doesn't work for your application, then a
> (distributed) lock manager may be used until such time that you can
> take it out. Some are using ZooKeeper for this.
> On Tue, Jun 29, 2010 at 11:45 AM, Ryan King <ryan@twitter.com> wrote:
>> On Tue, Jun 29, 2010 at 9:42 AM, Utku Can Topçu <utku@topcu.gen.tr> wrote:
>>> Hey Guys,
>>> Currently in a project I'm involved in, I need to have some columns holding
>>> incremented data.
>>> The easy approach for implementing a counter with increments is right now as
>>> I figured out is "read -> increment -> insert" however this approach is not
>>> an atomic operation and can easily be corrupted in time.
>>> Do you have any best practices in implementing an atomic counter on
>>> Cassandra?
>> https://issues.apache.org/jira/browse/CASSANDRA-1072