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From Andrew Bialecki <andrew.biale...@gmail.com>
Subject Re: Does replicate_on_write=true imply that CL.QUORUM for reads is unnecessary?
Date Thu, 30 May 2013 02:32:54 GMT
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.bialecki@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.)
>

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