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Date: Thu, 6 Feb 2014 07:11:11 +0000
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Subject: Re: CQL flow control
From: Ben Hood <0x6e6562@gmail.com>
To: user@cassandra.apache.org
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On Wed, Feb 5, 2014 at 7:32 PM, Edward Capriolo <edlinuxguru@gmail.com> wrote:
> I agree you can not really ask your database to capacity plan for you.
> Cassandra does have backpressure of sorts if  requests fail with
> TimedOutException or UnavailableException. You might be having a capacity
> problem.
>
> The way I would handle this is
> 1) prototype at scale (dark launches, similar hardware loaded with data you
> expect in production)
> 2) collect stats like 95 percentile response time, request/failures.
>
> When your 95 percentile starts dipping this is a good indication that it is
> time to deal with the performance issue.

This is a good point when you're assessing the end to end flow control
of a particular app. As I was saying to Rob, I'm looking at what
options a driver can provide, if any.