Re: Merge a sharded master into a single read-only slave

On Mon, Jun 2, 2014 at 12:52 PM, Kevin Goess <kgoess(at)bepress(dot)com> wrote:

> > So my conclusion is that for now, the best way to scale read-only
> queries for a sharded master is to
> > implement map-reduce at the application level.
>
> That's the conclusion I would expect. It's the price you pay for sharding,
> it's part of the deal.
>
> But it's also the benefit you get from sharding. Once your read traffic
> grows to the point that it's too much for a single host, you're going to
> have to re-shard it all again *anyway*. The whole point of sharding is
> that it allows you to grow outside the capacities of a single host.
>

​I am not sure I am following you completely. I can replicate the read-only
slaves almost as much as I want (with chained replication), so why would I
be limited to a single host ? You would have a point concerning database
size, but in my case, the main reason I need to shard is because of the
amount of writes.