Thanks a lot dormando for the reply. It is really valuable to us.

On Apr 22, 11:28 am, dormando <[email protected]> wrote:
> Memcached's architecture is a set of tradeoffs:
>
> - Add a little network roundtrip latency
>   - Gain global atomic invalidation
>   - Gain linearly expanding cache size
>
> Global invalidation means your cache can be more useful, and perhaps you
> can use it in more places.
>
> Expansive cache means (if you have enough data) that you hit your backend
> less often, which tends to make up for the "speed loss" from going over
> the network.
>
> If neither of those tradeoffs are valueable to you, don't set it up that
> way.
>
>
>
>
>
>
>
> On Sat, 21 Apr 2012, Suraj wrote:
> > Hi,
>
> > We are having a scenario, where for each request, we call memcache
> > about 250 times. Our memcache data size is not much and totals to
> > around 1 GB. Multiget is not an a straight forward option, as our
> > cache calls are scattered across the code and depends on the business
> > scenario.
>
> > Each server nearly serves 10 million requests per day and a cluster
> > combined serves nearly 1 billion requests a day. We are having a
> > gigabit ethernet. Our server side response time for each request is
> > and should be < 85 ms.
>
> > What approach should be ideal for this scenario?
>
> > 1. Run memcache on each server on unix socket.
> > This will reduce the network latency but increase the cache miss ratio
> > a bit and data redundancy, as nearly same data is present on each
> > node of the cluster.
> > We are having similar setup and see around 85% cache hit. Our expiry
> > time varies for different keys.
>
> > or
>
> > 2. Have a distributed memcache layer. This will probably increase the
> > cache hit ratio to more than 99%.
> > But this will add the network latency and may be a single point of
> > failure.
>
> > I did a very basic get bench marking on a low end machine.
> > 1. 100,000 get, 1 thread, memcache and benchmarking script on same
> > machine - 1.233s
> > 2. 100,000 get, 1 thread, memcache and benchmarking script on
> > different machine  - 9.538s
>
> > From this numbers, approach 1, the one we are doing right now seems to
> > be a better one.
> > Please let me know your opinion, about what approach seems to be
> > better or if there is any different suggestion.
>
> > Thanks.

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