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From Paul Prescod <>
Subject Re: Memcached protocol?
Date Mon, 05 Apr 2010 17:35:43 GMT
On Mon, Apr 5, 2010 at 10:19 AM, Ryan Daum <> wrote:
> Are these applications using memcached for caching or for something else?
> I don't see the point in putting Cassandra in as a level 1 or 2 cache
> replacement? Especially given as it does not support any reasonable
> expiration policy that would be of use in those circumstances.
> Ryan

You're right that without cache expiration, it's of questionable value
for page/fragment caches. I was just curious about what methods are
used out in the real world, so I looked at some big apps that I know
use memcached.

As far as client libraries go, I can attest that in Ruby at least, the
memcached client library is vastly faster than the thrift one. I don't
know about avro. In my tests with Ruby, the marshalling was dominating
the networking in Cassandra performance. 25% of the time in my
benchmark was used by a function called "write_byte" (which is
implemented in Ruby!). I would be happy to hear that I'm Doing
Something Wrong, but I think it's just a consequence of the thrift
protocol and the client implementation.

I have no idea whether Avro is better. I'm not sure if it works well
enough to be tested yet...

 Paul Prescod

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