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From Simon Metson <simonmet...@googlemail.com>
Subject Re: DynamoDB
Date Mon, 23 Jan 2012 22:04:52 GMT
Thanks for the summary George, interesting. 
Cheers
Simon


On Thursday, 19 January 2012 at 18:58, George Burt wrote:

> I was excited by it until I tried to see a use for it. The index is almost
> only a key store index. But you can have a very simple second index key.
> You can only find the second ken if you know the first. If your first key
> is the a customer and the second key is a date, then you can find all the
> documents for a customer. And you can find all the docs for a customer for
> a particular date. But you cannot find out who all posted on a particular
> date. Think ["cust1234","10-10-2012_001"] where the composite has to be
> unique (primary key).
> 
> But it is very fast. Think Redis if you have an EC2 machine in the same
> area as the DynamoDB (LAN speed). But, they throttle it to only allow the
> maximum requests you have paid for. But it is hard to pay for a cloud
> instance of Redis that has 50 gigs of storage, where it only costs $50 per
> month with DynamoDB. So the throughput is slower than Redis but the
> datasize can be much bigger.
> 
> A penny per hour buys you a max of 50 docs per second.
> 
> You can raise the max per second any time you like, but it has to stay at
> that rate for 24 hours.
> 
> This throttling is not too bad because you can raise it to any level at
> anytime, which is very, very powerful. In an instant, you could raise it
> to 100k units, which would give you 5 million reads per second and 1
> million writes. And it would actually deliver these speeds! Of course, it
> would cost you a minimum of $24,000 (and that is only if you dialed it back
> down, otherwise it is $24,000 per day.)
> 
> Still, for $72 per month, you could get a max of 500 reads per and 100
> writes. But, the problem is that you payload is limited to 1k. Well,
> actually, if you had a document that was 500k, it would consume the entire
> second's worth of capacity. This works out to 1.8 gigs of theoretical
> output per hour. In reality, the actual out put would be far lower.
> Clearly you can't move much data economically with this.
> 
> Storage is also a lot more expensive than S3 (roughly 8 or 9 times as much).
> 
> Also, it is a no-brainer in the sense that you don't have to worry about
> anything except setting the dial at what you need. It is very safe,
> redundant and is supposed to always have consistent performance at any
> scale.
> 
> I think on any economical sized installation, couch on an ec2 instance will
> out perform DynamoDB (because of the throttling) and you can store
> information for a fraction of the cost. And with DynamoDB, you don't
> really need replication.
> 
> So, I would say DynamoDB falls in between Redis and CouchDB.
> 
> George
> 
> 
> On Thu, Jan 19, 2012 at 9:51 AM, Arek Stryjski <arek.stryjski@gmail.com (mailto:arek.stryjski@gmail.com)>wrote:
> 
> > On Thu, Jan 19, 2012 at 01:19, Mark Hahn <mark@hahnca.com (mailto:mark@hahnca.com)>
wrote:
> > > 
> > > http://www.allthingsdistributed.com/2012/01/amazon-dynamodb.html
> > 
> > Wow it is this Dynamo!
> > 
> > Thanks for link,
> > Arek
> > 
> 
> 
> 
> 
> -- 
> George Burt
> President
> TrueShot Enterprises, LLC.
> (386) 208-1309
> Fax (213) 477-2195
> www.TrueShot.com (http://www.TrueShot.com)
> 12756 92nd Ter
> Live Oak, FL 32060
> 
> 



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