

Are spot instances killing the performance of Amazon EC2? - seldo
http://seldo.com/weblog/2010/01/15/are_spot_instances_killing_the_performance_of_amazon_ec2

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azm
I think you are making an assumption regarding availability vs price vs
demand. I would think that given the sort of capacity Amazon has, at some
point of time the cost of a spot instance would be the same as or higher than
the cost of a regular ec2 instance, at which time it would make more sense to
just get a regular instance.

Per my understanding the attraction of spot instances is that you can get
short-term instances at lower rates. Even as I say this I am making a big
assumption that Amazon's spare capacity is much larger than demand for sport
instances.

Finally slow ping times could be caused by any number of reasons, attributing
them to one particular cause based on a coincidental date might be a bit much.

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wmf
Even if EC2's RAM is all allocated that wouldn't necessarily lead to network
congestion, since network usage is workload-dependent. Conversely it would be
possible for EC2 to experience network congestion even when its RAM is not
full.

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lallysingh
I don't know the virtualization system they're using. Could some of the
(partially virtual) network stack be software based, and thusly respond to
memory pressure?

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timdorr
They use Xen. No idea on the network architecture, though.

