
Ask HN: How does Amazon EC2 compare to shared web hosting? - geuis
Are multiple AMI instances run on the same physical servers? If so, does the load from one customer's server instance negatively effect all of the others on the same hardware? I understand that you can instantly spool up additional servers to dynamically handle load, but do those individual instances suffer from performance issues if they're loaded on busy hardware?
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pskomoroch
1) yes. 2) no. 3) no. ...there is a minimum guaranteed performance level for
each instance type. for small instances (1 core), each user gets a minimum of
1/N of the system resources. If you fire up an extra-large instance, you
essentially get the whole box to yourself, including I/O.

see:
[http://docs.amazonwebservices.com/AWSEC2/2008-02-01/Develope...](http://docs.amazonwebservices.com/AWSEC2/2008-02-01/DeveloperGuide/)

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geuis
Thanks for the answers folks. My roommate is talking about needing tens of
thousands of dollars of servers for a company he's thinking about starting and
and my immediate thought was "why?" I just got my first EC2 instance up and
running from the terminal in OS X so I'm doing my little happy dance. Thanks
for the help.

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xenoterracide
yeah go with EC2 first... get users... and more users... until EC2 doesn't cut
it... then turn the virtual machines into dedicated servers somewhere. Truth
is you'd have to spend tens of thousands of dollars to get the reliability
amazon should be selling you for much less.

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metajack
The only downside to them, in my opinion, is that disk access is not super
fast. This makes running databases on them much slower than a properly set up
real machine.

That said, I fully expect amazon to fix this, just as they have already added
high memory and high cpu instances. They seem to take feedback seriously and
have addressed most of the major complaints to date.

Being able to provision new machines with a simple command is reason enough to
use them over more traditional places.

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elsewhen
we just ran some extensive testing to move a highly trafficked website from a
cluster of dedicated servers (at theplanet) to ec2. note that our application
is to use ec2 as a real-time web server. the bottom line:

dedicated servers allow for much faster ip takeover (critical for high-
availability) and had lower latency. ec2 rocks for scalability.

in the end we decided to hold off on ec2 until they address these 2
deficiencies.

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wmf
_Are multiple AMI instances run on the same physical servers?_

Yes. A physical server is probably 8 cores and 32GB RAM, so an instance is
1/Nth of that.

 _If so, does the load from one customer's server instance negatively effect
all of the others on the same hardware?_

Not much, since CPU and RAM are not oversubscribed. I don't know about the
disks and network.

