amazon ec2 hosting?

Simon Waters simonw at zynet.net
Tue Jul 13 11:29:15 CDT 2010


On Tuesday 13 July 2010 16:28:50 Doug Simmons wrote:
> 
> Do any of the list members have any experience with this service?

We are pondering a different cloud system based on XEN offering similar on a 
smaller scale than Amazon. Pricing is slightly cheaper, but not much in it. 
They charge for disk I/O bandwidth which required some quick checks on what 
we do, perils of expensive external storage systems.

In our case we've done a little more than 20 minutes research, but the 
conclusions aren't clear cut.

I think the motivation for moving to a cloud system is probably not solely 
financial, one has to expect that the option to migrate instances will add 
robustness, the option to add systems flexibility, and the scalability are 
the factors one is looking for. Also these systems have large robust storage 
systems which are beyond the pockets of most businesses.

My concern still is availability. Amazon EC2 I hear good things about. A 
couple of other providers we looked at are not bad, most don't have a track 
record you could point at and think "that is better than a decent hosting 
provider" and dedicated hardware - we routinely get 1 year plus uptimes on 
DELL hardware boxes that are a decade old - when we see top cloud providers 
off air for a couple of days at a time it doesn't convince me.

I've yet to use a virtualization product that didn't have 
virtualization "bugs", i.e. errors, downtime, or problems due to the 
virtualization process. The OpenVZ stuff we tried didn't memory map files 
correctly, one provider using XEN migrated our instance to different hardware 
for maintenance and when it woke up milliseconds later it was 1914 (Postfix 
said it wasn't doing anything till the date was plausible - which was 
probably wise - but did nothing for availability). What I've read of EC2 is 
that it is rather idiosyncratic compared to more recent virtualization 
offerings elsewhere, on the other hand they seem to have been free of major 
problems for a while.

The XEN provider we've looked at most closely seem promising, they seem to 
have resolved a lot of issues with their earlier system, but I have concerns 
at scalability because they limit the available RAM to each instance somewhat 
and when you have hundreds of gigabytes of data it would be nice to know you 
could scale RAM to something more substantial if needed, and serious disk 
space is expensive in these storage arrays. And they have zero track record 
on their new system because it is new. On the other hand I'm not THAT scared 
of virtualization just want to test it the whole way, which is time 
consuming.

One provider looked solid, but the pricing was high, and the 
marketing/emphasis was all to hosting enterprise servers rather than web 
servers (which is what we want). 

Anyone gone with a dual provider strategy - where they create instances at 
different cloud providers, and fail across on long outages? As that would 
address my key concerns about reliability, but it looks expensive and complex 
to implement.

If there were relatively cheap network storage systems around with suitable 
characteristics I'd be tempted to build our own XEN hosting system to get the 
advantages of virtualisation without the pain of a third party relationship. 
But I haven't read that bit of 'the Book of XEN' yet, and suspect the answer 
is "no".



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