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EC2 instances are not reliable: they degrade all the time. The solution, recommended by Amazon, is to have redundancy. So, plan on having at least two of every

EC2 instances are not reliable: they degrade all the time. The solution, recommended by Amazon, is to have redundancy. So, plan on having at least two of every type of server or using their services like RDS. Really, it is a rabbit hole that can lead to thousands of dollars each month very quickly. EC2 becomes efficient when talking about hundreds of thousands of customers if not more. You can end up with an impressively robust system but at a large of upfront cost: for startups probably not worth the ROI.

bretthoerner 15y ago
> for startups probably not worth the ROI. I definitely agree. That said, I think people seem to forget something. Amazon says: "your instance may go down and if it does we may just terminate it, reclaiming your ephemeral disk. All data not on EBS will be lost." Every other host (at least implicitly) says: "your instance/machine may go down, we will attempt to recover your data. The ability and speed depends largely on why the machine went down and whether we run RAID/etc on the machine." I've waited weeks for a disk repair from very well known/regarded non-Amazon hosts. Redundancy is needed everywhere, not just on Amazon. Bare metal still dies, controllers flake out, networks go down.
- sunsu 15y ago
  This is why I'm sticking with EC2 for now as well. Though one of my instances might go down or become unreliable, all I have to do to fix it is Stop and Start it! No messing with support tickets or waiting (sometimes hours) on someone to talk out to the data center to troubleshoot it. Its just fixed.
bermanoid 15y ago
EC2 instances are not reliable: they degrade all the time. The solution, recommended by Amazon, is to have redundancy. So, plan on having at least two of every type of server or using their services like RDS. With EC2 my approach has always been that if you've got enough traffic to justify it, you should move rather quickly to a load-balanced solution. This really forces you to stop relying on what's stored on any particular server, and focus your energy on making sure you can boot new ones and get them seamlessly into the rotation. Obviously this doesn't work for stuff like databases (for which I definitely recommend RDS or SimpleDB if they suit your needs), but even there, if you're hosting your own and make sure that the data goes on to EBS volumes instead of the instance stores, you can set things up so that you snapshot those volumes regularly and can boot up new database servers without trouble. Services like Rightscale can help manage stuff like this pretty easily, too, though they're probably a bit expensive for startups (and you've got to be willing to put in a little setup time, I've always found that their templates needed pretty substantial customization to suit my needs); in any case, Amazon is starting to pull more of that type of functionality into AWS itself, with stuff like CloudFormation and Elastic Beanstalk, so if I was starting now, I'd probably give those a closer look.
cperciva 15y ago
EC2 instances are not reliable: they degrade all the time You have an interesting definition of "all the time". In my experience, EC2 instances fail less often than dedicated servers.
- ericHosick 15y ago
  I didn't define it. You could have asked for clarification. We have had three instances degrade within a week. So far, we have had five instance degrade. At current degradation rate, nearly 100% of our production servers would degrade every year. It took a lot of work to try and get, from Amazon support, the expected degradation rates of their servers. Their response was as I described: implement redundancy. They never did let me know their expected degradation rate. Admittedly, we have not seen any degradation in a few months. However, this doesn't make me feel any better.

EC2 instances are not reliable: they degrade all the time. The solution, recommended by Amazon, is to have redundancy. So, plan on having at least two of every type of server or using their services like RDS. Really, it is a rabbit hole that can lead to thousands of dollars each month very quickly. EC2 becomes efficient when talking about hundreds of thousands of customers if not more. You can end up with an impressively robust system but at a large of upfront cost: for startups probably not worth the ROI.

bretthoerner 15y ago

> for startups probably not worth the ROI. I definitely agree. That said, I think people seem to forget something. Amazon says: "your instance may go down and if it does we may just terminate it, reclaiming your ephemeral disk. All data not on EBS will be lost." Every other host (at least implicitly) says: "your instance/machine may go down, we will attempt to recover your data. The ability and speed depends largely on why the machine went down and whether we run RAID/etc on the machine." I've waited weeks for a disk repair from very well known/regarded non-Amazon hosts. Redundancy is needed everywhere, not just on Amazon. Bare metal still dies, controllers flake out, networks go down.

sunsu 15y ago
This is why I'm sticking with EC2 for now as well. Though one of my instances might go down or become unreliable, all I have to do to fix it is Stop and Start it! No messing with support tickets or waiting (sometimes hours) on someone to talk out to the data center to troubleshoot it. Its just fixed.

bermanoid 15y ago

EC2 instances are not reliable: they degrade all the time. The solution, recommended by Amazon, is to have redundancy. So, plan on having at least two of every type of server or using their services like RDS. With EC2 my approach has always been that if you've got enough traffic to justify it, you should move rather quickly to a load-balanced solution. This really forces you to stop relying on what's stored on any particular server, and focus your energy on making sure you can boot new ones and get them seamlessly into the rotation. Obviously this doesn't work for stuff like databases (for which I definitely recommend RDS or SimpleDB if they suit your needs), but even there, if you're hosting your own and make sure that the data goes on to EBS volumes instead of the instance stores, you can set things up so that you snapshot those volumes regularly and can boot up new database servers without trouble. Services like Rightscale can help manage stuff like this pretty easily, too, though they're probably a bit expensive for startups (and you've got to be willing to put in a little setup time, I've always found that their templates needed pretty substantial customization to suit my needs); in any case, Amazon is starting to pull more of that type of functionality into AWS itself, with stuff like CloudFormation and Elastic Beanstalk, so if I was starting now, I'd probably give those a closer look.

cperciva 15y ago

EC2 instances are not reliable: they degrade all the time You have an interesting definition of "all the time". In my experience, EC2 instances fail less often than dedicated servers.

ericHosick 15y ago
I didn't define it. You could have asked for clarification. We have had three instances degrade within a week. So far, we have had five instance degrade. At current degradation rate, nearly 100% of our production servers would degrade every year. It took a lot of work to try and get, from Amazon support, the expected degradation rates of their servers. Their response was as I described: implement redundancy. They never did let me know their expected degradation rate. Admittedly, we have not seen any degradation in a few months. However, this doesn't make me feel any better.