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>Clueless engineers. The AWS instances don't fail more often or any differently than old school servers. Instance and host reliability aren't the issue here. T

>Clueless engineers. The AWS instances don't fail more often or any differently than old school servers. Instance and host reliability aren't the issue here. The issue is that a disgustingly high number of enterprises rely on vSphere High Availability and Fault-Tolerance features to restart VMs or keep them alive when an OS hangs or the host fails, instead of architecting for high availability at the app layer. To be entirely fair though, vSphere HA and FT are incredibly friendly to the bottom line relative to rebuilding apps that simply weren't designed for HA.

user5994461 10y ago
My bad. I didn't get that you were talking about the built-in vSphere HA. This thing is truly amazing =) I thought it was the usual complain about AWS instances dying and needing to be replaced on regular basis. That thing is a myth. An instances can run for years without any issues, if noone stops it manually.
- hodgesrm 10y ago
  Whether Amazon VMs go for years seems to be a matter of luck in my experience. You need to bake in HA for any service you really depend on either by having copies or ability to start new ones at will.
- maratd 10y ago
  > An instances can run for years without any issues, if noone stops it manually. Sometimes. And sometimes the hardware it was running on dies or there was a maintenance event. Now you have a message like this waiting for you: http://stackoverflow.com/questions/34259924/instance-retirement-instance-stop http://stackoverflow.com/questions/34259924/instance-retirem... Fail to notice? Bye bye instance. That said, you're right, it's not any more common than hardware failure. But that's common enough. Keep a backup and don't expect your stuff to always be there no matter what.
wmf 10y ago
vSphere HA and FT should work in AWS so those people should be happy.
jmgtan 10y ago
You can also do that in AWS using CloudWatch Auto Recovery functionality. Of course it's still better to design for HA, but if it's not possible Auto Recovery should be able to add a bit of resiliency.
carterehsmith 10y ago
> High Availability and Fault-Tolerance features to restart VMs or keep them alive when an OS hangs or the host fails "High Availability and Fault-Tolerance" would hopefully involve more than restarting the VM. I mean, you have like bajillion people that solved the above "challenge" with a three-line bash script. And not one of those people would call it "High Availability and Fault Tolerance". It's just a small shell script.
- wmf 10y ago
  vSphere HA indeed restarts the VM on a different host with its storage, network, etc. intact. This is so trivial that EC2 didn't offer it for years. vSphere FT replicates a VM while it runs so that it doesn't even notice the failure of one of the underlying servers.
  - carterehsmith 10y ago
    > vSphere HA indeed restarts the VM on a different host with its storage, network, etc. intact. This is so trivial that EC2 didn't offer it for years. How often is your hardware fucked up enough that you need to move to another machine? Honestly, if that happens often, there is something wrong with your hardware or your hardware provider or something. On a 900-servers fleet on AWS, yeah, sometimes it would warn me that "the server needs to be retired" or whatever. Then I stop the server, then start it. Sure, inconvenient, but happens maybe... once a month? In fact, the frequency is decreasing so maybe once every two months? > vSphere FT replicates a VM while it runs so that it doesn't even notice the failure of one of the underlying servers. That would be great, right? You paid some $ to VMWare and now your servers never go down? Excuse me but, that did not happen.
    - wmf 10y ago
      Enterprise data centers are probably much less reliable than AWS. My take on HA & DR in general is that it's the kind of thing that you might use once in your career but it's probably worth it since it saves you from being fired.

user5994461 10y ago

My bad. I didn't get that you were talking about the built-in vSphere HA. This thing is truly amazing =) I thought it was the usual complain about AWS instances dying and needing to be replaced on regular basis. That thing is a myth. An instances can run for years without any issues, if noone stops it manually.

hodgesrm 10y ago
Whether Amazon VMs go for years seems to be a matter of luck in my experience. You need to bake in HA for any service you really depend on either by having copies or ability to start new ones at will.
maratd 10y ago
> An instances can run for years without any issues, if noone stops it manually. Sometimes. And sometimes the hardware it was running on dies or there was a maintenance event. Now you have a message like this waiting for you: http://stackoverflow.com/questions/34259924/instance-retirement-instance-stop http://stackoverflow.com/questions/34259924/instance-retirem... Fail to notice? Bye bye instance. That said, you're right, it's not any more common than hardware failure. But that's common enough. Keep a backup and don't expect your stuff to always be there no matter what.

wmf 10y ago

vSphere HA and FT should work in AWS so those people should be happy.

jmgtan 10y ago

You can also do that in AWS using CloudWatch Auto Recovery functionality. Of course it's still better to design for HA, but if it's not possible Auto Recovery should be able to add a bit of resiliency.

carterehsmith 10y ago

> High Availability and Fault-Tolerance features to restart VMs or keep them alive when an OS hangs or the host fails "High Availability and Fault-Tolerance" would hopefully involve more than restarting the VM. I mean, you have like bajillion people that solved the above "challenge" with a three-line bash script. And not one of those people would call it "High Availability and Fault Tolerance". It's just a small shell script.

wmf 10y ago
vSphere HA indeed restarts the VM on a different host with its storage, network, etc. intact. This is so trivial that EC2 didn't offer it for years. vSphere FT replicates a VM while it runs so that it doesn't even notice the failure of one of the underlying servers.
- carterehsmith 10y ago
  > vSphere HA indeed restarts the VM on a different host with its storage, network, etc. intact. This is so trivial that EC2 didn't offer it for years. How often is your hardware fucked up enough that you need to move to another machine? Honestly, if that happens often, there is something wrong with your hardware or your hardware provider or something. On a 900-servers fleet on AWS, yeah, sometimes it would warn me that "the server needs to be retired" or whatever. Then I stop the server, then start it. Sure, inconvenient, but happens maybe... once a month? In fact, the frequency is decreasing so maybe once every two months? > vSphere FT replicates a VM while it runs so that it doesn't even notice the failure of one of the underlying servers. That would be great, right? You paid some $ to VMWare and now your servers never go down? Excuse me but, that did not happen.
  - wmf 10y ago
    Enterprise data centers are probably much less reliable than AWS. My take on HA & DR in general is that it's the kind of thing that you might use once in your career but it's probably worth it since it saves you from being fired.