3 ms·

> mainframes are basically redundant on everything Not only that but that redundancy is hidden from everything. Already decades ago the Hungarian electricity d

by chx 4y ago

> mainframes are basically redundant on everything Not only that but that redundancy is hidden from everything. Already decades ago the Hungarian electricity distributor had a "RAID" storage unit where one bunch of disks were at the capitol, the other bunch connected with fiber at another city -- and you talked to this thing as if it were an ordinary disk. Short of an invading army nothing could cause data loss on that thing -- simple aerial bombing wouldn't because the unit in the capitol was tens of meters underground... that's not concerns you have on your average web app.

bombcar 4y ago
Yeah, one thing that I've been really disappointed with is how UNRELIABLE the "cloud" is - unless you engineer all the reliability in the software itself. We have the technology and the capability to do things like run a VM and have it move between hardware when that hardware fails or needs replacement. but that would cost money.
- ghaff 4y ago
  VMs can often be configured to do "live migration" but that doesn't protect a running instance if the hardware it is running on fails completely. There is such a thing as fault tolerant hardware/software stacks but, yes, most modern architectures shift application resiliency higher up the stack.
- runako 4y ago
  > the capability to do things like run a VM and have it move between hardware when that hardware fails This is one of my favorite features of Google Cloud: https://cloud.google.com/compute/docs/instances/live-migration-process https://cloud.google.com/compute/docs/instances/live-migrati... Unfortunately, Google continues to be the third-string provider in the US, so I don't often get the opportunity to work with Google Cloud.
  - nzentzis 4y ago
    I want to be able to justify using Google Cloud for projects, but the fact that it’s a Google product is the main obstacle to that. If history is anything to go by, relying on Google products and services seems like a great way to set yourself up for major problems down the line. Either the product you’re using is shut down on short notice or some automation flags a false-positive and you’re left screaming into the void trying to get yourself unbanned.
- huslage 4y ago
  It’s not a live migration. It’s running an a VM in a sysplex which is in lockstep with its peer. There’s not a failover in the tradition sense..the I/O just goes from one side to the other.

by chx 4y ago

bombcar 4y ago

Yeah, one thing that I've been really disappointed with is how UNRELIABLE the "cloud" is - unless you engineer all the reliability in the software itself. We have the technology and the capability to do things like run a VM and have it move between hardware when that hardware fails or needs replacement. but that would cost money.

ghaff 4y ago
VMs can often be configured to do "live migration" but that doesn't protect a running instance if the hardware it is running on fails completely. There is such a thing as fault tolerant hardware/software stacks but, yes, most modern architectures shift application resiliency higher up the stack.
runako 4y ago
> the capability to do things like run a VM and have it move between hardware when that hardware fails This is one of my favorite features of Google Cloud: https://cloud.google.com/compute/docs/instances/live-migration-process https://cloud.google.com/compute/docs/instances/live-migrati... Unfortunately, Google continues to be the third-string provider in the US, so I don't often get the opportunity to work with Google Cloud.
- nzentzis 4y ago
  I want to be able to justify using Google Cloud for projects, but the fact that it’s a Google product is the main obstacle to that. If history is anything to go by, relying on Google products and services seems like a great way to set yourself up for major problems down the line. Either the product you’re using is shut down on short notice or some automation flags a false-positive and you’re left screaming into the void trying to get yourself unbanned.
huslage 4y ago
It’s not a live migration. It’s running an a VM in a sysplex which is in lockstep with its peer. There’s not a failover in the tradition sense..the I/O just goes from one side to the other.