27 ms·

Master slave failover will give you less than a second of downtime.

• hparadiz 3y ago
  Pretty much any provisioned vm can be split down the middle. Got 4 cpus and 4gb of ram? Congrats you have two vms with 2 cpus and 2gb of ram. Throw them into a 50/50 load balancer and never have any downtime.
  • toast0 3y ago
    Two vms on the same machine doesn't help when the machine fails. Also, I sure hope your loadbalancers don't suck. I've worked with some that had worse uptime than my servers, and worse capacity too. Went back to putting the two host addresses in DNS, which is mostly fine, but means a lot of waiting when you want to take a host out of rotation for disruptive maintenance.
    • hparadiz 3y ago
      I do this on AWS so the load balancer is managed for me. Never had issues. Two randomly provisioned vms are unlikely to be on the same bare metal.
      • aflukasz 3y ago
        You do have some control (quite typically?): https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placemen..., https://docs.hetzner.com/cloud/placement-groups/overview https://docs.hetzner.com/cloud/placement-groups/overview.
  • viraptor 3y ago
    VMs going down is not an unexpected event. It's not going to happen even day, but hosts crash, network goes down, datacentres experience thermal events, etc. Your solution may work for your own system crashes, but not most of the rented platform failure modes.