2 ms·

I actually used that example because they had this exact problem in the past, here's the link: https://blog.cloudflare.com/todays-outage-post-mortem-82515/ http

• peterwwillis 8y ago
  And Google had a similar issue recently where they didn't test their firmware upgrade auto rollback, so a boned firmware upgrade bricked a region until they could manually recover it. If they had rolled out to all regions at once, and all the devices were the same, it would have been chaos. Often the only thing preventing mass upgrades from becoming mass outages is some part of the network just happens to work differently.
  • close04 8y ago
    Well... sure. Just as long as you keep in mind that a "not really tested [something]" will very easily get replicated on multiple vendor devices. It's not like they did it because they hate Vendor1 but will make sure to test all the corner cases with Vendor2. Some scenarios will by design ensure you can't have all of them fail because they are not susceptible to the same failure modes. But to compensate you introduce additional failure modes (especially human error) by using a heterogeneous environment. Not to mention the expense. I was actually hoping for an interesting human independent failure. A cosmic radiation caused bit flip that would occur on a particular device. :) Human error can overcome any setup.