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I think about this problem every now and then for my own business, but not sure what the right answer is. Supporting multiple clouds requires more involved mana

by fovc 9y ago

I think about this problem every now and then for my own business, but not sure what the right answer is. Supporting multiple clouds requires more involved management of some pieces of infrastructure (e.g., DNS + healthchecks, DB replication), which introduces another point of failure. How do people who need to have more nines of availability manage this issue with cloud providers? (EC2 and RDS promise 3.5 nines per AZ, but I imagine outages are somewhat correlated across zones)

sokoloff 9y ago
Very, very few businesses should be architecting to ensure higher than 99.95% availability, IMO. (Less than 4.5 hours of downtime per year.) Users are patient enough to give you a pass if you're down that amount (especially if you're down that amount while 1/3rd of the internet is also down). Our largest e-commerce retail site does over $1BB/yr in fairly high-margin sales and still targets "only" 99.95% availability (generally it exceeds that with actual results, but we don't target higher than that). It's a hybrid of on-prem and cloud services backing that, migrating towards the cloud, but will never be 100% cloud as we own and run factories with on-prem equipment. (I know you asked "how" and I answered "whether", but I thought it relevant.)
dastbe 9y ago
for people who need more 9s of availability on a single cloud provider, you have to start going multi-region. aws takes region isolation/independence very seriously, and along with geographic independence gives you effectively two entirely independent clouds which just so happen to have the exact same APIs. Some of the (really great) Netflix blog posts[0] have talked about multi-region services. If you do go multi-cloud, I would be wary of picking regions that are located very close to each other. While you'll obviously get independent code and (likely) independent deployments, you're still susceptible to issues correlated with the physical location. [0] https://medium.com/netflix-techblog/global-cloud-active-active-and-beyond-a0fdfa2c3a45 https://medium.com/netflix-techblog/global-cloud-active-acti...

by fovc 9y ago

sokoloff 9y ago

Very, very few businesses should be architecting to ensure higher than 99.95% availability, IMO. (Less than 4.5 hours of downtime per year.) Users are patient enough to give you a pass if you're down that amount (especially if you're down that amount while 1/3rd of the internet is also down). Our largest e-commerce retail site does over $1BB/yr in fairly high-margin sales and still targets "only" 99.95% availability (generally it exceeds that with actual results, but we don't target higher than that). It's a hybrid of on-prem and cloud services backing that, migrating towards the cloud, but will never be 100% cloud as we own and run factories with on-prem equipment. (I know you asked "how" and I answered "whether", but I thought it relevant.)

dastbe 9y ago

for people who need more 9s of availability on a single cloud provider, you have to start going multi-region. aws takes region isolation/independence very seriously, and along with geographic independence gives you effectively two entirely independent clouds which just so happen to have the exact same APIs. Some of the (really great) Netflix blog posts[0] have talked about multi-region services. If you do go multi-cloud, I would be wary of picking regions that are located very close to each other. While you'll obviously get independent code and (likely) independent deployments, you're still susceptible to issues correlated with the physical location. [0] https://medium.com/netflix-techblog/global-cloud-active-active-and-beyond-a0fdfa2c3a45 https://medium.com/netflix-techblog/global-cloud-active-acti...