Regarding "Should we design our system so that if the datacenters where an app is deployed are vaporized, then the app keeps serving? No, this is a much thornier issue." does this mean that an app's data is stored in one and only one data center with no off-site backups?
I could understand that the off-site backup of an app isn't automatically started up when there is a burp in service from a datacenter, but if all of the data was lost from a datacenter would it just be gone? On Oct 7, 9:26 pm, Jon McAlister <[EMAIL PROTECTED]> wrote: > Should we allow control over where the app is serving from? Sure, that > sounds very reasonable, and is notably important for certain legal > reasons amongst our European customers. > > Should we design our system so that if the datacenters where an app is > deployed are vaporized, then the app keeps serving? No, this is a much > thornier issue. > > Notably, I disagree with the claim that true inter-continental > deployment of an app is a "basic premise of modern cloud computing", > mostly because this is really hard, and few systems actually get this > right. Think about it from the view of a datastore write. When you > write an entity, should that entity be immediately available on every > continent? The reasonable answer is no, because if we guaranteed that, > then the write latency would skyrocket. But if we don't guarantee > that, what do we guarantee instead? If the app is presently serving > from two continents, but we do not guarantee strong write behavior, > how are conflicting writes then to be merged? If one datacenter > disappears and then later comes back online, what happens to the > writes that were halfway applied but not yet fully merged? Do we > permit data to be dropped or do we try to reconcile this data, in > spite of the fact that it may be hours or days stale? > > The answer to the above questions rely heavily on the specifics of the > data and the behavior of the application, and most apps are happy to > avoid this issue and are fine serving from one or a small number of > locations. It's not a trivial thing to design one (or a handful of) > generic APIs that support true inter-continental application presence, > but this doesn't mean we'll give up trying to do so. We also welcome > any technical suggestions you have. For instance, how would you > presently solve this issue outside of Google App Engine? > > On Oct 7, 1:39 pm, "Andrew Badera" <[EMAIL PROTECTED]> wrote: > > > That's the point of the cloud -- if you're going to make your resources > > external, remote, you need to provide a means for assuring uptime. For some > > people, different geophysical locations are required for their service. > > Obviously GAE beta shouldn't see a true NEED for this while still in beta, > > but like SSL and everything else GAE lacks, there IS a need, it IS a basic > > premise of modern cloud computing. > > > On Tue, Oct 7, 2008 at 4:35 PM, Sal <[EMAIL PROTECTED]> wrote: > > > > So you want to be assured that if all the Google data centers in the > > > U.S. (over 12) go down (I wonder the probability of this), your GAE > > > application will still be up? > > > > On Oct 7, 11:35 am, "Andrew Badera" <[EMAIL PROTECTED]> wrote: > > > > Ahh ... availability and assurance? That's half the point of the cloud. > > > > > On Tue, Oct 7, 2008 at 2:34 PM, Sal <[EMAIL PROTECTED]> wrote: > > > > > > Honestly, why would anyone need to deploy their GAE applications to > > > > > international data centers? > > > > > > On Oct 7, 10:48 am, dleifker <[EMAIL PROTECTED]> wrote: > > > > > > What exactly does the term Google's Infrastructure imply? Once > > > > > > deployed does an application get deployed to regional (ie > > > > > > international) data centers? If not, from what general geographical > > > > > > area are the applications being served from? (US only?) And are > > > > > > there > > > > > > plans to allow an application to be deployed to international > > > > > > locations? > > > > > -- > > > > Thanks- > > > > - Andy Badera > > > > - [EMAIL PROTECTED] > > > > - (518) 641-1420 > > > > > -http://higherefficiency.net > > > > -http://changeroundup.com/ > > > > > -http://flipbitsnotburgers.blogspot.com/ > > > > -http://andrew.badera.us/ > > > > > - Google me:http://www.google.com/search?q=andrew+badera --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
