On Tue, Dec 03, 2013 at 12:43:22PM -0600, Andy Doan wrote: > On 12/03/2013 10:07 AM, Evan Dandrea wrote: > >Attached is the diagram Nick and Liam drew for how we might layout > >each component. Keep in mind this is for a single microrservice. We'd > >want this layout for each one. You can ignore the bit at the top for > >squid. We won't need that on the front of most things. Instead, a > >simple Apache in front of HAProxy will suffice. > > > http://ubuntuone.com/0w12vBEgDVn4YUMh5JkoMq > > Thinking about this generically, I'm not sure how specific these > issues relate to Django. ie - all solutions at a minimum are going > to require some sort of webserver and data-store and/or queue > system. The specific solutions to make each implementation > highly-available will differ, but they'll all require something. > > As we start to talk more concretely about high availability, I'm > starting to wonder if we should first ask "is it worth it?" ie - > what could we expect our availability to be if we just deployed a DB > and a couple of web-servers. If the answer is >98%, then is it worth > the man-hours required to get us to 99.9%? > > from another angle: the ppa-assigner component we have will probably > have less 100 operations a day. So are the odds of it being down at > the precise time one of those operations are executed already <1%? > > I'm really not wanting to sound lazy here. But this feels like its > snowballing to a place where getting a few components demo-worthy > might be growing too fast. However, if we don't do this now it might > make it too expensive later. >
I thought (perhaps incorrectly) that HA should be invisible to consumers of a service. Using that assumption we shouldn't have to design our services to be HA. We should be able to treat them as if they are a single instance. Which implies we can start with non-HA services and work toward adding the HA layer for those services that are critical. Thanks, Joe -- Mailing list: https://launchpad.net/~canonical-ci-engineering Post to : [email protected] Unsubscribe : https://launchpad.net/~canonical-ci-engineering More help : https://help.launchpad.net/ListHelp
