so having multiple data centers is step 1 of 4/5 9's. I've worked on some services that had 3-4 9's SLA. Getting there is really tough as others have stated. you have to auditing built into your service, capacity metrics, capacity planning, some kind of real-time monitoring, staff to respond to alerts, plan for handling system failures, training to handle outage and a dozen other things.
your best choice is to hire someone that has built a system that supports 4-5 9's and patiently work to get there. On Wed, Jun 22, 2011 at 7:16 PM, Les Hazlewood <l...@katasoft.com> wrote: > On Wed, Jun 22, 2011 at 4:11 PM, Peter Lin <wool...@gmail.com> wrote: >> >> you have to use multiple data centers to really deliver 4 or 5 9's of >> service > > We do, hence my question, as well as my choice of Cassandra :) > Best, > Les
