It may help to remove the UI from the model -- the UI does not guarantee a stateful session. The UI interacts with the management server using end-user API calls. Mutating API calls generally have 2 steps: 1. Create / modify the entity in the db 2. Call the backend provisioning steps. This is the orchestration engine. All backend provisioning happens asynchronously. The asynchronous job queue is a database table. If a job is incomplete due to a management server failure, other servers in the cluster are expected to roll the provisioning forward or roll it back.
On 1/17/13 9:16 PM, "Adnan Ashraf" <mohammad.adnan.ash...@gmail.com> wrote: >Thanks for the feedback. so how does CloudStack provide HA/failover >guarantees? (not just the apache CloudStack but also the Citrix enterprise >CloudPlatform and cloudPortal/CPBM)? > >A service provider using CloudStack would expect nothing breaks from two >angle: user's perspective and back-end provisioning services. During >provisioning of a VPC (which has many atomic steps) or in the middle of VM >creation process, the application dies (for whatever reason). This case >could easily result in half-baked (bad data) situation and abandoned >workflows loosing the provisioning process. > >What workarounds or maybe persistent state based retries or logic is in >place for this situation? > >Adnan > > >On Thu, Jan 17, 2013 at 7:56 PM, Chiradeep Vittal < >chiradeep.vit...@citrix.com> wrote: > >> As far as I know no one deploys in this manner. >> >> On 1/17/13 6:30 AM, "Adnan Ashraf" <mohammad.adnan.ash...@gmail.com> >> wrote: >> >> >Hi, >> > >> >I would appreciate if anyone can provide feedback on following >>questions: >> > >> >Roughly what is the number of cloudStack deployments that are in JVM >> >(tomcat or other server) cluster mode where all session objects, http >> >sessions, beans etc are seamlessly failed over to the other node in >>case >> >one of the node in the cluster deployment goes out of service and the >>user >> >sessions carry as if nothing happened in the background. >> > >> >What percent of customers choose not to deploy cloudstack in a cluster >> >mode >> >and why? >> > >> >What is the largest known cluster size in deployment today? >> > >> >thanks >> > >> >regards, >> >Adnan >> >>
