+1 Yes a good point Lakmal, to reduce the latency for a modification to propagate to all the instances we might need to replicate topology as well.
Thanks On Wed, Nov 26, 2014 at 2:44 PM, Lakmal Warusawithana <lak...@wso2.com> wrote: > > > On Wed, Nov 26, 2014 at 1:16 PM, Imesh Gunaratne <im...@apache.org> wrote: > >> Hi Devs, >> >> This is to discuss the clustering model of the cloud controller: >> >> >> >> >> As shown in the above diagram the idea is to have a coordinator node to >> handle data persistence logic and message publishing (topology, instance >> status, etc). The coordinator will be selected randomly and at a given time >> there will be only one coordinator. If the existing coordinator node goes >> down, another member will become the coordinator automatically (similar to >> carbon clustering agent). >> >> According to this design Autoscaler (AS)/Stratos Manager (SM) will talk >> to Cloud Controller (CC) via the Cloud Controller Service endpoint exposed >> via the load balancer. >> >> *Data Replication* >> When a request comes into one of the CC instances it will execute the >> necessary actions and update the data holder and/or topology which is in >> memory. At this point the data holder changes will be replicated to other >> instances using a distributed map. Once the coordinator receives the above >> updates it will persist the changes to the registry database. >> >> In this design we might not need to replicate the topology since it is >> already there in the message broker. The idea is to let coordinator publish >> the topology changes and the other members to listen to it. >> >> > IMO, we may need to replicate topology also, otherwise it may occur some > inconsistency. > > >> Please add your thoughts. >> >> Thanks >> >> >> -- >> Imesh Gunaratne >> >> Technical Lead, WSO2 >> Committer & PMC Member, Apache Stratos >> > > > > -- > Lakmal Warusawithana > Vice President, Apache Stratos > Director - Cloud Architecture; WSO2 Inc. > Mobile : +94714289692 > Blog : http://lakmalsview.blogspot.com/ > > -- Imesh Gunaratne Technical Lead, WSO2 Committer & PMC Member, Apache Stratos
