This is not only related to manual scaling, we should have some mechanism to persist associate polices (and run time changes) with cartridge subscription. Currently it does not required because we did not allow to change policies (run time update for policies) per subscription. But since we are planning to allow this we need some model to persist policies (and all other parameters), run time policy changes (min, threshold values etc).
On Wed, Oct 15, 2014 at 4:42 PM, Rajkumar Rajaratnam <rajkum...@wso2.com> wrote: > Hi Imesh, > > On Wed, Oct 15, 2014 at 4:26 PM, Imesh Gunaratne <im...@apache.org> wrote: > >> I do not think we need to specifically handle this, manual scaling also >> need to take the same path as the standard scaling decision. >> > > Hmm.. In manual scaling what we are doing is increasing the min count > right? Basically we are modifying the cluster object which is already > created and added to the topology. Please be kind enough to explain me if I > got it wrong. How it can take the same path as standard scaling? > > Thanks. > >> >> On Wed, Oct 15, 2014 at 10:03 AM, Rajkumar Rajaratnam <rajkum...@wso2.com >> > wrote: >> >>> Or else, we can have an API at CC side to update clusters and let CC to >>> publish ClusterUpdated event to topology topic. AS can simply listen to >>> this event and update the cluster context accordingly. Then we don't need >>> to introduce a new topic for AS to publish events and AS is already >>> listening to topology topic. IMO, this is a good approach. >>> >>> Wdyt? >>> >>> >>> On Wednesday, October 15, 2014, Rajkumar Rajaratnam <rajkum...@wso2.com> >>> wrote: >>> >>>> Hi, >>>> >>>> As you know, we are now supporting manual scaling for docker >>>> containers. Autoscaler has an API to update cluster properties like min >>>> replicas of a particular cluster. >>>> >>>> void updateClusterMonitor(String clusterId, Properties properties) >>>> throws InvalidArgumentException; >>>> >>>> We are not persisting anything about clusters at AS side, when we >>>> shutdown stratos. When we are restarting, we are reading topology and >>>> create/populate/update cluster monitors. >>>> >>>> Hence this new value for min replicas is not persisted when we shutdown >>>> the stratos. During manual scaling the min replicas is updated only in AS >>>> side, hence if we restart the stratos, this effect will be lost. >>>> >>>> So manual scaling should impact the topology. Here is a proposed >>>> solution. >>>> >>>> AS will provide an API to update cluster monitors, that is you can >>>> update properties of a cluster like min replicas. Once this API is called >>>> AS will send a *ClusterAltered* event to CC. Once CC gets this event, >>>> it will validate the properties, update the topology and send a >>>> *ClusterUpdated* event. Once AS gets this event, AS will update the >>>> cluster context with new values for properties like min replicas. Until we >>>> get cluster updated event, AS will not alter any properties. >>>> Then everything is consistent and manual scaling effects will be >>>> persisted. >>>> >>>> wdyt? >>>> >>>> Thanks. >>>> >>>> -- >>>> Rajkumar Rajaratnam >>>> Software Engineer | WSO2, Inc. >>>> Mobile +94777568639 | +94783498120 >>>> >>> >>> >>> -- >>> Rajkumar Rajaratnam >>> Software Engineer | WSO2, Inc. >>> Mobile +94777568639 | +94783498120 >>> >>> >> >> >> -- >> Imesh Gunaratne >> >> Technical Lead, WSO2 >> Committer & PMC Member, Apache Stratos >> > > > > -- > Rajkumar Rajaratnam > Software Engineer | WSO2, Inc. > Mobile +94777568639 | +94783498120 > -- Lakmal Warusawithana Vice President, Apache Stratos Director - Cloud Architecture; WSO2 Inc. Mobile : +94714289692 Blog : http://lakmalsview.blogspot.com/
