Regarding health monitoring in containers, as discussed the best approach would be to use a well-known docker container monitoring tool such as cAdvisor coupled with a cartridge agent instance per controller node.
Why do we use the term "replicas" for the Kubernetes control node instances? Are we looking at providing HA for controller nodes rather than treating them as a cluster of controller nodes. On Tue, Sep 16, 2014 at 7:04 AM, Nirmal Fernando <nirmal070...@gmail.com> wrote: > AFAIS Autoscaler's task is very simple in the container case. It just need > to create a kubernetes replication controller with the minimum number of > replicas initially via CC and need to update the number of replicas of the > same kubernetes replication controller (again via CC) based on the health > stats and make sure that the number of replicas are maintained under > maximum replicas count. > > > On Tue, Sep 16, 2014 at 3:20 PM, Lahiru Sandaruwan <lahi...@wso2.com> > wrote: > >> >> >> On Tue, Sep 16, 2014 at 2:57 PM, Lakmal Warusawithana <lak...@wso2.com> >> wrote: >> >>> >>> >>> On Tue, Sep 16, 2014 at 1:53 PM, Lahiru Sandaruwan <lahi...@wso2.com> >>> wrote: >>> >>>> Hi Akila, >>>> >>>> >>>> >>>> On Tue, Sep 16, 2014 at 12:49 PM, Akila Ravihansa Perera < >>>> raviha...@wso2.com> wrote: >>>> >>>>> Hi Raj, >>>>> >>>>> We can use the same CEP stream to publish cartridge agent health >>>>> stats. We can identify the instance type (container or VM type) by >>>>> retrieving member properties from the topology. But I don't think we >>>>> should >>>>> be doing that. >>>>> >>>>> IMO, we should not publish cartridge agent health stats from each and >>>>> every container. It's better if we can have a global agent per Kubernetes >>>>> host instance to monitor the health of every container and also in host >>>>> instance itself. We can use a container monitoring agent like cAdvisor to >>>>> collect container health stats. >>>>> >>>> >>>> This is a good model. We will anyway have an agent in docker host as it >>>> is a multi-tenant cartridge instance. Then we can improve same agent to >>>> take-care of it's docker instances. We might need to let it know that it is >>>> running in a docker host. >>>> >>>> Do you suggest we completely get rid of agent inside dockers? >>>> >>>> Thanks. >>>> >>>>> >>>>> +1 for having a separate CEP execution plan for handling Docker >>>>> containers scenario. >>>>> >>>>> As for the ContainerClusterMonitor, we should clearly outline the >>>>> responsibilities of container monitor and VM monitor. Because since we are >>>>> using Kubernetes for managing the life-cycle of containers, most of the >>>>> tasks are already taken care of. For eg - we don't need to start a new >>>>> container if an existing containers fails since Kubernetes will handle >>>>> that >>>>> failure. >>>>> >>>> >>>> My concern of letting Kubernetes control minimum values is, it is >>>> difficult to get the new member identified in Stratos side. Shall we take >>>> that control to Autoscaler as we do for VM clusters? >>>> >>> >>> Here Stratos will defining the min container count, but Kubernetes will >>> take care of up and running it. >>> >> >> Stratos might keep a higher value for active instances list for few >> minutes(until we get member fault for lost instance) in this case. It will >> affect Autoscaling decision and active instances shown in UIs. >> >> That was my initial concern. But if the Kubernetes is very fast on this >> HA action, it would be better to let Kubernetes handle it, as it would >> increase Stratos HA ability as well. >> >> Thanks. >> >> >>> >>> >>>> >>>> Thanks. >>>> >>>>> >>>>> WDYT? >>>>> >>>> >>>> >>>> >>>> -- >>>> -- >>>> Lahiru Sandaruwan >>>> Committer and PMC member, Apache Stratos, >>>> Senior Software Engineer, >>>> WSO2 Inc., http://wso2.com >>>> lean.enterprise.middleware >>>> >>>> email: lahi...@wso2.com cell: (+94) 773 325 954 >>>> blog: http://lahiruwrites.blogspot.com/ >>>> twitter: http://twitter.com/lahirus >>>> linked-in: http://lk.linkedin.com/pub/lahiru-sandaruwan/16/153/146 >>>> >>>> >>> >>> >>> -- >>> Lakmal Warusawithana >>> Vice President, Apache Stratos >>> Director - Cloud Architecture; WSO2 Inc. >>> Mobile : +94714289692 >>> Blog : http://lakmalsview.blogspot.com/ >>> >>> >> >> >> -- >> -- >> Lahiru Sandaruwan >> Committer and PMC member, Apache Stratos, >> Senior Software Engineer, >> WSO2 Inc., http://wso2.com >> lean.enterprise.middleware >> >> email: lahi...@wso2.com cell: (+94) 773 325 954 >> blog: http://lahiruwrites.blogspot.com/ >> twitter: http://twitter.com/lahirus >> linked-in: http://lk.linkedin.com/pub/lahiru-sandaruwan/16/153/146 >> >> > > > -- > Best Regards, > Nirmal > > Nirmal Fernando. > PPMC Member & Committer of Apache Stratos, > Senior Software Engineer, WSO2 Inc. > > Blog: http://nirmalfdo.blogspot.com/ > -- Imesh Gunaratne Technical Lead, WSO2 Committer & PMC Member, Apache Stratos
