We don't have to have 0 in server-mode operations right now, but we will have to have this as we transition to serverless. And yes, obviously, this will have to be done by something different than CPU utilization. :)
On Wed, Nov 2, 2016 at 7:46 PM, Lakmal Warusawithana <[email protected]> wrote: > > > On Wed, Nov 2, 2016 at 11:27 PM, Dmitry Sotnikov <[email protected]> wrote: > >> My point is that for serverless architecture, if load balancer can deal >> with the "0" situation (no containers are running, requests come in, a >> container is spun up and gets the request), then 1 also works. >> > > AFAIK, you can't put 0 as min count. (unless we support and send > upstream). Main reason is autoscaling currently implemented based on CPU > utilization, if it is 0 you can't calculate it. If we want to do this, we > should introduce autoscaling factor based on LB queue. > > > >> >> 2 as the minimum for HA configuration is a good approach for >> the server-oriented model. >> >> On Wed, Nov 2, 2016 at 10:46 AM, Deependra Ariyadewa <[email protected]> >> wrote: >> >>> >>> >>> On Wed, Nov 2, 2016 at 10:22 PM, Dmitry Sotnikov <[email protected]> >>> wrote: >>> >>>> Not for transactional stuff, right? If this is just a mediation or >>>> proxy service request and the host fails - the request would not >>>> automatically go to a second node anyway, right? >>>> >>> >>> Load balancer is the entry point to the Integration / AppCloud. If one >>> replica fails LB can route the request based on the liveness check. This >>> use case is valid for endpoint need high uptimes. >>> >>>> >>>> On Wed, Nov 2, 2016 at 9:41 AM, Deependra Ariyadewa <[email protected]> >>>> wrote: >>>> >>>>> >>>>> >>>>> On Wed, Nov 2, 2016 at 9:48 PM, Dmitry Sotnikov <[email protected]> >>>>> wrote: >>>>> >>>>>> Wouldn't minimum be set to 0 in true serverless experience? >>>>>> >>>>> >>>>> Yes, in the initial stage replica count should be 0 but in the running >>>>> state we have to have two copies of each instance to face server failures. >>>>> >>>>>> >>>>>> On Wed, Nov 2, 2016 at 9:16 AM, Deependra Ariyadewa <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> On Wed, Nov 2, 2016 at 1:04 PM, Kasun De Silva <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>>>> Hi All, >>>>>>>> >>>>>>>> Past couple of days I was working on a POC for the $subject. >>>>>>>> >>>>>>>> Following is the current model that AppCloud use to create >>>>>>>> application / services. Basically for each application / service >>>>>>>> AppCloud >>>>>>>> will create a *Deployment >> ReplicaSet >> Pod* in Kubernetes >>>>>>>> cluster. At this point each ReplicaSet created has only one replica >>>>>>>> which >>>>>>>> is a Pod. This deployment does not scale up or scale down under any >>>>>>>> circumstances. >>>>>>>> >>>>>>>> This effort is to bring up a new feature to autoscale the >>>>>>>> application / service deployed in AppCloud according to certain >>>>>>>> metrics. >>>>>>>> >>>>>>>> Basically as usual AppCloud will create a *Deployment >> RS >> Pod* >>>>>>>> in Kubernetes for each application / service created as in above >>>>>>>> scenario. >>>>>>>> >>>>>>>> With the new feature, user can set auto-scaling parameters in the >>>>>>>> application settings level. We are using Kubernetes v1.3.4, and by >>>>>>>> default >>>>>>>> it accepts following parameters for *Horizontal Pod Autoscaler* >>>>>>>> (HPA). >>>>>>>> >>>>>>>> 1. Minimum # of pods >>>>>>>> 2. Maximum # of pods >>>>>>>> 3. Target CPU Utilization >>>>>>>> >>>>>>>> >>>>>>>> and the autoscaling logic will be following, >>>>>>>> >>>>>>>> TargetNumOfPods = ceil(sum(CurrentPodsCPUUtilization) >>>>>>>> / TargetCPUUtilization) >>>>>>>> >>>>>>>> But target number of pods will be bounded by the values provided >>>>>>>> for the MinPods and MaxPods values. >>>>>>>> >>>>>>>> MinPods <= TargetNumOfPods <= MaxPods >>>>>>>> >>>>>>>> When user set the auto scale parameters AppCloud will basically >>>>>>>> create a Kubernetes HPA kind for the particular appllication / service >>>>>>>> version (This is on demand. we do not create an HPA kind for each >>>>>>>> application / service version that user creates.). So that HPA for that >>>>>>>> particular version will take responsibility of scaling up, scaling >>>>>>>> down of >>>>>>>> pods according to the given threshold. Following will be the model >>>>>>>> that we >>>>>>>> are using in Kubernetes with the autoscaling feature in AppCloud. >>>>>>>> >>>>>>> >>>>>>> In the server less paradigm user should get a simple application >>>>>>> creation user experience, therefore making the auto scaling feature as >>>>>>> the >>>>>>> default behavior is a good option. Also we have to send the minimum pod >>>>>>> count to 2 to support node failures. >>>>>>> >>>>>>>> >>>>>>>> Your thoughts and comments are welcome on this. >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Kasun >>>>>>>> >>>>>>>> -- >>>>>>>> *Kasun de Silva* >>>>>>>> Senior Software Engineer | Cloud TG >>>>>>>> >>>>>>>> WSO2 Inc <http://wso2.com>*. *|* E*mail : [email protected] | M >>>>>>>> obile: +94 77 794 4260 >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Deependra Ariyadewa >>>>>>> WSO2, Inc. http://wso2.com/ http://wso2.org >>>>>>> >>>>>>> email [email protected]; cell +94 71 403 5996 ; >>>>>>> Blog http://risenfall.wordpress.com/ >>>>>>> PGP info: KeyID: 'DC627E6F' >>>>>>> >>>>>>> *WSO2 - Lean . Enterprise . Middleware* >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Dmitry Sotnikov >>>>>> VP of Cloud; WSO2, Inc.; http://wso2.com/ >>>>>> email: [email protected]; cell: +1.949.303.9653; Skype: DSotnikov >>>>>> Lean . Enterprise . Middleware >>>>>> >>>>>> <http://wso2.com/signature> >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> Deependra Ariyadewa >>>>> WSO2, Inc. http://wso2.com/ http://wso2.org >>>>> >>>>> email [email protected]; cell +94 71 403 5996 ; >>>>> Blog http://risenfall.wordpress.com/ >>>>> PGP info: KeyID: 'DC627E6F' >>>>> >>>>> *WSO2 - Lean . Enterprise . Middleware* >>>>> >>>> >>>> >>>> >>>> -- >>>> Dmitry Sotnikov >>>> VP of Cloud; WSO2, Inc.; http://wso2.com/ >>>> email: [email protected]; cell: +1.949.303.9653; Skype: DSotnikov >>>> Lean . Enterprise . Middleware >>>> >>>> <http://wso2.com/signature> >>>> >>> >>> >>> >>> -- >>> Deependra Ariyadewa >>> WSO2, Inc. http://wso2.com/ http://wso2.org >>> >>> email [email protected]; cell +94 71 403 5996 ; >>> Blog http://risenfall.wordpress.com/ >>> PGP info: KeyID: 'DC627E6F' >>> >>> *WSO2 - Lean . Enterprise . Middleware* >>> >> >> >> >> -- >> Dmitry Sotnikov >> VP of Cloud; WSO2, Inc.; http://wso2.com/ >> email: [email protected]; cell: +1.949.303.9653; Skype: DSotnikov >> Lean . Enterprise . Middleware >> >> <http://wso2.com/signature> >> > > > > -- > Lakmal Warusawithana > Director - Cloud Architecture; WSO2 Inc. > Mobile : +94714289692 > Blog : http://lakmalsview.blogspot.com/ > > -- Dmitry Sotnikov VP of Cloud; WSO2, Inc.; http://wso2.com/ email: [email protected]; cell: +1.949.303.9653; Skype: DSotnikov Lean . Enterprise . Middleware <http://wso2.com/signature>
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