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?

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] | Mobile: +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>
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