Smart Policies for Auto scaling.

[Lakmal Warusawithana <la...@wso2.com>]

As I mention in the [LXC based Cartridges] mail we want to have smart
policies to auto scaling. Depending these policies Cloud Controller (CC)
should define correct topology based on auto scaler decision.

Will take PHP cartridge. Here some sample policies.

Policy 1 - 512 MB RAM, Auto scaling upto 2

Policy 2 - 1024 MB RAM, Auto scaling upto 2

Policy 3 - 512 MB RAM, Auto scaling upto 5 , Auto scaling into different VM

Policy 4 - 1024 MB RAM, Auto scaling upto 5 , Auto scaling into different
VM , Different HW

Policy 5 - 512 MB RAM, Auto scaling upto 5 , Auto scaling into different VM
, Different data center

Policy 6 - 2GB RAM, One Cartridge process for one VM

In the diagram, subscription B has policy 1. Its Cartridge process utilize
512MB RAM and auto scaling into same VM. So it has two Cartridge processes
running in same VM. Subscription C has policy 2. Its auto scale into
separate VM.

So depending on defined policy we can have different level of High
Availability. To implement this we need to have policy language to define
policies. From CC we should read these policies and define the appropriate
topology.

Policy can be define by devops who are setting up Stratos. These policies
will utilize/assign when subscribing to the cartridge.

I am highly appreciated your help to identify/use some policy language
implement this or any existing project that we can use in this area.  And
we are mostly welcome who can contribute in this.

thanks

-- 
Lakmal Warusawithana
Software Architect; WSO2 Inc.
Mobile : +94714289692
Blog : http://lakmalsview.blogspot.com/