On 7/2/12 6:24 PM, "David Nalley" <[email protected]> wrote:
>On Mon, Jul 2, 2012 at 2:08 PM, Ram Ganesh <[email protected]> wrote: >> Hi All, >> >> Briefly talking about the feature - AutoScale feature allows you to >>scale up or scale down the virtual instances that are being load >>balanced by load balancers like NetScaler based on certain conditions. >>This feature is an extension to the ELB feature in CloudStack. This >>feature is similar to AWS autoscale feature except that monitoring of >>server's(guest vm) health is done by load balancers like NetScaler and >>provisioning is done by CloudStack. Monitoring done by loadbalancers has >>couple of benefits >> - Loadbalancers are better placed to understand the health of >>the server as traditionally LB devices had monitoring capability >>inbuilt in it. >> - Decisions can be based not just on certain conventional >>counters like CPU, Memory etc but also on network counters like response >>time, bandwidth, connections etc >> - Decreases the load on CloudStack management server. > >But that inherently limits where AutoScale will work. This means all >of this work is inherently very niche, can only be tested by folks >with NS hardware, and only utilized by the same folks - and >autoscaling could be inherently useful in other situations that don't >have LB implications. >CloudStack has inherently been hypervisor agnostic, is there a reason >not to be LB agnostic as well? It seems to me that the proposed APIs are not too LB-specific (there's stuff about snmp ports and community strings that is specific to this implementation and should not belong in a generic API). I would imagine that an auto scaling implementation would have: 1. Monitors that know how to monitor a specific kind of load 2. Configuration of thresholds to get notified when the monitors detect a breach of thresholds 3. Actions to take on breach of thresholds I would like to see a generic framework such as this laid out and a description of how this specific implementation uses the framework. Also, the FS template has lots of questions (http://wiki.cloudstack.org/display/RelOps/Functional+Spec%28FS%29+Template ) which have not been answered.
