[DISCUSS] Method/Algorithm to gather Health Check states

[Vijay Venkatachalam <Vi...@citrix.com>]

Hi,

As part of HealthCheck feature review, I have suggested to introduce 
a new Capability for HealthCheck. So that any Network Element 
who has this capability can advertise it. 

Any alternative thoughts?

The most important part of health check functionality is to 
update the status of a destination VM in CS DB (as seen by the 
LB Appliance) on a scheduled thread launched every time interval.

So on every iteration, the need is to go to every LB rule and 
find the status of its destinations. 

I can think of 2 ways to get this done

Method 1:
  A.  List all the Health Monitors; For each monitor=>
  B.  Work backwards find the LbRule
  C. Find the network for LbRule
  D. Find the LB provider in the network
  E. Call LoadBalancingServiceProvider.updateStatus by passing LB and its destinations. 
  F. Which will reach the Resource and ultimately the Appliance

Method 2:
  A. List all the Networks; For each network =>
  B. Find the LB provider in the network
  C. Find the NetworkElement for the LB provider
  D. Proceed to (E.)  If NetworkElement has the HealthCheck Capability
  E. Call LoadBalancingServiceProvider.updateStatus by passing LB and its destinations. 
  F. Which will reach the Resource and ultimately the Appliance

I like the top down approach of Method 2. Any thoughts?

Thanks,
Vijay V.


From: Vijay Venkatachalam [mailto:noreply@reviews.apache.org] On Behalf Of Vijay Venkatachalam
Sent: Wednesday, March 06, 2013 6:10 PM
To: Vijay Venkatachalam
Cc: Rajesh Battala; cloudstack
Subject: Re: Review Request: AWS Style HealthCheck feature BugID : 664