fuel-dev team mailing list archive

[Bogdan Dobrelya <bdobrelia@xxxxxxxxxxxx>]

On 03/07/2014 03:30 AM, Andrew Woodward wrote:
> After speaking with the TrippleO folks about how they want to
> transition from supporting single controller plane, to only supporting
> HA controller plane, but allowing a controller plane to scale down to
> 1. I thought, why don't we do that?
> 
> Why should we:
> 1) Starting with a control plane that is HA ready has been requested
> multiple times
> 2) It gets rid of all kinds of separate code-paths to support two
> deployment types

+1 to that.
IMHO, it is a good idea indeed.
I remember my first installations of Fuel v0.99.x were made as HA case
with cluster size = 1.


> 3) It ensures that more code and components of HA are tested
> 4) It reduces the amount of unit tests that are needed to support
> testing both deployment types
> 5) It helps to ensure that scale up, scale swap (replace failed nodes)
> and later down are handled better.
> 
> And best of all, it already works! I've tested with only the patch
> below. We can deploy 1 controller and then add 2, and 3 with out any
> observed problems (OSTF passes in both cases)
> 
> To enable for the fuel CLI
> 
> diff --git a/nailgun/nailgun/task/task.py b/nailgun/nailgun/task/task.py
> index b4a3985..bfd2e8d 100644
> --- a/nailgun/nailgun/task/task.py
> +++ b/nailgun/nailgun/task/task.py
> @@ -438,9 +438,9 @@ class CheckBeforeDeploymentTask(object):
>              raise errors.NotEnoughControllers(
>                  "Not enough controllers, %s mode requires at least 1 "
>                  "controller" % (cluster_mode))
> -        elif cluster_mode == 'ha_compact' and controllers_count < 3:
> +        elif cluster_mode == 'ha_compact' and controllers_count < 1:
>              raise errors.NotEnoughControllers(
> -                "Not enough controllers, %s mode requires at least 3 "
> +                "Not enough controllers, %s mode requires at least 1 "
>                  "controllers" % (cluster_mode))
> 


-- 
Best regards,
Bogdan Dobrelya,
Skype #bogdando_at_yahoo.com
Irc #bogdando