Questions

[Clint Byrum]

On 2013-03-19 05:56, Dimiter Naydenov wrote:
>  On 19.03.2013 03:57, Mike Sam wrote:
>  > 2> How do you do distributed coordination with mongodb? like how
> do you do distributed locks and do not worry about race conditions for
> instance? in other words, do you even need zookeeper type of
> coordination for juju?
>  Most of the coordination with mongodb in juju-core is done with
> watchers and mgo transactions. Since juju is a distributed system
> aiming to scale to 100K nodes or more there are a lot of issues with
> concurrency and race conditions, we need a central place to sync what
> juju knows about the environment and get notified about changes.

Can you give an example of the type of an application driving juju to a 
single 100K node environment? Even with the kind of scale-out ARM 
servers are promising, you're talking about a single application that is 
driven into 100 racks of 1000 servers each. If you were talking about 
OpenStack, that would be a single region with 100K servers in it.

Might want to provide some safeties on destroy-environment for those 
apps... ;)

I'm not sure 100K is a worthy goal, but perhaps you have something 
specific in mind.