[chef] Re: Re: Re: Simultaneous node edits

[Daniel DeLeo < >]

On Wednesday, July 1, 2015 at 3:08 PM, Lamont Granquist wrote:

>  
> RFC #045 
> https://github.com/chef/chef-rfc/blob/master/rfc045-node_state_separation.md
>  is the closest thing we have for plans for addressing node editing 
> conflicts, but it still won't help you in the case of two admins doing a 
> knife node edit. It does address a lot of the use cases of #2.
>  
> #1 might be addressed better via something like a knife plugin the 
> converted the task the admins were doing into something more similar to 
> `knife node run_list add 'role[foo]'`. by getting it onto the command line 
> you narrow the race condition between reading the old value and writing the 
> new value. you could also make it even a bit more 
> declarative/idempotent/convergent so that running it twice by two admins 
> didn't result in duplicated edits (unlike knife node run_list add).
Policyfiles mitigate the problem by moving the really contentious part (the 
run_list) out of the node and into a different object which is shared between 
nodes. If you’re making heavy use of node-specific attributes it won’t help, 
but I’d recommend avoiding those as much as possible anyway.

--  
Daniel DeLeo