[chef] RE: Race Conditions

["Kadel-Garcia, Nico" < >]

Greg, I'm also pretty new to chef. But looking at the content of a Chef server, I see a PostgreSQL database running in /var/opt/chef-server/postgresql, so it looks like a database upload operation. That implies atomic transactions, so uploads one at a time sounds right.

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From: Greg Zapp
Sent: Friday, September 27, 2013 2:44 AM
To:
Subject: [chef] Race Conditions

Hello,

I have a few nagging questions about Chef.  One of them revolves around potential race conditions in updating nodes and databags on Chef Server.  For the life of me I am unable to find any information on how Chef updates node information on the server side.  Does it merge changed keys?  Does it fully overwrite all json keys?  If a client run starts and then some external force updates the node on the server, will node.save(s) on the client overwrite that information?  What about data bags?

I would appreciate any information that could be provided on this topic.  I'm considering drastic measures to to my lack of understanding of the internals:

*Only nodes update their attributes

*Databags have ONE writer, multiple readers

*Desired state stored in data bags

*Current state stored in node attributes or other data bags

@.@

Thanks,

   Greg