[chef] Re: performance and scalability of a chef server

[Adam Jacob < >]

On Mon, Aug 1, 2011 at 7:39 AM, david brpr 
<
 >
 wrote:
> i am currently evaluating Chef against puppet for my company and i am having
> a bit of trouble finding specific information regarding the performance and
> scalability of a chef server.

It depends on your environment. Chef scales by adding API endpoints
(chef-server-api, the webui) that are typically concurrency bound by
memory and eventually by CPU. On the back end, CouchDB and Solr both
have fairly well published scalability documentation - the gist is,
scale them vertically for a while, and when you need to, you can talk
about various sharding strategies.

> Would anyone have any metrics on the load that a single chef server can take
> in term node count based on a context (hardware and otherwise).

This depends on how big the chef server is. Most likely, you are going
to be bound by concurrency - RAM/CPU.

> Also the docs & wikis keep boasting about the horizontal scalability of chef
> but i cannot find any details on it.

It scales the same way a web application scales.

> How is it achieved/architect-ed?

Use load balancers/reverse proxies in front of the API and Web UI
endpoints, and use traditional HA techniques for CouchDB and Solr.

> what does it take to expand chef server cluster?

Add more API endpoints behind a LB/proxy.

> what are the implication in HA terms?

That it's a pretty typical scenario, if you have more than a passing
familiarity with scaling web applications.

Best,
Adam

-- 
Opscode, Inc.
Adam Jacob, Chief Product Officer
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