[chef] Re: Re: debugging slow knife?

[AJ Christensen < >]

Yo,

On 4 May 2011 13:39, Daniel DeLeo 
<
 >
 wrote:
> On Tuesday, May 3, 2011 at 9:54 AM, Michael Schueler wrote:
>
> Hi Chefs,
>
> I'm using the opscode platform.  Before 0.10 the knife command was
> unbearably slow.  It's definately at least twice as fast, but it's still
> kind of sluggish.  Even issuing the help command to knife takes 2 seconds.
>
> Some simple stuff:
>
> Off my MacBook Pro..
> % time knife node show e02
> <snip>
> knife node show e02  3.17s user 0.23s system 74% cpu 4.544 total
>
> % time knife help
> <snip>
> knife help  2.12s user 0.17s system 99% cpu 2.296 total
>
> % ruby -v
> ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-darwin10.7.0]
>
>
> My results are similar from an ec2 c1.xlarge...
>
> # time knife ec2 --help
> <snip>
> real    0m1.843s
> user    0m1.300s
> sys    0m0.550s
>
> # ruby -v
> ruby 1.8.7 (2010-01-10 patchlevel 249) [x86_64-linux]
>
>
> Is this expected?  It might not seem like much but it's enough to really
> slow me down and annoy me..
>
> This is something I've optimized as much as possible. Given knife's current
> architecture, it has to load all of the files to generate the help output,
> so whether or not the files are cached makes a huge difference (as shown by
> the numbers you've all posted).
> There are some things you can look in to:
> * Since knife has to load all commands including plugins when it runs, it's
> important that any plugins you have installed make use of lazy loading.
> * Running `gem clean` can improve your runtimes dramatically. It can also
> break things that depend on those gems, so be careful.
> After running gem clean, I'm seeing times around 0.6 seconds to run `knife
> -h` and `knife help` when the disk cache is hot.
> I'd certainly like to improve this further, especially for the case that the
> disk cache is cold, but this would require fairly substantial architectural
> changes to knife--and the gains from doing so could be fairly small compared
> to the factors that are our of our control (e.g., factors affected by `gem
> clean`).

After 'gem clean':

knife -h  0.30s user 0.08s system 98% cpu 0.391 total
knife help  0.49s user 0.16s system 99% cpu 0.663 total

Optimizing more than this seems like a waste of time! =D

>
> --
> Dan DeLeo
>
>
> Thanks
> Mike
>
>