Re: A Transformation of our Global Context

[Joao Eduardo Luis <joao@suse.de>]

On 06/10/2016 09:53 PM, Sage Weil wrote:
> On Fri, 10 Jun 2016, Adam C. Emerson wrote:
>> On 10/06/2016, Sage Weil wrote:
>>> FWIW the time thing is a bit of a red herring.  The only reason time takes
>>> cct is for the configuration clock skew.  That was added for debugging
>>> purposes but has never (to my knowledge) been used.  I'd be happy to rip
>>> it out.
>>
>> I wasn't aware of that. I'd asked once if the clock skew debug option
>> was really important (back with the original time patch) and was told
>> it was. The person I was talking to might have thought I was talking
>> about monitor clock skew or something.
>
> Ah, there is *one* teuthology test that sets this:
>
> $ git grep clock\ offset | cat
> suites/rados/multimon/tasks/mon_clock_with_skews.yaml:        clock offset: 10
>
> I'd be quite happy to drop this test, or kludge around it some other way
> (e.g., put a mon on a different host and change the system time), if it
> saves us as much code churn as I suspect it will...

i've been hacking a mon debug interface via the ceph tool to test 
features and do all sorts of nasty things (provided a given experimental 
feature is enabled and the user is really, really sure about it), and I 
think we could then use it to test clock skews just as well. It'd be a 
matter of telling a given monitor to just skew the response to the 
leader during the timecheck round.

   -Joao