Re: [Qemu-devel] [RFC 6/6] docs: Document QMP event rate limiting

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> On 09/28/2015 02:38 AM, Markus Armbruster wrote:
>
>>>> +++ b/docs/qmp/qmp-spec.txt
>>>> @@ -175,6 +175,11 @@ The format of asynchronous events is:
>>>>  For a listing of supported asynchronous events, please, refer to the
>>>>  qmp-events.txt file.
>>>>  
>>>> +Some events are rate-limited to at most one per second.  If more
>>>> +events arrive within one second, all but the last one are dropped, and
>>>> +the last one is delayed.  Rate-limiting applies to each kind of event
>>>> +separately.
>>>
>>> Do we also want to document that limits might be further tuned according
>>> to other elements of the event, with VSERPORT_CHANGE "id" as the example?
>> 
>> You need to interpret "each kind of event" in a sufficiently fuzzy
>> manner :)
>> 
>> Seriously, I'm open to suggestions for better language here.
>
> Maybe:
>
> Some events are rate-limited to at most one per second. If more events
> of the same type (along with any other fields that an event documents as
> being significant) arrive within one second, ...
>
> or:
>
> Some events are rate-limited to at most one per second, either for the
> event type in general, or additionally considering other significant
> fields as documented by a specific event.  If more equivalent events
> arrive within one second, ...
>
> But since you did point out that VSERPORT_CHANGE mentions the filtering
> on "id", I guess I won't try too much harder to paint the bikeshed any
> further.

I'll use this for inspiration when I prep the non-RFC patch.  Thanks!