Redfish EventService Implementation

[Ratan Gupta]

On 6/26/20 12:25 AM, Bills, Jason M wrote:
>
>
> On 6/25/2020 10:26 AM, Brad Bishop wrote:
>> One idea floating around to address these is inventing a journal
>> metadata scheme that is management interface agnostic.  I understand the
>> motivation behind that - it is much simpler for an application to slide
>> a single journal entry into the journal with all the metadata needed to
>> generate events, than it is for an application to snoop multiple signals
>> off dbus and pull events out of that.
>>
>> But I wonder if inventing a management interface agnostic scheme for
>> adding events to the journal is really just inventing a new data model
>> for how we represent things in a server - e.g. are we just working
>> around our dbus data model?  Maybe we should fix it instead, so that it
>> isn't so difficult for applications to use it?  With that said I don't
>> know how to do this and I could use more concrete details on which areas
>> of the data model make it hard to consume signals.  Does anyone have any
>> ideas or examples?
>>
>
> On this, I think we may want to separate logging vs. eventing both in 
> this feature discussion and in the tools we want to use.
>
> When we were talking about logging, I think the journal made sense 
> since it is designed for logging and has benefits around that usage.  
> However, I agree that it doesn't seem like the right tool for sending 
> and receiving events and signals and that D-Bus sounds like the right 
> tool for that.
>
> I think I'm still a little confused at the scope.  My understanding 
> was that this initial design for EventService was only for monitoring 
> event messages and not resources in general. It seems like it may not 
> make sense to try to use the same tools and approach for both message 
> monitoring and resource monitoring? Do we need to treat them 
> separately for now to simplify the discussion?
Jason, When you say event messages? What do you mean, Do you mean to say 
"/redfish/v1/Systems/system/Logservices/eventlog"?

If yes then this should also go as Resource Event, When ever any log 
entry gets created under System Log 
(/redfish/v1/Systems/system/Logservices/eventlog/entries), BMC would 
notify to the Redfish client saying that "ResourceCreated" with the URL 
of the Resource.

After receiving this event Redfish client will do a GET request on the 
URL(retrieved as part of event) to get the content of the log.

This will become generic infra for all types of events.

I would be coming up with few design approaches and downside with each 
approach to take it to conclusion.

Ratan