Hi Apparao,

On 2/20/20 12:49 AM, Puli, Apparao wrote:
Hi,

  I am sorry for late response as this mail is buried under and got struck back of my mind.

As i did mentioned in EventService design document, EventLog Monitor service is not common across the organizations( Example: Intel uses the redfish event logs file and inotify mechanism for monitoring the event logs. Where as IBM uses d-bus event log mechanism and they can relay on match rules). That said challenges with ResourceType mapping will be different in both monitoring mechanisms. This is good point. Initially when i started EventService design, i thought we can have mapping in bmcweb for ResourceTypes with set of MessageID's for Logged events ( As per Intel design) but not sure that may become difficult when we expand supported ResourceTypes.

If I am getting correctly, Here is the flow which Intel uses.

  1. Individual repo have to push the logs using sd_journal_send which will write to the file(/var/log/redfish) by using rsyslog daemon
          sd_journal_send("MESSAGE=%s", "journal text", "PRIORITY=%i", <LOG_LEVEL>,
                "REDFISH_MESSAGE_ID=%s",
                "ResourceEvent.1.0.ResourceCreated", NULL);


    
         Cons: Every application have to make the change(use sd_journal_send).
         My thought is backend application should not be aware of the redfish terminlogy.

   2. Some application(bmcweb) would do the Inotify on the path(/var/log/redfish) and send the event once there is any activity on this file.

> I thought we can have mapping in bmcweb for ResourceTypes with set of MessageID's for Logged events ( As 
per Intel design)

    Can you explain more here. What is your plan? How you would do the Resource Type based event filtering? REDFISH_MESSAGE_ID is different than the resource type.

As per my reading from below query, You are looking at d-bus match rules and ResourceTypes mapping which is more specific to d-bus event logging(IBM way of implementing event logging). reading it from journal logs will give more information but that will impact the performance to large extent. This might be one of the reason why we (Intel) uses Redfish message ID while logging redfish events logs to journal(You can refer design document for same at https://github.com/openbmc/docs/blob/master/architecture/redfish-logging-in-bmcweb.md). In opinion, in your d-bus if you are using some kind of filter(Example REDFISH_MESSAGE_ID) while logging in journal logs for all events and figure out the way to monitor the journal logs without impacting the performance, that should be ok as long as match filters are satisfied for Redfish EventService subscriptions and supported Types(Again differs with implementation).

Thanks,

-Appu

On 2/10/2020 1:52 AM, RAJESWARAN THILLAIGOVINDAN wrote:
ApparaRao.

As you have shown interest in this feature and submitted the design document, do you have any opinion on this? Do you see any merit in using D-Bus match in bmcweb to create event logs for life cycle events?  Please feel free to weigh in.

Thanks,
Rajes

On 01-02-2020 02:23, RAJESWARAN THILLAIGOVINDAN wrote:
Hi,

I am going through the bmcweb code for implementing Redfish EventService based on the design document https://gerrit.openbmc-project.xyz/c/openbmc/docs/+/24749. This design is hooked to the journal based Redfish Event Logging. For life cycle events(ResourceAdded, ResourceRemoved, ResourceUpdated),  using D-Bus match, bmcweb can create an event log. This requires a JSON dictionary, comprising an array of Redfish Resource Name and the D-Bus path. This approach works only in case of one to one mapping of Redfish Resource Name and the D-Bus path. For propertiesChanged events, if the Redfish Resource property is not on the same D-Bus path or the Redfish Resource property name is different from the D-Bus property name, then an additional JSON dictionary to maintain this information is required. With D-Bus match alone in the bmcweb, Redfish EventService can't be fully supported. For the Message Registers and the Resource Types that are supported, the relevant OpenBMC application must create an event log in the journal using either the phosphor::logging::entry or sd_journal_send() command.

After realizing that with D-Bus match in the bmcweb alone can't help to fully implement EventService, I prefer to avoid using D-Bus match in bmcweb. Instead, I prefer to modify the OpenBMC application that generated the event to create an event log in the journal. Do you see any advantage of using combination of D-Bus match in the bmcweb wherever it is possible and changes to OpenBMC application in other cases to create an event log ?

Your views are highly appreciated.

Thanks,
Rajes

Thanks
Ratan