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Brad Bishop bradleyb at
Wed Sep 5 08:34:56 AEST 2018

> On Sep 4, 2018, at 5:28 PM, Ed Tanous <ed.tanous at> wrote:
> On 09/04/2018 01:46 PM, Brad Bishop wrote:
>> But it seems like you are proposing that every application that wants to make
>> a log needs to have the logic to translate its internal data model to IPMI speak,
>> so it can make a journal call with all the IPMI metadata populated.  Am I
>> understanding correctly?  That doesn’t seem aligned with keeping IPMI isolated.
> I think a key here is that not all logs will be implicitly converted to IPMI logs.  Having them be identical was the design that we started with, and abandoned because IPMI has some requirements that don't cleanly map from a standard syslog/text style to IPMI.
>> A concrete example - phosphor-hwmon.  How do you intend to figure out something
>> like IPMI_SEL_SENSOR_PATH in the phosphor-hwmon application?  Actually it would
>> help quite a bit to understand how each of the fields in your sample below would
>> be determined by an arbitrary dbus application (like phosphor-hwmon).
> I'm not really understanding the root of the question.  If phosphor-hwmon is generating a threshold crossing log that stemmed from the /xyz/openbmc_project/sensors/my_super_awesome_temp_sensor, then it would simply fill that path into the IPMI_SEL_SENSOR_PATH field.  

ok, then this is my ignorance of IPMI showing.  I thought IPMI_SEL_SENSOR_PATH was
an IPMI construct...

If this is the case then why not just call it SENSOR_PATH?  Then other logging formats
could use that metadata key without it being weird that it has ‘ipmi_sel’ in the name
of it.  And can we apply the same logic to the other keys or do some of the other keys
have more complicated translation logic (than none at all as in the case of the sensor
path) ?

> This is the same kind of mapping that the associations produce today, but captured in journald instead of the mapper.
> Our thinking was that we could build either a static library, or a dbus daemon to simplify producing IPMI logs.  Because of the IPMI requirements around unique record ids, right now we're leaning toward the dbus interface with a single daemon responsible for IPMI SEL creation.

Thats great!  This is similar to how the phosphor-logging daemon creates dbus error
objects today.

Would you mind elaborating on this daemon and its dbus API?  I’m guessing it would probably
clear up any concerns I have.

> While technically it could be a part of phosphor-logging,

That isn’t what I was going for.  If you plan to implement a (separate) daemon that acts on
the journald metadata I think that is right approach too.

> we really want it to be easily removable for future platforms that have no need for IPMI, so the thought at this time it to keep it separate.


>> Further, if you expand this approach to further log formats other than SEL,
>> won’t the applications become a mess of translation logic from the applications
>> data mode <-> log format in use?
> I'm not really following this question.  Are there other binary log formats that we expect to come in the future that aren't text based, and could just be a journald translation?

Yes.  We have a binary format called PEL.  I doubt anyone would be interested in using
it but we need a foundation in OpenBMC that enables us to use it...

>  So far as I know, IPMI SEL is the only one on my road map that has weird requirements, and needs some translation.

Where is the translation happening?  In the new ipmi-sel daemon?  Or somewhere else?

>  I don't expect it to be a mess, and I'm running under the assumption that _most_ daemons won't care about or support IPMI given its limitations.

Well _all_ daemons already support IPMI SEL today.  The problem is just that the
implementation doesn’t scale.  I’m confused by _most_ daemons wouldn’t support

> You're right, this isn't intended to be a general solution for all binary logging formats, it's intended to be a short term hack while the industry transitions away from IPMI and toward something easier to generate arbitrarily.
>> I’d rather have a single approach that works for everyone; although, I’m
>> not sure how that would look.
> The single approach is where we started, and weren't able to come up with anything that even came close to working in a production sense.  If you have ideas here on how this could be built that are cleaner than what we're proposing, we're very much interested.

I’m still trying to understand what is being proposed.

>> This is called top posting, please try to avoid when using the mail-list.
>> It makes threaded conversation hard to follow and respond to.  thx.
> (Ed beats Jason with very big stick)

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