[genivi-dlt] changes in DLT; AUTOSAR harmonization

Lipka, Christoph (ADITJ/SWG) clipka at jp.adit-jv.com
Tue Feb 28 04:00:17 EST 2017


Hello Rinat,

Thanks for your effort in helping to stay aligned between GENIVI and AUTOSAR.
Could you please explain a bit the motivation of the AUTOSAR standard update and the proposed changes?

Regarding [1]. I want to distinguish here between AUTOSAR defined DLT Services and User defined DLT services as implemented in GENIVI. I appreciate the alignment of AUTOSAR defined services:
•         Set verbose mode
•         Set timing packets
•         Use ECU id
•         Use session id
•         Use timestamp
•         Use extended header
•         Get software version
•         Set communication interface maximum bandwidth
•         Message buffer overflow (will be replaced by a new DLT message “BufferOverflowNotification”)

User defined Services have been added to support features that make sense on Linux, but not necessarily supported by an AUTOSAR ECU (e.g. Logstorage, MultiNode). I actually like them to be untouched while aligning to new AUTOSAR specification update. These are in your list:
•         Message connection info
•         Message unregister context
•         Timezone
•         Marker
•         Offline log storage
•         (Dis)Connect passive Node
•         Passive Node status information
Some of them might be unnecessary or incomplete. E.g. why is there a unregister context message, but no message for registering a context, application or unregister an application?

Could you please share more information regarding all *LogChannel* related proposed Control Messages?

Regarding [2]: Connectionless implementation: You wrote DLT messages shall be sent nevertheless a client is connected or not. How does this fit to the implementation of startup buffering in GENIVI? In the current implementation, the DLT user library contains a startup buffer to be filled when DLT Daemon is not yet started. After connection to DLT Daemon is established, this buffer is flushed to DLT Daemon. The DLT Daemon itself also contains a ringbuffer which gets filled as long as no client is connected. This “double buffer” concept is critical to minimize the logging impact especially during system startup, where many applications get started and depending on the configured log level sending a hugh amount of log messages.
Both points need to be clarified.

We may have to step back and define and compare use cases of DLT from a AUTOSAR and Linux user perspective.

Besides that I have some more questions/remarks:
- This change is quite big, I propose to do a version update to DLT Daemon 3.0 for this implementation
- Are you already plan when this gets implemented?
- What changes to you expect for the DLT Viewer to support such changes? Do you plan to update DLT Viewer side?
- When thinking about such changes and when the implementation need to be updated, we may have to consider other Linux related topics like a
  * thread safe user library
  * DLT logging from within shared libraries 
  * DLT and container
  * security aspects 
  * etc.
  This is not necessarily related, but might be discussed as well.

There is already a session scheduled for the AMM: https://collab.genivi.org/wiki/display/genivi/AllMemberMeetingSpring2017SessionContent#AllMemberMeetingSpring2017SessionContent-DLTworkshopandreadout
Are you going to add description for it?
I just got the allowance to join the AMM and I am looking forward to discuss this topic with you and hopefully many other interested members.  

Best regards

Christoph Lipka
Software Group (ADITJ/SWG)

Tel. +81-(0)566 61-5124

From: Rinat.Asmus at bmw.de [mailto:Rinat.Asmus at bmw.de] 
Sent: Thursday, February 23, 2017 12:00 AM
To: genivi-diagnostic-log-and-trace at lists.genivi.org; eg-si at mail.genivi.org
Cc: Lipka, Christoph (ADITJ/SWG); Niemeyer, Ralph (ADITG/SW1)
Subject: changes in DLT; AUTOSAR harmonization

Dear GENIVI user list,
BMW is using DLT in several series projects. Some of the ECUs are using AUTOSAR, some are using other platforms. Unfortunately, current DLT implementations and specifications vary.
Our goal is  to reduce complexity and harmonize the GENIVI and future AUTOSAR implementations in respect to 
•         [1] The DLT Protocol including the defined DLT Control Messages
•         [2] A connectionless Implementation (DLT Messages shall be sent independently whether or not a Logging Device is connected to the ECU)
Regarding the topic [1] DLT Protocol: The available Control Messages shall be harmonized in the following way:
⇨  Set these DLT Control Messages to deprecated:
•         Message connection info
•         Message unregister context
•         Timezone
•         Marker
•         Offline log storage
•         (Dis)Connect passive Node
•         Passive Node status information
•         Set verbose mode
•         Set timing packets
•         Use ECU id
•         Use session id
•         Use timestamp
•         Use extended header
•         Get software version
•         Set communication interface maximum bandwidth
•         Message buffer overflow (will be replaced by a new DLT message “BufferOverflowNotification”)

⇨  Introduce these new DLT Control Messages:
•         GetDefaultTraceStatus 
•         GetLogChannelNames
•         GetTraceStatus
•         SetLogChannelAssignment
•         GetLogChannelThreshold 
•         SetLogChannelThreshold
•         BufferOverflowNotification (replaces the current  DLT message “Message buffer overflow”)
Regarding the topic [2] Connectionless implementation: 
The DLT implementation shall allow a connectionless mode which means that it should work without any mandatory interaction of a DLT Logging Device. 
For these two reasons, we would like to get in touch with you and would like to discuss further details in the upcoming GENIVI face 2 face meeting in May.
-- 
BMW Group
Rinat Asmus
AUTOSAR project lead
Hufelandstr. 1

Postal address:
80937 München

Tel: +49-89-382-65843
Mail: rinat.asmus at bmw.de
Web: http://www.bmwgroup.com/
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