[etherlab-users] Data logging service dropping data

[Richard Hacker]

dlsd logs to syslog

- Try to switch off ntp, if you are using it
- Are you experiencing the same problems when logging only one channel 
as well as lowering the sampling frequency


Am 09/11/2013 07:18 PM, schrieb Johnathan Van Why:
> On Wed, Sep 11, 2013 at 12:32 AM, Richard Hacker <ha at igh-essen.com> wrote:
>> Can you find anything in the logs for dlsd?
>
> I am having trouble finding the DLS log files. I see the file
> "logging" in the job directory, but it is empty.
>
> Do you know where I can find any log files?
>
> Thank You,
> Johnathan Van Why
> Dynamic Robotics Laboratory
> Oregon State University
>
>> Am 09/09/2013 08:04 PM, schrieb Johnathan Van Why:
>>
>>> On Mon, Sep 9, 2013 at 7:39 AM, Richard Hacker <ha at igh-essen.com> wrote:
>>>>
>>>>
>>>> Are you using a multi-processor system? If so, can try using HPET
>>>> (although this timing system is buggy by design - was developed together
>>>> with Microsoft ;) )
>>>
>>>
>>> I switched to the HPET, and it still drops data.
>>>
>>> Thank You,
>>> Johnathan Van Why
>>> Dynamic Robotics Laboratory
>>> Oregon State University
>>>
>>>> Am 09/06/2013 09:25 PM, schrieb Johnathan Van Why:
>>>>
>>>>> On Thu, Sep 5, 2013 at 11:38 PM, Richard Hacker <ha at igh-essen.com>
>>>>> wrote:
>>>>>>
>>>>>>
>>>>>> What is you underlying real-time operating system?
>>>>>
>>>>>
>>>>>
>>>>> I am doing my testing on Linux, patched with PREEMPT_RT for realtime.
>>>>>
>>>>>> The DLS has a problem when the RT system influences time on the PC.
>>>>>> This has
>>>>>> been experienced with RTAI.
>>>>>>
>>>>>> Ways to fix it? Watch the system's clock while the control system is
>>>>>> loaded
>>>>>> and make sure it is not "pulled" in any way.
>>>>>
>>>>>
>>>>>
>>>>> I have confirmed that there is no clock drift (note: the kernel's
>>>>> clocksource is the TSC). I disabled NTP and re-ran the test, with the
>>>>> same results (lost data and no clock drift).
>>>>>
>>>>> Do you have any other ideas?
>>>>>
>>>>> Thank you for the help,
>>>>> Johnathan Van Why
>>>>> Dynamic Robotics Laboratory
>>>>> Oregon State University
>>>>>
>>>>>> Am 09/06/2013 04:33 AM, schrieb Johnathan Van Why:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> We have been benchmarking EtherLab (we're considering switching to it
>>>>>>> as our robot control system), and have noticed that the Data Logging
>>>>>>> Service has been dropping data. We created over 100 independent
>>>>>>> sources in a Simulink model, deployed to EtherLab, and logged all
>>>>>>> sources at 1 kHz (over 400 KB/s total).
>>>>>>>
>>>>>>> After looking at the log data, we noticed that a significant amount of
>>>>>>> data was dropped. Every 15 minutes, the time variable would jump by 3
>>>>>>> minutes; the total data we collected was significantly less than we
>>>>>>> expected for the duration of the run.
>>>>>>>
>>>>>>> Is this a known issue? Are we asking too much of the Data Logging
>>>>>>> Service? Is there anything we can try in order to obtain reliable
>>>>>>> logging at this data rate?
>>>>>>>
>>>>>>> Thank you for any help,
>>>>>>> Johnathan Van Why
>>>>>>> Dynamic Robotics Laboratory
>>>>>>> Oregon State University
>>>>>>> _______________________________________________
>>>>>>> etherlab-users mailing list
>>>>>>> etherlab-users at etherlab.org
>>>>>>> http://lists.etherlab.org/mailman/listinfo/etherlab-users
>>>>>>>
>>>>>>
>>>>>> Mit freundlichem Gruß
>>>>>>
>>>>>> Richard Hacker
>>>>>>
>>>>>> --
>>>>>>
>>>>>> ------------------------------------------------------------------------
>>>>>>
>>>>>> Richard Hacker M.Sc.
>>>>>> richard.hacker at igh-essen.com
>>>>>> Tel.: +49 201 / 36014-16
>>>>>>
>>>>>> Ingenieurgemeinschaft IgH
>>>>>> Gesellschaft für Ingenieurleistungen mbH
>>>>>> Heinz-Bäcker-Str. 34
>>>>>> D-45356 Essen
>>>>>>
>>>>>> Amtsgericht Essen HRB 11500
>>>>>> USt-Id.-Nr.: DE 174 626 722
>>>>>> Geschäftsführung:
>>>>>> - Dr.-Ing. T. Finke,
>>>>>> - Dr.-Ing. W. Hagemeister
>>>>>> Tel.: +49 201 / 360-14-0
>>>>>> http://www.igh-essen.com
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------
>>>>
>>>>
>>>>
>>>> Mit freundlichem Gruß
>>>>
>>>> Richard Hacker
>>>>
>>>> --
>>>> ------------------------------------------------------------------------
>>>>
>>>> Richard Hacker M.Sc.
>>>> richard.hacker at igh-essen.com
>>>> Tel.: +49 201 / 36014-16
>>>>
>>>> Ingenieurgemeinschaft IgH
>>>> Gesellschaft für Ingenieurleistungen mbH
>>>> Heinz-Bäcker-Str. 34
>>>> D-45356 Essen
>>>>
>>>> Amtsgericht Essen HRB 11500
>>>> USt-Id.-Nr.: DE 174 626 722
>>>> Geschäftsführung:
>>>> - Dr.-Ing. T. Finke,
>>>> - Dr.-Ing. W. Hagemeister
>>>> Tel.: +49 201 / 360-14-0
>>>> http://www.igh-essen.com
>>>>
>>>> ------------------------------------------------------------------------
>>
>>
>> Mit freundlichem Gruß
>>
>> Richard Hacker
>>
>> --
>> ------------------------------------------------------------------------
>>
>> Richard Hacker M.Sc.
>> richard.hacker at igh-essen.com
>> Tel.: +49 201 / 36014-16
>>
>> Ingenieurgemeinschaft IgH
>> Gesellschaft für Ingenieurleistungen mbH
>> Heinz-Bäcker-Str. 34
>> D-45356 Essen
>>
>> Amtsgericht Essen HRB 11500
>> USt-Id.-Nr.: DE 174 626 722
>> Geschäftsführung:
>> - Dr.-Ing. T. Finke,
>> - Dr.-Ing. W. Hagemeister
>> Tel.: +49 201 / 360-14-0
>> http://www.igh-essen.com
>>
>> ------------------------------------------------------------------------

Mit freundlichem Gruß

Richard Hacker

-- 
------------------------------------------------------------------------

Richard Hacker M.Sc.
richard.hacker at igh-essen.com
Tel.: +49 201 / 36014-16

Ingenieurgemeinschaft IgH
Gesellschaft für Ingenieurleistungen mbH
Heinz-Bäcker-Str. 34
D-45356 Essen

Amtsgericht Essen HRB 11500
USt-Id.-Nr.: DE 174 626 722
Geschäftsführung:
- Dr.-Ing. T. Finke,
- Dr.-Ing. W. Hagemeister
Tel.: +49 201 / 360-14-0
http://www.igh-essen.com

------------------------------------------------------------------------