Le mer. 20 févr. 2019, à 09 h 10, Mosleh Uddin <mosleh1...@gmail.com> a écrit : > > Hello, > > Here is what I do to get the consistent behavior: > When the app is running as a service, lttng list -u does not display any > events, initially I do have to lttng enable-events and lttng start to see the > tracepoints in lttng view. However, after lttng start, I can disable all > events and I can still see the events coming through in lttng view. When I > run the app normally, lttng list -u displays the tracepoints I place in the > app, and all functionality of lttng works as expected. > > I apologize, I am in the process of trying to get you the outputs you are > asking for, however due to confidentiality with the app the outputs of > running the commands need to be reviewed by others. I will try to get this to > you as soon as I can. I understand.
Thanks, Francis > > I can say the service is being kick started by systemd. Also I believe the > app is mass-closing file descriptors when it is daemonizing. I tried to > dynamically load the liblttng-ust-fd.so but the behavior did not change. > > Thanks, > Mosleh > > On Tue, Feb 19, 2019 at 5:16 PM Francis Deslauriers > <francis.deslauri...@efficios.com> wrote: >> >> Hi Mosleh, >> Just to be clear: >> When you run your app as a service (background), lttng list -u doesn't >> display any events AND you see events in the live session without >> having run enable-event and start commands. >> When you run your app normally, lttng list -u displays events AND you >> only see events after running enable-event and start commands. >> Is that correct? >> >> Please provide the output of the lttng-sessiond in verbose mode using >> the following command: >> > lttng-sessiond -vvv >> please provide the output of your application as a service with this >> environment variable: LTTNG_UST_DEBUG=1 >> and please provide us with the service file describing how your >> service is started. >> Put all of this on a pastebin.com >> >> Is your application mass-closing file descriptors when it's >> daemonizing? how about using fork() syscall without an exec() after >> it? If so, have a look at this part of the UST man page: >> https://lttng.org/man/3/lttng-ust/v2.10/#doc-_using_lttng_ust_with_daemons >> >> Thank you, >> Francis >> >> >> Le mar. 19 févr. 2019, à 16 h 37, Mosleh Uddin <mosleh1...@gmail.com> a >> écrit : >> > >> > Hello, >> > >> > Sorry for the late reply. I was able to figure out the weird behavior from >> > the application. Turns out if I run my application as a service, lttng no >> > longer can see any of the UST tracepoints and causes the behavior I was >> > explaining. >> > When I execute the application normally (./app_name), the functionality is >> > as expected. Is this the expected behavior? Is there some way I can trace >> > the userspace application while running it as a service simultaneously? >> > >> > Thanks for any info, >> > Mosleh >> > >> > On Fri, Feb 15, 2019 at 2:48 PM Francis Deslauriers >> > <francis.deslauri...@efficios.com> wrote: >> >> >> >> Can you start the lttng-sessiond in verbose mode using the following >> >> command: >> >> > lttng-sessiond -vvv >> >> and then do the lttng create, start of application and lttng view on >> >> another console. >> >> >> >> Then copy the output of the sessiond on https://pastebin.com/ and send us >> >> the link. >> >> >> >> Thank you, >> >> Francis >> >> >> >> Le ven. 15 févr. 2019, à 14 h 36, Mosleh Uddin <mosleh1...@gmail.com> a >> >> écrit : >> >>> >> >>> That's correct, I don't enable any events or do: lttng start. >> >>> Here is some snapshots of starting everything up, followed by starting >> >>> my application. >> >>> >> >>> >> >>> Here are the outputs for the commands: >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> >> >>> Note that even though the session is inactive, when a trace event occurs >> >>> in my application it is being recorded in the appropriate directory: >> >>> >> >>> >> >>> >> >>> Also maybe important, the system has root only user. Would having the >> >>> application belonging to a different user and trying to run as root >> >>> cause these kinds of complications? I did notice when testing on a >> >>> raspberry pi that running an application as a root user would mean >> >>> running sessions as root user as well. >> >>> >> >>> Thanks, >> >>> Mosleh >> >>> >> >>> On Fri, Feb 15, 2019 at 11:55 AM Francis Deslauriers >> >>> <francis.deslauri...@efficios.com> wrote: >> >>>> >> >>>> Adding back lttng-dev mailing list. >> >>>> >> >>>> So you don't even run a lttng-enable-event command? >> >>>> That's odd. >> >>>> >> >>>> Can you send us the output of the following commands: >> >>>> Is it possible that there are other lttng-sessiond daemons running on >> >>>> the machine? >> >>>> > ps aux | grep "lttng-sessiond" >> >>>> Verify if there are other active tracing sessions: >> >>>> > lttng list >> >>>> Check the details of the current session: >> >>>> > lttng status >> >>>> >> >>>> Thank you, >> >>>> Francis >> >>>> >> >>>> Le ven. 15 févr. 2019, à 11 h 29, Mosleh Uddin <mosleh1...@gmail.com> a >> >>>> écrit : >> >>>> > >> >>>> > Hi Francis, >> >>>> > >> >>>> > Thank you for the quick response. >> >>>> > Just to clear things up, my application is running when I run that >> >>>> > command. >> >>>> > >> >>>> > The commands I am running are: >> >>>> > > lttng-sessiond -d >> >>>> > > lttng create my-sess --live >> >>>> > After this command I start my application. If I then do the command: >> >>>> > > lttng view >> >>>> > I will see the tracepoints in the application in the terminal even >> >>>> > though I have not done: lttng start. >> >>>> > >> >>>> > I thought it was strange that I cannot find my application in the: >> >>>> > lttng list command under any domain. >> >>>> > Also the reason I start my application after creating a session is >> >>>> > because the system automatically starts the application using systemd, >> >>>> > in order to get tracing data at all I have to manually stop the >> >>>> > application and start it again after creating a session. >> >>>> > >> >>>> > Thanks again for any help, >> >>>> > Mosleh >> >>>> > >> >>>> > On Fri, Feb 15, 2019 at 10:32 AM Francis Deslauriers >> >>>> > <francis.deslauri...@efficios.com> wrote: >> >>>> >> >> >>>> >> Hi Mosleh, >> >>>> >> It's expected to not see any event when running lttng list -u if no >> >>>> >> lttng-ust instrumented applications are running. >> >>>> >> >> >>>> >> What are the exact lttng commands you are running to see those >> >>>> >> unexpected events? >> >>>> >> >> >>>> >> Thank you, >> >>>> >> Francis >> >>>> >> >> >>>> >> >> >>>> >> Le ven. 15 févr. 2019, à 10 h 08, Mosleh Uddin >> >>>> >> <mosleh1...@gmail.com> a écrit : >> >>>> >> > >> >>>> >> > Hello, >> >>>> >> > >> >>>> >> > I am having a strange issue with my current application. For some >> >>>> >> > context, I have integrated LTTng into a Yocto build and put custom >> >>>> >> > trace points in my embedded system application. Once I load the >> >>>> >> > built image onto my system and start a session daemon, I try to >> >>>> >> > list all available userspace events (using lttng list -u), but no >> >>>> >> > events show up. >> >>>> >> > >> >>>> >> > The strange occurrence is when I create a session (lltng create >> >>>> >> > my-sess) and not start tracing the trace events will display on >> >>>> >> > the screen regardless (when starting session in live mode with >> >>>> >> > lttng view). I was wondering if anyone has any insight on this >> >>>> >> > issue I am having. >> >>>> >> > >> >>>> >> > Thanks for any assistance, >> >>>> >> > Mosleh >> >>>> >> > _______________________________________________ >> >>>> >> > lttng-dev mailing list >> >>>> >> > lttng-dev@lists.lttng.org >> >>>> >> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev >> >>>> >> >> >>>> >> -- >> >>>> >> Francis Deslauriers >> >>>> >> Computer Engineer >> >>>> >> EfficiOS inc. >> >>>> >> >>>> >> >>>> >> >>>> -- >> >>>> Francis Deslauriers >> >>>> Computer Engineer >> >>>> EfficiOS inc. >> >>> >> >>> _______________________________________________ >> >>> lttng-dev mailing list >> >>> lttng-dev@lists.lttng.org >> >>> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev >> >> >> >> >> >> >> >> -- >> >> Francis Deslauriers >> >> Computer Engineer >> >> EfficiOS inc. >> >> >> >> -- >> Francis Deslauriers >> Computer Engineer >> EfficiOS inc. -- Francis Deslauriers Computer Engineer EfficiOS inc. _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
