Hello, Sorry, I should be more specific. I am creating a custom yocto build. I have seen some examples where systemd is utilized to start the sessiond as a service. The limitation I have is that I don't want to include the whole lttng-tools librray in my build. I understand that the sessiond is an executable, I am just unsure how I could build or get this in my build. Moving forward from this I could use fork/exec to daemonize which would be simple. Is there perhaps a existing recipe?
Regards, Mosleh On Tue, Apr 2, 2019 at 6:01 PM Mosleh Uddin <mosleh1...@gmail.com> wrote: > Hi, > > That makes complete sense. I was more curious about the sessiond > executable. I'm guessing this is something I will have to create along with > my build? > > Regards, > Mosleh > > On Tue, Apr 2, 2019 at 5:18 PM Jonathan Rajotte-Julien < > jonathan.rajotte-jul...@efficios.com> wrote: > >> On Tue, Apr 02, 2019 at 04:54:00PM -0400, Mosleh Uddin wrote: >> > Hello, >> > >> > Could you give me some more insight into spawning my own sessiond? Sorry >> > I'm not completely clear on the topic. >> > Thank you for all your assistance. >> >> Normally lttng-sessiond is treated as a "server/service/daemon" (think >> http >> server as apache) and is *normally* launched as a daemon >> (systemd/sysVinit) at >> boot time. >> >> Managing manually the lifetime of a lttng-sessiond process is done the >> same way >> as any other process. You can manage it via the command line >> (./lttng-sessiond), via a >> service manager (systemd/upstart etc.) or with a custom service manager (a >> python script/c etc.). >> >> You could spawn a lttng-sessiond from your application with the >> appropriate >> parameters set to isolate it if you need. LTTNG_HOME is an important one. >> The >> output directory also can be manipulated. See man lttng-sessiond for more >> details. You will need to manage the process or leave it to a system >> administrator and only active tracing when a sessiond is present for >> example. >> >> Cheers >> >> > >> > Regards, >> > Mosleh >> > >> > On Wed, Mar 27, 2019 at 1:52 PM Jonathan Rajotte-Julien < >> > jonathan.rajotte-jul...@efficios.com> wrote: >> > >> > > Hi Mosleh, >> > > >> > > On Wed, Mar 27, 2019 at 12:09:54PM -0400, Mosleh Uddin wrote: >> > > > Hello, >> > > > >> > > > Thank you for the quick response. I was able to use the >> documentation you >> > > > provided to start a session and get tracepoint list. I do have some >> > > > follow-up questions: >> > > > >> > > > 1) I needed to create a session daemon before executing my custom >> > > > application. In the API I did see functionality to see if a daemon >> is >> > > > active, however, it is possible to spawn a session daemon in my >> custom >> > > app? >> > > >> > > liblttng-ctl does not expose a lttng-sessiond spawning function since >> by >> > > definition it is a daemon executable (think apache,mysql etc.), you >> will >> > > have to >> > > use system/popen/exec.. to spawn the lttng-sessiond process etc. if >> you >> > > want to >> > > control its lifetime using your custom application. >> > > >> > > > >> > > > 2) I am able to get a list of active traces lttng can see in >> userspace, I >> > > > enable all the traces and start tracing. The traces however seem to >> not >> > > be >> > > > written anywhere on my filesystem. Do I have to specify a location? >> Or >> > > am I >> > > > missing something? My current flow is: >> > > >> > > Please refer to the create command. If outputting locally you will >> need to >> > > pass >> > > a "file://...." url to lttng_create_session. >> > > >> > > You can check on the result for each steps using "lttng list" and >> "lttng >> > > list >> > > <session_name>" as you go to troubleshot your setup script. >> > > >> > > While debugging you can also start the lttng-sessiond in verbose mode >> to >> > > understand what is going on. >> > > >> > > Also note that you could also use the lttng "load" api if the session >> you >> > > are >> > > trying to load is "static" and always the same. You would only need to >> > > ship an >> > > xml file with your application. >> > > >> > > Cheers >> > > >> > > > >> > > > - Creating a session >> > > > - Specifying the domain >> > > > - Creating a handle >> > > > - Creating a channel (with default attributes) >> > > > - Enabling the channel >> > > > - Enabling event (for all traces) >> > > > - Start tracing >> > > > >> > > > Thanks again for all the assistance. >> > > > >> > > > Regards, >> > > > Mosleh >> > > > >> > > > On Tue, Mar 26, 2019 at 11:29 AM Jonathan Rajotte-Julien < >> > > > jonathan.rajotte-jul...@efficios.com> wrote: >> > > > >> > > >> >> -- >> Jonathan Rajotte-Julien >> EfficiOS >> >
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