[lttng-dev] error in generation of trace files

David Goulet dgoulet at efficios.com
Thu Feb 27 08:57:48 EST 2014


On 27 Feb (19:22:35), Mariya Rampurawala wrote:
> Thank you for the reply.
> So the following commands i run on my terminal:
> 
> mariya at HP:~$ lttng create mysession
> Session mysession created.
> Traces will be written in
> /home/mariya/lttng-traces/mysession-20140227-191901
> mariya at HP:~$ lttng enable-event -a -u
> All UST events are enabled in channel channel0

CCing back lttng-dev ML. If you have this problem, others have! :)

Ok so this means that you enable all user space event for that session
so you need to have an application that is instrumented with LTTng
userspace tracer (lttng-ust) in order to collect data from that app.
There are multiple examples in the git repository.

For the kernel (-a -k), you need to install lttng-modules and start
lttng-sessiond as root (or set yourself in the "tracing" group).

Hope this help!

Cheers!
David

> mariya at HP:~$ lttng start
> Tracing started for session mysession
> mariya at HP:~$ lttng stop
> Waiting for data availability
> Tracing stopped for session mysession
> mariya at HP:~$ lttng view
> Trace directory: /home/mariya/lttng-traces/mysession-20140227-191901
> 
> [error] Cannot open any trace for reading.
> 
> [error] opening trace "/home/mariya/lttng-traces/mysession-20140227-191901"
> for reading.
> 
> [error] none of the specified trace paths could be opened.
> 
> mariya at HP:~$ lttng-sessiond -vvv
> DEBUG3: Creating LTTng run directory: /home/mariya/.lttng [in
> create_lttng_rundir() at main.c:3692]
> DEBUG1: Client socket path /home/mariya/.lttng/client-lttng-sessiond [in
> main() at main.c:3995]
> DEBUG1: Application socket path /home/mariya/.lttng/apps-lttng-sessiond [in
> main() at main.c:3996]
> DEBUG1: LTTng run directory path: /home/mariya/.lttng [in main() at
> main.c:3997]
> DEBUG2: UST consumer 32 bits err path:
> /home/mariya/.lttng/ustconsumerd32/error [in main() at main.c:4006]
> DEBUG2: UST consumer 32 bits cmd path:
> /home/mariya/.lttng/ustconsumerd32/command [in main() at main.c:4008]
> DEBUG2: UST consumer 64 bits err path:
> /home/mariya/.lttng/ustconsumerd64/error [in main() at main.c:4017]
> DEBUG2: UST consumer 64 bits cmd path:
> /home/mariya/.lttng/ustconsumerd64/command [in main() at main.c:4019]
> Error: Already running daemon.
> 
> 
> 
> On Thu, Feb 27, 2014 at 7:12 PM, David Goulet <dgoulet at efficios.com> wrote:
> 
> > On 27 Feb (16:36:24), Mariya Rampurawala wrote:
> > > Hello,
> > >  I'm new to lttng. I use ubuntu 13.10. While performing basic operations,
> > > on command lttng view, i get the following error.
> > > [error] Cannot open any trace for reading.
> > >
> > > [error] opening trace
> > "/home/mariya/lttng-traces/mysession-20140227-163353"
> > > for reading.
> > >
> > > [error] none of the specified trace paths could be opened.
> > >
> > >
> > > the o/p of the command "lttng-sessiond --verbose" is as follows
> > >
> > > DEBUG3: Creating LTTng run directory: /home/mariya/.lttng [in
> > > create_lttng_rundir() at main.c:3692]
> > > DEBUG1: Client socket path /home/mariya/.lttng/client-lttng-sessiond [in
> > > main() at main.c:3995]
> > > DEBUG1: Application socket path /home/mariya/.lttng/apps-lttng-sessiond
> > [in
> > > main() at main.c:3996]
> > > DEBUG1: LTTng run directory path: /home/mariya/.lttng [in main() at
> > > main.c:3997]
> > > Error: Already running daemon.
> > >
> > > Could you please help me solve the error and proceed with my project?
> >
> > Hi,
> >
> > So like the error says, you have an already dunnring daemon but that
> > shouldn't stop you from tracing stuff.
> >
> > Can you provide step by step the command you did and from there we can
> > help you out more easily. The -vvv to the session daemon are good
> > information to have also!
> >
> > Thanks!
> > David
> >
> > > _______________________________________________
> > > lttng-dev mailing list
> > > lttng-dev at lists.lttng.org
> > > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
> >
> >
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 603 bytes
Desc: Digital signature
URL: <http://lists.lttng.org/pipermail/lttng-dev/attachments/20140227/625586f5/attachment-0001.pgp>


More information about the lttng-dev mailing list