---------------------------------------------------------------------- Message: 5 Date: Fri, 9 Aug 2013 10:54:49 -0400 From: J?r?mie Galarneau <jeremie.galarn...@efficios.com>
> On Fri, Aug 9, 2013 at 4:01 AM, Stanislav Vovk <stanislav.v...@ericsson.com> > wrote: > > In my system there are two users, root and Bob. I am starting sessiond at > > boot as root user. And instrumented programs are started as either root or > > Bob. I am logged in to the system and controlling lttng as root user. > > - When executing "lttng list -u" I see events registered by programs > > started as root. I don't see events from programs started as Bob. Why? Did > > I forget something? > > - Now I switch user to Bob in the shell. Executing "lttng list -u" does not > > give any output at all, instead a new sessiond is started. How can I have > > one sessiond for the whole system? > > A non-privileged user can only interact with a root session daemon if he is > part of the "tracing" group. Is it the case for "Bob" in this example? > > Reproducing your scenario here with "Bob" being part of the tracing group: > - Root can list its own sessions as well as Bob's > - Bob's user space events can also be seen by root > - Bob can't see the sessions created by root. Actually, a non-root user can also access the root daemon if he has sudo privileges. The root daemon will see the various user-space events, but it will *not* list the user sessions: the various lttng-sessiond daemons do not talk to each other. (This may become possible with a later version of lttng) To funnel all tracing through the root daemon, make sure any user lttng-sessiond daemons are killed and only the root lttng-sessiond daemon is running, then either make your users members of the 'tracing' group, or systematically use 'sudo lttng ...' or 'sudo -H lttng ...' from the user shells. The first form will put the trace outputs in each user's ~/lttng-traces, the second form will combine all trace outputs in /root/lttng-traces. You may need to chmod the resulting folders and files if you want to later access them as non-root. Daniel U. Thibault Protection des systèmes et contremesures (PSC) | Systems Protection & Countermeasures (SPC) Cyber sécurité pour les missions essentielles (CME) | Mission Critical Cyber Security (MCCS) R & D pour la défense Canada - Valcartier (RDDC Valcartier) | Defence R&D Canada - Valcartier (DRDC Valcartier) 2459 route de la Bravoure Québec QC G3J 1X5 CANADA Vox : (418) 844-4000 x4245 Fax : (418) 844-4538 NAC : 918V QSDJ <http://www.travelgis.com/map.asp?addr=918V%20QSDJ> Gouvernement du Canada | Government of Canada <http://www.valcartier.drdc-rddc.gc.ca/> _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
