Provided by: lttng-tools_2.7.1-2~fakesync1_amd64 bug

NAME

       lttng-sessiond - LTTng 2.x central tracing registry session daemon.

SYNOPSIS

       lttng-sessiond [OPTIONS]

DESCRIPTION

       The  LTTng  project  aims  at  providing  highly  efficient tracing tools for Linux.  It's
       tracers help tracking down performance issues and debugging  problems  involving  multiple
       concurrent processes and threads. Tracing across multiple systems is also possible.

       The  session  daemon,  acting  as  a tracing registry, allow you to interact with multiple
       tracers (kernel and user-space) inside the same container, a tracing session. Trace can be
       gathered  from  the  kernel  and/or  instrumented applications (lttng-ust(3)). Aggregating
       those traces is done using a viewer, like the babeltrace(1) text viewer.

       In order to trace the kernel, the session daemon needs  to  be  running  as  root.   LTTng
       provides  the  use  of  a  tracing group (default: tracing). Whomever is in that group can
       interact with the root session daemon and thus trace the kernel. Session daemons  can  co-
       exist  meaning  that  you  can  have a session daemon running as Alice that can be used to
       trace her applications along side with a root daemon or  even  a  Bob  daemon.  We  highly
       recommend to start the session daemon at boot time for stable and long term tracing.

       The session daemon is in charge of managing trace data consumers by spawning them when the
       time has come. The user don't need to manage the lttng-consumerd.

OPTIONS

       This program follows the usual GNU command line syntax with long options starting with two
       dashes. Below is a summary of the available options.

       -h, --help
              Show summary of possible options and commands

       -V, --version
              Show version.

       -v, --verbose
              Increase verbosity

              There  is  three  debugging  level which will print on stderr. Maximum verbosity is
              -vvv.

           --verbose-consumer
              Verbose mode for consumer. Activate DBG() macro.

       -d, --daemonize
              Start as a daemon

       -b, --background
              Start as a daemon, keeping console open

       -g, --group=NAME
              Specify the tracing group name. (default: tracing)

       -V, --version
              Show version number

       -S, --sig-parent
              Send SIGUSR1 to parent pid to notify readiness.

              This is used by lttng(1) to get notified when the session daemon is ready to accept
              command.  When  building  a  third party tool over liblttng-ctl, this option can be
              very handy to synchronize the control tool and the session daemon.

       -q, --quiet
              No output at all.

           --no-kernel
              No kernel tracer support

           --agent-tcp-port
              Agent application registration TCP port (default: 5345)

           --kmod-probes=probe1, probe2, ...
              Specify the kernel modules containing LTTng probes to load by the  session  daemon.
              Only the component name of the probe needs to be specified, e.g. to load the lttng-
              probe-irq and lttng-probe-sched use: --kmod-probes="irq, sched".

           --extra-kmod-probes=probe1, probe2, ...
              Specify extra kernel modules containing LTTng probes to be loaded  by  the  session
              daemon.  The  list  follows  the  format of the --kmod-probes option.  This list is
              appended to the list provided by --kmod-probes or, if --kmod-probes is missing,  to
              the default list of probes.

       -c, --client-sock=PATH
              Specify path for the client unix socket

       -a, --apps-sock PATH
              Specify path for apps unix socket

           --kconsumerd-err-sock=PATH
              Specify path for the kernel consumer error socket

           --kconsumerd-cmd-sock=PATH
              Specify path for the kernel consumer command socket

           --ustconsumerd32-err-sock=PATH
              Specify path for the 32-bit UST consumer error socket

           --ustconsumerd64-err-sock=PATH
              Specify path for the 64-bit UST consumer error socket

           --ustconsumerd32-cmd-sock=PATH
              Specify path for the 32-bit UST consumer command socket

           --ustconsumerd64-cmd-sock=PATH
              Specify path for the 64-bit UST consumer command socket

           --consumerd32-path=PATH
              Specify path for the 32-bit UST consumer daemon binary

           --consumerd32-libdir=PATH
              Specify path for the 32-bit UST consumer daemon libraries

           --consumerd64-path=PATH
              Specify path for the 64-bit UST consumer daemon binary

           --consumerd64-libdir=PATH
              Specify path for the 64-bit UST consumer daemon libraries

       -l, --load PATH
              Specify path from which to automatically load session configuration(s).

       -f, --config PATH
              Specify path from which to load daemon configuration.

LOADING SESSIONS

       By  default, the session daemon tries to load session configuration(s) located in the user
       default   directory   ~/.lttng/sessions/auto/   and   in   the   system   wide   one    in
       /etc/lttng/sessions/auto/.  Note that the directory containing the session's configuration
       and lttng-sessiond MUST have the same UID for them to be automatically loaded.

       Specifying a path with -l, --load PATH overrides the default directory and UID check.  The
       lttng-sessiond  will simply check if it's accessible and try to load every session file in
       it.

ENVIRONMENT VARIABLES

       Note that all command line options will override environment variables.

       LTTNG_CONSUMERD32_BIN
              Specify the 32-bit consumer binary path. --consumerd32-path override this variable.

       LTTNG_CONSUMERD64_BIN
              Specify the 64-bit consumer binary path. --consumerd64-path override this variable.

       LTTNG_CONSUMERD32_LIBDIR
              Specify the 64-bit library path  containing  libconsumer.so.   --consumerd32-libdir
              override this variable.

       LTTNG_CONSUMERD64_LIBDIR
              Specify  the  32-bit  library path containing libconsumer.so.  --consumerd64-libdir
              override this variable.

       LTTNG_DEBUG_NOCLONE
              Debug-mode disabling use of clone/fork. Insecure, but required to  allow  debuggers
              to work with sessiond on some operating systems.

       LTTNG_APP_SOCKET_TIMEOUT
              Control  the  timeout  of application's socket when sending and receiving commands.
              Takes an integer parameter: the timeout value, in seconds.  After  this  period  of
              time,  the  application  is  unregistered by the session daemon. A value of 0 or -1
              means an infinite timeout. Default value is 5 seconds.

       LTTNG_NETWORK_SOCKET_TIMEOUT
              Control timeout of socket connection, receive and send. Takes an integer parameter:
              the  timeout  value,  in  milliseconds.  A value of 0 or -1 uses the timeout of the
              operating system (this is the default).

       LTTNG_SESSION_CONFIG_XSD_PATH
              Specify the path that contains the XML session configuration schema (xsd).

       LTTNG_KMOD_PROBES
              Specify the kernel modules probes that should be loaded by the session daemon.

       LTTNG_EXTRA_KMOD_PROBES
              Specify extra kernel modules probes that should be loaded by the session daemon.

SEE ALSO

       babeltrace(1), lttng-ust(3), lttng(1)

LIMITATIONS

       For unprivileged user running lttng-sessiond, the maximum number of file  descriptors  per
       process  is  usually 1024. This limits the number of traceable applications since for each
       instrumented application there is two file descriptors per-CPU and  one  more  socket  for
       bidirectional communication.

       For  the  root  user,  the  limit  is  bumped to 65535. Future version will deal with this
       limitation.

BUGS

       No show stopper bugs are known yet in this version.

       If you encounter any issues or usability problem, please report it  on  our  mailing  list
       <lttng-dev@lists.lttng.org> to help improve this project.

CREDITS

       lttng-sessiond is distributed under the GNU General Public License version 2. See the file
       COPYING for details.

       A Web site is available at http://lttng.org for more information on the LTTng project.

       You can also find our git tree at http://git.lttng.org.

       Mailing lists for support and development: <lttng-dev@lists.lttng.org>.

       You can find us on IRC server irc.oftc.net (OFTC) in #lttng.

THANKS

       Thanks to Yannick Brosseau without whom this project would never have  been  so  lean  and
       mean!  Also  thanks  to the Ericsson teams working on tracing which helped us greatly with
       detailed bug reports and unusual test cases.

       Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA maintainer)
       and Jon Bernard for our Debian packages.

       Special  thanks  to Michel Dagenais and the DORSAL laboratory at Polytechnique de Montreal
       for the LTTng journey.

AUTHORS

       lttng-tools was originally written  by  Mathieu  Desnoyers,  Julien  Desfossez  and  David
       Goulet.  More  people  have since contributed to it. It is currently maintained by Jérémie
       Galarneau <jeremie.galarneau@efficios.com>.

                                         January 31, 2012                       LTTNG-SESSIOND(8)