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 follow 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, --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

           --jul-tcp-port
              JUL application registration TCP port (default: 5345)

       -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

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

       LTTNG_CONSUMERD64_LIBDIR
              Specifiy 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).

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 socktet 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 David Goulet <dgoulet@efficios.com>.

                                                January 31, 2012                               LTTNG-SESSIOND(8)