Provided by: lttng-tools_2.7.1-2~fakesync1_i386 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)