.TH "LTTNG-SESSIOND" "8" "January 31, 2012" "" ""
.SH "NAME"
-lttng-sessiond \(em LTTng 2.0 central tracing registry session daemon.
+lttng-sessiond \(em LTTng 2.x central tracing registry session daemon.
.SH "SYNOPSIS"
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
+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 the babeltrace(1) text
-viewer.
+(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 \fBtracing group\fP (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 use to trace her applications along side with a
-root daemon or even a Bob daemon. We highly recommand to start the session
+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
-one when the time as come. The user don't need to manage the lttng-consumerd.
+them when the time has come. The user don't need to manage the lttng-consumerd.
.SH "OPTIONS"
.PP
.BR "-d, --daemonize"
Start as a daemon
.TP
+.BR "-b, --background"
+Start as a daemon, keeping console open
+.TP
.BR "-g, --group=NAME"
Specify the tracing group name. (default: tracing)
.TP
Show version number
.TP
.BR "-S, --sig-parent"
-Send SIGCHLD to parent pid to notify readiness.
+Send SIGUSR1 to parent pid to notify readiness.
This is used by \fBlttng(1)\fP to get notified when the session daemon is ready
-to accept command. By building a third part tool over liblttng-ctl, this option
+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.
.TP
.BR "-q, --quiet"
.BR " --no-kernel"
No kernel tracer support
.TP
+.BR " --jul-tcp-port"
+JUL application registration TCP port (default: 5345)
+.TP
+.BR " --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".
+.TP
.BR "-c, --client-sock=PATH"
Specify path for the client unix socket
.TP
.TP
.BR " --consumerd64-libdir=PATH
Specify path for the 64-bit UST consumer daemon libraries
+.TP
+.BR "-l, --load PATH
+Specify path from which to automatically load session configuration(s).
+
+.SH "LOADING SESSIONS"
+
+.PP
+By default, the session daemon tries to load session configuration(s) located
+in the user default directory \fB~/.lttng/sessions/auto/\fP and in the system
+wide one in \fB/etc/lttng/sessions/auto\fP. Note that the directory containing
+the session's configuration and lttng-sessiond MUST have the same UID for them
+to be automatically loaded.
+
+Specifiying 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.
+.PP
+
.SH "ENVIRONMENT VARIABLES"
.PP
-Note that all command line options will override environmenal variables.
+Note that all command line options will override environment variables.
.PP
.PP
.IP "LTTNG_CONSUMERD32_BIN"
-Allow to specify the 32-bit consumer binary path. \fB--consumerd32-path\fP
+Specify the 32-bit consumer binary path. \fB--consumerd32-path\fP
override this variable.
.IP "LTTNG_CONSUMERD64_BIN"
-Allow to specify the 64-bit consumer binary path. \fB--consumerd64-path\fP
+Specify the 64-bit consumer binary path. \fB--consumerd64-path\fP
override this variable.
.IP "LTTNG_CONSUMERD32_LIBDIR"
-Allow to specifiy the 64-bit library path containing libconsumer.so.
+Specifiy the 64-bit library path containing libconsumer.so.
\fB--consumerd32-libdir\fP override this variable.
.IP "LTTNG_CONSUMERD64_LIBDIR"
-Allow to specifiy the 32-bit library path containing libconsumer.so.
+Specifiy the 32-bit library path containing libconsumer.so.
\fB--consumerd64-libdir\fP override this variable.
.IP "LTTNG_DEBUG_NOCLONE"
Debug-mode disabling use of clone/fork. Insecure, but required to allow
debuggers to work with sessiond on some operating systems.
+.IP "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.
+.IP "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).
+.IP "LTTNG_SESSION_CONFIG_XSD_PATH"
+Specify the path that contains the XML session configuration schema (xsd).
+.IP "LTTNG_KMOD_PROBES"
+Specify the kernel modules probes that should be loaded by the session daemon.
.SH "SEE ALSO"
.PP
babeltrace(1), lttng-ust(3), lttng(1)
.PP
+
+.SH "LIMITATIONS"
+
+.PP
+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.
+.PP
+
.SH "BUGS"
.PP
-No show stopper bugs known yet at this stable version.
+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.
.PP
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 help
-us greatly with detailled bug reports and unsual use cases.
+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.
projects / lttng-tools.git / blobdiff