-.TH "LTTNG" "1" "February 9, 2012" "" ""
+.TH "LTTNG" "1" "December 3rd, 2012" "" ""
.SH "NAME"
-lttng \(em LTTng 2.0 tracer control command line tool
+lttng \(em LTTng 2.1.x tracer control command line tool
.SH "SYNOPSIS"
involving multiple concurrent processes and threads. Tracing across multiple
systems is also possible.
-The \fBlttng\fP command line tool from lttng-tools package is used to control
+The \fBlttng\fP command line tool from the lttng-tools package is used to control
both kernel and user-space tracing. Every interactions with the tracer should
be done by this tool or by the liblttng-ctl provided with the lttng-tools
package.
LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry,
-which permits you to interact with multiple tracers (kernel and user-space)
+which allows you to interact with multiple tracers (kernel and user-space)
inside the same container, a tracing session. Traces can be gathered from the
kernel and/or instrumented applications (lttng-ust(3)). Aggregating and reading
those traces is done using the babeltrace(1) text viewer.
+We introduce the notion of \fBtracing domains\fP which is essentially a type of
+tracer (kernel or user space for now). In the future, we could see a third
+tracer being for instance an hypervisor. For some commands, you'll need to
+specify on which domain the command applies (-u or -k). For instance, enabling
+a kernel event, you must specify the kernel domain to the command so we know
+for which tracer this event is for.
+
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.
Every user-space applications instrumented with lttng-ust(3), will
.PP
.TP
-.BR "-h, --help"
+.BR "\-h, \-\-help"
Show summary of possible options and commands.
.TP
-.BR "-v, --verbose"
+.BR "\-v, \-\-verbose"
Increase verbosity.
-FIXME : details (-v : sessiond verbose, -vv : consumerd verbose, etc) ?
+Three levels of verbosity are available which are triggered by putting additional v to
+the option (\-vv or \-vvv)
.TP
-.BR "-q, --quiet"
+.BR "\-q, \-\-quiet"
Suppress all messages (even errors).
.TP
-.BR "-g, --group NAME"
+.BR "\-g, \-\-group NAME"
Set unix tracing group name. (default: tracing)
.TP
-.BR "-n, --no-sessiond"
+.BR "\-n, \-\-no-sessiond"
Don't automatically spawn a session daemon.
.TP
-.BR "--sessiond-path"
+.BR "\-\-sessiond\-path PATH"
Set session daemon full binary path.
.TP
-.BR "--list-options"
+.BR "\-\-list\-options"
Simple listing of lttng options.
.TP
-.BR "--list-commands"
+.BR "\-\-list\-commands"
Simple listing of lttng commands.
.SH "COMMANDS"
.nf
Add context to event(s) and/or channel(s).
-A context is basically extra information appended to a channel or event. For
-instance, you could ask the tracer to add the PID information within the
-"sched_switch" kernel event. You can also add performance monitoring unit
-counters (perf PMU) using the perf kernel API).
+A context is basically extra information appended to a channel. For instance,
+you could ask the tracer to add the PID information for all events in a
+channel. You can also add performance monitoring unit counters (perf PMU) using
+the perf kernel API).
For example, this command will add the context information 'prio' and two perf
counters (hardware branch misses and cache misses), to all events in the trace
data output:
-# lttng add-context -k -t prio -t perf:branch-misses -t perf:cache-misses
+# lttng add-context \-k \-t prio \-t perf:branch-misses \-t perf:cache-misses
-Please take a look at the help (-h/--help) for a detailed list of available
+Please take a look at the help (\-h/\-\-help) for a detailed list of available
contexts.
-If no channel and no event is given (-c/-e), the context is added to all
-channels (which applies automatically to all events in that channel). Otherwise
-the context will be added only to the channel (-c) and/or event (-e) indicated.
+If no channel is given (\-c), the context is added to all channels. Otherwise
+the context will be added only to the given channel (\-c).
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
--s, --session NAME
+\-s, \-\-session NAME
Apply on session name.
--c, --channel NAME
+\-c, \-\-channel NAME
Apply on channel name.
--e, --event NAME
- Apply on event name.
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
--t, --type TYPE
+\-t, \-\-type TYPE
Context type. You can repeat this option on the command line. Please
- use "lttng add-context -h" to list all available types.
+ use "lttng add-context \-h" to list all available types.
.fi
.IP
This sequence of commands will gather a trace executing a kretprobe hooked on
an empty function, gathering PMU counters LLC (Last Level Cache) misses
-information (see lttng add-context --help to see the list of available PMU
+information (see lttng add-context \-\-help to see the list of available PMU
counters).
# lttng create calibrate-function
-# lttng enable-event calibrate --kernel --function lttng_calibrate_kretprobe
-# lttng add-context --kernel -t perf:LLC-load-misses -t perf:LLC-store-misses \\
- -t perf:LLC-prefetch-misses
+# lttng enable-event calibrate \-\-kernel \-\-function lttng_calibrate_kretprobe
+# lttng add-context \-\-kernel \-t perf:LLC-load-misses \-t perf:LLC-store-misses \\
+ \-t perf:LLC-prefetch-misses
# lttng start
# for a in $(seq 1 10); do \\
- lttng calibrate --kernel --function;
+ lttng calibrate \-\-kernel \-\-function;
done
# lttng destroy
-# babeltrace $(ls -1drt ~/lttng-traces/calibrate-function-* | tail -n 1)
+# babeltrace $(ls \-1drt ~/lttng-traces/calibrate-function-* | tail \-n 1)
The output from babeltrace can be saved to a text file and opened in a
spreadsheet (e.g. oocalc) to focus on the per-PMU counter delta between
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
---function
+\-\-function
Dynamic function entry/return probe (default)
.fi
.IP
-.IP "\fBcreate\fP [OPTIONS] [NAME]
+.IP "\fBcreate\fP [NAME] [OPTIONS]
.nf
Create tracing session.
On creation, a \fB.lttngrc\fP file is created in your $HOME directory
containing the current session name. If NAME is omitted, a session name is
-automatically created having this form: 'auto-yyyymmdd-hhmms'.
+automatically created having this form: 'auto-yyyymmdd-hhmmss'.
-If no \fB-o, --output\fP is specified, the traces will be written in
+If no \fB\-o, \-\-output\fP is specified, the traces will be written in
$HOME/lttng-traces.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--o, --output PATH
+\-o, \-\-output PATH
Specify output path for traces
+
+Using these options, each API call can be controlled individually. For
+instance, \-C does not enable the consumer automatically. You'll need the \-e
+option for that.
+
+\-U, \-\-set-url=URL
+ Set URL for the consumer output destination. It is persistent for the
+ session lifetime. Redo the command to change it. This will set both
+ data and control URL for network.
+\-C, \-\-ctrl-url=URL
+ Set control path URL. (Must use -D also)
+\-D, \-\-data-url=URL
+ Set data path URL. (Must use -C also)
+
+.B URL FORMAT:
+
+proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
+
+Supported protocols are (proto):
+> file://...
+ Local filesystem full path.
+
+> net://...
+ This will use the default network transport layer which is TCP for both
+ control (PORT1) and data port (PORT2). The default ports are
+ respectively 5342 and 5343. Note that net[6]:// is not yet supported.
+
+> tcp[6]://...
+ Can only be used with -C and -D together
+
+NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
+
+.B EXAMPLES:
+
+# lttng create -U net://192.168.1.42
+Uses TCP and default ports for the given destination.
+
+# lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
+Uses TCP, default ports and IPv6.
+
+# lttng create s1 -U net://myhost.com:3229
+Create session s1 and set its consumer to myhost.com on port 3229 for control.
.fi
.IP
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-a, \-\-all
+ Destroy all sessions
+\-\-list-options
Simple listing of options
.fi
.nf
Enable tracing channel
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+To enable an event, you must enable both the event and the channel that
+contains it.
+
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
+
+It is important to note that if a certain type of buffers is used, the session
+will be set with that type and all other subsequent channel need to have the
+same type.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show this help
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session NAME
Apply on session name
--k, --kernel
+\-k, \-\-kernel
Apply to the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply to the user-space tracer
---discard
+\-\-discard
Discard event when subbuffers are full (default)
---overwrite
+\-\-overwrite
Flight recorder mode : overwrites events when subbuffers are full
---subbuf-size
- Subbuffer size in bytes (default: 4096, kernel default: 262144)
---num-subbuf
- Number of subbufers (default: 8, kernel default: 4)
---switch-timer
- Switch subbuffer timer interval in usec (default: 0)
---read-timer
- Read timer interval in usec (default: 200)
+\-\-subbuf-size SIZE
+ Subbuffer size in bytes {+k,+M,+G} (default: 4096, kernel default: 262144)
+ Needs to be a power of 2 for both tracers
+\-\-num-subbuf NUM
+ Number of subbuffers (default: 4)
+ Needs to be a power of 2 for both tracers
+\-\-switch-timer USEC
+ Switch subbuffer timer interval in µsec (default: 0)
+\-\-read-timer USEC
+ Read timer interval in µsec (UST default: 0, kernel default: 200000)
+\-\-output TYPE
+ Channel output type. Possible values: mmap, splice
+\-\-buffers-uid
+ Use per UID buffer (\-u only). Buffers are shared between applications
+ that have the same UID.
+\-\-buffers-pid
+ Use per PID buffer (\-u only). Each application has its own buffers.
+\-\-buffers-global
+ Use shared buffer for the whole system (\-k only)
+\-C, \-\-tracefile-size SIZE
+ Maximum size of each tracefile within a stream (in bytes).
+\-W, \-\-tracefile-count COUNT
+ Used in conjunction with \-C option, this will limit the number
+ of files created to the specified count.
+
+.B EXAMPLES:
+
+$ lttng enable-channel -C 4096 -W 32 chan1
+For each stream, the maximum size of a trace file will be 4096 bytes divided
+over a \fBmaximum\fP of 32 different files. The file count is appended after
+the stream number as seen in the following example. The last trace file is
+smaller than 4096 since it was not completely filled.
+
+ ~/lttng-traces/[...]/chan1_0_0 (4096)
+ ~/lttng-traces/[...]/chan1_0_1 (4096)
+ ~/lttng-traces/[...]/chan1_0_2 (3245)
+ ~/lttng-traces/[...]/chan1_1_0 (4096)
+ ...
+
+$ lttng enable-channel -C 4096
+This will create trace files of 4096 bytes and will create new ones as long as
+there is data available.
.fi
.IP
.nf
Enable tracing event
-A tracing event is always assigned to a channel. If \fB-c, --channel\fP is
+A tracing event is always assigned to a channel. If \fB\-c, \-\-channel\fP is
omitted, a default channel named '\fBchannel0\fP' is created and the event is
-added to it. For the user-space tracer, using \fB-a, --all\fP is the same as
+added to it. For the user-space tracer, using \fB\-a, \-\-all\fP is the same as
using the wildcard "*".
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session NAME
Apply on session name
--c, --channel
+\-c, \-\-channel NAME
Apply on channel name
--a, --all
- Enable all tracepoints
--k, --kernel
+\-a, \-\-all
+ Enable all tracepoints and syscalls. This actually enable a single
+ wildcard event "*".
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
---tracepoint
+\-\-tracepoint
Tracepoint event (default)
- userspace tracer supports wildcards at end of string. Don't forget to
quote to deal with bash expansion.
e.g.:
"*"
"app_component:na*"
---loglevel
- Tracepoint loglevel
---probe [addr | symbol | symbol+offset]
+\-\-loglevel NAME
+ Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h).
+\-\-loglevel-only NAME
+ Tracepoint loglevel (only this loglevel).
+
+ The loglevel or loglevel-only options should be combined with a
+ tracepoint name or tracepoint wildcard.
+\-\-probe [addr | symbol | symbol+offset]
Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...)
or hexadecimal (0xNNN...)
---function [addr | symbol | symbol+offset]
+\-\-function [addr | symbol | symbol+offset]
Dynamic function entry/return probe. Addr and offset can be octal
(0NNN...), decimal (NNN...) or hexadecimal (0xNNN...)
---syscall
- System call event
- Enabling syscalls tracing (kernel tracer), you will not be able to disable them
- with disable-event. This is a known limitation. You can disable the entire
- channel to do the trick.
+\-\-syscall
+ System call event. Enabling syscalls tracing (kernel tracer), you will
+ not be able to disable them with disable-event. This is a known
+ limitation. You can disable the entire channel to do the trick.
+
+\-\-filter 'expression'
+ Set a filter on a newly enabled event. Filter expression on event
+ fields and context. Event recording depends on evaluation. Only
+ specify on first activation of a given event within a session.
+ Filter only allowed when enabling events within a session before
+ tracing is started. If the filter fails to link with the event
+ within the traced domain, the event will be discarded.
+ Currently, filter is only implemented for the user-space tracer.
+
+ Expression examples:
+
+ 'intfield > 500 && intfield < 503'
+ '(stringfield == "test" || intfield != 10) && intfield > 33'
+ 'doublefield > 1.1 && intfield < 5.3'
+
+ Wildcards are allowed at the end of strings:
+ 'seqfield1 == "te*"'
+ In string literals, the escape character is a '\\'. Use '\\*' for
+ the '*' character, and '\\\\' for the '\\' character. Wildcard
+ match any sequence of characters, including an empty sub-string
+ (match 0 or more characters).
+
+ Context information can be used for filtering. The examples
+ below show usage of context filtering on process name (with a
+ wildcard), process ID range, and unique thread ID for filtering.
+ The process and thread ID of running applications can be found
+ under columns "PID" and "LWP" of the "ps -eLf" command.
+
+ '$ctx.procname == "demo*"'
+ '$ctx.vpid >= 4433 && $ctx.vpid < 4455'
+ '$ctx.vtid == 1234'
.fi
-.IP "\fBdisable-channel\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
+.IP "\fBdisable-channel\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]"
.nf
Disable tracing channel
Disabling a channel makes all event(s) in that channel to stop tracing. You can
enable it back by calling \fBlttng enable-channel NAME\fP again.
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session NAME
Apply on session name
--k, --kernel
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
.fi
-.IP "\fBdisable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
+.IP "\fBdisable-event\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]"
.nf
Disable tracing event
The event, once disabled, can be re-enabled by calling \fBlttng enable-event
NAME\fP again.
-If \fB-s, --session\fP is omitted, the session name is taken from the .lttngrc
+If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--s, --session
+\-s, \-\-session NAME
Apply on session name
--k, --kernel
+\-a, \-\-all-events
+ Disable all events. This does NOT disable "*" but rather
+ every known events of the session.
+\-k, \-\-kernel
Apply for the kernel tracer
--u, --userspace
+\-u, \-\-userspace
Apply for the user-space tracer
.fi
-.IP "\fBlist\fP [-k|-u] [SESSION [SESSION_OPTIONS]]"
+.IP "\fBlist\fP [\-k|\-u] [SESSION [SESSION_OPTIONS]]"
.nf
-List tracing session informations.
+List tracing session information.
With no arguments, it will list available tracing session(s).
-With -k alone, it will list all available kernel events (except the system
+With the session name, it will display the details of the session including
+the trace file path, the associated channels and their state (activated
+and deactivated), the activated events and more.
+
+With \-k alone, it will list all available kernel events (except the system
calls events).
-With -u alone, it will list all available user-space events from registered
-applications. Here is an example of 'lttng list -u':
+With \-u alone, it will list all available user-space events from registered
+applications. Here is an example of 'lttng list \-u':
PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello
ust_tests_hello:tptest_sighandler (type: tracepoint)
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
--k, --kernel
- Select kernel domain (FIXME : apparition de la notion de "domain" ici)
--u, --userspace
+\-k, \-\-kernel
+ Select kernel domain
+\-u, \-\-userspace
Select user-space domain.
-Session options:
--c, --channel NAME
+.B SESSION OPTIONS:
+
+\-c, \-\-channel NAME
List details of a channel
--d, --domain
+\-d, \-\-domain
List available domain(s)
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
.IP
-.IP "\fBstart\fP [OPTIONS] [NAME]"
+.IP "\fBstart\fP [NAME] [OPTIONS]"
.nf
Start tracing
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
.IP
-.IP "\fBstop\fP [OPTIONS] [NAME]"
+.IP "\fBstop\fP [NAME] [OPTIONS]"
.nf
Stop tracing
-It will stop tracing for all tracers for a specific tracing session.
+It will stop tracing for all tracers for a specific tracing session. Before
+returning, the command checks for data availability meaning that it will wait
+until the trace is readable for the session. Use \-\-no-wait to avoid this
+behavior.
If NAME is omitted, the session name is taken from the .lttngrc file.
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
+\-\-no-wait
+ Don't wait for data availability.
.fi
.IP
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show summary of possible options and commands.
---list-options
+\-\-list-options
Simple listing of options
.fi
By default, the babeltrace viewer will be used for text viewing.
-The SESSION_NAME is an optional session name. If not specified, lttng will get
-it from the configuration file (.lttngrc).
+If SESSION_NAME is omitted, the session name is taken from the .lttngrc file.
+
.fi
.B OPTIONS:
.nf
--h, --help
+\-h, \-\-help
Show this help
---list-options
+\-\-list-options
Simple listing of options
--t, --trace-path PATH
+\-t, \-\-trace-path PATH
Trace directory path for the viewer
--e, --viewer CMD
+\-e, \-\-viewer CMD
Specify viewer and/or options to use
This will completely override the default viewers so
please make sure to specify the full command. The trace
to the arguments
.fi
+.SH "EXIT VALUES"
+On success 0 is returned and a positive value on error. Value of 1 means a command
+error, 2 an undefined command, 3 a fatal error and 4 a command warning meaning that
+something went wrong during the command.
+
+Any other value above 10, please refer to
+.BR <lttng/lttng-error.h>
+for a detailed list or use lttng_strerror() to get a human readable string of
+the error code.
+
+.PP
.SH "ENVIRONMENT VARIABLES"
.PP
.PP
.PP
-.IP "LTTNG_SESSIOND_PATH_ENV"
-Allows to specify the full session daemon binary path to lttng command line
-tool. You can also use --sessiond-path option having the same effect.
+.IP "LTTNG_SESSIOND_PATH"
+Allows one to specify the full session daemon binary path to lttng command line
+tool. You can also use \-\-sessiond-path option having the same effect.
.SH "SEE ALSO"
-
-.PP
-babeltrace(1), lttng-ust(3), lttng-sessiond(8)
-.PP
+.BR babeltrace(1),
+.BR lttng-ust(3),
+.BR lttng-sessiond(8),
+.BR lttng-relayd(8),
+.BR lttng-health-check(3)
.SH "BUGS"
-.PP
-No show stopper bugs known yet at this stable 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.
+mailing list <lttng-dev@lists.lttng.org> to help improve this project or
+at https://bugs.lttng.org which is a bugtracker.
.SH "CREDITS"
.PP
-lttng is distributed under the GNU public license version 2. See the file
+lttng is distributed under the GNU General Public License version 2. See the file
COPYING for details.
.PP
A Web site is available at http://lttng.org for more information on the LTTng
.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
-helped us greatly with detailled bug reports and unusual test cases.
+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.
-.pp
+.PP
.SH "AUTHORS"
.PP
projects / lttng-tools.git / blobdiff