-.TH "LTTNG" "1" "December 3rd, 2012" "" ""
+.TH "LTTNG" "1" "May 13th, 2014" "" ""
.SH "NAME"
-lttng \(em LTTng 2.1.x tracer control command line tool
+lttng \(em LTTng 2.x tracer control command line tool
.SH "SYNOPSIS"
.PP
-.nf
lttng [OPTIONS] <COMMAND>
-.fi
.SH "DESCRIPTION"
.PP
The LTTng project aims at providing highly efficient tracing tools for Linux.
-It's tracers help tracking down performance issues and debugging problems
+Its tracers help track down performance issues and debug problems
involving multiple concurrent processes and threads. Tracing across multiple
systems is also possible.
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
+both kernel and user-space tracing. Every interaction with the tracer should
+be done by this tool or by the liblttng-ctl library provided by the lttng-tools
package.
LTTng uses a session daemon (lttng-sessiond(8)), acting as a tracing registry,
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.
+tracer (kernel, user space or JUL for now). In the future, we could see more
+tracer like for instance an hypervisor. For some commands, you'll need to
+specify on which domain the command operates (\-u, \-k or \-j). For instance,
+the kernel domain must be specified when enabling a kernel event.
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
+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
+root daemon or even a Bob daemon. We highly recommend starting the session
daemon at boot time for stable and long term tracing.
-Every user-space applications instrumented with lttng-ust(3), will
-automatically register to the session daemon. This feature gives you the
-ability to list available traceable applications and tracepoints on a per user
-basis. (See \fBlist\fP command).
+Each user-space application instrumented with lttng-ust(3) will automatically
+register with the root session daemon and its user session daemon. This allows
+each daemon to list the available traceable applications and tracepoints at any
+given moment (See the \fBlist\fP command).
.SH "OPTIONS"
.PP
Simple listing of lttng commands.
.SH "COMMANDS"
-.TP
-\fBadd-context\fP
-.nf
+.PP
+\fBadd-context\fP [OPTIONS]
+.RS
Add context to event(s) and/or channel(s).
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).
+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
+For example, this command will add the context information 'prio' and two per-CPU
+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
+.nf
+# lttng add-context \-k \-t prio \-t perf:cpu:branch-misses \\
+ \-t perf:cpu:cache-misses
+.fi
Please take a look at the help (\-h/\-\-help) for a detailed list of available
contexts.
-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).
+Perf counters are available as per-CPU ("perf:cpu:...") and per-thread
+("perf:thread:...") counters. Currently, per-CPU counters can only be
+used with the kernel tracing domain, and per-thread counters can only be
+used with the UST tracing domain.
+
+If no channel is given (\-c), the context is added to all channels that were
+already enabled. If the session has no channel, a default channel is created.
+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
file.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-s, \-\-session NAME
- Apply on session name.
-\-c, \-\-channel NAME
- Apply on channel name.
-\-k, \-\-kernel
- Apply for the kernel tracer
-\-u, \-\-userspace
- Apply for the user-space tracer
-\-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.
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-s, \-\-session NAME"
+Apply on session name.
+.TP
+.BR "\-c, \-\-channel NAME"
+Apply on channel name.
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.TP
+.BR "\-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.
+.RE
+.PP
-.IP "\fBcalibrate\fP"
-.nf
+.PP
+\fBcalibrate\fP [OPTIONS]
+.RS
Quantify LTTng overhead
The LTTng calibrate command can be used to find out the combined average
information (see lttng add-context \-\-help to see the list of available PMU
counters).
+.nf
# 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:cpu:LLC-load-misses \\
+ \-t perf:cpu:LLC-store-misses \\
+ \-t perf:cpu:LLC-prefetch-misses
# lttng start
# for a in $(seq 1 10); do \\
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)
+.fi
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
The average result, for the i7, on 10 samples:
+.nf
Average Std.Dev.
perf_LLC_load_misses: 5.0 0.577
perf_LLC_store_misses: 1.6 0.516
perf_LLC_prefetch_misses: 9.0 14.742
+.fi
As we can notice, the load and store misses are relatively stable across runs
(their standard deviation is relatively low) compared to the prefetch misses.
accounted for quite precisely, but prefetches within a function seems to behave
too erratically (not much causality link between the code executed and the CPU
prefetch activity) to be accounted for.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-k, \-\-kernel
- Apply for the kernel tracer
-\-u, \-\-userspace
- Apply for the user-space tracer
-\-\-function
- Dynamic function entry/return probe (default)
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.TP
+.BR "\-\-function"
+Dynamic function entry/return probe (default)
+.RE
+.PP
-.IP "\fBcreate\fP [NAME] [OPTIONS]
-.nf
+.PP
+\fBcreate\fP [NAME] [OPTIONS]
+.RS
Create tracing session.
A tracing session contains channel(s) which contains event(s). It is domain
-agnostic meaning that you can enable channels and events for either the
+agnostic, meaning that channels and events can be enabled for the
user-space tracer and/or the kernel tracer. It acts like a container
aggregating multiple tracing sources.
If no \fB\-o, \-\-output\fP is specified, the traces will be written in
$HOME/lttng-traces.
-.fi
+
+The $HOME environment variable can be overridden by defining the environment
+variable LTTNG_HOME. This is useful when the user running the commands has
+a non-writeable home directory.
+
+The session name MUST NOT contain the character '/'.
.B OPTIONS:
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-o, \-\-output PATH"
+Specify output path for traces
+.TP
+.BR "\-\-no-output"
+Traces will not be output
+.TP
+.BR "\-\-snapshot"
+Set the session in snapshot mode. Created in no-output mode and uses the
+URL, if one is specified, as the default snapshot output. Every channel will be set
+in overwrite mode and with mmap output (splice not supported).
+.TP
+.BR "\-\-live [USEC]"
+Set the session exclusively in live mode. The paremeter is the delay in micro
+seconds before the data is flushed and streamed. The live mode allows you to
+stream the trace and view it while it's being recorded by any tracer. For that,
+you need a lttng-relayd and this session requires a network URL (\-U or
+\-C/\-D). If no USEC nor URL is provided, the default is to use a timer value
+set to 1000000 and the network URL set to net://127.0.0.1.
+
+To read a live session, you can use babeltrace(1) or the live streaming
+protocol in doc/live-reading-protocol.txt. Here is an example:
+
.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-o, \-\-output PATH
- Specify output path for traces
+$ lttng-relayd -o /tmp/lttng
+$ lttng create --live 200000 -U net://localhost
+$ lttng enable-event -a --userspace
+$ lttng start
+.fi
+
+After the start, you'll be able to read the events while they are being
+recorded in /tmp/lttng.
+.TP
+.BR "\-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.
+.TP
+.BR "\-C, \-\-ctrl-url=URL"
+Set control path URL. (Must use -D also)
+.TP
+.BR "\-D, \-\-data-url=URL"
+Set data path URL. (Must use -C also)
+.PP
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.
+.TP
+.BR "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.
+.TP
+.BR "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
+.TP
+.BR "tcp[6]://..."
+Can only be used with -C and -D together
NOTE: IPv6 address MUST be enclosed in brackets '[]' (rfc2732)
.B EXAMPLES:
+.nf
# lttng create -U net://192.168.1.42
+.fi
Uses TCP and default ports for the given destination.
+.nf
# lttng create -U net6://[fe80::f66d:4ff:fe53:d220]
+.fi
Uses TCP, default ports and IPv6.
+.nf
# lttng create s1 -U net://myhost.com:3229
-Create session s1 and set its consumer to myhost.com on port 3229 for control.
.fi
+Create session s1 and set its consumer to myhost.com on port 3229 for control.
+.RE
+.PP
-.IP
-
-.IP "\fBdestroy\fP [OPTIONS] [NAME]"
-.nf
+.PP
+\fBdestroy\fP [NAME] [OPTIONS]
+.RS
Teardown tracing session
Free memory on the session daemon and tracer side. It's gone!
If NAME is omitted, the session name is taken from the .lttngrc file.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-a, \-\-all
- Destroy all sessions
-\-\-list-options
- Simple listing of options
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-a, \-\-all"
+Destroy all sessions
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.RE
+.PP
-.IP "\fBenable-channel\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
-.nf
+.PP
+\fBenable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
+.RS
Enable tracing channel
To enable an event, you must enable both the event and the channel that
If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
+Exactly one of \-k or -u must be specified.
+
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
+will be set with that type and all other subsequent channel needs to have the
same type.
-.fi
+
+Note that once the session has been started and enabled on the tracer side,
+it's not possible anymore to enable a new channel for that session.
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show this help
-\-\-list-options
- Simple listing of options
-\-s, \-\-session NAME
- Apply on session name
-\-k, \-\-kernel
- Apply to the kernel tracer
-\-u, \-\-userspace
- Apply to the user-space tracer
-
-\-\-discard
- Discard event when subbuffers are full (default)
-\-\-overwrite
- Flight recorder mode : overwrites events when subbuffers are full
-\-\-subbuf-size SIZE
- Subbuffer size in bytes (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 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.
+.TP
+.BR "\-h, \-\-help"
+Show this help
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-s, \-\-session NAME"
+Apply on session name
+.TP
+.BR "\-k, \-\-kernel"
+Apply to the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply to the user-space tracer
+.TP
+.BR "\-\-discard"
+Discard event when subbuffers are full (default)
+.TP
+.BR "\-\-overwrite"
+Flight recorder mode: overwrites events when subbuffers are full. The
+number of subbuffer must be 2 or more.
+.TP
+.BR "\-\-subbuf-size SIZE"
+Subbuffer size in bytes {+k,+M,+G}.
+(default UST uid: 131072, UST pid: 4096, kernel: 262144, metadata: 4096)
+Rounded up to the next power of 2.
+
+The minimum subbuffer size, for each tracer, is the max value between
+the default above and the system page size. You can issue this command
+to get the current page size on your system: \fB$ getconf PAGE_SIZE\fP
+.TP
+.BR "\-\-num-subbuf NUM"
+Number of subbuffers. (default UST uid: 4, UST pid: 4, kernel: 4,
+metadata: 2) Rounded up to the next power of 2.
+.TP
+.BR "\-\-switch-timer USEC"
+Switch subbuffer timer interval in µsec.
+(default UST uid: 0, UST pid: 0, kernel: 0, metadata: 0)
+.TP
+.BR "\-\-read-timer USEC"
+Read timer interval in µsec.
+(default UST uid: 0, UST pid: 0, kernel: 200000, metadata: 0)
+.TP
+.BR "\-\-output TYPE"
+Channel output type. Possible values: mmap, splice
+(default UST uid: mmap, UST pid: mmap, kernel: splice, metadata: mmap)
+.TP
+.BR "\-\-buffers-uid"
+Use per UID buffer (\-u only). Buffers are shared between applications
+that have the same UID.
+.TP
+.BR "\-\-buffers-pid"
+Use per PID buffer (\-u only). Each application has its own buffers.
+.TP
+.BR "\-\-buffers-global"
+Use shared buffer for the whole system (\-k only)
+.TP
+.BR "\-C, \-\-tracefile-size SIZE"
+Maximum size of each tracefile within a stream (in bytes).
+0 means unlimited. (default: 0)
+Note: traces generated with this option may inaccurately report
+discarded events as of CTF 1.8.
+.TP
+.BR "\-W, \-\-tracefile-count COUNT"
+Used in conjunction with \-C option, this will limit the number of files
+created to the specified count. 0 means unlimited. (default: 0)
.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
+.nf
+$ lttng enable-channel -k -C 4096 -W 32 chan1
+.fi
+For each stream, the maximum size of each trace file will be 4096 bytes and
+there will be a maximum 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.
+.nf
~/lttng-traces/[...]/chan1_0_0 (4096)
~/lttng-traces/[...]/chan1_0_1 (4096)
~/lttng-traces/[...]/chan1_0_2 (3245)
~/lttng-traces/[...]/chan1_1_0 (4096)
...
+.fi
-$ lttng enable-channel -C 4096
+.nf
+$ lttng enable-channel -k -C 4096
+.fi
This will create trace files of 4096 bytes and will create new ones as long as
there is data available.
-.fi
-
-.IP
+.RE
+.PP
-.IP "\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]"
-.nf
+.PP
+\fBenable-event\fP NAME[,NAME2,...] [-k|-u] [OPTIONS]
+.RS
Enable tracing event
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
-using the wildcard "*".
+added to it. If \fB\-c, \-\-channel\fP is omitted, but a non-default
+channel already exists within the session, an error is returned. 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
file.
-.fi
.B OPTIONS:
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-s, \-\-session NAME"
+Apply on session name
+.TP
+.BR "\-c, \-\-channel NAME"
+Apply on channel name
+.TP
+.BR "\-a, \-\-all"
+Enable all tracepoints and syscalls. This actually enables a single
+wildcard event "*".
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.TP
+.BR "\-j, \-\-jul"
+Apply for Java application using Java Util Logging interface (JUL)
+.TP
+.BR "\-\-tracepoint"
+Tracepoint event (default). Userspace tracer supports wildcards at the end
+of string. Don't forget to quote to deal with bash expansion.
+e.g.:
.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-s, \-\-session NAME
- Apply on session name
-\-c, \-\-channel NAME
- Apply on channel name
-\-a, \-\-all
- Enable all tracepoints and syscalls. This actually enable a single
- wildcard event "*".
-\-k, \-\-kernel
- Apply for the kernel tracer
-\-u, \-\-userspace
- Apply for the user-space tracer
-
-\-\-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 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]
- 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.
-
-\-\-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
+.TP
+.BR "\-\-loglevel NAME"
+Tracepoint loglevel range from 0 to loglevel. Listed in the help (\-h).
+For the JUL domain, the loglevel ranges are detailed with the \-\-help
+option thus starting from SEVERE to FINEST.
+.TP
+.BR "\-\-loglevel-only NAME"
+Tracepoint loglevel (only this loglevel).
+The loglevel or loglevel-only options should be combined with a
+tracepoint name or tracepoint wildcard.
+.TP
+.BR "\-\-probe (addr | symbol | symbol+offset)"
+Dynamic probe. Addr and offset can be octal (0NNN...), decimal (NNN...)
+or hexadecimal (0xNNN...)
+.TP
+.BR "\-\-function (addr | symbol | symbol+offset)"
+Dynamic function entry/return probe. Addr and offset can be octal
+(0NNN...), decimal (NNN...) or hexadecimal (0xNNN...)
+.TP
+.BR "\-\-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. Also note
+that per-syscall selection is not supported yet. Use with "-a" to enable
+all syscalls.
+.TP
+.BR "\-\-filter 'expression'"
+Set a filter on a newly enabled event. Filter expression on event
+fields and context. The event will be recorded if the filter's
+expression evaluates to TRUE. Only specify on first activation of a
+given event within a session.
+Specifying a filter is 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.
+Filtering is currently only implemented for the user-space tracer.
+
+Expression examples:
+
+.nf
+ 'intfield > 500 && intfield < 503'
+ '(strfield == "test" || intfield != 10) && intfield > 33'
+ 'doublefield > 1.1 && intfield < 5.3'
+.fi
+
+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 sequence. Wildcard
+matches any sequence of characters, including an empty sub-string
+(matches 0 or more characters).
+
+Context information can be used for filtering. The examples below shows
+usage of context filtering on the process name (using a wildcard), process ID
+range, and unique thread ID. The process and thread IDs of
+running applications can be found under columns "PID" and "LWP" of the
+"ps -eLf" command.
-.IP "\fBdisable-channel\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]"
.nf
+ '$ctx.procname == "demo*"'
+ '$ctx.vpid >= 4433 && $ctx.vpid < 4455'
+ '$ctx.vtid == 1234'
+.fi
+
+Context information is available to all filters whether or not the add-context
+command has been used to add it to the event's channel, as long as the context
+field exists for that domain. For example, the filter examples given above will
+never fail to link: no add-context is required for the event's channel.
+
+.TP
+.BR "\-x, \-\-exclude LIST"
+Add exclusions to UST tracepoints:
+Events that match any of the items in the comma-separated LIST are not
+enabled, even if they match a wildcard definition of the event.
+
+This option is also applicable with the \fB\-a, \-\-all\fP option,
+in which case all UST tracepoints are enabled except the ones whose
+names match any of the items in LIST.
+.RE
+.PP
+
+.PP
+\fBdisable-channel\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
+.RS
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.
+Disabling a channel disables the tracing of all of the channel's events. A channel
+can be re-enabled by calling \fBlttng enable-channel NAME\fP again.
If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-s, \-\-session NAME
- Apply on session name
-\-k, \-\-kernel
- Apply for the kernel tracer
-\-u, \-\-userspace
- Apply for the user-space tracer
-.fi
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-s, \-\-session NAME"
+Apply on session name
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.RE
+.PP
-.IP "\fBdisable-event\fP NAME[,NAME2,...] [\-k|\-u] [OPTIONS]"
-.nf
+.PP
+\fBdisable-event\fP NAME[,NAME2,...] (\-k | \-u) [OPTIONS]
+.RS
Disable tracing event
The event, once disabled, can be re-enabled by calling \fBlttng enable-event
If \fB\-s, \-\-session\fP is omitted, the session name is taken from the .lttngrc
file.
-.fi
+
+If \fB\-c, \-\-channel\fP is omitted, the default channel name is used.
+If \fB\-c, \-\-channel\fP is omitted, but a non-default channel already
+exists within the session, an error is returned.
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-s, \-\-session NAME
- Apply on session name
-\-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
- Apply for the user-space tracer
-.fi
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-s, \-\-session NAME"
+Apply on session name
+.TP
+.BR "\-c, \-\-channel NAME"
+Apply on channel name
+.TP
+.BR "\-a, \-\-all-events"
+Disable all events. This does NOT disable "*" but rather every known
+events of the session.
+.TP
+.BR "\-k, \-\-kernel"
+Apply for the kernel tracer
+.TP
+.BR "\-u, \-\-userspace"
+Apply for the user-space tracer
+.TP
+.BR "\-j, \-\-jul"
+Apply for Java application using Java Util Logging interface (JUL)
+.RE
+.PP
-.IP "\fBlist\fP [\-k|\-u] [SESSION [SESSION_OPTIONS]]"
-.nf
+.PP
+\fBlist\fP [OPTIONS] [SESSION [SESSION OPTIONS]]
+.RS
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
calls events).
+With \-j alone, the available JUL event from registered application will be
+list. The event corresponds to the Logger name in the Java JUL application.
With \-u alone, it will list all available user-space events from registered
applications. Here is an example of 'lttng list \-u':
+.nf
PID: 7448 - Name: /tmp/lttng-ust/tests/hello/.libs/lt-hello
ust_tests_hello:tptest_sighandler (type: tracepoint)
ust_tests_hello:tptest (type: tracepoint)
+.fi
You can now enable any event listed by using the name :
\fBust_tests_hello:tptest\fP.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-k, \-\-kernel
- Select kernel domain
-\-u, \-\-userspace
- Select user-space domain.
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-k, \-\-kernel"
+Select kernel domain
+.TP
+.BR "\-u, \-\-userspace"
+Select user-space domain.
+.TP
+.BR "\-j, \-\-jul"
+Apply for Java application using JUL
+.TP
+.BR "\-f, \-\-fields"
+List event fields
+.PP
.B SESSION OPTIONS:
-\-c, \-\-channel NAME
- List details of a channel
-\-d, \-\-domain
- List available domain(s)
-.fi
+.TP
+.BR "\-c, \-\-channel NAME"
+List details of a channel
+.TP
+.BR "\-d, \-\-domain"
+List available domain(s)
+.RE
+.PP
-.IP "\fBset-session\fP NAME"
-.nf
+.PP
+\fBload\fP [OPTIONS] [NAME]
+.RS
+Load tracing session configuration
+
+If NAME is omitted, all session configurations found in both the user's session
+configuration directory and the system session configuration directory will be
+loaded.
+
+.B OPTIONS:
+
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-a, \-\-all"
+Load all session configurations (default).
+.TP
+.BR "\-i, \-\-input-path PATH"
+Specify the input path for session configurations.
+.TP
+.BR "\-f, -\-force"
+Overwrite current session configuration(s) if a session of the same name
+already exists.
+.RE
+.PP
+
+.PP
+\fBsave\fP [OPTIONS] [SESSION]
+.RS
+Save tracing session configuration
+
+If SESSION is omitted, all session configurations will be saved to individual
+\fB.lttng\fP files under the user's session configuration directory (default:
+~/.lttng/sessions/ or /var/run/lttng/sessions/ for root user). The default
+session configuration file naming scheme is \fBSESSION.lttng\fP.
+
+.B OPTIONS:
+
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-a, \-\-all"
+Save all session configurations (default).
+.TP
+.BR "\-o, \-\-output-path PATH"
+Specify the output path for saved sessions. This overrides the default session
+configuration directory.
+.TP
+.BR "\-f, -\-force"
+Overwrite session configuration file if session name clashes.
+.RE
+.PP
+
+.PP
+\fBset-session\fP NAME [OPTIONS]
+.RS
Set current session name
Will change the session name in the .lttngrc file.
-.fi
.B OPTIONS:
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.RE
+.PP
+
+.PP
+\fBsnapshot\fP [OPTIONS] ACTION
+.RS
+Snapshot command for LTTng session.
+
+.B OPTIONS:
+
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+
+.PP
+.B ACTION:
+
+.TP
+\fBadd-output\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] <URL> | -C <URL> -D <URL>
+
+Setup and add an snapshot output for a session. Output are the destination
+where the snapshot will be sent. Only one output is permitted. To change it,
+you'll need to delete it and add back the new one.
+
+.TP
+\fBdel-output\fP ID | NAME [-s <NAME>]
+
+Delete an output for a session using the ID. You can either specify the
+output's ID that can be found with list-output or the name.
+
+.TP
+\fBlist-output\fP [-s <NAME>]
+
+List the output of a session. Attributes of the output are printed.
+
+.TP
+\fBrecord\fP [-m <SIZE>] [-s <NAME>] [-n <NAME>] [<URL> | -C <URL> -D <URL>]
+
+Snapshot a session's buffer(s) for all domains. If an URL is specified, it is
+used instead of a previously added output. Specifying only a name or/and a max
+size will override the current output values. For instance, you can record a
+snapshot with a custom maximum size or with a different name.
+
.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
+$ lttng snapshot add-output -n mysnapshot file:///data/snapshot
+[...]
+$ lttng snapshot record -n new_name_snapshot
.fi
-.IP
+The above will create a snapshot in /data/snapshot/new_name_snapshot* directory
+rather then in mysnapshot*/
-.IP "\fBstart\fP [NAME] [OPTIONS]"
-.nf
+.PP
+.B DETAILED ACTION OPTIONS
+
+.TP
+.BR "\-s, \-\-session NAME"
+Apply to session name.
+.TP
+.BR "\-n, \-\-name NAME"
+Name of the snapshot's output.
+.TP
+.BR "\-m, \-\-max-size SIZE"
+Maximum size in bytes of the snapshot. The maxium size does not include the
+metadata file. Human readable format is accepted: {+k,+M,+G}. For instance,
+\-\-max-size 5M
+
+The minimum size of a snapshot is computed by multiplying the total amount of
+streams in the session by the largest subbuffer size. This is to ensure
+fairness between channels when extracting data.
+.TP
+.BR "\-C, \-\-ctrl-url URL"
+Set control path URL. (Must use -D also)
+.TP
+.BR "\-D, \-\-data-url URL"
+Set data path URL. (Must use -C also)
+.RE
+.PP
+
+.PP
+\fBstart\fP [NAME] [OPTIONS]
+.RS
Start tracing
It will start tracing for all tracers for a specific tracing session.
-
If NAME is omitted, the session name is taken from the .lttngrc file.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.RE
+.PP
-.IP "\fBstop\fP [NAME] [OPTIONS]"
-.nf
+.PP
+\fBstop\fP [NAME] [OPTIONS]
+.RS
Stop tracing
It will stop tracing for all tracers for a specific tracing session. Before
behavior.
If NAME is omitted, the session name is taken from the .lttngrc file.
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-\-\-no-wait
- Don't wait for data availability.
-.fi
-
-.IP
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-\-no-wait"
+Don't wait for data availability.
+.RE
+.PP
-.IP "\fBversion\fP"
-.nf
+.PP
+\fBversion\fP
+.RS
Show version information
-.fi
.B OPTIONS:
-.nf
-\-h, \-\-help
- Show summary of possible options and commands.
-\-\-list-options
- Simple listing of options
-.fi
+.TP
+.BR "\-h, \-\-help"
+Show summary of possible options and commands.
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.RE
+.PP
-.IP
+.PP
+\fBview\fP [SESSION_NAME] [OPTIONS]
+.RS
+View traces of a tracing session. By default, the babeltrace viewer
+will be used for text viewing. If SESSION_NAME is omitted, the session
+name is taken from the .lttngrc file.
-.IP "\fBview\fP [SESSION_NAME] [OPTIONS]"
-.nf
-View traces of a tracing session
+.B OPTIONS:
+
+.TP
+.BR "\-h, \-\-help"
+Show this help
+.TP
+.BR "\-\-list-options"
+Simple listing of options
+.TP
+.BR "\-t, \-\-trace-path PATH"
+Trace directory path for the viewer
+.TP
+.BR "\-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 directory path of the session will be appended at the end to the
+arguments
+.RE
+.PP
-By default, the babeltrace viewer will be used for text viewing.
+.SH "JUL DOMAIN"
+This section explains the JUL domain (\-j, \-\-jul) where JUL stands for Java
+Util Logging. You can use that feature by using the \fBliblttng-ust-jul.so\fP
+from the lttng-ust(3) project.
-If SESSION_NAME is omitted, the session name is taken from the .lttngrc file.
+The LTTng Java Agent uses JNI to link the UST tracer to the Java application
+that uses the agent. Thus, it behaves similarly to the UST domain (\-u). When
+enabling events with the JUL domain, you enable a Logger name that will then be
+mapped to a default UST tracepoint called \fBlttng_jul:jul_event\fP in the
+\fBlttng_jul_channel\fP. Using the lttng-ctl API, any JUL events must use the
+tracepoint event type (same as \-\-tracepoint).
-.fi
+Because of the default immutable channel (\fBlttng_jul_channel\fP), the
+\fBenable-channel\fP command CAN NOT be used with the JUL domain thus not
+having any \-j option.
-.B OPTIONS:
+For JUL event, loglevels are supported with the JUL ABI values. Use \fBlttng
+enable-event \-h\fP to list them. Wildcards are NOT supported except the "*"
+meaning all events (same as \-a).
+
+Exactly like the UST domain, if the Java application has the same UID as you,
+you can trace it. Same goes for the tracing group accessing root applications.
+
+Finally, you can list every Logger name that are available from JUL registered
+applications to the session daemon by using \fBlttng list \-j\fP.
+
+Here is an example on how to use this domain.
.nf
-\-h, \-\-help
- Show this help
-\-\-list-options
- Simple listing of options
-\-t, \-\-trace-path PATH
- Trace directory path for the viewer
-\-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
- directory path of the session will be appended at the end
- to the arguments
+$ lttng list -j
+[...]
+$ lttng create aSession
+$ lttng enable-event -s aSession -j MyCustomLoggerName
+$ lttng start
.fi
+More information can be found in the lttng-ust documentation, see
+java-util-logging.txt
+.PP
+
.SH "EXIT VALUES"
+.PP
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>
+.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
.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.
+.PP
+
+.PP
+.IP "LTTNG_SESSION_CONFIG_XSD_PATH"
+Set the path in which the \fBsession.xsd\fP session configuration schema may be
+found.
+.PP
+
.SH "SEE ALSO"
.BR babeltrace(1),
.BR lttng-ust(3),
.BR lttng-sessiond(8),
.BR lttng-relayd(8),
-.BR lttng-health-check(3)
+
.SH "BUGS"
+.PP
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 or
at https://bugs.lttng.org which is a bugtracker.
+.PP
+
.SH "CREDITS"
.PP
projects / lttng-tools.git / blobdiff