1LTTNG-REGENERATE(1) LTTng Manual LTTNG-REGENERATE(1)
2
6 lttng-regenerate - Manage an LTTng tracing session's data regeneration
7
9 Regenerate the metadata of a session:
10 lttng [GENERAL OPTIONS] regenerate metadata [--session=SESSION]
12 Regenerate the state dump of a session:
14 lttng [GENERAL OPTIONS] regenerate statedump [--session=SESSION]
16
18 The lttng regenerate command regenerates specific data of a tracing
19 session.
20 As of this version, the metadata and statedump actions are available.
22 Regenerating a tracing session’s metadata
24 The lttng regenerate metadata action can be used to resample the offset
25 between the system’s monotonic clock and the wall-clock time.
26 This action is meant to be used to resample the wall-clock time
28 following a major NTP
29 <https://en.wikipedia.org/wiki/Network_Time_Protocol> correction. As
30 such, a system booting with an incorrect wall time can be traced before
31 its wall time is NTP-corrected. Regenerating the tracing session’s
32 metadata ensures that trace viewers can accurately determine the events
33 time relative to Unix Epoch.
34 If you use lttng-rotate(1) or lttng-enable-rotation(1) to make tracing
36 session rotations, this action regenerates the current and next trace
37 chunks’s metadata files.
38 Regenerating a tracing session’s state dump
40 The lttng regenerate statedump action can be used to collect up-to-date
41 state dump information during the tracing session. This is particularly
42 useful in snapshot (see lttng-snapshot(1)) or trace file rotation (see
43 lttng-enable-channel(1)) modes where the state dump information may be
44 lost.
45
47 General options are described in lttng(1).
48 -s SESSION, --session=SESSION
50 Regenerate the data of the tracing session named SESSION instead of
51 the current tracing session.
52 Program information
54 -h, --help
55 Show command help.
56 This option, like lttng-help(1), attempts to launch /usr/bin/man to
58 view the command’s man page. The path to the man pager can be
59 overridden by the LTTNG_MAN_BIN_PATH environment variable.
60 --list-options
62 List available command options.
63
65 The lttng regenerate metadata command can only be used on kernel and
66 user space tracing sessions (using per-user buffering), in non-live
67 mode.
68 See lttng-enable-channel(1) for more information about buffering
70 schemes and lttng-create(1) for more information about the different
71 tracing session modes.
72
74 LTTNG_ABORT_ON_ERROR
75 Set to 1 to abort the process after the first error is encountered.
76 LTTNG_HOME
78 Overrides the $HOME environment variable. Useful when the user
79 running the commands has a non-writable home directory.
80 LTTNG_MAN_BIN_PATH
82 Absolute path to the man pager to use for viewing help information
83 about LTTng commands (using lttng-help(1) or lttng COMMAND --help).
84 LTTNG_SESSION_CONFIG_XSD_PATH
86 Path in which the session.xsd session configuration XML schema may
87 be found.
88 LTTNG_SESSIOND_PATH
90 Full session daemon binary path.
91 The --sessiond-path option has precedence over this environment
93 variable.
94 Note that the lttng-create(1) command can spawn an LTTng session daemon
96 automatically if none is running. See lttng-sessiond(8) for the
97 environment variables influencing the execution of the session daemon.
98
100 $LTTNG_HOME/.lttngrc
101 User LTTng runtime configuration.
102 This is where the per-user current tracing session is stored
104 between executions of lttng(1). The current tracing session can be
105 set with lttng-set-session(1). See lttng-create(1) for more
106 information about tracing sessions.
107 $LTTNG_HOME/lttng-traces
109 Default output directory of LTTng traces. This can be overridden
110 with the --output option of the lttng-create(1) command.
111 $LTTNG_HOME/.lttng
113 User LTTng runtime and configuration directory.
114 $LTTNG_HOME/.lttng/sessions
116 Default location of saved user tracing sessions (see lttng-save(1)
117 and lttng-load(1)).
118 /usr/local/etc/lttng/sessions
120 System-wide location of saved tracing sessions (see lttng-save(1)
121 and lttng-load(1)).
122 Note
124 $LTTNG_HOME defaults to $HOME when not explicitly set.
125
127 0
128 Success
129 1
131 Command error
132 2
134 Undefined command
135 3
137 Fatal error
138 4
140 Command warning (something went wrong during the command)
141
143 If you encounter any issue or usability problem, please report it on
144 the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>.
145
147 · LTTng project website <https://lttng.org>
148 · LTTng documentation <https://lttng.org/docs>
150 · Git repositories <http://git.lttng.org>
152 · GitHub organization <http://github.com/lttng>
154 · Continuous integration <http://ci.lttng.org/>
156 · Mailing list <http://lists.lttng.org> for support and development:
158 lttng-dev@lists.lttng.org
159 · IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
161
163 This program is part of the LTTng-tools project.
164 LTTng-tools is distributed under the GNU General Public License version
166 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>. See the
167 LICENSE <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file
168 for details.
169
171 Special thanks to Michel Dagenais and the DORSAL laboratory
172 <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for
173 the LTTng journey.
174 Also thanks to the Ericsson teams working on tracing which helped us
176 greatly with detailed bug reports and unusual test cases.
177
179 lttng(1)
180LTTng 2.12.2 18 January 2018 LTTNG-REGENERATE(1)