1LTTNG-REGENERATE(1)              LTTng Manual              LTTNG-REGENERATE(1)
2
3
4

NAME

6       lttng-regenerate - Manage an LTTng tracing session's data regeneration
7

SYNOPSIS

9       Regenerate the metadata of a session:
10
11       lttng [GENERAL OPTIONS] regenerate metadata [--session=SESSION]
12
13       Regenerate the state dump of a session:
14
15       lttng [GENERAL OPTIONS] regenerate statedump [--session=SESSION]
16

DESCRIPTION

18       The lttng regenerate command regenerates specific data of a tracing
19       session.
20
21       As of this version, the metadata and statedump actions are available.
22
23   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
27       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
35   Regenerating a tracing session’s state dump
36       The lttng regenerate statedump action can be used to collect up-to-date
37       state dump information during the tracing session. This is particularly
38       useful in snapshot (see lttng-snapshot(1)) or trace file rotation (see
39       lttng-enable-channel(1)) modes where the state dump information may be
40       lost.
41

OPTIONS

43       General options are described in lttng(1).
44
45       -s SESSION, --session=SESSION
46           Regenerate the data of the tracing session named SESSION instead of
47           the current tracing session.
48
49   Program information
50       -h, --help
51           Show command help.
52
53           This option, like lttng-help(1), attempts to launch /usr/bin/man to
54           view the command’s man page. The path to the man pager can be
55           overridden by the LTTNG_MAN_BIN_PATH environment variable.
56
57       --list-options
58           List available command options.
59

LIMITATIONS

61       The lttng regenerate metadata command can only be used on kernel and
62       user space tracing sessions (using per-user buffering), in non-live
63       mode.
64
65       See lttng-enable-channel(1) for more information about buffering
66       schemes and lttng-create(1) for more information about the different
67       tracing session modes.
68

ENVIRONMENT VARIABLES

70       LTTNG_ABORT_ON_ERROR
71           Set to 1 to abort the process after the first error is encountered.
72
73       LTTNG_HOME
74           Overrides the $HOME environment variable. Useful when the user
75           running the commands has a non-writable home directory.
76
77       LTTNG_MAN_BIN_PATH
78           Absolute path to the man pager to use for viewing help information
79           about LTTng commands (using lttng-help(1) or lttng COMMAND --help).
80
81       LTTNG_SESSION_CONFIG_XSD_PATH
82           Path in which the session.xsd session configuration XML schema may
83           be found.
84
85       LTTNG_SESSIOND_PATH
86           Full session daemon binary path.
87
88           The --sessiond-path option has precedence over this environment
89           variable.
90
91       Note that the lttng-create(1) command can spawn an LTTng session daemon
92       automatically if none is running. See lttng-sessiond(8) for the
93       environment variables influencing the execution of the session daemon.
94

FILES

96       $LTTNG_HOME/.lttngrc
97           User LTTng runtime configuration.
98
99           This is where the per-user current tracing session is stored
100           between executions of lttng(1). The current tracing session can be
101           set with lttng-set-session(1). See lttng-create(1) for more
102           information about tracing sessions.
103
104       $LTTNG_HOME/lttng-traces
105           Default output directory of LTTng traces. This can be overridden
106           with the --output option of the lttng-create(1) command.
107
108       $LTTNG_HOME/.lttng
109           User LTTng runtime and configuration directory.
110
111       $LTTNG_HOME/.lttng/sessions
112           Default location of saved user tracing sessions (see lttng-save(1)
113           and lttng-load(1)).
114
115       /usr/local/etc/lttng/sessions
116           System-wide location of saved tracing sessions (see lttng-save(1)
117           and lttng-load(1)).
118
119           Note
120           $LTTNG_HOME defaults to $HOME when not explicitly set.
121

EXIT STATUS

123       0
124           Success
125
126       1
127           Command error
128
129       2
130           Undefined command
131
132       3
133           Fatal error
134
135       4
136           Command warning (something went wrong during the command)
137

BUGS

139       If you encounter any issue or usability problem, please report it on
140       the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>.
141

RESOURCES

143       ·   LTTng project website <http://lttng.org>
144
145       ·   LTTng documentation <http://lttng.org/docs>
146
147       ·   Git repositories <http://git.lttng.org>
148
149       ·   GitHub organization <http://github.com/lttng>
150
151       ·   Continuous integration <http://ci.lttng.org/>
152
153       ·   Mailing list <http://lists.lttng.org> for support and development:
154           lttng-dev@lists.lttng.org
155
156       ·   IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
157

COPYRIGHTS

159       This program is part of the LTTng-tools project.
160
161       LTTng-tools is distributed under the GNU General Public License version
162       2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>. See the
163       LICENSE <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file
164       for details.
165

THANKS

167       Special thanks to Michel Dagenais and the DORSAL laboratory
168       <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for
169       the LTTng journey.
170
171       Also thanks to the Ericsson teams working on tracing which helped us
172       greatly with detailed bug reports and unusual test cases.
173

AUTHORS

175       LTTng-tools was originally written by Mathieu Desnoyers, Julien
176       Desfossez, and David Goulet. More people have since contributed to it.
177
178       LTTng-tools is currently maintained by Jérémie Galarneau
179       <mailto:jeremie.galarneau@efficios.com>.
180

SEE ALSO

182       lttng(1)
183
184
185
186LTTng 2.10.7                      05/24/2019               LTTNG-REGENERATE(1)
Impressum