Fix: build: libcommon fd-tracker dependency is not available
[lttng-tools.git] / doc / man / lttng-regenerate.1.txt
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eded6438 1lttng-regenerate(1)
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4
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6NAME
7----
26f0c779 8lttng-regenerate - Regenerate specific data of an LTTng tracing session
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9
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11SYNOPSIS
12--------
26f0c779 13Regenerate the metadata of a tracing session:
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14
15[verse]
16*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *regenerate metadata* [option:--session='SESSION']
17
26f0c779 18Regenerate the state dump event records of a tracing session:
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19
20[verse]
21*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *regenerate statedump* [option:--session='SESSION']
22
26f0c779 23
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24DESCRIPTION
25-----------
26f0c779 26The `lttng regenerate` command regenerates specific data of:
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28With the option:--session='SESSION' option::
29 The tracing session named 'SESSION'.
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31Without the option:--session option::
32 The current tracing session (see man:lttng-concepts(7) to learn more
33 about the current tracing session).
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26f0c779 35See man:lttng-concepts(7) to learn more about tracing sessions.
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37As of this version, the `metadata` and `statedump` targets are
38available.
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40See the <<examples,EXAMPLES>> section below for usage examples.
41
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43Regenerate the metadata of a tracing session
44~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
45Use the `metadata` target to resample the offset between the monotonic
46clock and the wall time of the system, and then regenerate the metadata
47stream files.
48
49More specifically, you may want to resample the wall time
50following a major
51link:https://en.wikipedia.org/wiki/Network_Time_Protocol[NTP]
52correction. As such, LTTng can trace a system booting with an incorrect
53wall time before its wall time is NTP-corrected. Regenerating the
54metadata of the selected tracing session ensures that trace readers can
55accurately determine the event record timestamps relative to the
56Unix epoch.
57
58Note that if you plan to rotate (see man:lttng-concepts(7) to learn
59more) the selected tracing session, this target only regenerates the
60metadata stream files of the current and next trace chunks.
61
62[IMPORTANT]
63====
64You can only use the `metadata` target when the selected
65tracing session:
66
67* Is not in live mode (nloption:--live option of
68 man:lttng-create(1)).
69
70* If it has user space channels, they're configured to use a
71 per-user buffering scheme (nloption:--buffers-uid option of
72 man:lttng-enable-channel(1)).
73+
74See man:lttng-concepts(7) to learn more about channels.
75====
76
77
78Regenerate the state dump event records of a tracing session
79~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
80Use the `statedump` target to collect up-to-date state dump information
81and create corresponding event records.
82
83This is particularly useful if the selected tracing session is in
84snapshot mode (nloption:--snapshot option of the man:lttng-create(1)
85command) or if LTTng rotates trace files for one of its channels (see
86man:lttng-concepts(7)): in both cases, the state dump information may be
dbcf3dd3 87lost.
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f5511eea 90include::common-lttng-cmd-options-head.txt[]
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59b19c3c 93option:-s 'SESSION', option:--session='SESSION'::
26f0c779 94 Regenerate specific data of the tracing session named 'SESSION'
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95 instead of the current tracing session.
96
97
f5511eea 98include::common-lttng-cmd-help-options.txt[]
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100
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101include::common-lttng-cmd-after-options.txt[]
102
103
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104[[examples]]
105EXAMPLES
106--------
107.Regenerate the metadata of the current tracing session.
108====
109[role="term"]
110----
111$ lttng regenerate metadata
112----
113====
114
115.Regenerate the state dump event records of a specific tracing session.
116====
117See the option:--session option.
118
119[role="term"]
120----
121$ lttng regenerate statedump --session=my-session
122----
123====
124
125
f5511eea 126include::common-footer.txt[]
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127
128
129SEE ALSO
130--------
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131man:lttng(1),
132man:lttng-concepts(7)
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