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eded6438 | 1 | lttng-regenerate(1) |
4605890e | 2 | =================== |
d098bfda | 3 | :revdate: 17 May 2021 |
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4 | |
5 | ||
6 | NAME | |
7 | ---- | |
26f0c779 | 8 | lttng-regenerate - Regenerate specific data of an LTTng tracing session |
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9 | |
10 | ||
11 | SYNOPSIS | |
12 | -------- | |
26f0c779 | 13 | Regenerate 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 | 18 | Regenerate 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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24 | DESCRIPTION |
25 | ----------- | |
26f0c779 | 26 | The `lttng regenerate` command regenerates specific data of: |
dbcf3dd3 | 27 | |
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28 | With the option:--session='SESSION' option:: |
29 | The tracing session named 'SESSION'. | |
dbcf3dd3 | 30 | |
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31 | Without the option:--session option:: |
32 | The current tracing session (see man:lttng-concepts(7) to learn more | |
33 | about the current tracing session). | |
dbcf3dd3 | 34 | |
26f0c779 | 35 | See man:lttng-concepts(7) to learn more about tracing sessions. |
eded6438 | 36 | |
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37 | As of this version, the `metadata` and `statedump` targets are |
38 | available. | |
980bb5fd | 39 | |
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40 | See the <<examples,EXAMPLES>> section below for usage examples. |
41 | ||
eded6438 | 42 | |
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43 | Regenerate the metadata of a tracing session |
44 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
45 | Use the `metadata` target to resample the offset between the monotonic | |
46 | clock and the wall time of the system, and then regenerate the metadata | |
47 | stream files. | |
48 | ||
49 | More specifically, you may want to resample the wall time | |
50 | following a major | |
51 | link:https://en.wikipedia.org/wiki/Network_Time_Protocol[NTP] | |
52 | correction. As such, LTTng can trace a system booting with an incorrect | |
53 | wall time before its wall time is NTP-corrected. Regenerating the | |
54 | metadata of the selected tracing session ensures that trace readers can | |
55 | accurately determine the event record timestamps relative to the | |
56 | Unix epoch. | |
57 | ||
58 | Note that if you plan to rotate (see man:lttng-concepts(7) to learn | |
59 | more) the selected tracing session, this target only regenerates the | |
60 | metadata stream files of the current and next trace chunks. | |
61 | ||
62 | [IMPORTANT] | |
63 | ==== | |
64 | You can only use the `metadata` target when the selected | |
65 | tracing 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 | + | |
74 | See man:lttng-concepts(7) to learn more about channels. | |
75 | ==== | |
76 | ||
77 | ||
78 | Regenerate the state dump event records of a tracing session | |
79 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
80 | Use the `statedump` target to collect up-to-date state dump information | |
81 | and create corresponding event records. | |
82 | ||
83 | This is particularly useful if the selected tracing session is in | |
84 | snapshot mode (nloption:--snapshot option of the man:lttng-create(1) | |
85 | command) or if LTTng rotates trace files for one of its channels (see | |
86 | man:lttng-concepts(7)): in both cases, the state dump information may be | |
dbcf3dd3 | 87 | lost. |
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88 | |
89 | ||
f5511eea | 90 | include::common-lttng-cmd-options-head.txt[] |
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91 | |
92 | ||
59b19c3c | 93 | option:-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 | 98 | include::common-lttng-cmd-help-options.txt[] |
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99 | |
100 | ||
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101 | include::common-lttng-cmd-after-options.txt[] |
102 | ||
103 | ||
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104 | [[examples]] |
105 | EXAMPLES | |
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 | ==== | |
117 | See the option:--session option. | |
118 | ||
119 | [role="term"] | |
120 | ---- | |
121 | $ lttng regenerate statedump --session=my-session | |
122 | ---- | |
123 | ==== | |
124 | ||
125 | ||
f5511eea | 126 | include::common-footer.txt[] |
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127 | |
128 | ||
129 | SEE ALSO | |
130 | -------- | |
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131 | man:lttng(1), |
132 | man:lttng-concepts(7) |