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2e4886b8 PP |
1 | lttng-add-context(1) |
2 | ==================== | |
3 | ||
4 | ||
5 | NAME | |
6 | ---- | |
7 | lttng-add-context - Add context fields to an LTTng channel | |
8 | ||
9 | ||
10 | SYNOPSIS | |
11 | -------- | |
12 | Add context fields to a channel: | |
13 | ||
14 | [verse] | |
ce19b9ed | 15 | *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-context* |
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16 | (option:--kernel | option:--userspace | option:--jul | option:--log4j) |
17 | [option:--session='SESSION'] [option:--channel='CHANNEL'] | |
18 | option:--type='TYPE' [option:--type='TYPE']... | |
19 | ||
20 | List the available context fields: | |
21 | ||
22 | [verse] | |
d1cff337 | 23 | *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-context* option:--list |
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24 | |
25 | ||
26 | DESCRIPTION | |
27 | ----------- | |
28 | The `lttng add-context` command adds one or more context fields to a | |
29 | channel. | |
30 | ||
31 | Channels are created with the linklttng:lttng-enable-channel(1) command. | |
32 | ||
33 | When context fields are added to a channel, all the events emitted | |
34 | within this channel contain the dynamic values of those context fields. | |
35 | ||
36 | If the option:--session option is omitted, the current tracing session | |
37 | is used. If the option:--channel option is omitted, the context fields | |
38 | are added to all the selected tracing session's channels. | |
39 | ||
40 | Many context fields can be added to a channel at once by repeating the | |
41 | option:--type option. | |
42 | ||
43 | perf counters are available as per-CPU (`perf:cpu:` prefix) as well as | |
44 | per-thread (`perf:thread:` prefix) counters. Currently, per-CPU counters | |
45 | can only be used in the Linux kernel tracing domain, while per-thread | |
46 | counters can only be used in the user space tracing domain. | |
47 | ||
48 | Application-specific context fields can be added to a channel using the | |
49 | following syntax: | |
50 | ||
51 | [verse] | |
52 | $app.'PROVIDER':__TYPE__ | |
53 | ||
54 | with: | |
55 | ||
56 | 'PROVIDER':: | |
57 | Provider name. | |
58 | ||
59 | 'TYPE':: | |
60 | Context type name. | |
61 | ||
60f7980c PP |
62 | NOTE: Make sure to **single-quote** the type when running the command |
63 | from a shell, as `$` is a special character for variable substitution in | |
64 | most shells. | |
65 | ||
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66 | Use the option:--list option without other arguments to list the |
67 | available context field names. | |
68 | ||
69 | ||
70 | include::common-cmd-options-head.txt[] | |
71 | ||
72 | ||
73 | Domain | |
74 | ~~~~~~ | |
75 | One of: | |
76 | ||
77 | option:-j, option:--jul:: | |
78 | Add context to channel in the `java.util.logging` (JUL) domain. | |
79 | ||
80 | option:-k, option:--kernel:: | |
81 | Add context to channel in the Linux kernel domain. | |
82 | ||
83 | option:-l, option:--log4j:: | |
84 | Add context to channel in the Apache log4j domain. | |
85 | ||
86 | option:-u, option:--userspace:: | |
87 | Add context to channel in the user space domain. | |
88 | ||
89 | ||
90 | Target | |
91 | ~~~~~~ | |
92 | option:-c, option:--channel='CHANNEL':: | |
93 | Add context fields to a channel named 'CHANNEL' instead of adding | |
94 | them to all the channels. | |
95 | ||
96 | option:-s, option:--session='SESSION':: | |
97 | Add context fields to a channel in the tracing session named 'SESSION' | |
98 | instead of the current tracing session. | |
99 | ||
100 | ||
101 | Context | |
102 | ~~~~~~~ | |
103 | option:--list:: | |
104 | List the available context fields. Use this option alone. | |
105 | ||
106 | option:-t, option:--type='TYPE':: | |
107 | Add context field named 'TYPE'. This option can be repeated as | |
108 | many times as needed on the command-line. | |
109 | ||
110 | ||
111 | include::common-cmd-help-options.txt[] | |
112 | ||
113 | ||
114 | include::common-cmd-footer.txt[] | |
115 | ||
116 | ||
117 | SEE ALSO | |
118 | -------- | |
119 | linklttng:lttng(1) |