doc/man/lttng-add-context.1.txt

   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]
  15 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-context*
  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]
  23 *lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *add-context* option:--list
  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 man: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 $app.'PROVIDER':__TYPE__
  53
  54 with:
  55
  56 'PROVIDER'::
  57     Provider name.
  58
  59 'TYPE'::
  60     Context type name.
  61
  62 NOTE: Make sure to **single-quote** the type when running the command
  63 from a shell, as `$` is a special character for variable substitution in
  64 most shells.
  65
  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 man:lttng(1)