doc/man/lttng-relayd.8.txt

   1 lttng-relayd(8)
   2 ===============
   3
   4
   5 NAME
   6 ----
   7 lttng-relayd - LTTng 2 relay daemon
   8
   9
  10 SYNOPSIS
  11 --------
  12 [verse]
  13 *lttng-relayd* [option:--background | option:--daemonize]
  14              [option:--control-port='URL'] [option:--data-port='URL'] [option:--live-port='URL']
  15              [option:--output='PATH'] [option:-v | option:-vv | option:-vvv]
  16
  17
  18 DESCRIPTION
  19 -----------
  20 The http://lttng.org/[_Linux Trace Toolkit: next generation_] is an open
  21 source software package used for correlated tracing of the Linux kernel,
  22 user applications, and user libraries.
  23
  24 LTTng consists of Linux kernel modules (for Linux kernel tracing) and
  25 dynamically loaded libraries (for user application and library tracing).
  26
  27 The _LTTng relay daemon_ is responsible for receiving trace data from
  28 possibly remote LTTng session/consumer daemons and for writing it to
  29 the local file system. The relay daemon also accepts _LTTng live_
  30 connections from compatible viewers; this is the official approach to
  31 viewing LTTng events as they are emitted.
  32
  33 The relay daemon listens by default on all network interfaces to gather
  34 trace data, but only on localhost for LTTng live connections.
  35
  36 The relay daemon does not require any particular permissions, as long as
  37 it can write to the output directory and listen on the configured ports.
  38 If a user is within a secured network and/or has proper firewall
  39 settings, `lttng-relayd` can listen to LTTng live connections from _all_
  40 network interfaces by specifying `--live-port=tcp://0.0.0.0:5344`.
  41
  42 Once a trace has been streamed completely, the trace can be processed by
  43 any tool that can process an LTTng trace located on the local
  44 file system.
  45
  46
  47 [[output-directory]]
  48 Output directory
  49 ~~~~~~~~~~~~~~~~
  50 By default, the relay daemon writes the traces to:
  51
  52 [verse]
  53 $HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN'
  54
  55 with:
  56
  57 'HOSTNAME'::
  58     Remote hostname.
  59
  60 'SESSION'::
  61     Full session name.
  62
  63 'DOMAIN'::
  64     Tracing domain.
  65
  66 You can override the default output directory prefix
  67 (`$HOME/lttng-traces`) with the option:--output option. The other
  68 parts depend on the remote configuration.
  69
  70
  71 [[url-format]]
  72 URL format
  73 ~~~~~~~~~~
  74 The option:--control-port, option:--data-port, and option:--live-port
  75 options specify URLs.
  76
  77 The format of those URLs is:
  78
  79 [verse]
  80 tcp://('HOST' | 'IPADDR'):__PORT__
  81
  82 with:
  83
  84 ('HOST' | 'IPADDR')::
  85     Binding hostname or IP address (IPv6 address *must* be enclosed in
  86     brackets (`[` and `]`); see
  87     https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]).
  88
  89 'PORT'::
  90     TCP port.
  91
  92
  93 OPTIONS
  94 -------
  95 Daemon
  96 ~~~~~~
  97 option:-b, option:--background::
  98     Start as Unix daemon, but keep file descriptors (console) open.
  99     Use the option:--daemonize option instead to close the file
 100     descriptors.
 101
 102 option:-d, option:--daemonize::
 103     Start as Unix daemon, and close file descriptors (console). Use the
 104     option:--background option instead to keep the file descriptors
 105     open.
 106
 107 option:-g, option:--group='GROUP'::
 108     Use 'GROUP' as Unix tracing group (default: `tracing`).
 109
 110 option:-o, option:--output='PATH'::
 111     Set base directory of written trace data to 'PATH'.
 112 +
 113 See the <<output-directory,Output directory>> section above for more
 114 information.
 115
 116 option:-v, option:--verbose::
 117     Increase verbosity.
 118 +
 119 Three levels of verbosity are available, which are triggered by
 120 appending additional `v` letters to the option
 121 (that is, `-vv` and `-vvv`).
 122
 123
 124 Ports
 125 ~~~~~
 126 See the <<url-format,URL format>> section above for more information
 127 about the syntax of the following options' 'URL' argument.
 128
 129 option:-C, option:--control-port='URL'::
 130     Listen to control data on URL 'URL' (default: `tcp://0.0.0.0:5342`).
 131
 132 option:-D, option:--data-port='URL'::
 133     Listen to trace data on URL 'URL' (default: `tcp://0.0.0.0:5343`).
 134
 135 option:-L, option:--live-port='URL'::
 136     Listen to LTTng live connections on URL 'URL'
 137     (default: `tcp://0.0.0.0:5344`).
 138
 139
 140 Program information
 141 ~~~~~~~~~~~~~~~~~~~
 142 option:-h, option:--help::
 143     Show help.
 144
 145 option:-V, option:--version::
 146     Show version.
 147
 148
 149 ENVIRONMENT VARIABLES
 150 ---------------------
 151 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
 152     Socket connection, receive and send timeout (milliseconds). A value
 153     of 0 or -1 uses the timeout of the operating system (default).
 154
 155 `LTTNG_RELAYD_HEALTH`::
 156     Path to relay daemon health's socket.
 157
 158
 159 EXIT STATUS
 160 -----------
 161 *0*::
 162     Success
 163
 164 *1*::
 165     Error
 166
 167 *3*::
 168     Fatal error
 169
 170
 171 LIMITATIONS
 172 -----------
 173 As of this version, only the TCP protocol is supported for both control
 174 and data ports. In future versions, TCP will remain the sole available
 175 protocol for control data since those communications are low-volume and
 176 need absolute reliability; trace data could be carried over UDP.
 177
 178 For an unprivileged user running `lttng-relayd`, the maximum number of
 179 file descriptors per process is usually 1024. This limits the number of
 180 connections and opened trace files. This limit can be configured with
 181 *ulimit*(3).
 182
 183
 184 include::common-footer.txt[]
 185
 186
 187 SEE ALSO
 188 --------
 189 linklttng:lttng(1),
 190 linklttng:lttng-sessiond(8),
 191 linklttng:lttng-crash(1),
 192 linklttng:lttng-ust(3),
 193 linklttng:babeltrace(1)