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 https://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
  41 +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+.
  42
  43 Once a trace has been streamed completely, the trace can be processed by
  44 any tool that can process an LTTng trace located on the local
  45 file system.
  46
  47
  48 [[output-directory]]
  49 Output directory
  50 ~~~~~~~~~~~~~~~~
  51 By default (option:--group-output-by-host), the relay daemon writes the traces
  52 to:
  53
  54 [verse]
  55 $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN'
  56
  57 with:
  58
  59 'HOSTNAME'::
  60     Remote hostname.
  61
  62 'SESSION'::
  63     Full session name.
  64
  65 'DOMAIN'::
  66     Tracing domain.
  67
  68 You can group the output per session instead of per hostname with the
  69 option:--group-output-by-session option. This result in the following:
  70
  71 [verse]
  72
  73 $LTTNG_HOME/lttng-traces/'SESSION'/'HOST'/'DOMAIN'
  74
  75 You can override the default output directory prefix
  76 (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other
  77 parts depend on the remote configuration.
  78
  79
  80
  81 [[url-format]]
  82 URL format
  83 ~~~~~~~~~~
  84 The option:--control-port, option:--data-port, and option:--live-port
  85 options specify URLs.
  86
  87 The format of those URLs is:
  88
  89 [verse]
  90 tcp://('HOST' | 'IPADDR'):__PORT__
  91
  92 with:
  93
  94 ('HOST' | 'IPADDR')::
  95     Binding hostname or IP address (IPv6 address *must* be enclosed in
  96     brackets (`[` and `]`); see
  97     https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]).
  98
  99 'PORT'::
 100     TCP port.
 101
 102
 103 OPTIONS
 104 -------
 105 Daemon
 106 ~~~~~~
 107 option:-b, option:--background::
 108     Start as Unix daemon, but keep file descriptors (console) open.
 109     Use the option:--daemonize option instead to close the file
 110     descriptors.
 111
 112 option:-d, option:--daemonize::
 113     Start as Unix daemon, and close file descriptors (console). Use the
 114     option:--background option instead to keep the file descriptors
 115     open.
 116
 117 option:-g 'GROUP', option:--group='GROUP'::
 118     Use 'GROUP' as Unix tracing group (default: `tracing`).
 119
 120 option:-o 'PATH', option:--output='PATH'::
 121     Set base directory of written trace data to 'PATH'.
 122 +
 123 See the <<output-directory,Output directory>> section above for more
 124 information.
 125
 126 option:-p, option:--group-output-by-host::
 127     Organize the output directory by host. Default behavior.
 128 +
 129 See the <<output-directory,Output directory>> section above for more
 130 information.
 131
 132 option:-s, option:--group-output-by-session::
 133     Organize the output directory by session.
 134 +
 135 See the <<output-directory,Output directory>> section above for more
 136 information.
 137
 138 option:-v, option:--verbose::
 139     Increase verbosity.
 140 +
 141 Three levels of verbosity are available, which are triggered by
 142 appending additional `v` letters to the option
 143 (that is, `-vv` and `-vvv`).
 144
 145
 146 Ports
 147 ~~~~~
 148 See the <<url-format,URL format>> section above for more information
 149 about the syntax of the following options' 'URL' argument.
 150
 151 option:-C 'URL', option:--control-port='URL'::
 152     Listen to control data on URL 'URL' (default:
 153     +tcp://{default_network_control_bind_address}:{default_network_control_port}+).
 154
 155 option:-D 'URL', option:--data-port='URL'::
 156     Listen to trace data on URL 'URL' (default:
 157     +tcp://{default_network_data_bind_address}:{default_network_data_port}+).
 158
 159 option:-L 'URL', option:--live-port='URL'::
 160     Listen to LTTng live connections on URL 'URL'
 161     (default:
 162     +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+).
 163
 164
 165 Program information
 166 ~~~~~~~~~~~~~~~~~~~
 167 option:-h, option:--help::
 168     Show help.
 169
 170 option:-V, option:--version::
 171     Show version.
 172
 173
 174 ENVIRONMENT VARIABLES
 175 ---------------------
 176 `LTTNG_ABORT_ON_ERROR`::
 177     Set to 1 to abort the process after the first error is encountered.
 178
 179 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
 180     Socket connection, receive and send timeout (milliseconds). A value
 181     of 0 or -1 uses the timeout of the operating system (default).
 182
 183 `LTTNG_RELAYD_HEALTH`::
 184     Path to relay daemon health's socket.
 185
 186 `LTTNG_RELAYD_TCP_KEEP_ALIVE`::
 187     Set to 1 to enable TCP keep-alive.
 188 +
 189 The TCP keep-alive mechanism allows the detection of dead peers
 190 (man:lttng-sessiond(8)) in cases of unclean termination
 191 (for example, a hard reset) of a peer.
 192 +
 193 Supported on Linux and Solaris only. The default behaviour of the TCP
 194 keep-alive mechanism is OS-specific.
 195 +
 196 Search for `tcp_keepalive` in man:tcp(7) for more information.
 197
 198 `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`::
 199    The time threshold in seconds to abort a TCP connection after the keep-alive
 200    probing mechanism has failed.
 201 +
 202 Set to 0 or -1 to use the value chosen by the operating system (default).
 203 +
 204 Supported on Solaris 11 only.
 205 +
 206 Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information.
 207
 208 `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`::
 209     Number of seconds a connection needs to be idle before TCP begins
 210     sending out keep-alive probes.
 211 +
 212 Set to 0 or -1 to use the value chosen by the operating system (default).
 213 +
 214 Supported on Linux and Solaris 11 only.
 215 +
 216 On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000.
 217 +
 218 Search for `tcp_keepalive_time` and `tcp_keepalive_interval`
 219 in man:tcp(7) on Solaris 11 for more information.
 220
 221 `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`::
 222     Maximum number of TCP keep-alive probes to send before giving up and
 223     killing the connection if no response is obtained from the other end.
 224 +
 225 Set to 0 or -1 to use the value chosen by the operating system (default).
 226 +
 227 Supported on Linux only.
 228 +
 229 Search for `tcp_keepalive_probes` in man:tcp(7) for more information.
 230
 231 `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`::
 232     Number of seconds between TCP keep-alive probes.
 233 +
 234 Set to 0 or -1 to use the value chosen by the operating system (default).
 235 +
 236 Supported on Linux only.
 237 +
 238 Search for `tcp_keepalive_intvl` in man:tcp(7) for more information.
 239
 240
 241 FILES
 242 -----
 243 `$LTTNG_HOME/.lttng`::
 244     User LTTng runtime and configuration directory.
 245
 246 `$LTTNG_HOME/lttng-traces`::
 247     Default output directory of LTTng traces. This can be overridden
 248     with the option:--output option.
 249
 250 NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set.
 251
 252
 253 EXIT STATUS
 254 -----------
 255 *0*::
 256     Success
 257
 258 *1*::
 259     Error
 260
 261 *3*::
 262     Fatal error
 263
 264
 265 LIMITATIONS
 266 -----------
 267 As of this version, only the TCP protocol is supported for both control
 268 and data ports. In future versions, TCP will remain the sole available
 269 protocol for control data since those communications are low-volume and
 270 need absolute reliability; trace data could be carried over UDP.
 271
 272 For an unprivileged user running `lttng-relayd`, the maximum number of
 273 file descriptors per process is usually 1024. This limits the number of
 274 connections and opened trace files. This limit can be configured with
 275 *ulimit*(3).
 276
 277
 278 include::common-footer.txt[]
 279
 280
 281 SEE ALSO
 282 --------
 283 man:lttng(1),
 284 man:lttng-sessiond(8),
 285 man:lttng-crash(1),
 286 man:lttng-ust(3),
 287 man:babeltrace(1)