| 1 | lttng-relayd(8) |
| 2 | =============== |
| 3 | :revdate: 14 June 2021 |
| 4 | :daemon-bin-name: lttng-relayd |
| 5 | :daemon-ini-section: relayd |
| 6 | |
| 7 | |
| 8 | NAME |
| 9 | ---- |
| 10 | lttng-relayd - LTTng relay daemon |
| 11 | |
| 12 | |
| 13 | SYNOPSIS |
| 14 | -------- |
| 15 | [verse] |
| 16 | *lttng-relayd* [option:--background | option:--daemonize] [option:--config='PATH'] |
| 17 | [option:--control-port='URL'] [option:--data-port='URL'] [option:--fd-pool-size='COUNT'] |
| 18 | [option:--live-port='URL'] [option:--output='DIR'] [option:--group='GROUP'] |
| 19 | [option:--verbose]... [option:--working-directory='DIR'] |
| 20 | [option:--group-output-by-host | option:--group-output-by-session] [option:--disallow-clear] |
| 21 | |
| 22 | |
| 23 | DESCRIPTION |
| 24 | ----------- |
| 25 | include::common-intro.txt[] |
| 26 | |
| 27 | An LTTng relay daemon, `lttng-relayd`, is a program which receives trace |
| 28 | data from (possibly remote) LTTng session/consumer daemons and which |
| 29 | writes it to the local file system. The relay daemon also accepts LTTng |
| 30 | live connections from compatible readers (for example, |
| 31 | man:babeltrace2(1)); this is the recommended approach to read trace data |
| 32 | while the remote recording session is active. |
| 33 | |
| 34 | By default, a relay daemon listens on all network interfaces to receive |
| 35 | trace data, but only on `localhost` for LTTng live connections. Override |
| 36 | the listening URLs with the option:--control-port, option:--data-port, |
| 37 | and option:--live-port options (see the ``<<url-format,URL format>>'' |
| 38 | section below). For example, use the |
| 39 | option:--live-port=+tcp://0.0.0.0:{default_network_viewer_port}+ option |
| 40 | to make a relay daemon listen to LTTng live connections on all network |
| 41 | interfaces. |
| 42 | |
| 43 | Once LTTng has completely sent a trace to a relay daemon{nbsp}__RD__, |
| 44 | any LTTng trace reader can read the trace located on the local file |
| 45 | system of{nbsp}__RD__. |
| 46 | |
| 47 | By default, `lttng-relayd` doesn't start as a daemon. Make it a daemon |
| 48 | with the option:--daemonize or option:--background option. With those |
| 49 | options, `lttng-relayd` ensures the daemon is listening to incoming |
| 50 | connections before it exits. |
| 51 | |
| 52 | |
| 53 | include::common-daemon-cfg.txt[] |
| 54 | |
| 55 | INI configuration file example: |
| 56 | |
| 57 | [source,ini] |
| 58 | ---- |
| 59 | [relayd] |
| 60 | daemonize=yes |
| 61 | live-port=tcp://0.0.0.0:4567 |
| 62 | disallow-clear=yes |
| 63 | ---- |
| 64 | |
| 65 | |
| 66 | [[output-directory]] |
| 67 | Output directory |
| 68 | ~~~~~~~~~~~~~~~~ |
| 69 | The relay daemon uses different output path patterns depending on: |
| 70 | |
| 71 | * Its configuration. |
| 72 | + |
| 73 | See the ``<<cfg,Daemon configuration>>'' section above. |
| 74 | |
| 75 | * The recording session configuration of the connected peer. |
| 76 | * The LTTng session daemon (see man:lttng-sessiond(8)) version |
| 77 | of the connected peer. |
| 78 | |
| 79 | Consider the following variables: |
| 80 | |
| 81 | 'BASE':: |
| 82 | Base output directory: `$LTTNG_HOME/lttng-traces` (`$LTTNG_HOME` |
| 83 | defaults to `$HOME`) or the argument of the option:--output option. |
| 84 | |
| 85 | 'HOSTNAME':: |
| 86 | Hostname of the connected peer. |
| 87 | |
| 88 | 'SESSION':: |
| 89 | Recording session name. |
| 90 | |
| 91 | 'DATETIME':: |
| 92 | Unique recording session date/time. |
| 93 | |
| 94 | 'TRACEDIR':: |
| 95 | Custom trace directory path ('TRACEDIR' part of the argument of the |
| 96 | nloption:--set-url option of the man:lttng-create(1) command, if |
| 97 | any). |
| 98 | |
| 99 | 'SESSIONDV':: |
| 100 | The version of the LTTng session daemon of the connected peer. |
| 101 | |
| 102 | The relay daemon output path patterns are: |
| 103 | |
| 104 | With the option:--group-output-by-host option (hostname grouping):: |
| 105 | Without a custom trace directory::: |
| 106 | + |
| 107 | [verse] |
| 108 | 'BASE'/'HOSTNAME'/'SESSION'-'DATETIME' |
| 109 | |
| 110 | With a custom trace directory::: |
| 111 | + |
| 112 | [verse] |
| 113 | 'BASE'/'HOSTNAME'/'TRACEDIR' |
| 114 | |
| 115 | With the option:--group-output-by-session option (recording session grouping):: |
| 116 | Without a custom trace directory::: |
| 117 | 'SESSIONDV' is at least{nbsp}2.4:::: |
| 118 | + |
| 119 | [verse] |
| 120 | 'BASE'/'SESSION'/'HOSTNAME'-'DATETIME' |
| 121 | |
| 122 | Otherwise:::: |
| 123 | Defaults to the hostname grouping pattern: |
| 124 | + |
| 125 | [verse] |
| 126 | 'BASE'/'HOSTNAME'/'SESSION'-'DATETIME' |
| 127 | |
| 128 | With a custom trace directory::: |
| 129 | 'SESSIONDV' is at least 2.4:::: |
| 130 | + |
| 131 | [verse] |
| 132 | 'BASE'/'SESSION'/'HOSTNAME'-'DATETIME'/'TRACEDIR' |
| 133 | |
| 134 | Otherwise:::: |
| 135 | Defaults to the hostname grouping pattern: |
| 136 | + |
| 137 | [verse] |
| 138 | 'BASE'/'HOSTNAME'/'TRACEDIR' |
| 139 | |
| 140 | |
| 141 | [[url-format]] |
| 142 | URL format |
| 143 | ~~~~~~~~~~ |
| 144 | The argument of the option:--control-port='URL', |
| 145 | option:--data-port='URL', and option:--live-port='URL' options is an |
| 146 | URL. |
| 147 | |
| 148 | The format of 'URL' is: |
| 149 | |
| 150 | [verse] |
| 151 | tcp://('HOST' | 'IPADDR'):__PORT__ |
| 152 | |
| 153 | with: |
| 154 | |
| 155 | ('HOST' | 'IPADDR'):: |
| 156 | Binding hostname or IP address. |
| 157 | + |
| 158 | IPv6 address must be enclosed in square brackets (`[` and{nbsp}`]`); |
| 159 | see https://www.ietf.org/rfc/rfc2732.txt[RFC{nbsp}2732]. |
| 160 | |
| 161 | 'PORT':: |
| 162 | TCP port. |
| 163 | |
| 164 | |
| 165 | [[options]] |
| 166 | OPTIONS |
| 167 | ------- |
| 168 | General daemon configuration |
| 169 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 170 | option:-b, option:--background:: |
| 171 | Start as a Unix daemon, but keep file descriptors (console) open. |
| 172 | + |
| 173 | With this option, `lttng-relayd` ensures the daemon is listening |
| 174 | to incoming connections before it exits. |
| 175 | + |
| 176 | Use the option:--daemonize option instead to close the file descriptors. |
| 177 | |
| 178 | option:-f 'PATH', option:--config='PATH':: |
| 179 | Configure the daemon using the INI configuration file 'PATH' in |
| 180 | addition to the default configuration files and the command-line |
| 181 | options. |
| 182 | + |
| 183 | See the ``<<cfg,Daemon configuration>>'' section above. |
| 184 | |
| 185 | option:-d, option:--daemonize:: |
| 186 | Start as a Unix daemon and close file descriptors (console). |
| 187 | + |
| 188 | With this option, `lttng-relayd` ensures the daemon is listening |
| 189 | to incoming connections before it exits. |
| 190 | + |
| 191 | Use the option:--background option instead to keep the file descriptors |
| 192 | open. |
| 193 | |
| 194 | option:-x, option:--disallow-clear:: |
| 195 | Disallow clearing operations (see man:lttng-clear(1)). |
| 196 | + |
| 197 | See also the `LTTNG_RELAYD_DISALLOW_CLEAR` environment variable. |
| 198 | |
| 199 | option:--fd-pool-size='SIZE':: |
| 200 | Set the size of the file descriptor pool to 'SIZE' file descriptors. |
| 201 | + |
| 202 | 'SIZE' is the maximum number of file descriptors that the relay daemon |
| 203 | may keep open simultaneously. |
| 204 | + |
| 205 | Default: the soft `RLIMIT_NOFILE` resource limit of the process (see |
| 206 | man:getrlimit(2)). |
| 207 | |
| 208 | option:-g 'GROUP', option:--group='GROUP':: |
| 209 | Set the Unix tracing group to 'GROUP' instead of `tracing`. |
| 210 | + |
| 211 | This option is only meaningful when the `root` Unix user starts |
| 212 | `lttng-relayd`. |
| 213 | + |
| 214 | Members of the Unix tracing group may connect to the health check socket |
| 215 | of the relay daemon. |
| 216 | + |
| 217 | See also the `LTTNG_RELAYD_HEALTH` environment variable. |
| 218 | |
| 219 | option:-w 'DIR', option:--working-directory='DIR':: |
| 220 | Set the working directory of the processes the relay daemon creates |
| 221 | to 'DIR'. |
| 222 | + |
| 223 | See also the `LTTNG_RELAYD_WORKING_DIRECTORY` environment variable. |
| 224 | |
| 225 | option:-v, option:--verbose:: |
| 226 | Increase verbosity. |
| 227 | + |
| 228 | Specify this option up to three times to get more levels of verbosity. |
| 229 | |
| 230 | |
| 231 | Output |
| 232 | ~~~~~~ |
| 233 | See the ``<<output-directory,Output directory>>'' section above to learn |
| 234 | more. |
| 235 | |
| 236 | option:-p, option:--group-output-by-host:: |
| 237 | Group the written trace directories by hostname. |
| 238 | + |
| 239 | As of LTTng{nbsp}{lttng_version}, this is the default output grouping |
| 240 | strategy, but this may change in the future. |
| 241 | |
| 242 | option:-s, option:--group-output-by-session:: |
| 243 | Group the written trace directories by recording session name |
| 244 | instead of by hostname. |
| 245 | |
| 246 | option:-o 'DIR', option:--output='DIR':: |
| 247 | Set the base output directory of the written trace directories to |
| 248 | 'DIR'. |
| 249 | |
| 250 | |
| 251 | Ports |
| 252 | ~~~~~ |
| 253 | See the ``<<url-format,URL format>>'' section above to learn more about |
| 254 | the syntax of the 'URL' argument of the following options. |
| 255 | |
| 256 | option:-C 'URL', option:--control-port='URL':: |
| 257 | Listen to control data on URL 'URL'. |
| 258 | + |
| 259 | Default: |
| 260 | +tcp://{default_network_control_bind_address}:{default_network_control_port}+. |
| 261 | |
| 262 | option:-D 'URL', option:--data-port='URL':: |
| 263 | Listen to trace data on URL 'URL'. |
| 264 | + |
| 265 | Default: |
| 266 | +tcp://{default_network_data_bind_address}:{default_network_data_port}+. |
| 267 | |
| 268 | option:-L 'URL', option:--live-port='URL':: |
| 269 | Listen to LTTng live connections on URL 'URL'. |
| 270 | + |
| 271 | Default: |
| 272 | +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+. |
| 273 | |
| 274 | |
| 275 | Program information |
| 276 | ~~~~~~~~~~~~~~~~~~~ |
| 277 | include::common-help-option.txt[] |
| 278 | |
| 279 | option:-V, option:--version:: |
| 280 | Show version and quit. |
| 281 | |
| 282 | |
| 283 | EXIT STATUS |
| 284 | ----------- |
| 285 | *0*:: |
| 286 | Success |
| 287 | |
| 288 | *1*:: |
| 289 | Error |
| 290 | |
| 291 | *3*:: |
| 292 | Fatal error |
| 293 | |
| 294 | |
| 295 | ENVIRONMENT |
| 296 | ----------- |
| 297 | `LTTNG_ABORT_ON_ERROR`:: |
| 298 | Set to `1` to abort the process after the first error is |
| 299 | encountered. |
| 300 | |
| 301 | `LTTNG_NETWORK_SOCKET_TIMEOUT`:: |
| 302 | Socket connection, receive, and send timeout (milliseconds). |
| 303 | + |
| 304 | Set to `0` or `-1` to set an infinite timeout (default). |
| 305 | |
| 306 | `LTTNG_RELAYD_DISALLOW_CLEAR`:: |
| 307 | Set to `1` to disallow clearing operations (see man:lttng-clear(1)). |
| 308 | + |
| 309 | The option:--disallow-clear option overrides this environment variable. |
| 310 | |
| 311 | `LTTNG_RELAYD_HEALTH`:: |
| 312 | Path to the health check socket of the relay daemon. |
| 313 | |
| 314 | `LTTNG_RELAYD_TCP_KEEP_ALIVE`:: |
| 315 | Set to `1` to enable TCP keep-alive. |
| 316 | + |
| 317 | The TCP keep-alive mechanism allows the detection of dead peers |
| 318 | (man:lttng-sessiond(8)) in cases of unclean termination (for example, a |
| 319 | hard reset) of a peer. |
| 320 | + |
| 321 | Supported on Linux and Solaris only. The default behaviour of the TCP |
| 322 | keep-alive mechanism is OS-specific. |
| 323 | + |
| 324 | Search for `tcp_keepalive` in man:tcp(7) to learn more. |
| 325 | |
| 326 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`:: |
| 327 | The time threshold (seconds) to abort a TCP connection after the |
| 328 | keep-alive probing mechanism has failed. |
| 329 | + |
| 330 | Set to `0` or `-1` to use the value chosen by the operating system |
| 331 | (default). |
| 332 | + |
| 333 | Supported on Solaris 11 only. |
| 334 | + |
| 335 | Search for `tcp_keepalive_abort_threshold` in man:tcp(7) to learn more. |
| 336 | |
| 337 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`:: |
| 338 | Number of seconds a connection needs to be idle before TCP begins |
| 339 | sending out keep-alive probes. |
| 340 | + |
| 341 | Set to `0` or `-1` to use the value chosen by the operating system |
| 342 | (default). |
| 343 | + |
| 344 | Supported on Linux and Solaris 11 only. |
| 345 | + |
| 346 | On Solaris{nbsp}11, the accepted values are `-1`, `0`, and `10` to |
| 347 | `864000`. |
| 348 | + |
| 349 | Search for `tcp_keepalive_time` and `tcp_keepalive_interval` |
| 350 | in man:tcp(7) on Solaris{nbsp}11 to learn more. |
| 351 | |
| 352 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`:: |
| 353 | Maximum number of TCP keep-alive probes to send before giving up and |
| 354 | killing the connection if no response is obtained from the other end. |
| 355 | + |
| 356 | Set to `0` or `-1` to use the value chosen by the operating system |
| 357 | (default). |
| 358 | + |
| 359 | Supported on Linux only. |
| 360 | + |
| 361 | Search for `tcp_keepalive_probes` in man:tcp(7) to learn more. |
| 362 | |
| 363 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`:: |
| 364 | Number of seconds between TCP keep-alive probes. |
| 365 | + |
| 366 | Set to `0` or `-1` to use the value chosen by the operating system |
| 367 | (default). |
| 368 | + |
| 369 | Supported on Linux only. |
| 370 | + |
| 371 | Search for `tcp_keepalive_intvl` in man:tcp(7) to learn more. |
| 372 | |
| 373 | `LTTNG_RELAYD_WORKING_DIRECTORY`:: |
| 374 | Working directory of the processes the relay daemon creates. |
| 375 | + |
| 376 | The option:--working-directory option overrides this environment |
| 377 | variable. |
| 378 | |
| 379 | |
| 380 | FILES |
| 381 | ----- |
| 382 | `$LTTNG_HOME/.lttng`:: |
| 383 | Unix user's LTTng runtime and configuration directory. |
| 384 | |
| 385 | `$LTTNG_HOME/lttng-traces`:: |
| 386 | Default base output directory of LTTng traces. |
| 387 | + |
| 388 | Override this path with the option:--output option. |
| 389 | |
| 390 | NOTE: `$LTTNG_HOME` defaults to `$HOME`. |
| 391 | |
| 392 | |
| 393 | include::common-footer.txt[] |
| 394 | |
| 395 | |
| 396 | SEE ALSO |
| 397 | -------- |
| 398 | man:babeltrace2(1), |
| 399 | man:lttng(1), |
| 400 | man:lttng-sessiond(8) |