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              [option:--working-directory='PATH']
  17
  18
  19 DESCRIPTION
  20 -----------
  21 The http://lttng.org/[_Linux Trace Toolkit: next generation_] is an open
  22 source software package used for correlated tracing of the Linux kernel,
  23 user applications, and user libraries.
  24
  25 LTTng consists of Linux kernel modules (for Linux kernel tracing) and
  26 dynamically loaded libraries (for user application and library tracing).
  27
  28 The _LTTng relay daemon_ is responsible for receiving trace data from
  29 possibly remote LTTng session/consumer daemons and for writing it to
  30 the local file system. The relay daemon also accepts _LTTng live_
  31 connections from compatible viewers; this is the official approach to
  32 viewing LTTng events as they are emitted.
  33
  34 The relay daemon listens by default on all network interfaces to gather
  35 trace data, but only on localhost for LTTng live connections.
  36
  37 The relay daemon does not require any particular permissions, as long as
  38 it can write to the output directory and listen on the configured ports.
  39 If a user is within a secured network and/or has proper firewall
  40 settings, `lttng-relayd` can listen to LTTng live connections from _all_
  41 network interfaces by specifying
  42 +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+.
  43
  44 Once a trace has been streamed completely, the trace can be processed by
  45 any tool that can process an LTTng trace located on the local
  46 file system.
  47
  48
  49 [[output-directory]]
  50 Output directory
  51 ~~~~~~~~~~~~~~~~
  52 By default (option:--group-output-by-host), the relay daemon writes the traces
  53 to:
  54
  55 [verse]
  56 $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN'
  57
  58 with:
  59
  60 'HOSTNAME'::
  61     Remote hostname.
  62
  63 'SESSION'::
  64     Full session name.
  65
  66 'DOMAIN'::
  67     Tracing domain.
  68
  69 You can group the output per session instead of per hostname with the
  70 option:--group-output-by-session option. This result in the following:
  71
  72 [verse]
  73
  74 $LTTNG_HOME/lttng-traces/'SESSION'/'HOST'/'DOMAIN'
  75
  76 You can override the default output directory prefix
  77 (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other
  78 parts depend on the remote configuration.
  79
  80
  81
  82 [[url-format]]
  83 URL format
  84 ~~~~~~~~~~
  85 The option:--control-port, option:--data-port, and option:--live-port
  86 options specify URLs.
  87
  88 The format of those URLs is:
  89
  90 [verse]
  91 tcp://('HOST' | 'IPADDR'):__PORT__
  92
  93 with:
  94
  95 ('HOST' | 'IPADDR')::
  96     Binding hostname or IP address (IPv6 address *must* be enclosed in
  97     brackets (`[` and `]`); see
  98     https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]).
  99
 100 'PORT'::
 101     TCP port.
 102
 103
 104 OPTIONS
 105 -------
 106 Daemon
 107 ~~~~~~
 108 option:-b, option:--background::
 109     Start as Unix daemon, but keep file descriptors (console) open.
 110     Use the option:--daemonize option instead to close the file
 111     descriptors.
 112
 113 option:-d, option:--daemonize::
 114     Start as Unix daemon, and close file descriptors (console). Use the
 115     option:--background option instead to keep the file descriptors
 116     open.
 117
 118 option:-g 'GROUP', option:--group='GROUP'::
 119     Use 'GROUP' as Unix tracing group (default: `tracing`).
 120
 121 option:-o 'PATH', option:--output='PATH'::
 122     Set base directory of written trace data to 'PATH'.
 123 +
 124 See the <<output-directory,Output directory>> section above for more
 125 information.
 126
 127 option:-p, option:--group-output-by-host::
 128     Organize the output directory by host. Default behavior.
 129 +
 130 See the <<output-directory,Output directory>> section above for more
 131 information.
 132
 133 option:-s, option:--group-output-by-session::
 134     Organize the output directory by session.
 135 +
 136 See the <<output-directory,Output directory>> section above for more
 137 information.
 138
 139 option:-v, option:--verbose::
 140     Increase verbosity.
 141
 142 option:-w 'PATH', option:--working-directory='PATH'::
 143     Set the working directory of the processes this relay daemon creates.
 144 +
 145 Three levels of verbosity are available, which are triggered by
 146 appending additional `v` letters to the option
 147 (that is, `-vv` and `-vvv`).
 148
 149
 150 Ports
 151 ~~~~~
 152 See the <<url-format,URL format>> section above for more information
 153 about the syntax of the following options' 'URL' argument.
 154
 155 option:-C 'URL', option:--control-port='URL'::
 156     Listen to control data on URL 'URL' (default:
 157     +tcp://{default_network_control_bind_address}:{default_network_control_port}+).
 158
 159 option:-D 'URL', option:--data-port='URL'::
 160     Listen to trace data on URL 'URL' (default:
 161     +tcp://{default_network_data_bind_address}:{default_network_data_port}+).
 162
 163 option:-L 'URL', option:--live-port='URL'::
 164     Listen to LTTng live connections on URL 'URL'
 165     (default:
 166     +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+).
 167
 168
 169 Program information
 170 ~~~~~~~~~~~~~~~~~~~
 171 option:-h, option:--help::
 172     Show help.
 173
 174 option:-V, option:--version::
 175     Show version.
 176
 177
 178 ENVIRONMENT VARIABLES
 179 ---------------------
 180 `LTTNG_ABORT_ON_ERROR`::
 181     Set to 1 to abort the process after the first error is encountered.
 182
 183 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
 184     Socket connection, receive and send timeout (milliseconds). A value
 185     of 0 or -1 uses the timeout of the operating system (default).
 186
 187 `LTTNG_RELAYD_HEALTH`::
 188     Path to relay daemon health's socket.
 189
 190 `LTTNG_RELAYD_TCP_KEEP_ALIVE`::
 191     Set to 1 to enable TCP keep-alive.
 192 +
 193 The TCP keep-alive mechanism allows the detection of dead peers
 194 (man:lttng-sessiond(8)) in cases of unclean termination
 195 (for example, a hard reset) of a peer.
 196 +
 197 Supported on Linux and Solaris only. The default behaviour of the TCP
 198 keep-alive mechanism is OS-specific.
 199 +
 200 Search for `tcp_keepalive` in man:tcp(7) for more information.
 201
 202 `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`::
 203    The time threshold in seconds to abort a TCP connection after the keep-alive
 204    probing mechanism has failed.
 205 +
 206 Set to 0 or -1 to use the value chosen by the operating system (default).
 207 +
 208 Supported on Solaris 11 only.
 209 +
 210 Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information.
 211
 212 `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`::
 213     Number of seconds a connection needs to be idle before TCP begins
 214     sending out keep-alive probes.
 215 +
 216 Set to 0 or -1 to use the value chosen by the operating system (default).
 217 +
 218 Supported on Linux and Solaris 11 only.
 219 +
 220 On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000.
 221 +
 222 Search for `tcp_keepalive_time` and `tcp_keepalive_interval`
 223 in man:tcp(7) on Solaris 11 for more information.
 224
 225 `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`::
 226     Maximum number of TCP keep-alive probes to send before giving up and
 227     killing the connection if no response is obtained from the other end.
 228 +
 229 Set to 0 or -1 to use the value chosen by the operating system (default).
 230 +
 231 Supported on Linux only.
 232 +
 233 Search for `tcp_keepalive_probes` in man:tcp(7) for more information.
 234
 235 `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`::
 236     Number of seconds between TCP keep-alive probes.
 237 +
 238 Set to 0 or -1 to use the value chosen by the operating system (default).
 239 +
 240 Supported on Linux only.
 241 +
 242 Search for `tcp_keepalive_intvl` in man:tcp(7) for more information.
 243
 244
 245 FILES
 246 -----
 247 `$LTTNG_HOME/.lttng`::
 248     User LTTng runtime and configuration directory.
 249
 250 `$LTTNG_HOME/lttng-traces`::
 251     Default output directory of LTTng traces. This can be overridden
 252     with the option:--output option.
 253
 254 NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set.
 255
 256
 257 EXIT STATUS
 258 -----------
 259 *0*::
 260     Success
 261
 262 *1*::
 263     Error
 264
 265 *3*::
 266     Fatal error
 267
 268
 269 LIMITATIONS
 270 -----------
 271 As of this version, only the TCP protocol is supported for both control
 272 and data ports. In future versions, TCP will remain the sole available
 273 protocol for control data since those communications are low-volume and
 274 need absolute reliability; trace data could be carried over UDP.
 275
 276 For an unprivileged user running `lttng-relayd`, the maximum number of
 277 file descriptors per process is usually 1024. This limits the number of
 278 connections and opened trace files. This limit can be configured with
 279 *ulimit*(3).
 280
 281
 282 include::common-footer.txt[]
 283
 284
 285 SEE ALSO
 286 --------
 287 man:lttng(1),
 288 man:lttng-sessiond(8),
 289 man:lttng-crash(1),
 290 man:lttng-ust(3),
 291 man:babeltrace(1)