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:--fd-pool-size='COUNT']
  15              [option:--live-port='URL'] [option:--output='PATH']
  16              [option:-v | option:-vv | option:-vvv] [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:--fd-pool-size='COUNT'::
 119     Set the size of the file descritptor pool. This effectively sets a
 120     limit on the number of file descriptors that may be kept open
 121     simultaneously by the daemon (default: the soft RLIMIT_NOFILE resource
 122     limit of the process).
 123
 124 option:-g 'GROUP', option:--group='GROUP'::
 125     Use 'GROUP' as Unix tracing group (default: `tracing`).
 126
 127 option:-o 'PATH', option:--output='PATH'::
 128     Set base directory of written trace data to 'PATH'.
 129 +
 130 See the <<output-directory,Output directory>> section above for more
 131 information.
 132
 133 option:-p, option:--group-output-by-host::
 134     Organize the output directory by host. Default behavior.
 135 +
 136 See the <<output-directory,Output directory>> section above for more
 137 information.
 138
 139 option:-s, option:--group-output-by-session::
 140     Organize the output directory by session.
 141 +
 142 See the <<output-directory,Output directory>> section above for more
 143 information.
 144
 145 option:-v, option:--verbose::
 146     Increase verbosity.
 147
 148 option:-w 'PATH', option:--working-directory='PATH'::
 149     Set the working directory of the processes this relay daemon creates.
 150 +
 151 Three levels of verbosity are available, which are triggered by
 152 appending additional `v` letters to the option
 153 (that is, `-vv` and `-vvv`).
 154
 155
 156 Ports
 157 ~~~~~
 158 See the <<url-format,URL format>> section above for more information
 159 about the syntax of the following options' 'URL' argument.
 160
 161 option:-C 'URL', option:--control-port='URL'::
 162     Listen to control data on URL 'URL' (default:
 163     +tcp://{default_network_control_bind_address}:{default_network_control_port}+).
 164
 165 option:-D 'URL', option:--data-port='URL'::
 166     Listen to trace data on URL 'URL' (default:
 167     +tcp://{default_network_data_bind_address}:{default_network_data_port}+).
 168
 169 option:-L 'URL', option:--live-port='URL'::
 170     Listen to LTTng live connections on URL 'URL'
 171     (default:
 172     +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+).
 173
 174
 175 Program information
 176 ~~~~~~~~~~~~~~~~~~~
 177 option:-h, option:--help::
 178     Show help.
 179
 180 option:-V, option:--version::
 181     Show version.
 182
 183
 184 ENVIRONMENT VARIABLES
 185 ---------------------
 186 `LTTNG_ABORT_ON_ERROR`::
 187     Set to 1 to abort the process after the first error is encountered.
 188
 189 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
 190     Socket connection, receive and send timeout (milliseconds). A value
 191     of 0 or -1 uses the timeout of the operating system (default).
 192
 193 `LTTNG_RELAYD_HEALTH`::
 194     Path to relay daemon health's socket.
 195
 196 `LTTNG_RELAYD_TCP_KEEP_ALIVE`::
 197     Set to 1 to enable TCP keep-alive.
 198 +
 199 The TCP keep-alive mechanism allows the detection of dead peers
 200 (man:lttng-sessiond(8)) in cases of unclean termination
 201 (for example, a hard reset) of a peer.
 202 +
 203 Supported on Linux and Solaris only. The default behaviour of the TCP
 204 keep-alive mechanism is OS-specific.
 205 +
 206 Search for `tcp_keepalive` in man:tcp(7) for more information.
 207
 208 `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`::
 209    The time threshold in seconds to abort a TCP connection after the keep-alive
 210    probing mechanism has failed.
 211 +
 212 Set to 0 or -1 to use the value chosen by the operating system (default).
 213 +
 214 Supported on Solaris 11 only.
 215 +
 216 Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information.
 217
 218 `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`::
 219     Number of seconds a connection needs to be idle before TCP begins
 220     sending out keep-alive probes.
 221 +
 222 Set to 0 or -1 to use the value chosen by the operating system (default).
 223 +
 224 Supported on Linux and Solaris 11 only.
 225 +
 226 On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000.
 227 +
 228 Search for `tcp_keepalive_time` and `tcp_keepalive_interval`
 229 in man:tcp(7) on Solaris 11 for more information.
 230
 231 `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`::
 232     Maximum number of TCP keep-alive probes to send before giving up and
 233     killing the connection if no response is obtained from the other end.
 234 +
 235 Set to 0 or -1 to use the value chosen by the operating system (default).
 236 +
 237 Supported on Linux only.
 238 +
 239 Search for `tcp_keepalive_probes` in man:tcp(7) for more information.
 240
 241 `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`::
 242     Number of seconds between TCP keep-alive probes.
 243 +
 244 Set to 0 or -1 to use the value chosen by the operating system (default).
 245 +
 246 Supported on Linux only.
 247 +
 248 Search for `tcp_keepalive_intvl` in man:tcp(7) for more information.
 249
 250
 251 FILES
 252 -----
 253 `$LTTNG_HOME/.lttng`::
 254     User LTTng runtime and configuration directory.
 255
 256 `$LTTNG_HOME/lttng-traces`::
 257     Default output directory of LTTng traces. This can be overridden
 258     with the option:--output option.
 259
 260 NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set.
 261
 262
 263 EXIT STATUS
 264 -----------
 265 *0*::
 266     Success
 267
 268 *1*::
 269     Error
 270
 271 *3*::
 272     Fatal error
 273
 274
 275 LIMITATIONS
 276 -----------
 277 As of this version, only the TCP protocol is supported for both control
 278 and data ports. In future versions, TCP will remain the sole available
 279 protocol for control data since those communications are low-volume and
 280 need absolute reliability; trace data could be carried over UDP.
 281
 282 For an unprivileged user running `lttng-relayd`, the maximum number of
 283 file descriptors per process is usually 1024. This limits the number of
 284 connections and opened trace files. This limit can be configured with
 285 *ulimit*(3).
 286
 287
 288 include::common-footer.txt[]
 289
 290
 291 SEE ALSO
 292 --------
 293 man:lttng(1),
 294 man:lttng-sessiond(8),
 295 man:lttng-crash(1),
 296 man:lttng-ust(3),
 297 man:babeltrace(1)