doc/man/lttng-relayd.8.txt

   1 lttng-relayd(8)
   2 ===============
   3 :revdate: 5 June 2018
   4
   5
   6 NAME
   7 ----
   8 lttng-relayd - LTTng 2 relay daemon
   9
  10
  11 SYNOPSIS
  12 --------
  13 [verse]
  14 *lttng-relayd* [option:--background | option:--daemonize]
  15              [option:--control-port='URL'] [option:--data-port='URL'] [option:--live-port='URL']
  16              [option:--output='PATH'] [option:-v | option:-vv | option:-vvv]
  17              [option:--working-directory='PATH']
  18
  19
  20 DESCRIPTION
  21 -----------
  22 The https://lttng.org/[_Linux Trace Toolkit: next generation_] is an open
  23 source software package used for correlated tracing of the Linux kernel,
  24 user applications, and user libraries.
  25
  26 LTTng consists of Linux kernel modules (for Linux kernel tracing) and
  27 dynamically loaded libraries (for user application and library tracing).
  28
  29 The _LTTng relay daemon_ is responsible for receiving trace data from
  30 possibly remote LTTng session/consumer daemons and for writing it to
  31 the local file system. The relay daemon also accepts _LTTng live_
  32 connections from compatible viewers; this is the official approach to
  33 viewing LTTng events as they are emitted.
  34
  35 The relay daemon listens by default on all network interfaces to gather
  36 trace data, but only on localhost for LTTng live connections.
  37
  38 The relay daemon does not require any particular permissions, as long as
  39 it can write to the output directory and listen on the configured ports.
  40 If a user is within a secured network and/or has proper firewall
  41 settings, `lttng-relayd` can listen to LTTng live connections from _all_
  42 network interfaces by specifying
  43 +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+.
  44
  45 Once a trace has been streamed completely, the trace can be processed by
  46 any tool that can process an LTTng trace located on the local
  47 file system.
  48
  49
  50 [[output-directory]]
  51 Output directory
  52 ~~~~~~~~~~~~~~~~
  53 By default, the relay daemon writes the traces to:
  54
  55 [verse]
  56 $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN'
  57
  58 with:
  59
  60 'HOSTNAME'::
  61     Remote hostname.
  62
  63 'SESSION'::
  64     Full session name.
  65
  66 'DOMAIN'::
  67     Tracing domain.
  68
  69 You can override the default output directory prefix
  70 (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other
  71 parts depend on the remote configuration.
  72
  73
  74 [[url-format]]
  75 URL format
  76 ~~~~~~~~~~
  77 The option:--control-port, option:--data-port, and option:--live-port
  78 options specify URLs.
  79
  80 The format of those URLs is:
  81
  82 [verse]
  83 tcp://('HOST' | 'IPADDR'):__PORT__
  84
  85 with:
  86
  87 ('HOST' | 'IPADDR')::
  88     Binding hostname or IP address (IPv6 address *must* be enclosed in
  89     brackets (`[` and `]`); see
  90     https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]).
  91
  92 'PORT'::
  93     TCP port.
  94
  95
  96 OPTIONS
  97 -------
  98 Daemon
  99 ~~~~~~
 100 option:-b, option:--background::
 101     Start as Unix daemon, but keep file descriptors (console) open.
 102     Use the option:--daemonize option instead to close the file
 103     descriptors.
 104
 105 option:-d, option:--daemonize::
 106     Start as Unix daemon, and close file descriptors (console). Use the
 107     option:--background option instead to keep the file descriptors
 108     open.
 109
 110 option:-g 'GROUP', option:--group='GROUP'::
 111     Use 'GROUP' as Unix tracing group (default: `tracing`).
 112
 113 option:-o 'PATH', option:--output='PATH'::
 114     Set base directory of written trace data to 'PATH'.
 115 +
 116 See the <<output-directory,Output directory>> section above for more
 117 information.
 118
 119 option:-w 'PATH', option:--working-directory='PATH'::
 120     Set the working directory of the processes this relay daemon creates.
 121
 122 option:-v, option:--verbose::
 123     Increase verbosity.
 124 +
 125 Three levels of verbosity are available, which are triggered by
 126 appending additional `v` letters to the option
 127 (that is, `-vv` and `-vvv`).
 128
 129
 130 Ports
 131 ~~~~~
 132 See the <<url-format,URL format>> section above for more information
 133 about the syntax of the following options' 'URL' argument.
 134
 135 option:-C 'URL', option:--control-port='URL'::
 136     Listen to control data on URL 'URL' (default:
 137     +tcp://{default_network_control_bind_address}:{default_network_control_port}+).
 138
 139 option:-D 'URL', option:--data-port='URL'::
 140     Listen to trace data on URL 'URL' (default:
 141     +tcp://{default_network_data_bind_address}:{default_network_data_port}+).
 142
 143 option:-L 'URL', option:--live-port='URL'::
 144     Listen to LTTng live connections on URL 'URL'
 145     (default:
 146     +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+).
 147
 148
 149 Program information
 150 ~~~~~~~~~~~~~~~~~~~
 151 option:-h, option:--help::
 152     Show help.
 153
 154 option:-V, option:--version::
 155     Show version.
 156
 157
 158 ENVIRONMENT VARIABLES
 159 ---------------------
 160 `LTTNG_ABORT_ON_ERROR`::
 161     Set to 1 to abort the process after the first error is encountered.
 162
 163 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
 164     Socket connection, receive and send timeout (milliseconds). A value
 165     of 0 or -1 uses the timeout of the operating system (default).
 166
 167 `LTTNG_RELAYD_HEALTH`::
 168     Path to relay daemon health's socket.
 169
 170 `LTTNG_RELAYD_TCP_KEEP_ALIVE`::
 171     Set to 1 to enable TCP keep-alive.
 172 +
 173 The TCP keep-alive mechanism allows the detection of dead peers
 174 (man:lttng-sessiond(8)) in cases of unclean termination
 175 (for example, a hard reset) of a peer.
 176 +
 177 Supported on Linux and Solaris only. The default behaviour of the TCP
 178 keep-alive mechanism is OS-specific.
 179 +
 180 Search for `tcp_keepalive` in man:tcp(7) for more information.
 181
 182 `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`::
 183    The time threshold in seconds to abort a TCP connection after the keep-alive
 184    probing mechanism has failed.
 185 +
 186 Set to 0 or -1 to use the value chosen by the operating system (default).
 187 +
 188 Supported on Solaris 11 only.
 189 +
 190 Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information.
 191
 192 `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`::
 193     Number of seconds a connection needs to be idle before TCP begins
 194     sending out keep-alive probes.
 195 +
 196 Set to 0 or -1 to use the value chosen by the operating system (default).
 197 +
 198 Supported on Linux and Solaris 11 only.
 199 +
 200 On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000.
 201 +
 202 Search for `tcp_keepalive_time` and `tcp_keepalive_interval`
 203 in man:tcp(7) on Solaris 11 for more information.
 204
 205 `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`::
 206     Maximum number of TCP keep-alive probes to send before giving up and
 207     killing the connection if no response is obtained from the other end.
 208 +
 209 Set to 0 or -1 to use the value chosen by the operating system (default).
 210 +
 211 Supported on Linux only.
 212 +
 213 Search for `tcp_keepalive_probes` in man:tcp(7) for more information.
 214
 215 `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`::
 216     Number of seconds between TCP keep-alive probes.
 217 +
 218 Set to 0 or -1 to use the value chosen by the operating system (default).
 219 +
 220 Supported on Linux only.
 221 +
 222 Search for `tcp_keepalive_intvl` in man:tcp(7) for more information.
 223
 224 `LTTNG_RELAYD_WORKING_DIRECTORY`::
 225     Working directory of the processes this relay daemon creates.
 226 +
 227 The option:--working-directory option overrides this variable.
 228
 229
 230 FILES
 231 -----
 232 `$LTTNG_HOME/.lttng`::
 233     User LTTng runtime and configuration directory.
 234
 235 `$LTTNG_HOME/lttng-traces`::
 236     Default output directory of LTTng traces. This can be overridden
 237     with the option:--output option.
 238
 239 NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set.
 240
 241
 242 EXIT STATUS
 243 -----------
 244 *0*::
 245     Success
 246
 247 *1*::
 248     Error
 249
 250 *3*::
 251     Fatal error
 252
 253
 254 LIMITATIONS
 255 -----------
 256 As of this version, only the TCP protocol is supported for both control
 257 and data ports. In future versions, TCP will remain the sole available
 258 protocol for control data since those communications are low-volume and
 259 need absolute reliability; trace data could be carried over UDP.
 260
 261 For an unprivileged user running `lttng-relayd`, the maximum number of
 262 file descriptors per process is usually 1024. This limits the number of
 263 connections and opened trace files. This limit can be configured with
 264 *ulimit*(3).
 265
 266
 267 include::common-footer.txt[]
 268
 269
 270 SEE ALSO
 271 --------
 272 man:lttng(1),
 273 man:lttng-sessiond(8),
 274 man:lttng-crash(1),
 275 man:lttng-ust(3),
 276 man:babeltrace(1)