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