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