1LTTNG-RELAYD(8) LTTng Manual LTTNG-RELAYD(8)
2
6 lttng-relayd - LTTng 2 relay daemon
7
9 lttng-relayd [--background | --daemonize]
10 [--control-port=URL] [--data-port=URL] [--live-port=URL]
11 [--output=PATH] [-v | -vv | -vvv]
12
14 The Linux Trace Toolkit: next generation <https://lttng.org/> is an
15 open source software package used for correlated tracing of the Linux
16 kernel, user applications, and user libraries.
17 LTTng consists of Linux kernel modules (for Linux kernel tracing) and
19 dynamically loaded libraries (for user application and library
20 tracing).
21 The LTTng relay daemon is responsible for receiving trace data from
23 possibly remote LTTng session/consumer daemons and for writing it to
24 the local file system. The relay daemon also accepts LTTng live
25 connections from compatible viewers; this is the official approach to
26 viewing LTTng events as they are emitted.
27 The relay daemon listens by default on all network interfaces to gather
29 trace data, but only on localhost for LTTng live connections.
30 The relay daemon does not require any particular permissions, as long
32 as it can write to the output directory and listen on the configured
33 ports. If a user is within a secured network and/or has proper firewall
34 settings, lttng-relayd can listen to LTTng live connections from all
35 network interfaces by specifying --live-port=tcp://0.0.0.0:5344.
36 Once a trace has been streamed completely, the trace can be processed
38 by any tool that can process an LTTng trace located on the local file
39 system.
40 Output directory
42 By default, the relay daemon writes the traces to:
43 $LTTNG_HOME/lttng-traces/HOSTNAME/SESSION/DOMAIN
45 with:
47 HOSTNAME
49 Remote hostname.
50 SESSION
52 Full session name.
53 DOMAIN
55 Tracing domain.
56 You can override the default output directory prefix
58 ($LTTNG_HOME/lttng-traces) with the --output option. The other parts
59 depend on the remote configuration.
60 URL format
62 The --control-port, --data-port, and --live-port options specify URLs.
63 The format of those URLs is:
65 tcp://(HOST | IPADDR):PORT
67 with:
69 (HOST | IPADDR)
71 Binding hostname or IP address (IPv6 address must be enclosed in
72 brackets ([ and ]); see RFC 2732
73 <https://www.ietf.org/rfc/rfc2732.txt>).
74 PORT
76 TCP port.
77
79 Daemon
80 -b, --background
81 Start as Unix daemon, but keep file descriptors (console) open. Use
82 the --daemonize option instead to close the file descriptors.
83 -d, --daemonize
85 Start as Unix daemon, and close file descriptors (console). Use the
86 --background option instead to keep the file descriptors open.
87 -g GROUP, --group=GROUP
89 Use GROUP as Unix tracing group (default: tracing).
90 -o PATH, --output=PATH
92 Set base directory of written trace data to PATH.
93 See the Output directory section above for more information.
95 -v, --verbose
97 Increase verbosity.
98 Three levels of verbosity are available, which are triggered by
100 appending additional v letters to the option (that is, -vv and
101 -vvv).
102 Ports
104 See the URL format section above for more information about the syntax
105 of the following options' URL argument.
106 -C URL, --control-port=URL
108 Listen to control data on URL URL (default: tcp://0.0.0.0:5342).
109 -D URL, --data-port=URL
111 Listen to trace data on URL URL (default: tcp://0.0.0.0:5343).
112 -L URL, --live-port=URL
114 Listen to LTTng live connections on URL URL (default:
115 tcp://localhost:5344).
116 Program information
118 -h, --help
119 Show help.
120 -V, --version
122 Show version.
123
125 LTTNG_ABORT_ON_ERROR
126 Set to 1 to abort the process after the first error is encountered.
127 LTTNG_NETWORK_SOCKET_TIMEOUT
129 Socket connection, receive and send timeout (milliseconds). A value
130 of 0 or -1 uses the timeout of the operating system (default).
131 LTTNG_RELAYD_HEALTH
133 Path to relay daemon health’s socket.
134 LTTNG_RELAYD_TCP_KEEP_ALIVE
136 Set to 1 to enable TCP keep-alive.
137 The TCP keep-alive mechanism allows the detection of dead peers
139 (lttng-sessiond(8)) in cases of unclean termination (for example, a
140 hard reset) of a peer.
141 Supported on Linux and Solaris only. The default behaviour of the
143 TCP keep-alive mechanism is OS-specific.
144 Search for tcp_keepalive in tcp(7) for more information.
146 LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD
148 The time threshold in seconds to abort a TCP connection after the
149 keep-alive probing mechanism has failed.
150 Set to 0 or -1 to use the value chosen by the operating system
152 (default).
153 Supported on Solaris 11 only.
155 Search for tcp_keepalive_abort_threshold in tcp(7) for more
157 information.
158 LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME
160 Number of seconds a connection needs to be idle before TCP begins
161 sending out keep-alive probes.
162 Set to 0 or -1 to use the value chosen by the operating system
164 (default).
165 Supported on Linux and Solaris 11 only.
167 On Solaris 11, the accepted values are -1, 0, and 10 to 864000.
169 Search for tcp_keepalive_time and tcp_keepalive_interval in tcp(7)
171 on Solaris 11 for more information.
172 LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT
174 Maximum number of TCP keep-alive probes to send before giving up
175 and killing the connection if no response is obtained from the
176 other end.
177 Set to 0 or -1 to use the value chosen by the operating system
179 (default).
180 Supported on Linux only.
182 Search for tcp_keepalive_probes in tcp(7) for more information.
184 LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL
186 Number of seconds between TCP keep-alive probes.
187 Set to 0 or -1 to use the value chosen by the operating system
189 (default).
190 Supported on Linux only.
192 Search for tcp_keepalive_intvl in tcp(7) for more information.
194
196 $LTTNG_HOME/.lttng
197 User LTTng runtime and configuration directory.
198 $LTTNG_HOME/lttng-traces
200 Default output directory of LTTng traces. This can be overridden
201 with the --output option.
202 Note
204 $LTTNG_HOME defaults to $HOME when not explicitly set.
205
207 0
208 Success
209 1
211 Error
212 3
214 Fatal error
215
217 As of this version, only the TCP protocol is supported for both control
218 and data ports. In future versions, TCP will remain the sole available
219 protocol for control data since those communications are low-volume and
220 need absolute reliability; trace data could be carried over UDP.
221 For an unprivileged user running lttng-relayd, the maximum number of
223 file descriptors per process is usually 1024. This limits the number of
224 connections and opened trace files. This limit can be configured with
225 ulimit(3).
226
228 If you encounter any issue or usability problem, please report it on
229 the LTTng bug tracker <https://bugs.lttng.org/projects/lttng-tools>.
230
232 · LTTng project website <https://lttng.org>
233 · LTTng documentation <https://lttng.org/docs>
235 · Git repositories <http://git.lttng.org>
237 · GitHub organization <http://github.com/lttng>
239 · Continuous integration <http://ci.lttng.org/>
241 · Mailing list <http://lists.lttng.org> for support and development:
243 lttng-dev@lists.lttng.org
244 · IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
246
248 This program is part of the LTTng-tools project.
249 LTTng-tools is distributed under the GNU General Public License version
251 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>. See the
252 LICENSE <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file
253 for details.
254
256 Special thanks to Michel Dagenais and the DORSAL laboratory
257 <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for
258 the LTTng journey.
259 Also thanks to the Ericsson teams working on tracing which helped us
261 greatly with detailed bug reports and unusual test cases.
262
264 lttng(1), lttng-sessiond(8), lttng-crash(1), lttng-ust(3),
265 babeltrace(1)
266LTTng 2.11.1 5 June 2018 LTTNG-RELAYD(8)