lttng-relayd(8)

1LTTNG-RELAYD(8)                  LTTng Manual                  LTTNG-RELAYD(8)
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NAME

6       lttng-relayd - LTTng 2 relay daemon
7

SYNOPSIS

9       lttng-relayd [--background | --daemonize]
10                    [--control-port=URL] [--data-port=URL] [--live-port=URL]
11                    [--output=PATH] [-v | -vv | -vvv]
12

DESCRIPTION

14       The Linux Trace Toolkit: next generation <http://lttng.org/> is an open
15       source software package used for correlated tracing of the Linux
16       kernel, user applications, and user libraries.
17
18       LTTng consists of Linux kernel modules (for Linux kernel tracing) and
19       dynamically loaded libraries (for user application and library
20       tracing).
21
22       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
28       The relay daemon listens by default on all network interfaces to gather
29       trace data, but only on localhost for LTTng live connections.
30
31       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://localhost:5344.
36
37       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
41   Output directory
42       By default, the relay daemon writes the traces to:
43
44           $LTTNG_HOME/lttng-traces/HOSTNAME/SESSION/DOMAIN
45
46       with:
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48       HOSTNAME
49           Remote hostname.
50
51       SESSION
52           Full session name.
53
54       DOMAIN
55           Tracing domain.
56
57       You can override the default output directory prefix
58       ($LTTNG_HOME/lttng-traces) with the --output option. The other parts
59       depend on the remote configuration.
60
61   URL format
62       The --control-port, --data-port, and --live-port options specify URLs.
63
64       The format of those URLs is:
65
66           tcp://(HOST | IPADDR):PORT
67
68       with:
69
70       (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
75       PORT
76           TCP port.
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OPTIONS

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
84       -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
88       -g GROUP, --group=GROUP
89           Use GROUP as Unix tracing group (default: tracing).
90
91       -o PATH, --output=PATH
92           Set base directory of written trace data to PATH.
93
94           See the Output directory section above for more information.
95
96       -v, --verbose
97           Increase verbosity.
98
99           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
103   Ports
104       See the URL format section above for more information about the syntax
105       of the following options' URL argument.
106
107       -C URL, --control-port=URL
108           Listen to control data on URL URL (default: tcp://0.0.0.0:5342).
109
110       -D URL, --data-port=URL
111           Listen to trace data on URL URL (default: tcp://0.0.0.0:5343).
112
113       -L URL, --live-port=URL
114           Listen to LTTng live connections on URL URL (default:
115           tcp://localhost:5344).
116
117   Program information
118       -h, --help
119           Show help.
120
121       -V, --version
122           Show version.
123

ENVIRONMENT VARIABLES

125       LTTNG_ABORT_ON_ERROR
126           Set to 1 to abort the process after the first error is encountered.
127
128       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
132       LTTNG_RELAYD_HEALTH
133           Path to relay daemon health’s socket.
134
135       LTTNG_RELAYD_TCP_KEEP_ALIVE
136           Set to 1 to enable TCP keep-alive.
137
138           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
142           Supported on Linux and Solaris only. The default behaviour of the
143           TCP keep-alive mechanism is OS-specific.
144
145           Search for tcp_keepalive in tcp(7) for more information.
146
147       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
151           Set to 0 or -1 to use the value chosen by the operating system
152           (default).
153
154           Supported on Solaris 11 only.
155
156           Search for tcp_keepalive_abort_threshold in tcp(7) for more
157           information.
158
159       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
163           Set to 0 or -1 to use the value chosen by the operating system
164           (default).
165
166           Supported on Linux and Solaris 11 only.
167
168           On Solaris 11, the accepted values are -1, 0, and 10 to 864000.
169
170           Search for tcp_keepalive_time and tcp_keepalive_interval in tcp(7)
171           on Solaris 11 for more information.
172
173       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
178           Set to 0 or -1 to use the value chosen by the operating system
179           (default).
180
181           Supported on Linux only.
182
183           Search for tcp_keepalive_probes in tcp(7) for more information.
184
185       LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL
186           Number of seconds between TCP keep-alive probes.
187
188           Set to 0 or -1 to use the value chosen by the operating system
189           (default).
190
191           Supported on Linux only.
192
193           Search for tcp_keepalive_intvl in tcp(7) for more information.
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FILES

196       $LTTNG_HOME/.lttng
197           User LTTng runtime and configuration directory.
198
199       $LTTNG_HOME/lttng-traces
200           Default output directory of LTTng traces. This can be overridden
201           with the --output option.
202
203           Note
204           $LTTNG_HOME defaults to $HOME when not explicitly set.
205

EXIT STATUS

207       0
208           Success
209
210       1
211           Error
212
213       3
214           Fatal error
215

LIMITATIONS

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
222       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

BUGS

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

RESOURCES

232       ·   LTTng project website <http://lttng.org>
233
234       ·   LTTng documentation <http://lttng.org/docs>
235
236       ·   Git repositories <http://git.lttng.org>
237
238       ·   GitHub organization <http://github.com/lttng>
239
240       ·   Continuous integration <http://ci.lttng.org/>
241
242       ·   Mailing list <http://lists.lttng.org> for support and development:
243           lttng-dev@lists.lttng.org
244
245       ·   IRC channel <irc://irc.oftc.net/lttng>: #lttng on irc.oftc.net
246

COPYRIGHTS

248       This program is part of the LTTng-tools project.
249
250       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

THANKS

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
260       Also thanks to the Ericsson teams working on tracing which helped us
261       greatly with detailed bug reports and unusual test cases.
262

AUTHORS

264       LTTng-tools was originally written by Mathieu Desnoyers, Julien
265       Desfossez, and David Goulet. More people have since contributed to it.
266
267       LTTng-tools is currently maintained by Jérémie Galarneau
268       <mailto:jeremie.galarneau@efficios.com>.
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