6a1f0bee229ce31c3dd5c0b8991f58613a4ec89b
[lttng-tools.git] / 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
17
18 DESCRIPTION
19 -----------
20 The https://lttng.org/[_Linux Trace Toolkit: next generation_] is an open
21 source software package used for correlated tracing of the Linux kernel,
22 user applications, and user libraries.
23
24 LTTng consists of Linux kernel modules (for Linux kernel tracing) and
25 dynamically loaded libraries (for user application and library tracing).
26
27 The _LTTng relay daemon_ is responsible for receiving trace data from
28 possibly remote LTTng session/consumer daemons and for writing it to
29 the local file system. The relay daemon also accepts _LTTng live_
30 connections from compatible viewers; this is the official approach to
31 viewing LTTng events as they are emitted.
32
33 The relay daemon listens by default on all network interfaces to gather
34 trace data, but only on localhost for LTTng live connections.
35
36 The relay daemon does not require any particular permissions, as long as
37 it can write to the output directory and listen on the configured ports.
38 If a user is within a secured network and/or has proper firewall
39 settings, `lttng-relayd` can listen to LTTng live connections from _all_
40 network interfaces by specifying
41 +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+.
42
43 Once a trace has been streamed completely, the trace can be processed by
44 any tool that can process an LTTng trace located on the local
45 file system.
46
47
48 [[output-directory]]
49 Output directory
50 ~~~~~~~~~~~~~~~~
51 By default, the relay daemon writes the traces to:
52
53 [verse]
54 $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN'
55
56 with:
57
58 'HOSTNAME'::
59 Remote hostname.
60
61 'SESSION'::
62 Full session name.
63
64 'DOMAIN'::
65 Tracing domain.
66
67 You can override the default output directory prefix
68 (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other
69 parts depend on the remote configuration.
70
71
72 [[url-format]]
73 URL format
74 ~~~~~~~~~~
75 The option:--control-port, option:--data-port, and option:--live-port
76 options specify URLs.
77
78 The format of those URLs is:
79
80 [verse]
81 tcp://('HOST' | 'IPADDR'):__PORT__
82
83 with:
84
85 ('HOST' | 'IPADDR')::
86 Binding hostname or IP address (IPv6 address *must* be enclosed in
87 brackets (`[` and `]`); see
88 https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]).
89
90 'PORT'::
91 TCP port.
92
93
94 OPTIONS
95 -------
96 Daemon
97 ~~~~~~
98 option:-b, option:--background::
99 Start as Unix daemon, but keep file descriptors (console) open.
100 Use the option:--daemonize option instead to close the file
101 descriptors.
102
103 option:-d, option:--daemonize::
104 Start as Unix daemon, and close file descriptors (console). Use the
105 option:--background option instead to keep the file descriptors
106 open.
107
108 option:-g 'GROUP', option:--group='GROUP'::
109 Use 'GROUP' as Unix tracing group (default: `tracing`).
110
111 option:-o 'PATH', option:--output='PATH'::
112 Set base directory of written trace data to 'PATH'.
113 +
114 See the <<output-directory,Output directory>> section above for more
115 information.
116
117 option:-v, option:--verbose::
118 Increase verbosity.
119 +
120 Three levels of verbosity are available, which are triggered by
121 appending additional `v` letters to the option
122 (that is, `-vv` and `-vvv`).
123
124
125 Ports
126 ~~~~~
127 See the <<url-format,URL format>> section above for more information
128 about the syntax of the following options' 'URL' argument.
129
130 option:-C 'URL', option:--control-port='URL'::
131 Listen to control data on URL 'URL' (default:
132 +tcp://{default_network_control_bind_address}:{default_network_control_port}+).
133
134 option:-D 'URL', option:--data-port='URL'::
135 Listen to trace data on URL 'URL' (default:
136 +tcp://{default_network_data_bind_address}:{default_network_data_port}+).
137
138 option:-L 'URL', option:--live-port='URL'::
139 Listen to LTTng live connections on URL 'URL'
140 (default:
141 +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+).
142
143
144 Program information
145 ~~~~~~~~~~~~~~~~~~~
146 option:-h, option:--help::
147 Show help.
148
149 option:-V, option:--version::
150 Show version.
151
152
153 ENVIRONMENT VARIABLES
154 ---------------------
155 `LTTNG_ABORT_ON_ERROR`::
156 Set to 1 to abort the process after the first error is encountered.
157
158 `LTTNG_NETWORK_SOCKET_TIMEOUT`::
159 Socket connection, receive and send timeout (milliseconds). A value
160 of 0 or -1 uses the timeout of the operating system (default).
161
162 `LTTNG_RELAYD_HEALTH`::
163 Path to relay daemon health's socket.
164
165 `LTTNG_RELAYD_TCP_KEEP_ALIVE`::
166 Set to 1 to enable TCP keep-alive.
167 +
168 The TCP keep-alive mechanism allows the detection of dead peers
169 (man:lttng-sessiond(8)) in cases of unclean termination
170 (for example, a hard reset) of a peer.
171 +
172 Supported on Linux and Solaris only. The default behaviour of the TCP
173 keep-alive mechanism is OS-specific.
174 +
175 Search for `tcp_keepalive` in man:tcp(7) for more information.
176
177 `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`::
178 The time threshold in seconds to abort a TCP connection after the keep-alive
179 probing mechanism has failed.
180 +
181 Set to 0 or -1 to use the value chosen by the operating system (default).
182 +
183 Supported on Solaris 11 only.
184 +
185 Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information.
186
187 `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`::
188 Number of seconds a connection needs to be idle before TCP begins
189 sending out keep-alive probes.
190 +
191 Set to 0 or -1 to use the value chosen by the operating system (default).
192 +
193 Supported on Linux and Solaris 11 only.
194 +
195 On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000.
196 +
197 Search for `tcp_keepalive_time` and `tcp_keepalive_interval`
198 in man:tcp(7) on Solaris 11 for more information.
199
200 `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`::
201 Maximum number of TCP keep-alive probes to send before giving up and
202 killing the connection if no response is obtained from the other end.
203 +
204 Set to 0 or -1 to use the value chosen by the operating system (default).
205 +
206 Supported on Linux only.
207 +
208 Search for `tcp_keepalive_probes` in man:tcp(7) for more information.
209
210 `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`::
211 Number of seconds between TCP keep-alive probes.
212 +
213 Set to 0 or -1 to use the value chosen by the operating system (default).
214 +
215 Supported on Linux only.
216 +
217 Search for `tcp_keepalive_intvl` in man:tcp(7) for more information.
218
219
220 FILES
221 -----
222 `$LTTNG_HOME/.lttng`::
223 User LTTng runtime and configuration directory.
224
225 `$LTTNG_HOME/lttng-traces`::
226 Default output directory of LTTng traces. This can be overridden
227 with the option:--output option.
228
229 NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set.
230
231
232 EXIT STATUS
233 -----------
234 *0*::
235 Success
236
237 *1*::
238 Error
239
240 *3*::
241 Fatal error
242
243
244 LIMITATIONS
245 -----------
246 As of this version, only the TCP protocol is supported for both control
247 and data ports. In future versions, TCP will remain the sole available
248 protocol for control data since those communications are low-volume and
249 need absolute reliability; trace data could be carried over UDP.
250
251 For an unprivileged user running `lttng-relayd`, the maximum number of
252 file descriptors per process is usually 1024. This limits the number of
253 connections and opened trace files. This limit can be configured with
254 *ulimit*(3).
255
256
257 include::common-footer.txt[]
258
259
260 SEE ALSO
261 --------
262 man:lttng(1),
263 man:lttng-sessiond(8),
264 man:lttng-crash(1),
265 man:lttng-ust(3),
266 man:babeltrace(1)
This page took 0.051036 seconds and 3 git commands to generate.