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f5595c32 PP |
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 | ----------- | |
a18d9544 | 20 | The https://lttng.org/[_Linux Trace Toolkit: next generation_] is an open |
f5595c32 PP |
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_ | |
c93eadad PP |
40 | network interfaces by specifying |
41 | +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+. | |
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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 | ~~~~~~~~~~~~~~~~ | |
00331055 JR |
51 | By default (option:--group-output-by-host), the relay daemon writes the traces |
52 | to: | |
f5595c32 PP |
53 | |
54 | [verse] | |
2ff6d569 | 55 | $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN' |
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56 | |
57 | with: | |
58 | ||
59 | 'HOSTNAME':: | |
60 | Remote hostname. | |
61 | ||
62 | 'SESSION':: | |
63 | Full session name. | |
64 | ||
65 | 'DOMAIN':: | |
66 | Tracing domain. | |
67 | ||
00331055 JR |
68 | You can group the output per session instead of per hostname with the |
69 | option:--group-output-by-session option. This result in the following: | |
70 | ||
71 | [verse] | |
72 | ||
73 | $LTTNG_HOME/lttng-traces/'SESSION'/'HOST'/'DOMAIN' | |
74 | ||
f5595c32 | 75 | You can override the default output directory prefix |
2ff6d569 | 76 | (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other |
f5595c32 PP |
77 | parts depend on the remote configuration. |
78 | ||
79 | ||
00331055 | 80 | |
f5595c32 PP |
81 | [[url-format]] |
82 | URL format | |
83 | ~~~~~~~~~~ | |
84 | The option:--control-port, option:--data-port, and option:--live-port | |
85 | options specify URLs. | |
86 | ||
87 | The format of those URLs is: | |
88 | ||
89 | [verse] | |
90 | tcp://('HOST' | 'IPADDR'):__PORT__ | |
91 | ||
92 | with: | |
93 | ||
94 | ('HOST' | 'IPADDR'):: | |
95 | Binding hostname or IP address (IPv6 address *must* be enclosed in | |
96 | brackets (`[` and `]`); see | |
97 | https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]). | |
98 | ||
99 | 'PORT':: | |
100 | TCP port. | |
101 | ||
102 | ||
103 | OPTIONS | |
104 | ------- | |
105 | Daemon | |
106 | ~~~~~~ | |
107 | option:-b, option:--background:: | |
108 | Start as Unix daemon, but keep file descriptors (console) open. | |
109 | Use the option:--daemonize option instead to close the file | |
110 | descriptors. | |
111 | ||
112 | option:-d, option:--daemonize:: | |
113 | Start as Unix daemon, and close file descriptors (console). Use the | |
114 | option:--background option instead to keep the file descriptors | |
115 | open. | |
116 | ||
59b19c3c | 117 | option:-g 'GROUP', option:--group='GROUP':: |
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118 | Use 'GROUP' as Unix tracing group (default: `tracing`). |
119 | ||
59b19c3c | 120 | option:-o 'PATH', option:--output='PATH':: |
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121 | Set base directory of written trace data to 'PATH'. |
122 | + | |
123 | See the <<output-directory,Output directory>> section above for more | |
124 | information. | |
125 | ||
00331055 JR |
126 | option:-p, option:--group-output-by-host:: |
127 | Organize the output directory by host. Default behavior. | |
128 | + | |
129 | See the <<output-directory,Output directory>> section above for more | |
130 | information. | |
131 | ||
132 | option:-s, option:--group-output-by-session:: | |
133 | Organize the output directory by session. | |
134 | + | |
135 | See the <<output-directory,Output directory>> section above for more | |
136 | information. | |
137 | ||
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138 | option:-v, option:--verbose:: |
139 | Increase verbosity. | |
140 | + | |
141 | Three levels of verbosity are available, which are triggered by | |
142 | appending additional `v` letters to the option | |
143 | (that is, `-vv` and `-vvv`). | |
144 | ||
145 | ||
146 | Ports | |
147 | ~~~~~ | |
148 | See the <<url-format,URL format>> section above for more information | |
149 | about the syntax of the following options' 'URL' argument. | |
150 | ||
59b19c3c | 151 | option:-C 'URL', option:--control-port='URL':: |
c93eadad PP |
152 | Listen to control data on URL 'URL' (default: |
153 | +tcp://{default_network_control_bind_address}:{default_network_control_port}+). | |
f5595c32 | 154 | |
59b19c3c | 155 | option:-D 'URL', option:--data-port='URL':: |
c93eadad PP |
156 | Listen to trace data on URL 'URL' (default: |
157 | +tcp://{default_network_data_bind_address}:{default_network_data_port}+). | |
f5595c32 | 158 | |
59b19c3c | 159 | option:-L 'URL', option:--live-port='URL':: |
f5595c32 | 160 | Listen to LTTng live connections on URL 'URL' |
c93eadad PP |
161 | (default: |
162 | +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+). | |
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163 | |
164 | ||
165 | Program information | |
166 | ~~~~~~~~~~~~~~~~~~~ | |
167 | option:-h, option:--help:: | |
168 | Show help. | |
169 | ||
170 | option:-V, option:--version:: | |
171 | Show version. | |
172 | ||
173 | ||
174 | ENVIRONMENT VARIABLES | |
175 | --------------------- | |
9bbd8e06 MD |
176 | `LTTNG_ABORT_ON_ERROR`:: |
177 | Set to 1 to abort the process after the first error is encountered. | |
178 | ||
f5595c32 PP |
179 | `LTTNG_NETWORK_SOCKET_TIMEOUT`:: |
180 | Socket connection, receive and send timeout (milliseconds). A value | |
181 | of 0 or -1 uses the timeout of the operating system (default). | |
182 | ||
183 | `LTTNG_RELAYD_HEALTH`:: | |
184 | Path to relay daemon health's socket. | |
185 | ||
e0512bf5 JR |
186 | `LTTNG_RELAYD_TCP_KEEP_ALIVE`:: |
187 | Set to 1 to enable TCP keep-alive. | |
188 | + | |
189 | The TCP keep-alive mechanism allows the detection of dead peers | |
190 | (man:lttng-sessiond(8)) in cases of unclean termination | |
191 | (for example, a hard reset) of a peer. | |
192 | + | |
193 | Supported on Linux and Solaris only. The default behaviour of the TCP | |
194 | keep-alive mechanism is OS-specific. | |
195 | + | |
196 | Search for `tcp_keepalive` in man:tcp(7) for more information. | |
197 | ||
198 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`:: | |
199 | The time threshold in seconds to abort a TCP connection after the keep-alive | |
200 | probing mechanism has failed. | |
201 | + | |
202 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
203 | + | |
204 | Supported on Solaris 11 only. | |
205 | + | |
206 | Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information. | |
207 | ||
208 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`:: | |
209 | Number of seconds a connection needs to be idle before TCP begins | |
210 | sending out keep-alive probes. | |
211 | + | |
212 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
213 | + | |
214 | Supported on Linux and Solaris 11 only. | |
215 | + | |
216 | On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000. | |
217 | + | |
218 | Search for `tcp_keepalive_time` and `tcp_keepalive_interval` | |
219 | in man:tcp(7) on Solaris 11 for more information. | |
220 | ||
221 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`:: | |
222 | Maximum number of TCP keep-alive probes to send before giving up and | |
223 | killing the connection if no response is obtained from the other end. | |
224 | + | |
225 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
226 | + | |
227 | Supported on Linux only. | |
228 | + | |
229 | Search for `tcp_keepalive_probes` in man:tcp(7) for more information. | |
230 | ||
231 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`:: | |
232 | Number of seconds between TCP keep-alive probes. | |
233 | + | |
234 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
235 | + | |
236 | Supported on Linux only. | |
237 | + | |
238 | Search for `tcp_keepalive_intvl` in man:tcp(7) for more information. | |
239 | ||
f5595c32 | 240 | |
900690ca PP |
241 | FILES |
242 | ----- | |
243 | `$LTTNG_HOME/.lttng`:: | |
244 | User LTTng runtime and configuration directory. | |
245 | ||
246 | `$LTTNG_HOME/lttng-traces`:: | |
247 | Default output directory of LTTng traces. This can be overridden | |
248 | with the option:--output option. | |
249 | ||
250 | NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set. | |
251 | ||
252 | ||
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253 | EXIT STATUS |
254 | ----------- | |
255 | *0*:: | |
256 | Success | |
257 | ||
258 | *1*:: | |
259 | Error | |
260 | ||
261 | *3*:: | |
262 | Fatal error | |
263 | ||
264 | ||
265 | LIMITATIONS | |
266 | ----------- | |
267 | As of this version, only the TCP protocol is supported for both control | |
268 | and data ports. In future versions, TCP will remain the sole available | |
269 | protocol for control data since those communications are low-volume and | |
270 | need absolute reliability; trace data could be carried over UDP. | |
271 | ||
272 | For an unprivileged user running `lttng-relayd`, the maximum number of | |
273 | file descriptors per process is usually 1024. This limits the number of | |
274 | connections and opened trace files. This limit can be configured with | |
275 | *ulimit*(3). | |
276 | ||
277 | ||
278 | include::common-footer.txt[] | |
279 | ||
280 | ||
281 | SEE ALSO | |
282 | -------- | |
7c1a4458 PP |
283 | man:lttng(1), |
284 | man:lttng-sessiond(8), | |
285 | man:lttng-crash(1), | |
286 | man:lttng-ust(3), | |
287 | man:babeltrace(1) |