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f5595c32 PP |
1 | lttng-relayd(8) |
2 | =============== | |
4605890e | 3 | :revdate: 5 June 2018 |
f5595c32 PP |
4 | |
5 | ||
6 | NAME | |
7 | ---- | |
8 | lttng-relayd - LTTng 2 relay daemon | |
9 | ||
10 | ||
11 | SYNOPSIS | |
12 | -------- | |
13 | [verse] | |
14 | *lttng-relayd* [option:--background | option:--daemonize] | |
15 | [option:--control-port='URL'] [option:--data-port='URL'] [option:--live-port='URL'] | |
16 | [option:--output='PATH'] [option:-v | option:-vv | option:-vvv] | |
6ab3f69a | 17 | [option:--working-directory='PATH'] |
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18 | |
19 | ||
20 | DESCRIPTION | |
21 | ----------- | |
a18d9544 | 22 | The https://lttng.org/[_Linux Trace Toolkit: next generation_] is an open |
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23 | source software package used for correlated tracing of the Linux kernel, |
24 | user applications, and user libraries. | |
25 | ||
26 | LTTng consists of Linux kernel modules (for Linux kernel tracing) and | |
27 | dynamically loaded libraries (for user application and library tracing). | |
28 | ||
29 | The _LTTng relay daemon_ is responsible for receiving trace data from | |
30 | possibly remote LTTng session/consumer daemons and for writing it to | |
31 | the local file system. The relay daemon also accepts _LTTng live_ | |
32 | connections from compatible viewers; this is the official approach to | |
33 | viewing LTTng events as they are emitted. | |
34 | ||
35 | The relay daemon listens by default on all network interfaces to gather | |
36 | trace data, but only on localhost for LTTng live connections. | |
37 | ||
38 | The relay daemon does not require any particular permissions, as long as | |
39 | it can write to the output directory and listen on the configured ports. | |
40 | If a user is within a secured network and/or has proper firewall | |
41 | settings, `lttng-relayd` can listen to LTTng live connections from _all_ | |
c93eadad PP |
42 | network interfaces by specifying |
43 | +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+. | |
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44 | |
45 | Once a trace has been streamed completely, the trace can be processed by | |
46 | any tool that can process an LTTng trace located on the local | |
47 | file system. | |
48 | ||
49 | ||
50 | [[output-directory]] | |
51 | Output directory | |
52 | ~~~~~~~~~~~~~~~~ | |
53 | By default, the relay daemon writes the traces to: | |
54 | ||
55 | [verse] | |
2ff6d569 | 56 | $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN' |
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57 | |
58 | with: | |
59 | ||
60 | 'HOSTNAME':: | |
61 | Remote hostname. | |
62 | ||
63 | 'SESSION':: | |
64 | Full session name. | |
65 | ||
66 | 'DOMAIN':: | |
67 | Tracing domain. | |
68 | ||
69 | You can override the default output directory prefix | |
2ff6d569 | 70 | (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other |
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71 | parts depend on the remote configuration. |
72 | ||
73 | ||
74 | [[url-format]] | |
75 | URL format | |
76 | ~~~~~~~~~~ | |
77 | The option:--control-port, option:--data-port, and option:--live-port | |
78 | options specify URLs. | |
79 | ||
80 | The format of those URLs is: | |
81 | ||
82 | [verse] | |
83 | tcp://('HOST' | 'IPADDR'):__PORT__ | |
84 | ||
85 | with: | |
86 | ||
87 | ('HOST' | 'IPADDR'):: | |
88 | Binding hostname or IP address (IPv6 address *must* be enclosed in | |
89 | brackets (`[` and `]`); see | |
90 | https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]). | |
91 | ||
92 | 'PORT':: | |
93 | TCP port. | |
94 | ||
95 | ||
96 | OPTIONS | |
97 | ------- | |
98 | Daemon | |
99 | ~~~~~~ | |
100 | option:-b, option:--background:: | |
101 | Start as Unix daemon, but keep file descriptors (console) open. | |
102 | Use the option:--daemonize option instead to close the file | |
103 | descriptors. | |
104 | ||
105 | option:-d, option:--daemonize:: | |
106 | Start as Unix daemon, and close file descriptors (console). Use the | |
107 | option:--background option instead to keep the file descriptors | |
108 | open. | |
109 | ||
59b19c3c | 110 | option:-g 'GROUP', option:--group='GROUP':: |
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111 | Use 'GROUP' as Unix tracing group (default: `tracing`). |
112 | ||
59b19c3c | 113 | option:-o 'PATH', option:--output='PATH':: |
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114 | Set base directory of written trace data to 'PATH'. |
115 | + | |
116 | See the <<output-directory,Output directory>> section above for more | |
117 | information. | |
118 | ||
6ab3f69a JR |
119 | option:-w 'PATH', option:--working-directory='PATH':: |
120 | Set the working directory of the processes this relay daemon creates. | |
121 | ||
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122 | option:-v, option:--verbose:: |
123 | Increase verbosity. | |
124 | + | |
125 | Three levels of verbosity are available, which are triggered by | |
126 | appending additional `v` letters to the option | |
127 | (that is, `-vv` and `-vvv`). | |
128 | ||
129 | ||
130 | Ports | |
131 | ~~~~~ | |
132 | See the <<url-format,URL format>> section above for more information | |
133 | about the syntax of the following options' 'URL' argument. | |
134 | ||
59b19c3c | 135 | option:-C 'URL', option:--control-port='URL':: |
c93eadad PP |
136 | Listen to control data on URL 'URL' (default: |
137 | +tcp://{default_network_control_bind_address}:{default_network_control_port}+). | |
f5595c32 | 138 | |
59b19c3c | 139 | option:-D 'URL', option:--data-port='URL':: |
c93eadad PP |
140 | Listen to trace data on URL 'URL' (default: |
141 | +tcp://{default_network_data_bind_address}:{default_network_data_port}+). | |
f5595c32 | 142 | |
59b19c3c | 143 | option:-L 'URL', option:--live-port='URL':: |
f5595c32 | 144 | Listen to LTTng live connections on URL 'URL' |
c93eadad PP |
145 | (default: |
146 | +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+). | |
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147 | |
148 | ||
149 | Program information | |
150 | ~~~~~~~~~~~~~~~~~~~ | |
151 | option:-h, option:--help:: | |
152 | Show help. | |
153 | ||
154 | option:-V, option:--version:: | |
155 | Show version. | |
156 | ||
157 | ||
158 | ENVIRONMENT VARIABLES | |
159 | --------------------- | |
9bbd8e06 MD |
160 | `LTTNG_ABORT_ON_ERROR`:: |
161 | Set to 1 to abort the process after the first error is encountered. | |
162 | ||
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163 | `LTTNG_NETWORK_SOCKET_TIMEOUT`:: |
164 | Socket connection, receive and send timeout (milliseconds). A value | |
165 | of 0 or -1 uses the timeout of the operating system (default). | |
166 | ||
167 | `LTTNG_RELAYD_HEALTH`:: | |
168 | Path to relay daemon health's socket. | |
169 | ||
e0512bf5 JR |
170 | `LTTNG_RELAYD_TCP_KEEP_ALIVE`:: |
171 | Set to 1 to enable TCP keep-alive. | |
172 | + | |
173 | The TCP keep-alive mechanism allows the detection of dead peers | |
174 | (man:lttng-sessiond(8)) in cases of unclean termination | |
175 | (for example, a hard reset) of a peer. | |
176 | + | |
177 | Supported on Linux and Solaris only. The default behaviour of the TCP | |
178 | keep-alive mechanism is OS-specific. | |
179 | + | |
180 | Search for `tcp_keepalive` in man:tcp(7) for more information. | |
181 | ||
182 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`:: | |
183 | The time threshold in seconds to abort a TCP connection after the keep-alive | |
184 | probing mechanism has failed. | |
185 | + | |
186 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
187 | + | |
188 | Supported on Solaris 11 only. | |
189 | + | |
190 | Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information. | |
191 | ||
192 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`:: | |
193 | Number of seconds a connection needs to be idle before TCP begins | |
194 | sending out keep-alive probes. | |
195 | + | |
196 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
197 | + | |
198 | Supported on Linux and Solaris 11 only. | |
199 | + | |
200 | On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000. | |
201 | + | |
202 | Search for `tcp_keepalive_time` and `tcp_keepalive_interval` | |
203 | in man:tcp(7) on Solaris 11 for more information. | |
204 | ||
205 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`:: | |
206 | Maximum number of TCP keep-alive probes to send before giving up and | |
207 | killing the connection if no response is obtained from the other end. | |
208 | + | |
209 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
210 | + | |
211 | Supported on Linux only. | |
212 | + | |
213 | Search for `tcp_keepalive_probes` in man:tcp(7) for more information. | |
214 | ||
215 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`:: | |
216 | Number of seconds between TCP keep-alive probes. | |
217 | + | |
218 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
219 | + | |
220 | Supported on Linux only. | |
221 | + | |
222 | Search for `tcp_keepalive_intvl` in man:tcp(7) for more information. | |
223 | ||
508a802c JR |
224 | `LTTNG_RELAYD_WORKING_DIRECTORY`:: |
225 | Working directory of the processes this relay daemon creates. | |
226 | + | |
227 | The option:--working-directory option overrides this variable. | |
228 | ||
f5595c32 | 229 | |
900690ca PP |
230 | FILES |
231 | ----- | |
232 | `$LTTNG_HOME/.lttng`:: | |
233 | User LTTng runtime and configuration directory. | |
234 | ||
235 | `$LTTNG_HOME/lttng-traces`:: | |
236 | Default output directory of LTTng traces. This can be overridden | |
237 | with the option:--output option. | |
238 | ||
239 | NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set. | |
240 | ||
241 | ||
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242 | EXIT STATUS |
243 | ----------- | |
244 | *0*:: | |
245 | Success | |
246 | ||
247 | *1*:: | |
248 | Error | |
249 | ||
250 | *3*:: | |
251 | Fatal error | |
252 | ||
253 | ||
254 | LIMITATIONS | |
255 | ----------- | |
256 | As of this version, only the TCP protocol is supported for both control | |
257 | and data ports. In future versions, TCP will remain the sole available | |
258 | protocol for control data since those communications are low-volume and | |
259 | need absolute reliability; trace data could be carried over UDP. | |
260 | ||
261 | For an unprivileged user running `lttng-relayd`, the maximum number of | |
262 | file descriptors per process is usually 1024. This limits the number of | |
263 | connections and opened trace files. This limit can be configured with | |
264 | *ulimit*(3). | |
265 | ||
266 | ||
267 | include::common-footer.txt[] | |
268 | ||
269 | ||
270 | SEE ALSO | |
271 | -------- | |
7c1a4458 PP |
272 | man:lttng(1), |
273 | man:lttng-sessiond(8), | |
274 | man:lttng-crash(1), | |
275 | man:lttng-ust(3), | |
276 | man:babeltrace(1) |