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1 | lttng-relayd(8) |
2 | =============== | |
990cbf52 | 3 | :revdate: 5 June 2018 |
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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] | |
17 | ||
18 | ||
19 | DESCRIPTION | |
20 | ----------- | |
21 | The http://lttng.org/[_Linux Trace Toolkit: next generation_] is an open | |
22 | source software package used for correlated tracing of the Linux kernel, | |
23 | user applications, and user libraries. | |
24 | ||
25 | LTTng consists of Linux kernel modules (for Linux kernel tracing) and | |
26 | dynamically loaded libraries (for user application and library tracing). | |
27 | ||
28 | The _LTTng relay daemon_ is responsible for receiving trace data from | |
29 | possibly remote LTTng session/consumer daemons and for writing it to | |
30 | the local file system. The relay daemon also accepts _LTTng live_ | |
31 | connections from compatible viewers; this is the official approach to | |
32 | viewing LTTng events as they are emitted. | |
33 | ||
34 | The relay daemon listens by default on all network interfaces to gather | |
35 | trace data, but only on localhost for LTTng live connections. | |
36 | ||
37 | The relay daemon does not require any particular permissions, as long as | |
38 | it can write to the output directory and listen on the configured ports. | |
39 | If a user is within a secured network and/or has proper firewall | |
40 | settings, `lttng-relayd` can listen to LTTng live connections from _all_ | |
c93eadad PP |
41 | network interfaces by specifying |
42 | +--live-port=tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+. | |
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43 | |
44 | Once a trace has been streamed completely, the trace can be processed by | |
45 | any tool that can process an LTTng trace located on the local | |
46 | file system. | |
47 | ||
48 | ||
49 | [[output-directory]] | |
50 | Output directory | |
51 | ~~~~~~~~~~~~~~~~ | |
52 | By default, the relay daemon writes the traces to: | |
53 | ||
54 | [verse] | |
2ff6d569 | 55 | $LTTNG_HOME/lttng-traces/'HOSTNAME'/'SESSION'/'DOMAIN' |
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56 | |
57 | with: | |
58 | ||
59 | 'HOSTNAME':: | |
60 | Remote hostname. | |
61 | ||
62 | 'SESSION':: | |
63 | Full session name. | |
64 | ||
65 | 'DOMAIN':: | |
66 | Tracing domain. | |
67 | ||
68 | You can override the default output directory prefix | |
2ff6d569 | 69 | (`$LTTNG_HOME/lttng-traces`) with the option:--output option. The other |
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70 | parts depend on the remote configuration. |
71 | ||
72 | ||
73 | [[url-format]] | |
74 | URL format | |
75 | ~~~~~~~~~~ | |
76 | The option:--control-port, option:--data-port, and option:--live-port | |
77 | options specify URLs. | |
78 | ||
79 | The format of those URLs is: | |
80 | ||
81 | [verse] | |
82 | tcp://('HOST' | 'IPADDR'):__PORT__ | |
83 | ||
84 | with: | |
85 | ||
86 | ('HOST' | 'IPADDR'):: | |
87 | Binding hostname or IP address (IPv6 address *must* be enclosed in | |
88 | brackets (`[` and `]`); see | |
89 | https://www.ietf.org/rfc/rfc2732.txt[RFC 2732]). | |
90 | ||
91 | 'PORT':: | |
92 | TCP port. | |
93 | ||
94 | ||
95 | OPTIONS | |
96 | ------- | |
97 | Daemon | |
98 | ~~~~~~ | |
99 | option:-b, option:--background:: | |
100 | Start as Unix daemon, but keep file descriptors (console) open. | |
101 | Use the option:--daemonize option instead to close the file | |
102 | descriptors. | |
103 | ||
104 | option:-d, option:--daemonize:: | |
105 | Start as Unix daemon, and close file descriptors (console). Use the | |
106 | option:--background option instead to keep the file descriptors | |
107 | open. | |
108 | ||
59b19c3c | 109 | option:-g 'GROUP', option:--group='GROUP':: |
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110 | Use 'GROUP' as Unix tracing group (default: `tracing`). |
111 | ||
59b19c3c | 112 | option:-o 'PATH', option:--output='PATH':: |
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113 | Set base directory of written trace data to 'PATH'. |
114 | + | |
115 | See the <<output-directory,Output directory>> section above for more | |
116 | information. | |
117 | ||
118 | option:-v, option:--verbose:: | |
119 | Increase verbosity. | |
120 | + | |
121 | Three levels of verbosity are available, which are triggered by | |
122 | appending additional `v` letters to the option | |
123 | (that is, `-vv` and `-vvv`). | |
124 | ||
125 | ||
126 | Ports | |
127 | ~~~~~ | |
128 | See the <<url-format,URL format>> section above for more information | |
129 | about the syntax of the following options' 'URL' argument. | |
130 | ||
59b19c3c | 131 | option:-C 'URL', option:--control-port='URL':: |
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132 | Listen to control data on URL 'URL' (default: |
133 | +tcp://{default_network_control_bind_address}:{default_network_control_port}+). | |
f5595c32 | 134 | |
59b19c3c | 135 | option:-D 'URL', option:--data-port='URL':: |
c93eadad PP |
136 | Listen to trace data on URL 'URL' (default: |
137 | +tcp://{default_network_data_bind_address}:{default_network_data_port}+). | |
f5595c32 | 138 | |
59b19c3c | 139 | option:-L 'URL', option:--live-port='URL':: |
f5595c32 | 140 | Listen to LTTng live connections on URL 'URL' |
c93eadad PP |
141 | (default: |
142 | +tcp://{default_network_viewer_bind_address}:{default_network_viewer_port}+). | |
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143 | |
144 | ||
145 | Program information | |
146 | ~~~~~~~~~~~~~~~~~~~ | |
147 | option:-h, option:--help:: | |
148 | Show help. | |
149 | ||
150 | option:-V, option:--version:: | |
151 | Show version. | |
152 | ||
153 | ||
154 | ENVIRONMENT VARIABLES | |
155 | --------------------- | |
9bbd8e06 MD |
156 | `LTTNG_ABORT_ON_ERROR`:: |
157 | Set to 1 to abort the process after the first error is encountered. | |
158 | ||
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159 | `LTTNG_NETWORK_SOCKET_TIMEOUT`:: |
160 | Socket connection, receive and send timeout (milliseconds). A value | |
161 | of 0 or -1 uses the timeout of the operating system (default). | |
162 | ||
163 | `LTTNG_RELAYD_HEALTH`:: | |
164 | Path to relay daemon health's socket. | |
165 | ||
f0c0545a JR |
166 | `LTTNG_RELAYD_TCP_KEEP_ALIVE`:: |
167 | Set to 1 to enable TCP keep-alive. | |
168 | + | |
169 | The TCP keep-alive mechanism allows the detection of dead peers | |
170 | (man:lttng-sessiond(8)) in cases of unclean termination | |
171 | (for example, a hard reset) of a peer. | |
172 | + | |
173 | Supported on Linux and Solaris only. The default behaviour of the TCP | |
174 | keep-alive mechanism is OS-specific. | |
175 | + | |
176 | Search for `tcp_keepalive` in man:tcp(7) for more information. | |
177 | ||
178 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_ABORT_THRESHOLD`:: | |
179 | The time threshold in seconds to abort a TCP connection after the keep-alive | |
180 | probing mechanism has failed. | |
181 | + | |
182 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
183 | + | |
184 | Supported on Solaris 11 only. | |
185 | + | |
186 | Search for `tcp_keepalive_abort_threshold` in man:tcp(7) for more information. | |
187 | ||
188 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_IDLE_TIME`:: | |
189 | Number of seconds a connection needs to be idle before TCP begins | |
190 | sending out keep-alive probes. | |
191 | + | |
192 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
193 | + | |
194 | Supported on Linux and Solaris 11 only. | |
195 | + | |
196 | On Solaris{nbsp}11, the accepted values are -1, 0, and 10 to 864000. | |
197 | + | |
198 | Search for `tcp_keepalive_time` and `tcp_keepalive_interval` | |
199 | in man:tcp(7) on Solaris 11 for more information. | |
200 | ||
201 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_MAX_PROBE_COUNT`:: | |
202 | Maximum number of TCP keep-alive probes to send before giving up and | |
203 | killing the connection if no response is obtained from the other end. | |
204 | + | |
205 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
206 | + | |
207 | Supported on Linux only. | |
208 | + | |
209 | Search for `tcp_keepalive_probes` in man:tcp(7) for more information. | |
210 | ||
211 | `LTTNG_RELAYD_TCP_KEEP_ALIVE_PROBE_INTERVAL`:: | |
212 | Number of seconds between TCP keep-alive probes. | |
213 | + | |
214 | Set to 0 or -1 to use the value chosen by the operating system (default). | |
215 | + | |
216 | Supported on Linux only. | |
217 | + | |
218 | Search for `tcp_keepalive_intvl` in man:tcp(7) for more information. | |
219 | ||
f5595c32 | 220 | |
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221 | FILES |
222 | ----- | |
223 | `$LTTNG_HOME/.lttng`:: | |
224 | User LTTng runtime and configuration directory. | |
225 | ||
226 | `$LTTNG_HOME/lttng-traces`:: | |
227 | Default output directory of LTTng traces. This can be overridden | |
228 | with the option:--output option. | |
229 | ||
230 | NOTE: `$LTTNG_HOME` defaults to `$HOME` when not explicitly set. | |
231 | ||
232 | ||
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233 | EXIT STATUS |
234 | ----------- | |
235 | *0*:: | |
236 | Success | |
237 | ||
238 | *1*:: | |
239 | Error | |
240 | ||
241 | *3*:: | |
242 | Fatal error | |
243 | ||
244 | ||
245 | LIMITATIONS | |
246 | ----------- | |
247 | As of this version, only the TCP protocol is supported for both control | |
248 | and data ports. In future versions, TCP will remain the sole available | |
249 | protocol for control data since those communications are low-volume and | |
250 | need absolute reliability; trace data could be carried over UDP. | |
251 | ||
252 | For an unprivileged user running `lttng-relayd`, the maximum number of | |
253 | file descriptors per process is usually 1024. This limits the number of | |
254 | connections and opened trace files. This limit can be configured with | |
255 | *ulimit*(3). | |
256 | ||
257 | ||
258 | include::common-footer.txt[] | |
259 | ||
260 | ||
261 | SEE ALSO | |
262 | -------- | |
7c1a4458 PP |
263 | man:lttng(1), |
264 | man:lttng-sessiond(8), | |
265 | man:lttng-crash(1), | |
266 | man:lttng-ust(3), | |
267 | man:babeltrace(1) |