1BABELTRACE2-SOURCE() BABELTRACE2-SOURCE()
2
6 babeltrace2-source.ctf.lttng-live - Babeltrace 2's LTTng live source
7 component class
8
10 A Babeltrace 2 source.ctf.lttng-live message iterator connects to a
11 local or remote LTTng (see <https://lttng.org/>) relay daemon, receives
12 the streams of a specific tracing session, and emits corresponding
13 messages.
14 CTF streams over
16 LTTng live (TCP)
17 |
18 | +--------------------+
19 | | src.ctf.lttng-live |
20 '-->| |
21 | out @--> Sorted messages of one
22 +--------------------+ or more streams
23 More information about LTTng live is available in the LTTng
25 Documentation (see <https://lttng.org/docs/#doc-lttng-live>).
26 See babeltrace2-intro(7) to learn more about the Babeltrace 2 project
28 and its core concepts.
29 A source.ctf.lttng-live component has a single output port: its message
31 iterator muxes (sorts) the messages from the various CTF data streams
32 internally.
33 A source.ctf.lttng-live message iterator handles the messages of one,
35 and only one LTTng tracing session. A single LTTng tracing session can
36 contain one or more traces, depending on the active tracing domains and
37 the configured user space buffering scheme.
38 The component connects to an LTTng relay daemon using the inputs
40 parameter. This is an array of exactly one string which is the URL of
41 the LTTng relay daemon to connect to.
42 By default, if the remote tracing session name does not exist, the
44 message iterator returns "try again later". This default mode makes the
45 message iterator never end: even if the remote tracing session is
46 destroyed, the message iterator keeps on waiting for a tracing session
47 with the same name to exist. You can change this behaviour with the
48 session-not-found-action initialization parameter.
49 Note
51 As of this version, you can only create one message iterator per
52 source.ctf.lttng-live component. This is because the LTTng live
53 protocol accepts at most one client per tracing session per LTTng
54 relay daemon.
55
57 inputs=URL [array of one string]
58 Use URL to connect to the LTTng relay daemon.
59 URL is an array of exactly one string of which the format is:
61 net[4]://RDHOST[:RDPORT]/host/TGTHOST/SESSION
63 RDHOST
65 LTTng relay daemon’s host name or IP address.
66 RDPORT
68 LTTng relay daemon’s listening port.
69 If not specified, the component uses the default port (5344).
71 TGTHOST
73 Target’s host name or IP address.
74 SESSION
76 Name of the LTTng tracing session from which to receive data.
77 session-not-found-action=(continue | fail | end) [optional string]
79 When the message iterator does not find the specified remote
80 tracing session (SESSION part of the inputs parameter), do one of:
81 continue (default)
83 Keep on trying, returning "try again later" to the downstream
84 user until the tracing session exists.
85 With this action, the message iterator never ends, as the LTTng
87 live protocol cannot currently indicate that a tracing session
88 will never exist.
89 fail
91 Fail.
92 end
94 End.
95
97 +--------------------+
98 | src.ctf.lttng-live |
99 | |
100 | out @
101 +--------------------+
102 Output
104 out
105 Single output port.
106
108 babeltrace.support-info
109 See babeltrace2-query-babeltrace.support-info(7) to learn more about
110 this query object.
111 For a string input which honors the LTTng live URL format (see the
113 inputs parameter), the result object is 0.75.
114 sessions
116 You can query the sessions object to get a list of available LTTng
117 tracing sessions for a given LTTng relay daemon URL.
118 Parameters:
120 url=URL [string]
122 Use URL to connect to the LTTng relay daemon.
123 The format of URL is:
125 net[4]://RDHOST[:RDPORT]
127 RDHOST
129 LTTng relay daemon’s host name or IP address.
130 RDPORT
132 LTTng relay daemon’s listening port.
133 If not specified, the query operation uses the default port
135 (5344).
136 Result object (array of maps, one element for each available tracing
138 session):
139 client-count [unsigned integer]
141 Current number of LTTng live clients connected to the relay daemon
142 to receive data from this tracing session.
143 session-name [string]
145 Tracing session’s name.
146 stream-count [unsigned integer]
148 Current number of CTF streams in this tracing sessions, including
149 the metadata streams.
150 target-hostname [string]
152 Hostname of the tracing session.
153 This is not necessarily the relay daemon’s hostname.
155 timer-us [unsigned integer]
157 Tracing session’s configured live timer’s period (µs) (see lttng-
158 create(1)).
159 url [string]
161 URL to use as the first element of the inputs parameter to connect
162 to the same LTTng relay daemon and receive data from this tracing
163 session.
164
166 If you encounter any issue or usability problem, please report it on
167 the Babeltrace bug tracker (see
168 <https://bugs.lttng.org/projects/babeltrace>).
169
171 The Babeltrace project shares some communication channels with the
172 LTTng project (see <https://lttng.org/>).
173 • Babeltrace website (see <https://babeltrace.org/>)
175 • Mailing list (see <https://lists.lttng.org>) for support and
177 development: lttng-dev@lists.lttng.org
178 • IRC channel (see <irc://irc.oftc.net/lttng>): #lttng on
180 irc.oftc.net
181 • Bug tracker (see <https://bugs.lttng.org/projects/babeltrace>)
183 • Git repository (see <https://git.efficios.com/?p=babeltrace.git>)
185 • GitHub project (see <https://github.com/efficios/babeltrace>)
187 • Continuous integration (see
189 <https://ci.lttng.org/view/Babeltrace/>)
190 • Code review (see <https://review.lttng.org/q/project:babeltrace>)
192
194 The Babeltrace 2 project is the result of hard work by many regular
195 developers and occasional contributors.
196 The current project maintainer is Jérémie Galarneau
198 <mailto:jeremie.galarneau@efficios.com>.
199
201 This component class is part of the Babeltrace 2 project.
202 Babeltrace is distributed under the MIT license (see
204 <https://opensource.org/licenses/MIT>).
205
207 babeltrace2-intro(7), babeltrace2-plugin-ctf(7), lttng-relayd(8),
208 lttng-create(1)
209 BABELTRACE2-SOURCE()