1 babeltrace-source.ctf.lttng-live(7)
2 ===================================
3 :manpagetype: component class
4 :revdate: 5 October 2017
9 babeltrace-source.ctf.lttng-live - Babeltrace's LTTng live source
15 The Babeltrace compcls:source.ctf.lttng-live source component class,
16 provided by the man:babeltrace-plugin-ctf(7) plugin, once instantiated,
17 connects to a local or remote http://lttng.org/[LTTng] relay daemon and
18 emits the received notifications on its output ports. More information
19 about LTTng live is available in the
20 http://lttng.org/docs/#doc-lttng-live[LTTng Documentation].
22 A compcls:source.ctf.lttng-live component handles the notifications of
23 one, and only one LTTng tracing session. A single LTTng tracing session
24 can contain one or more traces, depending on the active tracing domains
25 and the configured user space buffering scheme.
27 The component connects to an LTTng relay daemon using the param:url
30 For each trace, the component creates one output port per effective data
31 stream. The name of a data stream output port is `stream-` followed by
32 its unique LTTng live ID within the tracing session.
34 The component names each trace `[HOSTNAME/]SESSION/PATH`, with:
37 Value of the trace's `hostname` environment constant. If this
38 environment constant does not exist, or if its value is not a
39 string, then this part is omitted.
45 Other path elements up to the trace directory containing the
46 `metadata` file from the LTTng relay daemon's point of view.
60 myhost/auto-20150909-223909/ust/uid/1000/64-bit
63 A compcls:source.ctf.lttng-live never blocks: it asks the downstream
64 component to try again later instead.
67 INITIALIZATION PARAMETERS
68 -------------------------
69 param:url='URL' (string, mandatory)::
70 The URL to use to connect to the LTTng relay daemon. The format
75 net[4]://__RDHOST__[:__RDPORT__]/host/__TGTHOST__/__SESSION__
78 LTTng relay daemon's host name or IP address.
81 LTTng relay daemon's listening port. If not specified, the default
85 Target's host name or IP address.
88 Name of the LTTng tracing session from which to receive data.
96 When you create the component, its only output port is `no-stream`. This
97 port exists as long as there is no data stream output port. The port
98 only asks the downstream component to try again later.
100 For each received LTTng trace, the component creates one output port for
101 each effective data stream. The name of a data stream output port is
102 `stream-ID`, where `ID` is a unique LTTng live ID within the tracing
110 You can query the `sessions` object to get a list of available LTTng
111 live tracing sessions for a given LTTng relay daemon URL.
115 `url` (string, mandatory)::
116 The URL to use to connect to the LTTng relay daemon. The format
121 net[4]://__RDHOST__[:__RDPORT__]
124 LTTng relay daemon's host name or IP address.
127 LTTng relay daemon's listening port. If not specified, the default
131 Returned object (array of maps, one element for each tracing session):
134 URL to use as the param:url parameter to connect to the same LTTng
135 relay daemon and receive data from this tracing session.
137 `target-hostname` (string)::
138 Hostname of the tracing session. This is not necessarily the
139 relay daemon's hostname.
141 `session-name` (string)::
142 Tracing session's name.
144 `timer-us` (integer)::
145 Tracing session's configured live timer (µs)
146 (see man:lttng-create(1)).
148 `stream-count` (integer)::
149 Current number of streams in this tracing sessions, including the
152 `client-count` (integer)::
153 Current number of LTTng live clients connected to the relay daemon
154 to receive data from this tracing session.
159 A compcls:source.ctf.lttng-live component only accepts a connection
160 to one of its output port if all its output ports are connected to the
161 input ports of the same downstream component.
164 ENVIRONMENT VARIABLES
165 ---------------------
166 include::common-ctf-plugin-env.txt[]
171 include::common-common-compat-env.txt[]
173 `BABELTRACE_SRC_CTF_LTTNG_LIVE_LOG_LEVEL`::
174 Component class's log level. The available values are the
175 same as for the manopt:babeltrace(1):--log-level option of
179 include::common-footer.txt[]
184 man:babeltrace-plugin-ctf(7),
185 man:babeltrace-intro(7),