| 1 | babeltrace-source.ctf.lttng-live(7) |
| 2 | =================================== |
| 3 | :manpagetype: component class |
| 4 | :revdate: 5 October 2017 |
| 5 | |
| 6 | |
| 7 | NAME |
| 8 | ---- |
| 9 | babeltrace-source.ctf.lttng-live - Babeltrace's LTTng live source |
| 10 | component class |
| 11 | |
| 12 | |
| 13 | DESCRIPTION |
| 14 | ----------- |
| 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]. |
| 21 | |
| 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. |
| 26 | |
| 27 | The component connects to an LTTng relay daemon using the param:url |
| 28 | parameter. |
| 29 | |
| 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. |
| 33 | |
| 34 | The component names each trace `[HOSTNAME/]SESSION/PATH`, with: |
| 35 | |
| 36 | `HOSTNAME`:: |
| 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. |
| 40 | |
| 41 | `SESSION`:: |
| 42 | Tracing session name. |
| 43 | |
| 44 | `PATH`:: |
| 45 | Other path elements up to the trace directory containing the |
| 46 | `metadata` file from the LTTng relay daemon's point of view. |
| 47 | For example: |
| 48 | + |
| 49 | ---- |
| 50 | kernel |
| 51 | ---- |
| 52 | + |
| 53 | ---- |
| 54 | ust/uid/1000/64-bit |
| 55 | ---- |
| 56 | |
| 57 | For example: |
| 58 | |
| 59 | ---- |
| 60 | myhost/auto-20150909-223909/ust/uid/1000/64-bit |
| 61 | ---- |
| 62 | |
| 63 | A compcls:source.ctf.lttng-live never blocks: it asks the downstream |
| 64 | component to try again later instead. |
| 65 | |
| 66 | |
| 67 | INITIALIZATION PARAMETERS |
| 68 | ------------------------- |
| 69 | param:url='URL' (string, mandatory):: |
| 70 | The URL to use to connect to the LTTng relay daemon. The format |
| 71 | of 'URL' is: |
| 72 | + |
| 73 | -- |
| 74 | [verse] |
| 75 | net[4]://__RDHOST__[:__RDPORT__]/host/__TGTHOST__/__SESSION__ |
| 76 | |
| 77 | 'RDHOST':: |
| 78 | LTTng relay daemon's host name or IP address. |
| 79 | |
| 80 | 'RDPORT':: |
| 81 | LTTng relay daemon's listening port. If not specified, the default |
| 82 | port, 5344, is used. |
| 83 | |
| 84 | 'TGTHOST':: |
| 85 | Target's host name or IP address. |
| 86 | |
| 87 | 'SESSION':: |
| 88 | Name of the LTTng tracing session from which to receive data. |
| 89 | -- |
| 90 | |
| 91 | |
| 92 | PORTS |
| 93 | ----- |
| 94 | Output |
| 95 | ~~~~~~ |
| 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. |
| 99 | |
| 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 |
| 103 | session. |
| 104 | |
| 105 | |
| 106 | QUERY OBJECTS |
| 107 | ------------- |
| 108 | `sessions` |
| 109 | ~~~~~~~~~~ |
| 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. |
| 112 | |
| 113 | Parameters: |
| 114 | |
| 115 | `url` (string, mandatory):: |
| 116 | The URL to use to connect to the LTTng relay daemon. The format |
| 117 | of 'URL' is: |
| 118 | + |
| 119 | -- |
| 120 | [verse] |
| 121 | net[4]://__RDHOST__[:__RDPORT__] |
| 122 | |
| 123 | 'RDHOST':: |
| 124 | LTTng relay daemon's host name or IP address. |
| 125 | |
| 126 | 'RDPORT':: |
| 127 | LTTng relay daemon's listening port. If not specified, the default |
| 128 | port, 5344, is used. |
| 129 | -- |
| 130 | |
| 131 | Returned object (array of maps, one element for each tracing session): |
| 132 | |
| 133 | `url` (string):: |
| 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. |
| 136 | |
| 137 | `target-hostname` (string):: |
| 138 | Hostname of the tracing session. This is not necessarily the |
| 139 | relay daemon's hostname. |
| 140 | |
| 141 | `session-name` (string):: |
| 142 | Tracing session's name. |
| 143 | |
| 144 | `timer-us` (integer):: |
| 145 | Tracing session's configured live timer (µs) |
| 146 | (see man:lttng-create(1)). |
| 147 | |
| 148 | `stream-count` (integer):: |
| 149 | Current number of streams in this tracing sessions, including the |
| 150 | metadata streams. |
| 151 | |
| 152 | `client-count` (integer):: |
| 153 | Current number of LTTng live clients connected to the relay daemon |
| 154 | to receive data from this tracing session. |
| 155 | |
| 156 | |
| 157 | LIMITATIONS |
| 158 | ----------- |
| 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. |
| 162 | |
| 163 | |
| 164 | ENVIRONMENT VARIABLES |
| 165 | --------------------- |
| 166 | include::common-ctf-plugin-env.txt[] |
| 167 | |
| 168 | |
| 169 | Component class |
| 170 | ~~~~~~~~~~~~~~~ |
| 171 | include::common-common-compat-env.txt[] |
| 172 | |
| 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 |
| 176 | man:babeltrace(1). |
| 177 | |
| 178 | |
| 179 | include::common-footer.txt[] |
| 180 | |
| 181 | |
| 182 | SEE ALSO |
| 183 | -------- |
| 184 | man:babeltrace-plugin-ctf(7), |
| 185 | man:babeltrace-intro(7), |
| 186 | man:lttng-relayd(8), |
| 187 | man:lttng-create(1) |