класс компонента live-источника LTTng от Babeltrace 2 (Babeltrace 2's LTTng live source component class)
Имя (Name)
babeltrace2-source.ctf.lttng-live - Babeltrace 2's LTTng live
source component class
Описание (Description)
A Babeltrace 2 source.ctf.lttng-live message iterator connects to
a local or remote LTTng (see <https://lttng.org/>) relay daemon,
receives the streams of a specific tracing session, and emits
corresponding messages.
CTF streams over
LTTng live (TCP)
|
| +--------------------+
| | src.ctf.lttng-live |
'-->| |
| out @--> Sorted messages of one
+--------------------+ or more streams
More information about LTTng live is available in the LTTng
Documentation (see <https://lttng.org/docs/#doc-lttng-live>).
See babeltrace2-intro(7) to learn more about the Babeltrace 2
project and its core concepts.
A source.ctf.lttng-live component has a single output port: its
message iterator muxes (sorts) the messages from the various CTF
data streams internally.
A source.ctf.lttng-live message iterator handles the messages of
one, and only one LTTng tracing session. A single LTTng tracing
session can contain one or more traces, depending on the active
tracing domains and the configured user space buffering scheme.
The component connects to an LTTng relay daemon using the inputs
parameter. This is an array of exactly one string which is the
URL of the LTTng relay daemon to connect to.
By default, if the remote tracing session name does not exist,
the message iterator returns "try again later". This default mode
makes the message iterator never end: even if the remote tracing
session is destroyed, the message iterator keeps on waiting for a
tracing session with the same name to exist. You can change this
behaviour with the session-not-found-action initialization
parameter.
Note
As of this version, you can only create one message iterator
per source.ctf.lttng-live component. This is because the
LTTng live protocol accepts at most one client per tracing
session per LTTng relay daemon.
Параметры инициализации (Initialization parameters)
inputs=URL [array of one string]
Use URL to connect to the LTTng relay daemon.
URL is an array of exactly one string of which the format is:
net[4]://RDHOST[:RDPORT]/host/TGTHOST/SESSION
RDHOST
LTTng relay daemon's host name or IP address.
RDPORT
LTTng relay daemon's listening port.
If not specified, the component uses the default port
(5344).
TGTHOST
Target's host name or IP address.
SESSION
Name of the LTTng tracing session from which to receive
data.
session-not-found-action=(continue | fail | end) [optional
string]
When the message iterator does not find the specified remote
tracing session (SESSION part of the inputs parameter), do
one of:
continue (default)
Keep on trying, returning "try again later" to the
downstream user until the tracing session exists.
With this action, the message iterator never ends, as the
LTTng live protocol cannot currently indicate that a
tracing session will never exist.
fail
Fail.
end
End.
Порты (Ports)
+--------------------+
| src.ctf.lttng-live |
| |
| out @
+--------------------+
Output
out
Single output port.
QUERY OBJECTS
babeltrace.support-info
See babeltrace2-query-babeltrace.support-info(7) to learn more
about this query object.
For a string input which honors the LTTng live URL format (see
the inputs parameter), the result object is 0.75.
sessions
You can query the sessions object to get a list of available
LTTng tracing sessions for a given LTTng relay daemon URL.
Parameters:
url=URL [string]
Use URL to connect to the LTTng relay daemon.
The format of URL is:
net[4]://RDHOST[:RDPORT]
RDHOST
LTTng relay daemon's host name or IP address.
RDPORT
LTTng relay daemon's listening port.
If not specified, the query operation uses the default
port (5344).
Result object (array of maps, one element for each available
tracing session):
client-count [unsigned integer]
Current number of LTTng live clients connected to the relay
daemon to receive data from this tracing session.
session-name [string]
Tracing session's name.
stream-count [unsigned integer]
Current number of CTF streams in this tracing sessions,
including the metadata streams.
target-hostname [string]
Hostname of the tracing session.
This is not necessarily the relay daemon's hostname.
timer-us [unsigned integer]
Tracing session's configured live timer's period (µs) (see
lttng-create(1)).
url [string]
URL to use as the first element of the inputs parameter to
connect to the same LTTng relay daemon and receive data from
this tracing session.
Ошибки (баги) (Bugs)
If you encounter any issue or usability problem, please report it
on the Babeltrace bug tracker (see
<https://bugs.lttng.org/projects/babeltrace>).
Ресурсы (Resources)
The Babeltrace project shares some communication channels with
the LTTng project (see <https://lttng.org/>).
• Babeltrace website (see <https://babeltrace.org/>)
• Mailing list (see <https://lists.lttng.org>) for support and
development: lttng-dev@lists.lttng.org
• IRC channel (see <irc://irc.oftc.net/lttng>): #lttng on
irc.oftc.net
• Bug tracker (see
<https://bugs.lttng.org/projects/babeltrace>)
• Git repository (see
<https://git.efficios.com/?p=babeltrace.git>)
• GitHub project (see <https://github.com/efficios/babeltrace>)
• Continuous integration (see
<https://ci.lttng.org/view/Babeltrace/>)
• Code review (see
<https://review.lttng.org/q/project:babeltrace>)
