babeltrace2-run - Man Page

Create a Babeltrace 2 trace processing graph and run it

Synopsis

babeltrace2 [GENERAL OPTIONS] run [--retry-duration=TIME-US]
            --connect=CONN-RULE... COMPONENTS

Description

The run command creates a Babeltrace 2 trace processing graph and runs it.

See babeltrace2-intro(7) to learn more about the Babeltrace 2 project and its core concepts.

The run command dynamically loads Babeltrace 2 plugins which supply component classes. With the run command, you specify which component classes to instantiate as components and how to connect them.

The steps to write a babeltrace2 run command line are:

Specify which component classes to instantiate as components with many --component options and how to configure them.
This is the COMPONENTS part of the synopsis. See “Create components” to learn more.
Specify how to connect components together with one or more --connect options.
See “Connect components” to learn more.

Note

The babeltrace2-convert(1) command is a specialization of the run command for the very common case of converting one or more traces: it generates a run command line and executes it. You can use its --run-args or --run-args-0 option to make it print the equivalent run command line instead.

Create components

To create a component, use the --component option. This option specifies:

The name of the component, unique amongst all the component names of the trace processing graph.
The type of the component class to instantiate: source, filter, or sink.
The name of the plugin in which to find the component class to instantiate.
The name of the component class to instantiate.

Use the --component option multiple times to create multiple components. You can instantiate the same component class multiple times as different components.

At any point in the command line, the --base-params sets the current base initialization parameters and the --reset-base-params resets them. When you specify a --component option, its initial initialization parameters are a copy of the current base initialization parameters.

Immediately following a --component option on the command line, the created component is known as the current component (until the next --component option).

The --params=PARAMS option adds parameters to the current component’s initialization parameters. If PARAMS contains a key which exists in the current component’s initialization parameters, this parameter is replaced.

Connect components

The components which you create from component classes with the --component option (see “Create components”) add input and output ports depending on their type. An output port is from where messages, like trace events, are sent. An input port is where messages are received. For a given component, each port has a unique name.

The purpose of the run command is to create a trace processing graph, that is, to know which component ports to connect together. The command achieves this with the help of the connection rules that you provide with one or more --connect=CONN-RULE options.

The format of CONN-RULE is:

UP-COMP-PAT[.UP-PORT-PAT]:DOWN-COMP-PAT[.DOWN-PORT-PAT]

UP-COMP-PAT: Upstream component name pattern.
UP-PORT-PAT: Upstream (output) port name pattern.
DOWN-COMP-PAT: Downstream component name pattern.
DOWN-PORT-PAT: Downstream (input) port name pattern.

When a source or filter component adds a new output port within the processing graph, the run command does the following to find an input port to connect it to:

For each connection rule (--connect options, in order):
  If the output port's component's name matches UP-COMP-PAT and the
  output port's name matches UP-PORT-PAT:
    For each component COMP in the trace processing graph:
      If the name of COMP matches DOWN-COMP-PAT:
        Select the first input port of COMP of which the name matches
        DOWN-PORT-PAT, or fail with no match.

No possible connection: fail with no match.

UP-COMP-PAT, UP-PORT-PAT, DOWN-COMP-PAT, and DOWN-PORT-PAT are globbing patterns where only the wildcard character, *, is special: it matches zero or more characters. You must escape the *, ?, [, ., :, and \ characters with \.

When you do not specify UP-PORT-PAT or DOWN-PORT-PAT, they are equivalent to *.

You can leverage this connection mechanism to specify fallbacks with a careful use of wildcards, as the order of the --connect options on the command line is significant. For example:

--connect='A.out*:B.in*' --connect=A:B --connect='*:C'

With those connection rules, the run command connects:

Any output port of which the name starts with out of component A to the first input port of which the name starts with in of component B.
Any other output port of component A to the first available input port of component B.
Any other output port (of any component except A) to the first available input port of component C.

The run command fails when it cannot find an input port to which to connect a given output port using the provided connection rules.

See “Examples” for more examples.

Options

General

You can use those options before the command name.

See babeltrace2(1) for more details.

-d, --debug: Legacy option: this is equivalent to --log-level=TRACE.
-l LVL, --log-level=LVL: Set the log level of all known Babeltrace 2 loggers to LVL.
--omit-home-plugin-path: Do not search for plugins in $HOME/.local/lib/babeltrace2/plugins.
--omit-system-plugin-path: Do not search for plugins in /usr/local/lib/babeltrace2/plugins.
--plugin-path=PATH[:PATH]...: Add PATH to the list of paths in which plugins can be found.
-v, --verbose: Legacy option: this is equivalent to --log-level=INFO.

Component creation

See “Create components” for more details.

-b PARAMS, --base-params=PARAMS

Set the current base parameters to PARAMS.

You can reset the current base parameters with the --reset-base-params option.

See the --params option for the format of PARAMS.

-c NAME:COMP-CLS-TYPE.PLUGIN-NAME.COMP-CLS-NAME, --component=NAME:COMP-CLS-TYPE.PLUGIN-NAME.COMP-CLS-NAME

Create a component named NAME from the component class of type COMP-CLS-TYPE named COMP-CLS-NAME found in the plugin named PLUGIN-NAME, and set it as the current component.

The available values for TYPE are:

source, src: Source component class.
filter, flt: Filter component class.
sink: Sink component class.

The initial initialization parameters of this component are copied from the current base initialization parameters (see the --base-params option).

-l LVL, --log-level=LVL

Set the log level of the current component to LVL.

The available values for LVL are:

NONE, N

Logging is disabled.

FATAL, F

Severe errors that lead the execution to abort immediately.

This level should be enabled in production.

ERROR, E

Errors that might still allow the execution to continue.

Usually, once one or more errors are reported at this level, the application, plugin, or library won’t perform any more useful task, but it should still exit cleanly.

This level should be enabled in production.

WARN, WARNING, W

Unexpected situations which still allow the execution to continue.

This level should be enabled in production.

INFO, I

Informational messages that highlight progress or important states of the application, plugins, or library.

This level can be enabled in production.

DEBUG, D

Debugging information, with a higher level of details than the TRACE level.

This level should NOT be enabled in production.

TRACE, T

Low-level debugging context information.

This level should NOT be enabled in production.

-p PARAMS, --params=PARAMS

Add PARAMS to the initialization parameters of the current component.

If PARAMS contains a key which exists in the current component’s initialization parameters, replace the parameter.

The format of PARAMS is a comma-separated list of NAME=VALUE assignments:

NAME=VALUE[,NAME=VALUE]...

NAME: Parameter name (C identifier plus the :, ., and - characters).

VALUE

One of:

null, nul, NULL: null value.
true, TRUE, yes, YES: true boolean value.
false, FALSE, no, NO: false boolean value.
Binary (0b prefix), octal (0 prefix), decimal, or hexadecimal (0x prefix) unsigned (with + prefix) or signed 64-bit integer.
Double precision floating point number (scientific notation is accepted).
Unquoted string with no special characters, and not matching any of the null and boolean value symbols above.
Double-quoted string (accepts escape characters).
Array, formatted as an opening [, a comma-separated list of VALUE, and a closing ].
Map, formatted as an opening {, a comma-separated list of NAME=VALUE assignments, and a closing }.

You may put whitespaces around the individual = (assignment), , (separator), [ (array beginning), ] (array end), { (map beginning), and } (map end) characters.

Example:

--params='many=null, fresh=yes, condition=false, squirrel=-782329,
          play=+23, observe=3.14, simple=beef,
          needs-quotes="some string",
          escape.chars-are:allowed="a \" quote",
          things=[1, "hello", 2.71828],
          frog={slow=2, bath=[bike, 23], blind=NO}'

Important
Like in the example above, make sure to single-quote the whole argument when you run this command from a shell, as it can contain many special characters.

-r, --reset-base-params

Reset the current base parameters.

You can set the current base parameters with the --base-params option.

Component connection

-x CONN-RULE, --connect=CONN-RULE

Add the connection rule CONN-RULE.

The format of CONN-RULE is:

UP-COMP-PAT[.UP-PORT-PAT]:DOWN-COMP-PAT[.DOWN-PORT-PAT]

UP-COMP-PAT: Upstream component name pattern.
UP-PORT-PAT: Upstream (output) port name pattern.
DOWN-COMP-PAT: Downstream component name pattern.
DOWN-PORT-PAT: Downstream (input) port name pattern.

See “Connect components” to learn more.

Graph configuration

--retry-duration=TIME-US

Set the duration of a single retry to TIME-US µs when a sink component reports "try again later" (busy network or file system, for example).

Default: 100000 (100 ms).

Command information

-h, --help: Show the command’s help and quit.

Examples

Example 1. Create a single-port source component and a single-port sink component and connect them.

$ babeltrace2 run --component=A:src.plug.my-src \
                  --component=B:sink.plug.my-sink \
                  --connect=A:B

Possible resulting graph:

+-----------------+    +-------------------+
| src.plug.my-src |    | sink.plug.my-sink |
|       [A]       |    |         [B]       |
|                 |    |                   |
|             out @--->@ in                |
+-----------------+    +-------------------+

Example 2. Use the --params option to set the current component’s initialization parameters.

In this example, the --params option only applies to component the-source.

$ babeltrace2 run --component=the-source:src.my-plugin.my-src \
                  --params=offset=123,flag=true \
                  --component=the-sink:sink.my-plugin.my-sink \
                  --connect=the-source:the-sink

Example 3. Use the --base-params and --reset-base-params options to set and reset the current base initialization parameters.

In this example, the effective initialization parameters of the created components are:

Component A

offset=1203, flag=false

Component B

offset=1203, flag=true, type=event

Component C

ratio=0.25

$ babeltrace2 run --base-params=offset=1203,flag=false \
                  --component=A:src.plugin.compcls \
                  --component=B:flt.plugin.compcls \
                  --params=flag=true,type=event \
                  --reset-base-params \
                  --component=C:sink.plugin.compcls \
                  --params=ratio=0.25 \
                  --connect=A:B --connect=B:C

Example 4. Specify a component connection fallback rule.

In this example, any A output port of which the name starts with foo is connected to a B input port of which the name starts with nin. Any other A output port is connected to a B input port of which the name starts with oth.

The order of the --connect options is important here: the opposite order would create a system in which the first rule is always satisfied, and any A output port, whatever its name, would be connected to a B input port with a name that starts with oth.

$ babeltrace2 run --component=A:src.plug.my-src \
                  --component=B:sink.plug.my-sink \
                  --connect='A.foo*:B:nin*' --connect='A:B.oth*'

Possible resulting graph:

+-----------------+    +-------------------+
| src.plug.my-src |    | sink.plug.my-sink |
|       [A]       |    |        [B]        |
|                 |    |                   |
|            foot @--->@ nine              |
|         foodies @--->@ ninja             |
|       some-port @--->@ othello           |
|           hello @--->@ other             |
+-----------------+    +-------------------+

Environment Variables

Babeltrace 2 library

BABELTRACE_EXEC_ON_ABORT=CMDLINE

Execute the command line CMDLINE, as parsed like a UNIX 98 shell, when any part of the Babeltrace 2 project unexpectedly aborts.

The application only aborts when the executed command returns, ignoring its exit status.

This environment variable is ignored when the application has the setuid or the setgid access right flag set.

BABELTRACE_TERM_COLOR=(AUTO | NEVER | ALWAYS)

Force the terminal color support for the babeltrace2(1) program and the project’s plugins.

The available values are:

AUTO: Only emit terminal color codes when the standard output and error streams are connected to a color-capable terminal.
NEVER: Never emit terminal color codes.
ALWAYS: Always emit terminal color codes.

BABELTRACE_TERM_COLOR_BRIGHT_MEANS_BOLD=0

Set to 0 to emit SGR (see <https://en.wikipedia.org/wiki/ANSI_escape_code>) codes 90 to 97 for bright colors instead of bold (SGR code 1) and standard color codes (SGR codes 30 to 37).

BABELTRACE_PLUGIN_PATH=PATHS

Set the list of directories, in order, in which dynamic plugins can be found before other directories are considered to PATHS (colon-separated, or semicolon on Windows).

LIBBABELTRACE2_DISABLE_PYTHON_PLUGINS=1

Disable the loading of any Babeltrace 2 Python plugin.

LIBBABELTRACE2_INIT_LOG_LEVEL=LVL

Force the Babeltrace 2 library’s initial log level to be LVL.

If this environment variable is set, it overrides the log level set by the --log-level option for the Babeltrace 2 library logger.

The available values for LVL are:

NONE, N

Logging is disabled.

FATAL, F

Severe errors that lead the execution to abort immediately.

This level should be enabled in production.

ERROR, E

Errors that might still allow the execution to continue.

Usually, once one or more errors are reported at this level, the application, plugin, or library won’t perform any more useful task, but it should still exit cleanly.

This level should be enabled in production.

WARN, WARNING, W

Unexpected situations which still allow the execution to continue.

This level should be enabled in production.

INFO, I

Informational messages that highlight progress or important states of the application, plugins, or library.

This level can be enabled in production.

DEBUG, D

Debugging information, with a higher level of details than the TRACE level.

This level should NOT be enabled in production.

TRACE, T

Low-level debugging context information.

This level should NOT be enabled in production.

LIBBABELTRACE2_NO_DLCLOSE=1

Make the Babeltrace 2 library leave any dynamically loaded modules (plugins and plugin providers) open at exit. This can be useful for debugging purposes.

LIBBABELTRACE2_PLUGIN_PROVIDER_DIR=DIR

Set the directory from which the Babeltrace 2 library dynamically loads plugin provider shared objects to DIR.

If this environment variable is set, it overrides the default plugin provider directory.

Babeltrace 2 Python bindings

BABELTRACE_PYTHON_BT2_LOG_LEVEL=LVL

Force the Babeltrace 2 Python bindings log level to be LVL.

If this environment variable is set, it overrides the log level set by the --log-level option for the Python bindings logger.

The available values for LVL are:

NONE, N

Logging is disabled.

FATAL, F

Severe errors that lead the execution to abort immediately.

This level should be enabled in production.

ERROR, E

Errors that might still allow the execution to continue.

Usually, once one or more errors are reported at this level, the application, plugin, or library won’t perform any more useful task, but it should still exit cleanly.

This level should be enabled in production.

WARN, WARNING, W

Unexpected situations which still allow the execution to continue.

This level should be enabled in production.

INFO, I

Informational messages that highlight progress or important states of the application, plugins, or library.

This level can be enabled in production.

DEBUG, D

Debugging information, with a higher level of details than the TRACE level.

This level should NOT be enabled in production.

TRACE, T

Low-level debugging context information.

This level should NOT be enabled in production.

CLI

BABELTRACE_CLI_LOG_LEVEL=LVL

Force babeltrace2 CLI’s log level to be LVL.

If this environment variable is set, it overrides the log level set by the --log-level option for the CLI logger.

The available values for LVL are:

NONE, N

Logging is disabled.

FATAL, F

Severe errors that lead the execution to abort immediately.

This level should be enabled in production.

ERROR, E

Errors that might still allow the execution to continue.

Usually, once one or more errors are reported at this level, the application, plugin, or library won’t perform any more useful task, but it should still exit cleanly.

This level should be enabled in production.

WARN, WARNING, W

Unexpected situations which still allow the execution to continue.

This level should be enabled in production.

INFO, I

Informational messages that highlight progress or important states of the application, plugins, or library.

This level can be enabled in production.

DEBUG, D

Debugging information, with a higher level of details than the TRACE level.

This level should NOT be enabled in production.

TRACE, T

Low-level debugging context information.

This level should NOT be enabled in production.

BABELTRACE_CLI_WARN_COMMAND_NAME_DIRECTORY_CLASH=0

Disable the warning message which babeltrace2-convert(1) prints when you convert a trace with a relative path that’s also the name of a babeltrace2 command.

BABELTRACE_DEBUG=1

Legacy variable: equivalent to setting the --log-level option to TRACE.

BABELTRACE_VERBOSE=1

Legacy variable: equivalent to setting the --log-level option to INFO.

Files

$HOME/.local/lib/babeltrace2/plugins: User plugin directory.
/usr/local/lib/babeltrace2/plugins: System plugin directory.
/usr/local/lib/babeltrace2/plugin-providers: System plugin provider directory.

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>)

babeltrace2-run - Man Page

Synopsis

Description

Create components

Connect components

Options

General

Component creation

Component connection

Graph configuration

Command information

Examples

Environment Variables

Babeltrace 2 library

Babeltrace 2 Python bindings

CLI

Files

Exit Status

Bugs

Resources

Authors

Copyright

See Also

Referenced By