[lttng-tools.git] / doc / man / lttng-regenerate.1.txt

lttng-regenerate(1)
=================


NAME
----
lttng-regenerate - Manage an LTTng tracing session's data regeneration


SYNOPSIS
--------
Regenerate the metadata of a session:

[verse]
*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *regenerate metadata* [option:--session='SESSION']

Regenerate the state dump of a session:

[verse]
*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *regenerate statedump* [option:--session='SESSION']

DESCRIPTION
-----------
The `lttng regenerate` command regenerates specific data of a tracing session.

As of this version, the `metadata` and `statedump` actions are
available.


Regenerating a tracing session's metadata
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The `lttng regenerate metadata` action can be used to resample the offset
between the system's monotonic clock and the wall-clock time.

This action is meant to be used to resample the wall-clock time following a
major link:https://en.wikipedia.org/wiki/Network_Time_Protocol[NTP] correction.
As such, a system booting with an incorrect wall time can be traced before its
wall time is NTP-corrected. Regenerating the tracing session's metadata ensures
that trace viewers can accurately determine the events time relative to Unix
Epoch.


Regenerating a tracing session's state dump
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The `lttng regenerate statedump` action can be used to collect up-to-date state
dump information during the tracing session. This is particularly useful in
snapshot (see man:lttng-snapshot(1)) or trace file rotation (see
man:lttng-enable-channel(1)) modes where the state dump information may be
lost.


include::common-cmd-options-head.txt[]


option:-s 'SESSION', option:--session='SESSION'::
    Regenerate the data of the tracing session named 'SESSION'
    instead of the current tracing session.


include::common-cmd-help-options.txt[]


LIMITATIONS
-----------
The `lttng regenerate metadata` command can only be used on kernel and
user space tracing sessions (using per-user buffering), in non-live
mode.

See man:lttng-enable-channel(1) for more information about
buffering schemes and man:lttng-create(1) for more information
about the different tracing session modes.


include::common-cmd-footer.txt[]


SEE ALSO
--------
man:lttng(1)
Commit	Line	Data
	1	lttng-regenerate(1)
	2	=================
	3
	4
	5	NAME
	6	----
	7	lttng-regenerate - Manage an LTTng tracing session's data regeneration
	8
	9
	10	SYNOPSIS
	11	--------
	12	Regenerate the metadata of a session:
	13
	14	[verse]
	15	lttng ['linkgenoptions:(GENERAL OPTIONS)'] regenerate metadata [option:--session='SESSION']
	16
	17	Regenerate the state dump of a session:
	18
	19	[verse]
	20	lttng ['linkgenoptions:(GENERAL OPTIONS)'] regenerate statedump [option:--session='SESSION']
	21
	22	DESCRIPTION
	23	-----------
	24	The `lttng regenerate` command regenerates specific data of a tracing session.
	25
	26	As of this version, the `metadata` and `statedump` actions are
	27	available.
	28
	29
	30	Regenerating a tracing session's metadata
	31	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	32	The `lttng regenerate metadata` action can be used to resample the offset
	33	between the system's monotonic clock and the wall-clock time.
	34
	35	This action is meant to be used to resample the wall-clock time following a
	36	major link:https://en.wikipedia.org/wiki/Network_Time_Protocol[NTP] correction.
	37	As such, a system booting with an incorrect wall time can be traced before its
	38	wall time is NTP-corrected. Regenerating the tracing session's metadata ensures
	39	that trace viewers can accurately determine the events time relative to Unix
	40	Epoch.
	41
	42
	43	Regenerating a tracing session's state dump
	44	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	45	The `lttng regenerate statedump` action can be used to collect up-to-date state
	46	dump information during the tracing session. This is particularly useful in
	47	snapshot (see man:lttng-snapshot(1)) or trace file rotation (see
	48	man:lttng-enable-channel(1)) modes where the state dump information may be
	49	lost.
	50
	51
	52	include::common-cmd-options-head.txt[]
	53
	54
	55	option:-s 'SESSION', option:--session='SESSION'::
	56	Regenerate the data of the tracing session named 'SESSION'
	57	instead of the current tracing session.
	58
	59
	60	include::common-cmd-help-options.txt[]
	61
	62
	63	LIMITATIONS
	64	-----------
	65	The `lttng regenerate metadata` command can only be used on kernel and
	66	user space tracing sessions (using per-user buffering), in non-live
	67	mode.
	68
	69	See man:lttng-enable-channel(1) for more information about
	70	buffering schemes and man:lttng-create(1) for more information
	71	about the different tracing session modes.
	72
	73
	74	include::common-cmd-footer.txt[]
	75
	76
	77	SEE ALSO
	78	--------
	79	man:lttng(1)