[lttng-docs.git] / contents / understanding-lttng / core-concepts / channel / intro.md

---
id: channel
---

A _channel_ is a set of events with specific parameters and potential
added context information. Channels have unique names per domain within
a tracing session. A given event is always registered to at least one
channel; having the same enabled event in two channels makes
this event being recorded twice everytime it occurs.

Channels may be individually enabled or disabled. Occurring events of
a disabled channel never make it to recorded events.

The fundamental role of a channel is to keep a shared ring buffer, where
events are eventually recorded by the tracer and consumed by a consumer
daemon. This internal ring buffer is divided into many sub-buffers of
equal size.

Channels, when created, may be fine-tuned thanks to a few parameters,
many of them related to sub-buffers. The following subsections explain
what those parameters are and in which situations you should manually
adjust them.
Commit	Line	Data
5e0cbfb0 PP	1	---
	2	id: channel
	3	---
	4
	5	A _channel_ is a set of events with specific parameters and potential
	6	added context information. Channels have unique names per domain within
	7	a tracing session. A given event is always registered to at least one
47bfcb75 PP	8	channel; having the same enabled event in two channels makes
47bfcb75 PP	9	this event being recorded twice everytime it occurs.
5e0cbfb0 PP	10
5e0cbfb0 PP	11	Channels may be individually enabled or disabled. Occurring events of
47bfcb75	12	a disabled channel never make it to recorded events.
5e0cbfb0 PP	13
	14	The fundamental role of a channel is to keep a shared ring buffer, where
	15	events are eventually recorded by the tracer and consumed by a consumer
	16	daemon. This internal ring buffer is divided into many sub-buffers of
	17	equal size.
	18
	19	Channels, when created, may be fine-tuned thanks to a few parameters,
	20	many of them related to sub-buffers. The following subsections explain
	21	what those parameters are and in which situations you should manually
	22	adjust them.