contents/understanding-lttng/core-concepts/channel/intro.md

   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
   8 channel; having the same enabled event in two channels makes
   9 this event being recorded twice everytime it occurs.
  10
  11 Channels may be individually enabled or disabled. Occurring events of
  12 a disabled channel never make it to recorded events.
  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.