X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=contents%2Fusing-lttng%2Fcontrolling-tracing%2Flttng-live.md;h=d67c2d1d461ca835e717524e586ac31cd46a4073;hb=d9a0e8b1a2834c9fa52c6df79217800ac3581a77;hp=26b11c151a47510111b06a7dc68744d4fb3d3c44;hpb=b80ba3062f71ca7dd34abc956e5cfe9d84d90f35;p=lttng-docs.git diff --git a/contents/using-lttng/controlling-tracing/lttng-live.md b/contents/using-lttng/controlling-tracing/lttng-live.md index 26b11c1..d67c2d1 100644 --- a/contents/using-lttng/controlling-tracing/lttng-live.md +++ b/contents/using-lttng/controlling-tracing/lttng-live.md @@ -14,15 +14,16 @@ _LTTng live_. LTTng live is implemented, in LTTng, solely on the relay daemon side. As trace data is sent over the network to a relay daemon by a (possibly -remote) consumer daemon, a _tee_ may be created: trace data will be -recorded to trace files _as well as_ being transmitted to a -connected live viewer: +remote) consumer daemon, a _tee_ is created: trace data is recorded to +trace files _as well as_ being transmitted to a connected live viewer: -
- - - -
+
+LTTng live +
+ The relay daemon creates a tee, forwarding the trace data + to both trace files and a live viewer. +
+
In order to use this feature, a tracing session must created in live mode on the target system: @@ -31,18 +32,18 @@ mode on the target system: lttng create --live -An optional parameter may be passed to `--live` to set the interval -of time (in microseconds) between flushes to the network -(1 second is the default): +An optional parameter may be passed to `--live` to set the period +(in microseconds) between flushes to the network +(1 second is the default). With:
 lttng create --live 100000
 
-will flush every 100 ms. +the daemons flush their data every 100 ms. If no network output is specified to the `create` command, a local -relay daemon will be spawned. In this very common case, viewing a live +relay daemon is spawned. In this very common case, viewing a live trace is easy: enable events and start tracing as usual, then use `lttng view` to start the default live viewer: @@ -50,7 +51,7 @@ trace is easy: enable events and start tracing as usual, then use lttng view -The correct arguments will be passed to the live viewer so that it +The correct arguments are passed to the live viewer so that it may connect to the local relay daemon and start reading live events. You may also wish to use a live viewer not running on the target @@ -73,7 +74,7 @@ babeltrace --input-format lttng-live net://localhost Then, choose a tracing session and start viewing events as they arrive -using LTTng live, e.g.: +using LTTng live:
 babeltrace --input-format lttng-live net://localhost/host/hostname/my-session