LTTng » LTTng-tools

When start tracing on multiple sessions, the tracing fails to start for all apps and no error code is received. Instead success is returned.
In that case, the session gets created; but no tracing occurs (see the steps below to see how we encounter the problem).

What we do is the following:
1. We run instrumented apps for a long long time.
2. we create multiple sessions at the same time with some shared events
3. we start tracing on all of them at time t.
4. At t+x1 seconds, we destroy session1 and move the files somewhere.
At t+x2 seconds, we destroy session2 and move the files somewhere.
… and so on.
5. we repeat steps 2-4 many times.

After a few iterations, lttng tools fails to start tracing for all apps for one session.
The failure keeps happening every z iterations for the same session; where z < 10.

The issue might be happening because LTTng Tools thinks that the session was restarted and thus skipping any setup needed!