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Bug #301

Sporadic LTTng Tools Failure to Start Tracing for All Apps yet Returns Success

Added by Amer Alhalabi about 8 years ago. Updated about 8 years ago.

Status:
Resolved
Priority:
High
Target version:
-
Start date:
07/11/2012
Due date:
% Done:

0%

Estimated time:

Description

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!


Files

lttng_tools_output.txt (4.87 MB) lttng_tools_output.txt lttng-sessiond -vvv output Amer Alhalabi, 07/11/2012 12:07 PM
fork_app_output.txt (2.03 MB) fork_app_output.txt instrumented forked application Amer Alhalabi, 07/11/2012 12:07 PM
thread_app_output.txt (1.04 MB) thread_app_output.txt instrumented multithreaded application Amer Alhalabi, 07/11/2012 12:07 PM
normal_app_output.txt (948 KB) normal_app_output.txt instrumented single-threaded application Amer Alhalabi, 07/11/2012 12:07 PM
#1

Updated by Mathieu Desnoyers about 8 years ago

Can you confirm that the commits:

(stable-2.0)

commit b2e909a5ebc46bdee027ed508968886d9d1251b8
Author: Mathieu Desnoyers <>
Date: Wed Jul 11 18:23:12 2012 -0400

Fix: The session list count should provide unique identifiers
Never decrement it.
Reported-by: Amer Alhalabi &lt;&gt;
Signed-off-by: Mathieu Desnoyers &lt;&gt;

(master)

commit e74ecf5ad921a3edccacad4d79deb484cd19b1d5
Author: Mathieu Desnoyers <>
Date: Wed Jul 11 18:23:12 2012 -0400

Fix: The session list count should provide unique identifiers
Never decrement it.
Reported-by: Amer Alhalabi &lt;&gt;
Signed-off-by: Mathieu Desnoyers &lt;&gt;

fix this issue ?

Thanks,

Mathieu

#2

Updated by Amer Alhalabi about 8 years ago

The issue has been fixed.
Thanks!

#3

Updated by Mathieu Desnoyers about 8 years ago

  • Status changed from New to Resolved
  • Assignee set to Mathieu Desnoyers

Fixed by commits:

(stable-2.0)

commit b2e909a5ebc46bdee027ed508968886d9d1251b8
Author: Mathieu Desnoyers <>
Date: Wed Jul 11 18:23:12 2012 -0400

(master)

commit e74ecf5ad921a3edccacad4d79deb484cd19b1d5
Author: Mathieu Desnoyers <>
Date: Wed Jul 11 18:23:12 2012 -0400

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