<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><hr id="zwchr"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From: </b>"David Lindström" <david.lindstrom@percepio.se><br><b>To: </b>lttng-dev@lists.lttng.org<br><b>Sent: </b>Tuesday, November 5, 2013 9:15:14 AM<br><b>Subject: </b>[lttng-dev] Tagging traces with arbitrary data (as in custom metadata)<br><div><br></div><div dir="ltr"><div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000"><div>Hi, I was wondering if there’s a way to tag a trace with some additional
information. A general example would be to include a description of the current
experiment. One way to do this currently would be to create a custom
lttng-message application with some UST tracepoint and then just log that to a
separate channel, but that would be pretty ugly. It would be much cleaner to
insert extra fields into the metadata stream. Is something like that possible in
current versions of LTTng and/or would it be possible to add it for a future
version?</div></div></div></blockquote><div><br></div><div>The CTF metadata has an environment (env {}) section that contains this kind of information. LTTng already uses it to store the tracer version and some info about the system. We could eventually add a feature like this, a "tag", that would be added to the CTF environment information. I would guess that users would provide this tag on the lttng command line for their session, and it would be passed to the tracers by sessiond.<br></div><div><br></div><div>Thoughts ?<br></div><div><br></div><div>Thanks,<br></div><div><br></div><div>Mathieu<br></div><div><br></div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div dir="ltr"><div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000"><div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000">Mvh<br>David
Lindström</div></div></div><br>_______________________________________________<br>lttng-dev mailing list<br>lttng-dev@lists.lttng.org<br>http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev<br></blockquote><div><br><br></div><div><br></div><div>-- <br></div><div><span name="x"></span>Mathieu Desnoyers<br>EfficiOS Inc.<br>http://www.efficios.com<span name="x"></span><br></div></div></body></html>