----- Original Message ----- > From: "David Lindström" <[email protected]> > To: "Mathieu Desnoyers" <[email protected]>, "DavidLindström" > <[email protected]> > Cc: [email protected] > Sent: Tuesday, November 5, 2013 9:49:08 AM > Subject: Re: [lttng-dev] Tagging traces with arbitrary data (as in > custommetadata)
> > From: Mathieu Desnoyers > > > Sent: Tuesday, November 05, 2013 3:20 PM > > > To: DavidLindström > > > Cc: [email protected] > > > Subject: Re: [lttng-dev] Tagging traces with arbitrary data (as in > > custommetadata) > > > ----- Original Message ----- > > > > From: "David Lindström" <[email protected]> > > > > > > To: [email protected] > > > > > > Sent: Tuesday, November 5, 2013 9:15:14 AM > > > > > > Subject: [lttng-dev] Tagging traces with arbitrary data (as in custom > > > metadata) > > > > > > 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? > > > > > 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. > > > Thoughts ? > > I have no idea how this would be implemented, I’m only looking at potential > uses. A simple tag field in the env{} section should cover my initial use > cases. I have to wonder though, how much more complicated it would be to > allow multiple named tags? For example, tags.description = ”Some > description” instead of tag = “Some description”? This could be called "user-provided environment", and could look like this in the metadata: env { .... user.myenvname = "text"; } > Also, how would one specify this? As an option to the lttng create command or > as a separate command (lttng set-tag ...)? lttng set-env "text" Thoughts ? Thanks, Mathieu > Mvh > David Lindström > > Thanks, > > > Mathieu > > > > Mvh > > > > > > David Lindström > > > > > > _______________________________________________ > > > > > > lttng-dev mailing list > > > > > > [email protected] > > > > > > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev > > > > > -- > > > Mathieu Desnoyers > > > EfficiOS Inc. > > > http://www.efficios.com > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
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