Re: [linuxtools-dev] LTTng/TMF live trace streaming support plan?

[Alexandre Montplaisir <alexmonthy@xxxxxxxxxxxx>]

Hi Aaron,

On 13-02-11 04:09 PM, Aaron Spear wrote:
> Hi all, 
>
> I have a use case where I have a channel of events that come in dynamically in a proprietary format in XML. For a proof of concept I created an adapter that munged this data to log files, and then I imported the log files into a TMF derived trace. This works OK, but this is NOT what I want to do really. What I really want to do is take these events and dynamically push them into a layer that serializes/persists them as CTF. So that when acquisition is done, I can then load this same trace and it is simply loading CTF (and be able to leverage other future CTF goodness). 
>
> I know that there is work on-going for live trace streaming for LTTng.  I am wondering what the plan is on the Eclipse side of this?  Is there going to be an component that manages the connectivity to the LTTng relay daemon and in Java does buffering/flushing to disk of CTF events?  Are there any architecture docs I can look at?  I would really like to collaborate on this.

Since LTTng is our reference implementation, our plan was to wait until
live-reading was supported in LTTng itself (at least in beta form)
before starting to work on supporting it in TMF. From what I hear,
live-reading will be part of LTTng 2.3 or 2.4 (2.2 is the version
currently in development).

Right now we are working on connecting to a locally-running relay
daemon, so that one can start a trace on a remote system and bring it to
their machine. But only post-mortem reading is possible, for now. That's
probably all that will be in the Kepler release, next June.

We did talk about eventually reimplementing that relayd protocol in the
Eclipse plugin itself. This would allow someone to start a trace on a
remote system, and look at it live in TMF (and *optionally* save it to
disk), without needing a local, arch-specific relayd running. Which is
pretty cool! But that's still a long way off...


If you would like to contribute to making it happen faster, the LTTng
guys could probably use a hand in defining/testing the live-reading
spec. Or we, on the Eclipse side, could always use help in implementing
the relayd-in-Eclipse. Pick your poison ;)


Thanks,
--
Alexandre Montplaisir
Eclipse Linux Tools committer