lttng-dev.lists.lttng.org archive mirror
 help / color / mirror / Atom feed
From: Dave Bort via lttng-dev <lttng-dev@lists.lttng.org>
To: lttng-dev@lists.lttng.org
Subject: [lttng-dev] babeltrace2: reading metadata + events from a single CTF file
Date: Sun, 6 Sep 2020 13:46:48 -0700	[thread overview]
Message-ID: <CAM-pDOyr2VN94eWJahkRX47rTp=YSOwvyZL5iVO2bETaaLx+1Q@mail.gmail.com> (raw)


[-- Attachment #1.1: Type: text/plain, Size: 1296 bytes --]

Hello! I'm adding CTF-compatible tracing to a custom/experimental OS and
have a question:

Can babeltrace2 read from a single CTF output file that contains both the
metadata stream and the binary trace streams?

My little trace system would like to bundle everything related to a trace
into a single file, making it easier to pass around (since there's not much
filesystem/network support yet). The CTF spec provides a way to embed the
metadata stream in the same bitstream as the data streams, but
https://babeltrace.org/docs/v2.0/man7/babeltrace2-source.ctf.fs.7/ says
that the `metadata` file needs to be separate. I see that LTTng manages
trace output as a collection of files, with a separate `metadata` file.

I'd rather avoid writing a custom tool to find and extract the metadata
stream from the full stream before passing the data on to babeltrace2 or
TraceCompass, but so far it looks like I may need to.

Would it be appropriate to add support for this
to babeltrace2-source.ctf.fs? Or would this warrant a new source.ctf
plugin? If I'm going to write some new code to handle this situation, I may
as well try to add it to the project.

Thank you! I'm really looking forward to benefiting from the
CTF/babeltrace/LTTng/TraceCompass work you've all done over the years. :)

--Dave Bort

[-- Attachment #1.2: Type: text/html, Size: 1557 bytes --]

[-- Attachment #2: Type: text/plain, Size: 156 bytes --]

_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

             reply	other threads:[~2020-09-07 12:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-06 20:46 Dave Bort via lttng-dev [this message]
2020-09-08 14:53 ` Philippe Proulx via lttng-dev
2020-09-08 20:40   ` Dave Bort via lttng-dev

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAM-pDOyr2VN94eWJahkRX47rTp=YSOwvyZL5iVO2bETaaLx+1Q@mail.gmail.com' \
    --to=lttng-dev@lists.lttng.org \
    --cc=dbort@dbort.com \
    --subject='Re: [lttng-dev] babeltrace2: reading metadata + events from a single CTF file' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).