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LTTng: An open-source tracing framework for Linux

lttng.org

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Re: LTTng: An open-source tracing framework for Linux

#3

Post by cbab »

dmix wrote: post #2

Wow, open source sites are getting nice designs these days. Is there a business behind this project or is it via donation? The documentation is excellent.

Thanks, we worked quite hard on this new redesign!

edit: Yes, EfficiOS [1] is the open source business behind the LTTng project :).

[1] - https://www.efficios.com/

Re: LTTng: An open-source tracing framework for Linux

#5

Post by cbab »

jordigh wrote: post #4

Here is a pretty cool presentation about it, in French: https://www.youtube.com/watch?v=9XokHJadkq4 The slides are in English, if that helps: http://lttng.org/files/papers/presentations/lttng20tracingfo...

You can also find all the presentations/publications that we did through the years here [1].

[1] - http://lttng.org/publications/

Re: LTTng: An open-source tracing framework for Linux

#8

Post by dmix »

cbab wrote: post #3
dmix wrote: post #2

Wow, open source sites are getting nice designs these days. Is there a business behind this project or is it via donation? The documentation is excellent.

Thanks, we worked quite hard on this new redesign! edit: Yes, EfficiOS [1] is the open source business behind the LTTng project :). [1] - https://www.efficios.com/

Some UX feedback after attempting to install it on Fedora:

1) Clicked Fedora on install docs

2) Installed lttng-tools and lttng-ust RPMs

3) Clicked Getting Started in docs. Ran "lttng list --kernel".

3a) Got an error saying I need to run the systemd service.

4) Started systemd service (didn't see this mentioned in the docs?)

5) Reran "lttng list --kernel".... error saying I'm missing a module

5a) Reread docs, realized I need to build LTTng-modules. Which led me to find out I need to also build liburcu

6) Installed liburcu but got an error building lttng-modules https://gist.github.com/dmix/d2d4c3c1b823e82486bf (I could submit this as a bug report?)

So I gave up to attempt the install another time.

Re: LTTng: An open-source tracing framework for Linux

#9

Post by abusque »

hitlin37 wrote: post #6

how different is this from oprofile?

Well, I've never used OProfile myself, so please take this answer with a grain of salt, but from a quick perusal of their website, and as the project's name seems to suggest, OProfile is a sampling profiler, which usually means it will collect data from counters at given intervals of time, producing a number of statistics over time. This generally implies a somewhat significant overhead, and consequent performance drop.

LTTng, on the other hand, is a tracer, which means it collects events from the kernel (using the built-in tracepoint facilities) as they happen. It's also possible to trace userspace apps (with lttng-ust), or define your own tracepoints. This has the benefit of being much more detailed, and also has a much smaller overhead.

You might be interested in reading the "What is Tracing?" section of the lttng docs [0], which does a far better job at explaining this than I do.

[0] - http://lttng.org/docs/#doc-nuts-and-bolts

Re: LTTng: An open-source tracing framework for Linux

#10

Post by cbab »

dmix wrote: post #8
cbab wrote: post #3

Earlier quoted context omitted.

Thanks, we worked quite hard on this new redesign! edit: Yes, EfficiOS [1] is the open source business behind the LTTng project :). [1] - https://www.efficios.com/

Some UX feedback after attempting to install it on Fedora: 1) Clicked Fedora on install docs 2) Installed lttng-tools and lttng-ust RPMs 3) Clicked Getting Started in docs. Ran "lttng list --kernel". 3a) Got an error saying I need to run the systemd service. 4) Started systemd service (didn't see this mentioned in the docs?) 5) Reran "lttng list --kernel".... error saying I'm missing a module 5a) Reread docs, realize…

Thanks for reporting your issues on Fedora.

4) We will definitely fix that omission.

5a) liburcu is a dependency of the lttng-ust and lttng-tools. The dependency should be accounted for in the respective Fedora packages.

6) Yes please submit a bug for this at [1]. We will investigate that failure to build on Fedora.

[1] - http://bugs.lttng.org/projects/lttng-modules

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