project update march 20th 2012

For the past weeks along with the preparation of the stable release of LTTng 2.0 (especially the Babeltrace API part) and LTTngTop development, I have been experimenting with Google Rocksteady.

This application is the monitoring solution used at Google, so it is designed to be highly scalable and distributed.

project update 28 feb 2012

A long time passed since my last update...

I have now started my Ph. D. I am still focusing on using the tracing as a useful and efficient problem-solving facility, but this time it will deal with the scalability. One of the early goal being to use the tracing in large data center as a highly granular monitoring interface. A lot remains to be defined, but that is the general idea.

Update 14/12/2011

My master thesis has been accepted so I'm presenting it on december 15th.

LTTngTop live is nearly complete, it is now working again with all the API changes that occured while I was writing (one month without coding and the kernel consumer is a whole new beast !), I should be able to push it into the master branch by the end of the week. Once this is done and tested on various setups, I will move the LTTngTop repository to and make a public announcement.

Back to preparing my presentation now...

Project update 23 nov 2011

Since the last update I have been writing my master thesis and two papers.

The writing is now over, the master thesis has been submitted to the jury members and the two papers are submitted to journals. In both case I'm waiting for the review comments.

During that time, I'm back on coding and brainstorming for precise ideas of Ph .D research subject.

For the coding part, my first focus is to finally finish the merge of the code for lttngtop live mode.


Project update september 29th 2011

All custom babeltrace patches are now merged upstream !

I apologize for those who already had cloned my repository but the changes were too big to just fix my repository so I had to rebase.

Now since there are no custom babeltrace patches anymore in this tree, maintaining and merging upstream patches will be easy and I won't need to rebase again !

The git tree is available here :;a=summary

Project update 14-09-2011

Lots of merging of patches into babeltrace to ensure lttngtop does not remain a fork of babeltrace, still need to merge the mmap patch for live reading and most of the custom babeltrace code should be mainlined.

This week : start to work on automating the syscalls prototype export, to give an easy and clean way to create up to date syscalls probe in lttng-modules. Also finish the mainlining and rebase lttngtop to this cleaner code base.



Project update 07-09-2011

API work in babeltrace :

- Add callbacks (used to be hooks) infrastructure

- Add seek mechanism

Still need a lot of work, but the basic tests integrate well in lttngtop and don't break babeltrace, continue the merging this week.


Update 31-08-2011

  • Back from Linuxcon where I gave the talk "Tracing in the Real World".
  • lttngtop is now public;a=summary (not yet announced on ltt-dev but during the conference)
  • in a separate private branch lttngtop is parsing traces in live mode : reads the buffer directly from memory, only the metadata file is spliced to disk, at each refresh it only does a few ioctl syscalls, seems more efficient than "top", need benchmark now

Project update 26th of july to 2nd august

Full perf support working in lttngtop : ability to select which counter to display, and sort the list based on a specific counter, at each period (by default 1 second) the counter is reset to 0, so the view gives the user the summary of what happened in the last period. Like in the cputop view, this view allows the user to pause the refresh and go back in time.

Next step : change the  backend to allow recalculation of each counters based on the trace and not on precalculated counters to give more flexibility, which means a big cleanup in babeltrace lib.