All posts by rbowen

Flight delay out of Amsterdam

Yesterday I flew from Amsterdam to Prague on the 2:30pm flight, scheduled to arrive around 4pm.

Boarding began on time. This being Amsterdam, you don’t just walk out of the gate onto the plane – there’s a bus that takes you from the gate out to the plane. So, we all got on the bus, and got on the plane. No trouble.

At this point (unbeknownst to all of the passengers) one passenger calls a flight attendant over and reports that the bag which he/she has boarded with is not, in fact, his/her bag.

This started a chain of events from which there was no escape, due to both airline and federal policy.

A full security sweep of the plane was ordered, which involved everyone getting off of the plane. There was quite a bit of confusion – I assume they were trying to avoid panicking anybody, and so communication was slow? – but eventually we all got off of the plane, and back onto the buses. After sitting on the bus for a while, we started to drive around the plane parking area, making several loops.

At one point, the driver told us that the pilot had been arrested, and later that a passenger had been arrested. Neither one of these turned out to be true.

Finally, the driver got word that we had to go back to the terminal, and so we headed that direction, only to turn back a minute or two later with new instructions. Back at the plane, we sat for a while, and then did in fact go back to the terminal, where we were issued new boarding passes for the rescheduled flight, now scheduled for 5:30pm. We also received a generous 5 Euro voucher for dinner. (Yes, that was sarcastic. That won’t even get you a sandwich at Schiphol.)

Meanwhile, the flight crew exceeded its mandatory maximum on-the-clock time, and were relieved of duty, so the 5:30 flight was cancelled. Fortunately, there was a KLM plan and crew with nothing to do, and they picked up the flight.

Throughout this entire process, various passengers were loudly demanding more information! Answers! Explanations! None of which in any way helped things along. Others offered advice as to how to handle the situation, which was equally unhelpful, since a procedure was being observed, which wasn’t open to improvisation.

What remains a mystery is why the passenger waited until we were all on board to notify someone that he/she had the wrong bag.

CERN CentOS Dojo, part 4 of 4, Geneva

This is part 4 of a series about my visit to CERN in Geneva. You can read the entire series here:

On Friday evening, I went downtown Geneva with several of my colleagues and various people that had attended the event.

CERN is right on the France/Switzerland border, so we’ve been going back and forth between the two countries several times a day, often not really knowing what country we were actually in.

I had been to Geneva when I was younger, but I really couldn’t say for sure when that was. The only thing I remember was the fountain – the Jet D’Eau – so I wanted to see that again. It was every bit as impressive as I remembered it.

CERN and Geneva

However, it was the end of a very long day, and between that, and jet lag, I was absolutely exhausted, so headed back to the hotel. I hope to go downtown again for a few hours this afternoon, but I kind of wanted to get these articles written while the memories were fresh.

When I was a kid, I dreamed that some day I would have a job traveling around the world, getting paid to see cool things. I think a lot of people dream of that. I have had the amazing good luck to achieve that goal. I have the best coworkers in the world, and I get to do things that I’m passionate about, every single day. The only way that this could be better is if I could have my beloved travel with me. Perhaps some day.


CERN CentOS Dojo, part 3 of 4: Friday Dojo

On Friday, I attended the CentOS Dojo at CERN, in Meyrin Switzerland.

CentOS dojos are small(ish) gatherings of CentOS enthusiasts that happen all over the world. Each one has a different focus depending on where it is held and the people that plan and attend it.

You can read more about dojos HERE.

On Friday, we had roughly 60-70 people in attendance, in a great auditorium provided by CERN. We had 97 people registered, and 75% is pretty standard turnout for free-to-register events, so we were very pleased.

You can get a general idea of the size of the crowd in this video:

The full schedule of talks can be seen here:

There was an emphasis on large-scale computing, since that’s what CERN does. And the day started with an overview of the CERN cloud computing cluster. Every time I attend this talk (and I’ve seen it perhaps 6 times now) the numbers are bigger and more impressive.

CERN and Geneva

This time, they reported 279 thousands cores in their cluster. That’s a lot. And it’s all running RDO. This makes me insanely proud to be a small part of that endeavor.

Other presentations included reports from various SIGs. SIGs are Special Interest Groups within CentOS. This is where the work is done to develop projects on top of CentOS, including packaging, testing, and promotion of those projects. You can read more about the SIGs here:

If you want to see your project distributed in the CentOS distro, a SIG is the way to make this happen. Drop by the centos-devel mailing list to propose a SIG or join an existing one.

The entire day was recorded, so watch this space for the videos and slides from the various presentations.

The CERN folks appeared very pleased with the day, and stated their intention to do the event again on an annual basis, if all works out. These things aren’t free to produce, of course (even though we strive to make them always free to attend) so if your organization is interested in sponsoring future dojos, please contact me. I’ll also be publishing a blog post over on in the coming days about what’s involved in doing one of these events, in case you’d like to host one at your own facility..

CERN Centos Dojo, event report: 2 of 4 – CERN tours

(This post is the second in a series of four. They are gathered here.)

The second half of Thursday was where we got to geek out and tour various parts of CERN.

I was a physics minor in college, many years ago, and had studied not just CERN, but many of the actual pieces of equipment we got to tour, so this was a great privilege.

We started by touring the data center where the data from all of the various physics experiments is crunched into useful information and discoveries. This was amazing for a number of reasons.

From the professional side, CERN is the largest installation of RDO – the project I work with at work – that we know of. 279 thousand cores running RDO OpenStack.

For those not part of my geek world, that translates into hundreds of thousands of physical computers, arranged in racks, crunching data to unlock the secrets of the universe.

For those that are part of my geek world, you can understand why this was an exciting thing to see in person and walk through.

The full photo album is here, but I want to particularly show a couple of shots:

Visiting CERN

Here we have several members of the RDO and CentOS team standing in front of some of the systems that run RDO.

Visiting CERN

And here we have a photo that only a geek can love – this is the actual computer on which the very first website ran. Yes, boys and girls, that’s Tim Berners-Lee’s desktop computer from the very first days of the World Wide Web. It’s ok to be jealous.

There will also be some video over on my YouTube channel, but I haven’t yet had an opportunity to edit and post that stuff.

Next, we visited the exhibit about the Superconducting Super Collider, also known as the Large Hadron Collider. This was stuff that I studied in college, and have geeked out about for the years since then.

There are pictures from this in the larger album, but I want to point out one particular picture of something that absolutely blew my mind.

Most of the experiments in the LHC involve accelerating sub-atomic particles (mostly protons) to very high speeds – very close to the speed of light – and then crashing them into something. When this happens, bits of it fly off in random directions, and the equipment has to detect those bits and learn things about them – their mass, speed, momentum, and so on.

In the early days, one of the the ways that they did this was to build a large chamber and string very fine wires across it, so that when the particles hit those wires it would cause electrical impulses.

Those electrical impulses were captured by these:

CERN visit

Those are individual circuit boards. THOUSANDS of them, each individually hand-soldered. Those are individual resistors, capacitors, and ICs, individually soldered to boards. The amount of work involved – the dedication, time, and attention to detail – is simply staggering. This photo is perhaps 1/1000th of the total number of boards. If you’ve done any hand-soldering or electronic projects, you’ll have a small sense of the scale of this thing. I was absolutely staggered by this device.

Outside on the lawn were several pieces of gigantic equipment that were used in the very early days of particle physics, and this was like having the pages of my college text book there in front of me. I think my colleagues thought I’d lost my mind a little.

College was a long time ago, and most of the stuff I learned has gone away, but I still have the sense of awe of it all. That an idea (let’s smash protons together!) resulted in this stuff – and more than 10,000 people working in one place to make it happen, is really a testament to the power of the human mind. I know some of my colleagues were bored by it all, but I am still reeling a little from being there, and seeing and touching these things. I am so grateful to Tim Bell and Thomas Oulevey for making this astonishing opportunity available to me.

Finally, we visited the ATLAS experiment, where they have turned the control room into a fish tank where you can watch the scientists at work.

CERN visit

What struck me particularly here was that most of the people in the room were so young. I hope they have a sense of the amazing opportunity that they have here. I expect that a lot of these kids will go on to change the world in ways that we haven’t even thought of yet. I am immensely jealous of them.

So, that was the geek chapter of our visit. Please read the rest of the series for the whole story.

CERN Centos Dojo 2017, Event report (1 of 4): Thursday meeting

Over the last few days I’ve been in Geneva for the CERN CentOS Dojo, 2017 edition.

(This is part 1 of a series of four posts. They are gathered here.)

On Thursday, prior to the main event, a smaller group of CentOS core community got together for some deep-dive discussions around the coming challenges that the project is facing, and constructive ways to address them.

This meeting was very potentially productive. I say potentially because some great decisions were made, with universal approval, but everything depends on the execution. Some of these decisions will take a great deal of work over the coming months. Of course, nobody is averse to hard work, but we all also have other things to do. So we need to keep the long-term health of the project firmly in mind, and find time for these tasks.


The full notes from that meeting have been posted to the Centos-devel mailing list for further discussion.

The attendees were from many different organizations, countries, and cultures. While the various organizations represented have rather different goals and motivations, there was great unity of purpose – ensuring the long-term health of the CentOS project.

Topics covered were focused on removing roadblocks to forward movement on the project, and removing obstacles to new contributors to the project coming on board and getting things done. This was very encouraging.

We were disappointed that a number of prominent community members were unable to attend. Notably, Karanbir was absent due to a broken toe:


Continuing discussion of the topics will happen on the centos-devel mailing list, and, as always, people who want to step up to assist in any of the identified tasks are encouraged to speak up and volunteer.

CentOS is a community of project communities, and works best when those projects identify the things that will make them more productive, and then step up to make those things happen.


CERN Centos Dojo 2017, Event report (0 of 4)

For the last few days I’ve been in Geneva for the CentOS dojo at CERN.

What’s CERN? –

What’s a dojo? –

What’s CentOS? –

A lot has happened that I want to write about, so I’ll be breaking this into several posts:

(As usual, if you’re attempting to follow along on Facebook, you’ll be missing all of the photos and videos, so you’ll really want to go directly to my blog, at



For the second time this year, I’m sitting in a place that I have read about for decades. I’m in a conference room at CERN, attending a CentOS meeting. CERN is the home of the Superconducting Super Collider, as well as being the birth place of the World Wide Web.

This afternoon I’ll tour the data center where a lot of the computing for the SSC happens, as well as seeing some of the actual experiments. Photos to come later this evening.

The earlier visit referenced above was Oak Ridge National Labs. I actually visited ORNL when I was in college, but on my most recent visit I got to visit Titan – one of the world’s largest supercomputers – and actually walk through it. It was very loud.


The day that started awful ended pretty well.

I woke up this morning, to make a long story short, with pain in my chest and left arm. We called 911 and the ambulance came. The EMTs checked me out and recommended that I go to the hospital. 5 hours later, I was discharged. They couldn’t find anything wrong. We figure that I just have a pulled muscle in my neck and shoulder.

Anyways, we had planned to go hiking today, so we decided to go ahead and do it anyway. We climbed chimney tops. Isaiah and I made it to the top, you can see my pictures on Flickr.

I’m not certain, but I think the last time I climbed chimney tops was at least 20 years ago. Perhaps a little bit more. It was a lot harder hike this time than it was then. I remember jogging up to the peak with Tim and Tony and Eddie.

But we made it to the top and back with no ill effects. My neck and chest and shoulder feel the same now as they did this morning. So I guess there’s nothing to worry about.

Event report: OpenStack PTG

Last week I attended the second OpenStack PTG, in Denver. The first one was held in Atlanta back in February.

This is not an event for everyone, and isn’t your standard conference. It’s a working meeting – a developers’ summit at which the next release of the OpenStack software is planned. The website is pretty blunt about who should, and should not, attend. So don’t sign up without knowing what your purpose is there, or you’ll spend a lot of time wondering why you’re there.

I went to do the second installment of my video series, interviewing the various project teams about what they did in the just-released version, and what they anticipate coming in the next release.

The first of these, at the PTG in Atlanta, featured only Red Hat engineers. (Those videos are HERE.) However, after reflection, I decided that it would be best to not limit it, but to expand it to the entire community, focusing on cross-company collaboration, and trying to get as many projects represented as I could.

So, in Denver I asked the various project PTL (project technical leads) to do an interview, or to assemble a group of people from the project to do interviews. I did 22 interviews, and I’m publishing those on the RDO YouTube channel – – just as fast as I can get them edited.

I also hosted an RDO get-together to celebrate the Pike release, and we had just over 60 people show up for that. Thank you all so much for attending! (Photos and video from that coming soon to a blog near you!)

So, watch my YouTube channel, and hopefully by the end of next week I’ll have all of those posted.

I love working with the OpenStack community because they remind me of Open Source in the old days, when developers cared about the project and the community at least as much, and often more, than about the company that happens to pay their paycheck. It’s very inspiring to listen to these brilliant men and women talking about their projects.

Video noise reduction using kdenlive and audacity

I’ve been doing interviews at the OpenStack PTG this week, and the space I started in was very noisy. I’ve been trying to figure out how to reduce background noise, and I think I finally figured it out.

(I’m sure that the same process works with other tools, but these are the ones that I use.)

In short, the process is this:

  1. Extract audio from original recording
  2. Noise reduction in Audacity
  3. Add video and noise-reduced track to kdenlive.
  4. Mute video track, and “group” the audio and video tracks
  5. Edit as usual

In more detail, here’s how you do that:

  1. Extract audio from original recording:

At the command line, convert the video directly to an mp3. ffmpeg takes care of the details:

ffmpeg -i original_video.mp4 original_audio.mp3

2. Open the audio track in Audacity, and noise-reduce

Select a section of the audio where nobody’s talking. This gives you the typical background noise that you want to remove. The longer this section is, the better your overall noise reduction will be.

Click “Effect” -> “Noise Reduction”, and then press the “Get Noise Profile” button.

Now, unselect the section (ie, by clicking anywhere in the track) then remove that noise from the entire track by clicking “Effect” -> “Noise Reduction” and clicking “OK”.

DO NOT make any edits that change the length of the track, as it must be exactly the same length as the video clip.

Now export the track again as an mp3.

3. In kdenlive, add the original video, and the new audio.

Add the two clips – the original video and the new audio to the timeline and make sure that they line up exactly.

4. Mute the video track by clicking the speaker icon next to the track.

Click the video track, then control-click the audio track. Press control-G (or right-click and select the “Group clips” option) to group the tracks into a single unit.

5. Edit as usual

In particular, when you cut or drag one clip, it will also happen to the other, so cutting out sections will affect both tracks, and they’ll stay in sync.