No-no-no, light speed is too slow!
Yes, we’ll have to go right to… ludicrous speed!
So, I recently brought up the topic of writers notes in the LibreOffice ESC call. More specifically: the
SwNodeIndex class, which is, if one broadly simplifies an iterator over the container holding all the paragraphs of a text document. Before my modifications, the
SwNodes container class had all these SwNodeIndices in a homegrown intrustive double linked list, to be able to ensure these stay valid e.g. if a
SwNode gets deleted/removed. Still — as usual with performance topics — wild guesses arent helpful, and measurements should trump over intuition. I used valgrind for that, and measured the number of instructions needed for loading the ODF spec. Since I did the same years and years ago on the old OpenOffice.org performance project, I just checked if we regressed against that. Its comforting that we did not at all — we were much faster, but that measurement has to be taken with a few pounds of salt, as a lot of other things differ between these two measurements (e.g. we now have a completely new build system, compiler versions etc.). But its good we are moving in the right direction.
(-235% of total)
(-15% of total)
(-0.7% of total)
(2.6% of total)
|week after x.y.0||development||release candidates||finalized releases|
The last two columns are most visible to most visitors of the LibreOffice website. Those are the versions found on the LibreOffice Fresh and LibreOffice Stable download pages. We are in roughly at week 18 after 4.2.0 release now, and the versions available are 4.2.4 fresh and 4.1.6 stable. A careful reader will note that according to that schedule we should be at 4.2.3 and 4.1.5 — that is true, but the 4.2 series still had an extra 4.2.1 intermediate release to adjust the schedule of 4.2 in direction of the current plan. This is not expected for future releases (also note that there is always some flexibility in the plan to allow for holidays etc.)
If you count all the prereleases, release candidates and releases, you will find that we do 25 of those in 26 weeks. Beside the fact that this is a lot of work for release engineers, one might wonder if anyone can keep up with that, and if so — how? The answer to that depends on how you are using LibreOffice.
self deployment on LibreOffice fresh
If you are an user or a small business installing LibreOffice yourself, you will probably run LibreOffice fresh and the table above simplifies for you as follows:
|week after x.y.0||development||release candidates||finalized releases|
The last column shows the releases you are running. If you are a member of the LibreOffice community it would be very helpful if you also spend some time of this 6 months period for three actions:
- running at least one of the release candidates in the table (available for download here) before the final is released.
- running at least one beta releases in the table. Note that there will be a bug hunting session on the 4.3.0 beta release this week, that will help you get started.
- running a nightly build once anywhere in the weeks 1-18. Note that if you are getting excited about seeing the latest and greatest builds while they are still steaming, there are tools that can help you with this on Linux and Windows.
If you do these each of these three things once in the timeframe of six months and report any issues you find, you are helping LibreOffice already a lot — and you are making sure that the finalized releases of the fresh series are not only containing all the latest features, but also free of severe regressions.
bigger deployments on LibreOffice stable
If you are not installing LibreOffice yourself, but instead have a major deployment administrated centrally, things are a bit different. You might be more conservative and interested in the releases from LibreOffice stable. And you probably have professional support from a certified developer or a company employing certified developers.
|week after x.y.0||development||release candidates||finalized releases|
If you intend to deploy one series of LibreOffice (e.g. 4.3), there are two things that are highly recommended to be done:
- make the alpha or beta releases available quickly to interested volunteers in your deployment early. They might find bugs or regressions that are specific to your use of the software.
- make the release candidates of versions that you intent to deploy available early to your users.
Of these two actions, the first is by far the most important: It identifies issues early on in the life cycle and gives both your support provider and the LibreOffice developer community at large time to resolve the issue. In fact, I would argue that if you have a major deployment, the only excuse for not making available prereleases, is that you made available nightly builds.
So, Ubuntu qualifies as a “bigger deployment” and I have to take care of LibreOffice on it. Also people want to be able to run the latest and greatest LibreOffice releases from the LibreOffice fresh series. Do I follow my recommendations here? Yes, mostly I do:
- both LibreOffice fresh and LibreOffice stable series are available from PPAs for Ubuntu and are updated regularly and quickly when an rc2 is available.
- prereleases are made available as bibisect repositories rather quick (build on Ubuntu 12.04 LTS). In addition, fully packaged versions of LibreOffice are build in the prereleases PPA as early as starting with beta1.
So, you are invited to run or test builds from these PPAs — or download the bibisect repositories — to keep LibreOffice releases coming in the steady and stable fashion they do. Finally, there is a bug hunting session for LibreOffice this week and as said above, no matter if you are running a huge deployment or installing on your own, you are helping LibreOffice — and yourself, as a user of LibreOffice — a lot by testing the prereleases:
I hope that someone gets my message in a bottle
This needs some background first: LibreOffice 4.2 modified the UNO API to pop up a message box in a slight way against LibreOffice 4.1. This was properly announced in our LibreOffice 4.2 release notes many moons ago:
The following UNO interfaces and services were changed […] com.sun.star.awt.XMessageBox, com.sun.star.awt.XMessageBoxFactory
Luckily, LibreOffice extensions can specify a minimal version, so extensions using the new MessageBox-API can explicitly request a version of LibreOffice 4.2 or newer. This change in our sdk-examples shows how an extension can be updated to use the new API and explicitly require a version of LibreOffice 4.2 and higher. All this happened already with LibreOffice 4.2.0 being released and has nothing yet to do with the change in LibreOffice 4.2.4.
So what was changed in LibreOffice 4.2.4? Well, in addition to the LibreOffice version, old extensions sometimes just ask for an “OpenOffice.org version”. Most LibreOffice versions answered its version was “3.4”, so this old backwards compatible check was not very helpful anyway. So in LibreOffice 4.2.4 this value was changed to “4.1”, which might make some old extensions aware of the incompatible API change. That’s all.
- Most extensions using the MessageBox API have already been changed at 4.2.0 (or have been fixed by Linux distros)
- Extensions should use “LibreOffice-minimal-version” anyway by now (see example above on how to do that), it is the best way to ensure you get a well known API with welldocumented changes.
So, the short answer to the question to “what changed in LibreOffice 4.2.4?” is: Nothing, if your extension uses LibreOffice-minimal-version as recommended.
Sie singt Tag und Nacht neue Lieder,
von den Palmen am blauen Meer
So, the LibreOffice Las Palmas Hackfest 2014 is over and it was awesome. I have to thank Alberto Ruiz and University of Las Palmas de Gran Canaria for their excellent hosting and support. We had the opportunity to present the LibreOffice project to the students of the university, and we did so with a set of short talks to cover a lot of ground without too much boring details. Here is the hand of my slides:
You can find a video of all the talks in the session on youtube. My talk starts around minute 35 and is followed by Kendys nice intro on improving the LibreOffice UI. In addition to the video, I also made a few pictures on the event, you can find them in this album.
The achievements section of this Hackfest is still being populated, but despite being a smaller Hackfest, there seems to have been quite some productive work done in total. It was also very encouraging to see curious students from the university drop by, we tried to give them a gentle introduction on ways to contribute and learn more.
Our next LibreOffice Hackfest will be on June, 27-28 in Paris as has just been announced.
“I fought the law and the law won”
So in a few minutes, I will be leaving for the meeting at Open Knowledge Lab in Hamburg for Code for Germany in Hamburg — but I dont want to show up empty-handed. Earlier I learned about BundesGit which is a project to put all federal german laws in a git repository in easily parsable markdown language. This project was featured prominently e.g. on Wired, Heise and got me wondering that having all those laws available at the tip of your hand would be quite useful for lawyers. So here I went and quickly wrote an extension to do just that. When you install the extension:
- it downloads all the german federal laws from github and indexes them on the next restart of LibreOffice (completely in the background without annoying the user)
- that takes about ~5 minutes (and it only checks for updates on the next start, so no redownload)
- once indexed you can insert a part of a law easily in any text in Writer using the common abbreviations that lawyers use for these:
- Type the abbreviation of the paragraph on an otherwise empty line, e.g. “gg 1″ for the first Artikel of the Grundgesetz
- press Ctrl-Shift-G (G for Git, Gesetz or whatever you intend it to mean)
- LibreOffice will replace the abbreviation with the part of that law
Now this is still a proof-of-concept:
- It requires a recent version (1.9 or higher) of git in the path. While that is for example true in the upcoming version of Ubuntu 14.04 LTS, other distributions might still have older versions of git, or — on Windows — none at all: Packing a git binary into the extension is left as an exercise for the reader.
- I have not checked it to parse all the different laws and find all the paragraphs. It also ignores some non-text content in the repository for now. Patches welcome!
- While it stays in the background most of the time intentionally to not get into the way of the user, it could use some error reporting or logging, so users are not left in the dark if it fails to work.
On the other hand, the extension is a good example what you can do with less than 300 lines of Python3 (including tests) in LibreOffice extensions. Thus the code was hopefully verbosely enough commented and was uploaded to sdk-examples repository, where it lives alongside this LibreOffice does print on Tuesdays extension that also serves as an example. Of course, if there other useful repositories of texts online, it can be quickly adapted to provide those too.
Im kind of over gettin told to throw my hands up in the air
So, somewhere between the LibreOffice 4.2.0 and the 4.1.5 release, bugs.freedesktop.org broke through 25.000 reported bugs. A time to throw the hands up in despair? Not at all, as the following chart shows:
- 7% of reports are still unconfirmed or need more information
- 22% are confirmed and unresolved issues, that are not enhancements requests
- 6.5% are unresolved enhancement requests.
On the other hand:
- 33% of all reports have been fixed in some way
- and 30% are invalid or duplicates.
Its interesting to see how now a quarter of the confirmed unresolved reports are asking for new features and enhancements. Its gets even more encouraging, if you take into account that the number of bugs reports is at a long term constant 20-25 reports per day, while over 40% of the bugs intentionally or collaterally fixed changed their state in the last 12 month. So we are picking up speed in triaging and fixing bugs, while the influx of new reports stays constant.
If you are interested, please help QA quite a bit in all this by writing good bug reports, identifying duplicates, confirming new reports, bibisecting regressions, run and test daily builds and prereleases or otherwise helping with the QA Easy Hacks!
It’s so hard when it doesn’t come easy
It’s so hard when it doesn’t come fast
So, LibreOffice 4.2 is released, FOSDEM is over, was very nice and I am back home in Hamburg after a week in London. I missed the LibreOffice UX Hackfest for that, which I heard was also awesome. So without further ado, here are the slides from my quick talk at FOSDEM:
and some errata for it: On slide 13 it says “the same file is also hardlinked from workdir/” — thats not true for quite a while already. LibreOffice keeps around exactly one copy of a library, unlike the confusing three copies that we had in LibreOffice 3.3. This should be a lot less confusing to the curious first time contributor.
Reviewing all these changes in toto, it became how much we simplified getting involved with LibreOffice through this. As the lyrics quoted above say: “Back when we started, we didn’t know how hard it was”.
If there is just one number to take away from all these slides, its that a noop rebuild for LibreOffice on a three year old developer notebook with the distro provided GNU make 3.81 takes just 17 seconds(*). And slide 7 shows still some possibilities to still speed things up beyond that — and while at current speeds it might not be worth it on Linux, it might be worthwhile for e.g. Windows, which is traditionally rather slow when it comes to file I/O.
On a related note, over time we improved the way new contributors can submit their changes on our instance of gerrit in many ways. Thanks a lot to David, Norbert and Robert for the work on this. One only has to look at one of daily digests generated from activity on gerrit and imagine we would still get one mail for each change, update and merge to the mailing list for manual patch tracking as we did in the early days. Thanks a lot also to Mathias Michel for his work on the script!
So if you haven’t done that yet, consider graping an EasyHack and get started!
(*) This includes checking 1.3GB of generated c++ dependency files for some >8000 object files, which we simplify to <350MB.
“Eins, zwei, drei, vier, fuenf, sechs, sieben, acht”
So LibreOffice 4.2.0 release candidate 3 has been tagged yesterday evening. A good time to look back at the cycle and look at some numbers. The number of issues fixed in the 4.2 series are in line with our historic trends:
- 1131 bugs fixed for 4.2.0 beta 1 (at 4.1.0 we had 1045 bugs fixed at that point)
- 48 bugs fixed for 4.2.0 beta 2 (at 4.1.0 we had 76 bugs fixed)
- 67 bugs fixed for 4.2.0 release candidate 1 (at 4.1.0 we had 59 bugs fixed)
- 53 bugs fixed for 4.2.0 release candidate 2 (at 4.1.0 we had 86 bugs fixed)
There is no page for the third release candidate yet, but I assume it to be no exception. Fixing issues is mainly done by development, although QA does the preparation for that by triaging a bug well. But QA also does quite a bit of work before a bug is triaged, and this is not directly locked to changes in code. So I had a look at the numbers simply in the timeframe between the tagging of 4.1.0 rc3 (2013-07-17) and 4.2.0 rc3 (yesterday). In this timeframe, QA did:
- confirm 3114 bugs (change of ever_confirmed).
- resolve 3393 bugs (change of resolution and not unresolved now, this includes the bugs fixed by development).
Naturally, these can not be simply be added up: for example, a bug can be confirmed and then be resolved by fixing it. If all of that happens in the timeframe (as it likely will for a relevant bug), it will appear in all the above counts. Meanwhile, in this timeframe 4092 bugs have been filed by endusers. Of those new bugs filed, 9.3% where enhancement requests. Since not all resolved bugs need to be confirmed (e.g. invalid bugs), these numbers add up nicely.
Speaking of quality, another thing to look at is regressions. How many of those will be fixed in 4.2 as of now? Here is the rundown:
- 1 regression introduced in 3.4 or before
- 2 regressions introduced in 3.5 or before
- 3 regressions introduced in 3.6 or before
- 2 regressions introduced in 4.0 or before
- 8 regressions introduced in 4.1 or before
- 51 regressions introduced on master or found in betas and release candidates
As you can see, most of the regressions fixed with this have actually never been released. This should be encouraging news to those testing daily builds: If you do that, you will be rewarded with quick bug fixes. Still, only fixing 16 regressions that were visible in previous releases seems a rather low count for a release. Well, this is because this count does not count fixed regressions that are also backported to the updates on the 4.1 stable series. As regressions are usually worth that effort, this is usually done unless it is to risky a change for that. If you look for regressions that were fixed in 4.2 and also backported to 4.1, you as of now get a count of:
- 230 regressions fixed in 4.2 that were also backported to the 4.1 series
in addition. See this earlier post for more details on how the backporting works and some numbers on it.
Speaking of regressions, we have a pretty unique tool to corner them: bibisect. How well does this work? I keep tracking these in bugzilla for the last months. Currently 176 bugs have been bibisected, with the number of unresolved bibisected bugs staying constant in the 60-70 range. That is encouraging, as it means that for each regression bibisected, a developer fixes a bibisected regression. This happens currently at a rate of ~2 bugs per week, which is not too bad, as such regressions might be quite hard cornercases that without bibisect would be tricky to pin down. However, only ~14% of our unresolved regressions are bibisected as of now. Clearly, we can improve that ratio with more bibisecting and get more regressions fixed even quicker.
Ok, admittedly, this was a boring and dry post on bug numbers. What can I do to lighten you up? Here is catcontent, presented in LibreOffice Draw 4.2 running on Ubuntu trusty with the awesome new libreoffice-style-sifr icon theme:
tl;dr: We are doing well, but could use even more people testing daily builds and do bibisects.
Sometimes I wonder if the world’s so small,
Can we ever get away from the sprawl?
So these days, most people prefer to use an IDE to navigate their source code. This has often been greeted with some defensive elitism of the “real programmers” kind since the early days of the open sourcing of StarOffice. One does not simply load a code base the size of LibreOffice in your wimpy IDE: while it is possible somehow in the end, its a lot more trouble than its worth to manually set up e.g. all the include path manually to get the fancy stuff like autocompletion. Add to that, that e.g. UNO headers are generated during the build and header were at distributed over multiple IDE unfriendly locations, with many headers even available as copies from multiple locations, before we fixed that.
All these things are fixed now. And while LibreOffice still is a huge beast with our new build system we can get a holistic view of what needs to get build where, how and when. This makes it easy, almost trivial to generate an IDE project file from the build system. And to prove this point, I did just that for the kdevelop IDE. This isnt limited in principle to this one IDE — in fact the kdevelop specific part of this is some 150 lines of Python. So no matter what IDE you use: Eclipse, Netbeans, Anjuta, Visual Studio, Code::Blocks or XCode — you should be able to adapt this. In fact, while writing this, I find there is already work going on for XCode. Feel invited to join the party and make LibreOffice trivially buildable in your favourite IDE!
So as announced to the developer list, this allows you to make navigating, editing, building, testing and running LibreOffice much easier, giving you features like:
- building a module from the IDE
- building all of LibreOffice from the IDE
- nondebug and debug build configs for the above
- starting LibreOffice from the IDE
- running unitchecks, slowchecks and subsequentchecks from the IDE
Dont believe it? Here is a video featuring a stuttering german guy (me) on the audio track showing this:
If you want to show this around on social media, there is also a shorter version featuring the essentials (make sure to link to the HD versions).
A closing note: A long time, common IDEs embrace and extended into the buildsystems so once you used an IDE, you could only use this one IDE and no other. In retrospect, this is obviously doing it wrong. With the current approach, we can make LibreOffice easily buildable in any IDE on any platform. A very important fact for a product available on so many platforms.
addendum: As Karl Fogel wrote “LibreOffice is now ridiculously easy to build.“ before we even had this, it just shows that one can always do better. ;)
He asked me if I’d seen a road with so much dust and sand.
And I said, “Listen, I’ve travelled every road in this here land!”
I’ve been everywhere, man.
I’ve been everywhere, man.
So about a month ago I travelled in one week from Hamburg via Zürich and San Francisco to Oakland and then via San Francisco, Munich and Basel to Freiburg to attend the LibreOffice Hackfest Freiburg 2013 and back to Hamburg. The Freiburg Hackfest is the third and last Hackevent we had in Germany this year (after the Impress Sprint in Dresden and the Hackfest in Hamburg) nicely accompanying the international events like the LibreOffice conference in Milan and our usual presence at FOSDEM.
I have to admit that I arrived at this event with some travel fatigue and some upcoming Ubuflu, so I was not too productive myself, but its good to see fixes like for example in the kde integration (Jan-Marek), in Calc (Eilidh), for enabling bitcoin donations (Florian), to mail merge (again Jan-Marek), to Math (Marcos), for the build system (Michael and David) happening (or at least be prepared at the event). A big “Thank You” to all the angels of the Chaos Computer Club Freiburg that organized the event — when I learned that I would need to travel to the US right before this, I had some doubts if it would result in “remote-organization-troubles” given this was a first time in Freiburg. This was completely unfounded, the support of our hosts was amazing and they seemed to have made a deal with Eris to take revenge for the original snub somewhere else on this weekend. ;)
So, given that I did not do much coding (just some preparation for the KDevelop integration for LibreOffice, more on that later), what can I offer you? Catcontent was not available (no cats at this Hackfest), so I give you the second best thing: the deputy chairman of the board of the Document Foundation patrolling the premises on a skateboard:
So, whats next? FOSDEM! We will of course be there again, and back-to-back with the event we will have a user experience Hackfest in Bruessels. So come and join us:
Take the corner, going to crash
Headlights, head on, headlines
Another junkie lives too fast
Yeah, lives way too fast, fast, fast, woh
So, LibreOffice 4.2.0 alpha1 has been tagged upstream a week ago. It is an alpha release, essentially only a tagged snapshot of the LibreOffice master branch and as such might eat your kitten and kill unsuspecting relatives. On the other hand, if you absolutely are of the type that Metallica roars about in the above quote and therefore you are running the development release of Ubuntu (trusty tahr, which will become Ubuntu 14.04 LTS), you can add the LibreOffice prereleases PPA and try it out and report bugs. Of course, you should not use this in a production environment of any kind!
Im happy to see that this build available again a week earlier than last year, as early testing allows more bugs to be triaged and fixed in time. The more important difference though is that last year, the alpha version was build on the stable and released version of Ubuntu, while this year the version is already build against the early and moving development version of Ubuntu.
We gonna do what they say can’t be done
We’ve got a long way to go and a short time to get there
So, the LibreOffice conference in Milan is just past us and it was awesome — if you missed it, Kohei posted a very nice set of pictures from that event. If you are interested in the talks too, you can find both streams and slides for almost all the talks. One other talk from the conference, I would like to hightlight is Michael Stahls gbuild talk — it was a long journey from when gbuild was still a pet project of mine, but now as the migration is now finished, things unlocked and we (*) are now really reaping what we sowed.
Almost, as e.g. while I was able and eager to send the slides for the lightning talks I moderated, I somehow forgot to do so for my own slides for my talk on tb3. It will hopefully end up on the conference site at some point, but for now I uploaded at at speakerdeck (with the odp originals on the wiki and here):
I didnt bring my own camera and thus missed making pictures during e.g. the lively QA roundtable, but Rob made sure that we get at least some photo on the last day (when many were already on the way home):
So in the next days, I will be hopping over atlantic for a visit to the west coast, just to return to turn “eastbound and down, loaded up and trucking” to be at Freiburg for the Hackfest again. A big Thank You in advance to Tauon and Florian Effenberger, who took over a lot of my organizer duties on this one due to this tight scheduling. Oh, and of course, I hope to see many of you there!
(*) actually they: By far, the most awesome stuff is now done by others than me
I’m easy like Sunday morning
That’s why I’m easy
I’m easy like Sunday morning
So, Ubuntu 13.10 (Saucy Salamander) was released into the wild and comes with a fresh LibreOffice version: 4.1.2. Since the last major version of LibreOffice (4.0) was branched off, 11.034 commits by more than 200 different committers were done upstream up to the release that is now in Ubuntu 13.10. (*) The LibreOffice 4.1 features and fixes page gives an overview what is new with this release: rotating images, embedded fonts, improved interoperability — to name a few.
In the Ubuntu/Debian packaging repository, some 513 commits by 5 authors have been done between the version Ubuntu 13.04 was released with and the just released version. The majority of those commits have been done by Rene Engelhard of Debian. A big “Thank you” for all that work! Now leaving this release behind with a “Girl, Im leaving you tomorrow” on my mind, I am looking forward to what the name for Ubuntu t-series will be, as there does not seem to be an announcement yet (although there have been eager suggestions), start to brace myself for the early cycle madness again and prepare to make sure that Ubuntu t-series will get the best LibreOffice 4.2.
So much for looking backwards. A lot of people are shy and assume they could never be one of the contributors making a dent in LibreOffice, or even get started. Let me show you how wrong that assumption is:
This little chart shows Easy Hacks resolved by newcomers to the project. Easy Hacks are tasks that get need to be done on LibreOffice and can be done without understanding all of the million lines of code and more than 20 years of history — quite a few do not even require C++ skills. They are specifically selected for that — and if you run into any trouble solving those, you can jump in at #libreoffice-dev to get help. So get yourself a LibreOffice build (here’s a video on how easy that is on Ubuntu — with dubstep soundtrack), find yourself an Easy Hack and get going!
(*) I didnt bother to check for the exact number, because checking for duplicates in email addresses is tiresome.
Note: An earlier version of this post talked about 22.000 commits — that was an error on my part fiddling with the scripting late at night.
Go, Greased Lightnin’
You’re burnin’ up the quarter mile
So the conference schedule for the LibreOffice conference in Milan has just been published. The talks, workshops and sessions on the schedule encompass only the so far officially registered sessions. If you have another exciting and urgent topic that you want to share with the others at the conference, you may still get to present a lightning talk in the session on Thursday after lunch!
For that, just send a email to email@example.com right now containing:
- your name
- the title of your talk
- the length/format you want to use:
- freeform 5 minutes (*) lightning talk
- Pecha Kucha talk (20 slides, 20 seconds each = 6 minutes 20 seconds)
Excited to see you all in Milan next week!
(*) changed from 15 minutes earlier as there has been more demand for 5 minutes freeform than for 15 minutes sessions.
I’ve got the power.
So, Im back from vacation. One of the things I did was reorganizing my hardware, and for doing so, I bought a wattmeter to measure what my machines and toys actually consume. A lot of the stuff was what I expected, but there where a few nasty surprises:
| (all values in Watt)
||Ideapad S12||Thinkpad W520||Bertha||TV||Pandaboard ES|
|power supply only||0||0.2||2.5||0.3||0.1|
|desktop w/o display||13||10||122||130||6.1|
From this set a few surprising takeaways:
- The wimpy Ideapad S12 with its Atom CPU eats more power when idling than the Thinkpad W520 with its beefy i7 Quad-Core and 16GB of RAM (13 Watts vs. 10 Watts).
- My TV doing nothing but waiting for the remote to tell it to turn itself on eats more power that each of my notebooks (15 Watts vs. 10/13 Watts).
- Running my desktop (Bertha) as an tinderbox for LibreOffice 24/7 would cost me ~1.000EUR per annum. Doing it with three of those boxes would a very expensive and noisy alternative to what others sell as a room heater.
- My TV eats 30 Watts more when displaying the black screen of a disconnected HDMI signal than with normal TV display. Maybe its expensive to search for a signal?
- Compiling LibreOffice without ccache on my Notebook kicks the power consumption to 90 Watts — but only for a few minutes. Then the thermal controls throttle the machine down to 70 or even 35 Watts, which seems all the machine can disperse over sustained periods.
And then there where these leftover pieces to measure, no surprises there, just a confirmation of my suspicion that the old Asus notebook I run as a home server is eating way too much power:
|(all values in Watt)
||bits and pieces|
|mic preamp off||1.1|
|mic preamp on||10|
|“home server” (decommissioned Asus Z53 notebook)||30|
My tentative conclusions are:
- replacing my old “home server” with something ARM-based like a Raspberry Pi or a Pandaboard breaks even after one year — I should do that.
- Even when under load, a ARM-based Pandaboard has a modest power consumption.
- I will completely turn off my TV on principle as the standby consumption is just pure impudence. As a bonus it prevents my BluRay player from kicking on the 100 Watt TV when I throw in a audio CD (Thanks Panasonic, for providing this excellent and “useful” integration).
- A cheap Netbook might be less powerful, but it hardly consumes less than a high-end Notebook when idling. You get what you pay for.
- I bought a cooler for my Notebook, hoping to unlock it from choking itself with thermal restriction. It should be a good idea in general as the logs not only talked about throttling, but also about more scary MCEs.
- Buying a wattmeter is a good decision, when you run nontrivial amounts of hardware.
Addendum: The 2.5 Watts for Bertha when off may seem bad — but its not at all, if you consider it is running a lights-out management on that.
Stop right there I gotta know right now before we go any further
Let me sleep on it and I’ll give you an answer in the morning
So, I did some work recently to possibly make our tinderboxes more efficient and scalable — which is a bit ironic as I recently hinted others at Paul Grahams advise to “do things that do not scale”. At LibreOffice we currently have tinderbox setup that served us as good as it could in the first years: It gave a quick overview of the basic health of current development branch of LibreOffice. But LibreOffice takes some time to build and test and with 50-100 commits to master each day it is playing catch-up with a moving target.
And whle they did a good job at this, they also have a few distinct weaknesses: For one, these tinderboxes would also mail everyone who commited on a branch since the last known good build if they were unhappy. Since they do not know anything about each other, with a generic breaker each tinderbox would do that on its own. In a tragic imitation of a certain comic this would result in the incremental Linux tinderbox reporting after 5 minutes something went wrong, with all the other tinderboxes dribbling in with the same message over time, finalized by the full Windows build tinderbox excitedly reporting to 200 people (as a slow builder would have more commits between builds) that something was amiss — possibly hours after it was fixed again. This resulted in these messages being filtered away by most users and even worse: the Windows tinderbox reports, which should be the most useful of them, as most developers use Linux as development platform, being easily ignored as “someone else broke it”.
So I set out improve the situation with the initial goal:
- to start make tinderboxes being able to coordinate
- to make it possible to easily collate the information from multiple builders
- while leaving the control over what is build with the owner of the tinderbox (as most of these boxes are sponsored, we dont want to make them into drones)
- for slow platforms like Windows or ARM enable bisecting a breaker as the frequency of builds is too low for those in the commit range to feel personally responsible
- while bisecting a breaker, also keep an eye one the branch moving forward (as in: dont try to bisect a breaker further when it was fixed in the meantime)
And I am happy to report to have reached this initial goal with tb3 which is a tinderbox coordinator written in Python3 and having as many lines of codes for unittests as for the product itself. So how is tb3 intended to work?
Leaving control over what is build with the owner of the tinderbox
tb3 is build around the idea, that the information about the state of the source is collected and managed by a central “tinderbox coordinator” and one or more tinderboxes go to it to:
- ask for something to build, giving the coordinator a branch and a platform that they are interested to work for
- report that they have started to build a certain state and give an estimate on when they will be finished
- report that they have finished to build a certain state and give a result
Note that the first two steps are separate: The tinderbox is essentially just asking for a suggestion on what to build — its not promising to actually follow these proposals. It can come back and report to be building something completely different(*). Now the proposals the coordinator hands out come with a score. Just looking at a classical tinderbox mode, which will always build the current HEAD of a branch on a specific platform, the score of the highest ranking proposal will be equal to the number of commits since the last finished build. With tb3, a tinderbox can watch multiple branches (e.g. a development branch and a release branch) and commit itself to building the one which saw the most commits since the last finished. It can also use multipliers and use something like “if there are 10 times as many new commits on the development branch as on the release branch, then build that, otherwise stick to the release branch” or use limits: “I only want run a build if there are at least 5 new commits”.
Coordinating multiple tinderboxes
So how do we coordinate multiple tinderboxes and ensure that e.g. if someone pushes 9 commits to master, we do not get five Linux tinderboxes to build that last commit and then sprinkle everyones mailbox over the next hour? Here is where the “coordinator” part truly kicks in. The first tinderbox that asks for something to build will get proposals with scores as shown by the green line in the chart below: The highest score is the “9″ of the newest commit — the commit that has the biggest distance from the last build. If the first tinderbox reported to have taken on that proposed build, what would a second tinderbox that also asks to build something see? It makes little sense to give it the same build as the first tinderbox. Optimistically assuming that tinderbox will report something back, the best thing this second box can do is build something with the biggest distance to to the finished build and to the build running on the first tinderbox. As such, the coordinator will send it scored as denoted by the blue line and if the tinderbox accepts it will build commit 5 — which is why a third tinderbox asking for something to build, while the other two are running, will get proposals as per the pink line and thus be suggested to build commit 3.
Trusting tinderboxes … a bit
Now these tinderboxes “promised” to build some commit. But can we give the tinderbox unconstrained trust? E.g. should we never ever tell any other tinderbox to build this one commit, because some other tinderbox promised to build it? The answer is obviously no: As a tinderbox is a gift, the owner should be allowed to reboot or reassign a tinderbox for other tasks at any time with imprudence. This is why the tinderbox gives the coordinator an estimated duration for its build and the tinderbox coordinator “reserves” this commit for that time. As you did see in the last chart the commit that just had a tinderbox running got scores of zero. As time goes by the coodinator looses trust in the tinderbox to still report back: the chart below shows the scores given after twice the time the tinderbox gave as an estimate has passed. You see the blue line now scores highest at commit 6, not commit 5 and the pink line scores highest at commit 5, not commit 3 — so as the coordinator looses trust in the running tinderboxes to come back, it again proposes to do builds closer to the already scheduled ones.
Another thing to note is that the highest score is rising: While in the first chart, each running tinderbox lowered the highest score by one (green line: highest at 9, blue line: highest at 8, pink line: highest at 7) after twice the time has passed, the highscores are all around 9 again.
Bisecting a breaker
Should a branch be broken, it usually would be very helpful if the tinderboxes would help bisecting. This is especially true for slow platforms and builds like Windows, ARM or the document load torturer by Markus. However, we do not want the tinderbox to over fixate on that, as our branch is a moving target. If there is a build breaker somewhere in a range of 256 commits, we do not want a slow tinderbox to bust away for 8 builds to find the offending one, and while doing that leave the head of the branch unwatched for a long time. So by default, the bisecting proposals have a highscore that is equal to the number of commits to bisect still. As such, by default, a tinderbox will be told to bisect — as long as:
- the head of the branch is still broken
- there are more commits in the bisect range, than there are new commit on the branch.
Otherwise, the tinderbox will be told to build the latest commit, to check if the branch is still broken or fixed in the meantime. As such the coordinator will guard against commiting tinderboxes to bisect a breaker that was already fixed. Therefore the coordinator knows a few more states than plain ‘good’ or ‘bad’ for a commit:
- UNKNOWN — nothing known yet
- RUNNING — a tinderbox is currently claiming to run this commit
- GOOD — a tinderbox was happy with it
- BAD — a tinderbox was unhappy with it
- ASSUMED_GOOD — not tested, but the previous and the next finished build were good
- ASSUMED_BAD — not tested, but the previous and the next finished build were bad
- POSSIBLY_BREAKING — not tested, but the previous finished build was good and the next finished build was bad
- POSSIBLY_FIXING — not tested, but the previous finished build was bad and the next finished build was good
- BREAKING — this one was bad, while the previous commit was good
Here is some example output
$ ./tb3-show-history --repo ~/checkouts/core.git --platform linux --branch 65134fb75c3e94b7869fb6d490f88bf4b252760e --history-count 10 65134fb75c3e94b7869fb6d490f88bf4b252760e started on 2013-07-25 17:27:30.383767 with builder ubuntu-tinderbox and finished on 2013-07-25 17:40:41.226494 -- artifacts at 65134fb75c3e94b7869fb6d490f88bf4b252760e-137476605045.out, state: BAD (took 0:13:10.842727) 6100d94078d37cb1413a0e45460cee480ba3e211 started on None with builder None and finished on None -- artifacts at None, state: ASSUMED_BAD 24d46ea66485ff8b5bca49ec587b41547787bf42 started on None with builder None and finished on None -- artifacts at None, state: ASSUMED_BAD d041980a7aad0e6d111752ca98db42f9853a3c6b started on 2013-07-25 17:40:52.587150 with builder ubuntu-tinderbox and finished on 2013-07-25 17:53:04.204549 -- artifacts at d041980a7aad0e6d111752ca98db42f9853a3c6b-137476685269.out, state: BAD (took 0:12:11.617399) 3b28ec6855e5df0629427752d7dafae1f0a277d4 started on None with builder None and finished on None -- artifacts at None, state: ASSUMED_BAD cca0b9ae02603ab88ec7d8810aab2a8a1b4efda2 started on 2013-07-25 18:08:01.201013 with builder ubuntu-tinderbox and finished on 2013-07-25 18:20:39.536451 -- artifacts at cca0b9ae02603ab88ec7d8810aab2a8a1b4efda2-137476848124.out, state: BREAKING (took 0:12:38.335438) 767b02bd7614059dd80d0cd1be306d9b63291f31 started on 2013-07-25 17:53:14.745394 with builder ubuntu-tinderbox and finished on 2013-07-25 18:07:42.527839 -- artifacts at 767b02bd7614059dd80d0cd1be306d9b63291f31-137476759480.out, state: GOOD (took 0:14:27.782445) c852f83bc4d91de51c61ad4be0edf1b848247eaa started on None with builder None and finished on None -- artifacts at None, state: ASSUMED_GOOD 0d874ee2e452ea67c03a27bf1a7f26d0ffc617dc started on None with builder None and finished on None -- artifacts at None, state: ASSUMED_GOOD ff14c3b595ebe71153f97ebb8871cf024ea76959 started on 2013-07-25 17:12:58.024727 with builder ubuntu-tinderbox and finished on 2013-07-25 17:27:17.439374 -- artifacts at ff14c3b595ebe71153f97ebb8871cf024ea76959-137476517809.out, state: GOOD (took 0:14:19.414647)
Some details and missing bits
The coordinator stores the results in git notes as JSON objects. This has multiple advantages: There is no need for a external database and the state of the notes are under revision control. It also has one disadvantage: Its not exactly quick. However the revision control can help to mitigate that mostly — as e.g. a webfrontend can easily ask: “what changed on the state since I last polled you?” and do incremental updates from there.
Which brings me to the missing bits: The stuff that tells the world the state of the repo on a webfrontend, RSS feed, IRC Bots or via email digests. The second missing bit is some kind of privilege separating between the tinderboxes and the coordinator. tb3 is currently churning away on the Sun Ultra 24 that I donated to the Document Foundation doing duty as an Ubuntu tinderbox, but coordinator and tinderbox are still running on the same account — even though as separate processes. As setuid for scripts is messy business, I plan to give tb3 a trivial REST-like interface on a non-public HTTP server. In addition to being able to offload the authentication and authorization problems outside of tb3 to something considering it a solved problem, it also makes integration in webfrontends etc. simple (esp. given that all the data is in JSON already anyway.)
In the long run, the scoring of tb3 also should make it easier for the buildbots that do duty on gerrit to make a call on if they should test build something there or if their help is more needed for tinderbox duty.
- coordinate multiple tinderboxes working on the same build scenario or branch
- coordinate one tinderbox working on multiple build scenarios or multiple branches
- make tinderboxes bisect without loosing sight of the head of a branch
- especially help tests and builds that are painfully slow
They can also create builds for bibisect along the way, but that is a story for another day.
(*) This is helpful for some test suites like e.g. subsequentcheck. If you do a build as proposed by the coordinator, you can cheaply report back the result of the build only. And since you then can just the subsequentcheck test suite on top of the build of that commit (and only on that commit), you can then report to be running these tests and report the results without ever caring if the coordinator thinks this commit has as high priority for this.
postscriptum: Yeah, I know, I promised to be on vacation now and not harass you with any posts, but this is a scheduled blogpost and as such does not count.
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