Artikel getaggt mit postgresql

What I do

It’s been a decade ago when I did my first steps with contributing to Free Software, about seven years when I joined Debian, and about 6 with Canonical and Ubuntu. Time for some reflection what I have done over these years!

Distribution Packaging and Maintenance

My first sponsored Debian upload ever was cracklib2, which seriously needed some love and was looking for a new maintainer. So in that upload I managed to close all outstanding bugs. Thanks to my mentor Martin Godisch about providing a lot of guidance for this!

Since then I’ve maintained various packages, where the most popular ones are certainly the free database server “PostgreSQL” (see next section) and the e-book management software “Calibre”.

“Maintaining” by and large means “making it really easy to get and use this software”. This decomposes to:

  • Packaging it in a way that a simple apt-get install makes the software work out of the box (as far as possible)
  • Provide a default configuration/customizations so that it integrates and plays well with the rest of the system; this includes the paths and permissions for log files, log rotation, debconf, configuration file standards, etc.
  • Be the front line for bug reports from users, sort, answer, and de-duplicate them, and either fix them myself, or forward useful bugs to upstream.
  • Providing security updates for stable releases
  • To some extent, help with the development of the software; this gets mostly driven by user demand, and of course my personal interests.

In August 2004 I got employed by Canonical to work full time on Ubuntu, which pretty much turned a hobby into a profession. I never regretted this in the past years, it’s an awesome job to do!

In principle I’m doing the same thing in Ubuntu as well: Bring stuff from developers to the people out there. Except with a different focus, in Ubuntu my daily bread and butter is the GNOME desktop and stuff around (and immediately below) it. And even though after a long day of bug triaging and debugging I feel a bit low-hearted (“50.000 bugs away from perfection”), when I take a step back and see how much the usage of Free Software in the world has grown since 2004, I am very proud of being part of Ubuntu, which certainly has its fair contribution and share in this growth. So what seemed like a crazy idea from Mark back in 2004 actually has made a remarkable progress.

In the beginning of Ubuntu I mostly sent back patches to the Debian bug tracker, but this evolved quite a bit on both sides: These days I try to keep “my” packages in sync and commit stuff directly to Debian, which works very well with e. g. the pkg-utopia team, which is responsible for HAL, udisks, upower, PolicyKit, and related packages. At this point I want to thank Michael Biebl for being such an awesome guy on the Debian side! Also, it seems that Debian has moved a fair bit away from the strong “Big Maintainer Lock” towards team based maintenance, so these days it is easier than ever to commit stuff directly to Debian for a lot of packages, without much fuss.

PostgreSQL

I have done a handful of changes to PostgreSQL, but these mostly concerned easy packaging and crash fixes, nothing out of the ordinary. I’m not really a PostgreSQL upstream developer.

The thing I am really proud of is the postgresql-common package, which is a very nice example what a distro can provide on top of upstream: If you install the upstream tarball, you have to manually care for creating clusters, providing a sensible configuration for them, set up SSL, set up log rotation, etc. With postgresql-common, this is all done automatically. The biggest feature it provides is a robust and automatic way of upgrading between major releases with the pg_upgradecluster tool, which takes care of a dozen corner cases and the nontrivial process of dumping the old cluster and reloading the new one. Also, you can effortlessy run several instances of the same version in parallel, so that you can e. g. have a production and a development instance, or try the new 9.0 RC1 while still running the 8.4 production one. (more details)

Crash Reporting with Apport

This has been a pet peeve of mine pretty much from day 1. Back in the old days, crashes in software were a pain to track down: many crashes are hard to reproduce, it takes ages to get useful information from bug reporters, and a lot of data cannot be recovered any more when you try to reproduce and analyze a crash after the fact.

With the growing demand for QA from both Canonical and Ubuntu, in 2006 I finally got some time to start Apport, which would make all this a lot easier: It intercepts crashes as they happen, collects the data that we as a developer need, and makes it very easy for the user to submit them as a bug report. This is accompanied by a backend service (called “retracers”) which would reprocess the bug reports by taking the core dump, reproducing a chroot with the packages and versions that the reporter had, installing the debugging symbols, and re-running gdb, to produce a fully symbolic stack trace.

See this bug report for how this looks like. Since then, tons of crashes were fixed, way more than we could ever have done “the old way” with asking users to rebuild with “-g -O0″, running gdb, etc.

By today, Apport has grown quite a bit: rich bug reports, per-package hooks, automatic duplication of crashes, interactive GUI elements in hooks, etc.

Plumbing Development

Handling hotpluggable hardware has always interested me, since the day when I got my first USB stick and it was ridiculously hard (from an user perspective) to use it:

    $ su -
    # mount -t vfat -o uid=1000 /dev/sda1 /mnt

My first go at this was to write pmount which would allow normal users to mount hotpluggable storage without root privileges and worrying about mount paths and options, and then integrate it into GNOME and HAL. Personally I abandoned it years ago, but it seems other people still use it, so I’m glad that Vincent Fourmond took over the maintenance now.

Since then, the entire stack evolved quite a bit: HAL grew to something useful and rather secure, and finally into some monstrous unmaintainable beast, which is why it was declared dead in 2008, and replaced with the “U” stack: udev, udisks, upower, etc. I enjoy hacking on that a lot, and since it’s part of my Desktop Team Tech Lead/Developer role in Canonical, I can spend some company time on it. so far I worked on bug fixes, small new features, and writing a rather comprehensive test suite for udisks (see my udisks commits so far). I also did a fair share of porting stuff away from HAL to the new stack, including some permanent commitments like maintaining the keymaps in udev.

GNOME

Before I started with Canonical I was never much of a GUI person: I was fully content with fvwm and a few xterms around it. But as an Ubuntu developer I do dogfooding, and thus I switched to GNOME for my day to day work. It didn’t take long before I really fell in love with it!

Similar to my Debian packages, my upstream involvement with GNOME is mostly integration and bug fixing. As already explained, we get a looooot of bug reports, so my focus is mostly on bug fixing. To date, I sent 93 patches to bugzilla. Since January 2010 I became a committer, so that it’s easier for me to get patches upstream.

Debugging problems and fixing bugs is a pretty tedious task, but I still enjoy the rewarding nice feeling when you finally tracked down something and can close a bug with 50 duplicates, and you have made people’s life a little bit easier from now on.

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PostgreSQL 9.0 RC1 available for testing

PostgreSQL 9.0 with a whole lot of new features and improvements is nearing completion. The first release candidate was just announced.

As with the beta versions, I uploaded RC1 to Debian experimental again. If you want to test/use them on Ubuntu 10.04 (Lucid Lynx), you can get packages from my “PostgreSQL backports for stable Ubuntu releases” PPA. Please let me know if you need them for other releases.

Just for the records, both Debian 6.0 “Squeeze” and Ubuntu 10.10 “Maverick Meerkat” will release and officially support 8.4 only, as 9.0 is too late for the feature freezes of both. Also, it will take quite some time to update all the packaged extensions to 9.0. As usual, 9.0 will be provided as official backports for both Debian and Ubuntu.

Happy testing!

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Celebrating the 1000th postgresql-common commit

I just did the 1000th commit of postgresql-common, the Debian/Ubuntu PostgreSQL management utilities. Wow, what started as a small hack in December 2004 to be able to install several major PostgreSQL versions in parallel has turned out to be a > 600 kB project providing a comprehensive tool set for uniformly setting up, upgrading, and maintaining PostgreSQL database instances from version 7.4 up to the just announced 9.0 beta-1, with a comprehensive test suite that I’m really proud of (it tests just about every aspect, option, and corner case of the installation, integration, upgrade, locale support, and error handling, and takes about half an hour on my system).

The actual commit is rather dull though, it’s just the release/upload tag for version 107 which I just uploaded to Debian unstable (it will hit Ubuntu maverick and backports soon). 107 introduces support for PostgreSQL 9.0, and I fixed up the scripts and tests enough so that all the tests pass now, and thus it’s good for public release.

I also uploaded the 9.0 beta 1 server itself now. It’ll be in Debian’s NEW queue for a bit, and hit experimental in a few days (or hours; recently the ftpmasters have been awesome!) It has a few cool new features (see the announcement), and upstream really appreciates testing and feedback. So, bug reports appreciated!

In particular, if you have existing 8.4 clusters you can just try to pg_upgradecluster them to 9.0 beta 1. Remember, if anything goes wrong, the cluster of the previous version is still intact and untouched, so you can run upgrades as many times as you like and only pg_dropcluster the old one when you’re completely satisfied with the upgrade.

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PostgreSQL bug fix releases up for testing in Ubuntu

PostgreSQL did microrelease updates three weeks ago: 8.4.3, 8.3.10, and 8.1.20 are the ones relevant for Debian/Ubuntu. There haven’t been reports about regressions in Debian or the upstream lists so far, so it’s time to push these into stable releases.

The new releases are in Lucid Beta-2, and hardy/jaunty/karmic-proposed. If you are running PostgreSQL, please upgrade to the proposed versions and give feedback to LP #557408.

Updates for Debian Lenny are prepared as well, and await release team ack.

On a related note, I recently fixed quite a major problem in pg_upgradecluster in postgresql-common 106: It did not copy database-level ACLs and configuration settings (Debian #543506). Fixing this required some reenginering of the upgrade process. It’s all thoroughly test case’d, but practical feedback would be very welcome! Remember, if anything goes wrong, the cluster of the previous version is still intact and untouched, so you can run upgrades as many times as you like and only pg_dropcluster the old one when you’re completely satisfied with the upgrade.

Thanks,

Martin

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New PostgreSQL releases need testing

Yesterday PostgreSQL released new security/bug fix microreleases 8.4.2, 8.3.9, and 8.1.19, which fix two security issues and a whole bunch of bugs.

Updates for all supported Ubuntu releases are built in the ubuntu-security-proposed PPA. They pass the upstream and postgresql-common test suites, but more testing is heavily appreciated! Please give feedback in bug LP#496923.

Thanks!

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PostgreSQL security/bug fix update, please test

PostgreSQL recently published new point releases which fix the usual range of important bugs (data loss/wrong results, etc.) and additionally fix another case of insecure “security definer” functions (the analogon to setuid programs in file system space for SQL functions) (CVE-2007-6600). Please see the complete changes for 8.1.18 (Ubuntu 6.06 LTS), 8.3.8 (Ubuntu 8.04 LTS, 8.10, and 9.04), and 8.4.1 (Ubuntu 9.10).

8.4.1 is already in Ubuntu 9.10 and in my PostgreSQL Backports PPA for Ubuntu 8.04 LTS and 9.04. Updates for the other supported Ubuntu releases are currently in -proposed, waiting for testing feedback.

If you use PostgreSQL, please give the -proposed packages some testing and report back in Ubuntu bug #430544. Thanks!

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PostgreSQL 8.4beta1 available for testing

Some days ago, the first public beta of PostgreSQL 8.4 was announced. I uploaded a CVS snapshot to Debian experimental two weeks ago, but it didn’t make it out of NEW yet.

Packaging the actual 8.4 bits was actually pretty easy, just took me half a day to adapt the 8.3 packaging and eventually figuring out how to build the entire documentation from SGML sources with Debian/Ubuntu’s broken docbook-utils.

I spent much more work work on supporting 8.4 in postgresql-common, especially with the new per-database locales, migrating changed postgresql.conf parameters in pg_upgradecluster, and so on. Now almost all of the > 1000 tests pass, so I believe it is pretty solid now.

The only exception is the changed behaviour in verifying the server side’s SSL certificate from the client side. At first I thought it was a bug, and reported it to upstream, but it evolved into a pretty lengthy and interesting discussion about the right defaults for SSL verification. I’ll work on better defaults, and the test suite to pass 100% soon.

I invite you give the beta a good beating. Packages for Ubuntu 8.04 LTS and 9.04 are in my
postgresql PPA. Due to postgresql-common, you can safely run 8.4 in parallel with existing 8.3 instances, test-upgrade your 8.3 ones to 8.4 and compare them, etc.

Feedback appreciated!

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